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Sample records for basin clastic reservoirs

  1. Simulation of the mulltizones clastic reservoir: A case study of Upper Qishn Clastic Member, Masila Basin-Yemen

    Science.gov (United States)

    Khamis, Mohamed; Marta, Ebrahim Bin; Al Natifi, Ali; Fattah, Khaled Abdel; Lashin, Aref

    2017-06-01

    The Upper Qishn Clastic Member is one of the main oil-bearing reservoirs that are located at Masila Basin-Yemen. It produces oil from many zones with different reservoir properties. The aim of this study is to simulate and model the Qishn sandstone reservoir to provide more understanding of its properties. The available, core plugs, petrophysical, PVT, pressure and production datasets, as well as the seismic structural and geologic information, are all integrated and used in the simulation process. Eclipse simulator was used as a powerful tool for reservoir modeling. A simplified approach based on a pseudo steady-state productivity index and a material balance relationship between the aquifer pressure and the cumulative influx, is applied. The petrophysical properties of the Qishn sandstone reservoir are mainly investigated based on the well logging and core plug analyses. Three reservoir zones of good hydrocarbon potentiality are indicated and named from above to below as S1A, S1C and S2. Among of these zones, the S1A zone attains the best petrophysical and reservoir quality properties. It has an average hydrocarbon saturation of more than 65%, high effective porosity up to 20% and good permeability record (66 mD). The reservoir structure is represented by faulted anticline at the middle of the study with a down going decrease in geometry from S1A zone to S2 zone. It is limited by NE-SW and E-W bounding faults, with a weak aquifer connection from the east. The analysis of pressure and PVT data has revealed that the reservoir fluid type is dead oil with very low gas liquid ratio (GLR). The simulation results indicate heterogeneous reservoir associated with weak aquifer, supported by high initial water saturation and high water cut. Initial oil in place is estimated to be around 628 MM BBL, however, the oil recovery during the period of production is very low (<10%) because of the high water cut due to the fractures associated with many faults. Hence, secondary and

  2. Application of advanced reservoir characterization, simulation and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S.P.; Asquith, G.B.; Barton, M.D.; Cole, A.G.; Gogas, J.; Malik, M.A.; Clift, S.J.; Guzman, J.I.

    1997-11-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. This project involves reservoir characterization of two Late Permian slope and basin clastic reservoirs in the Delaware Basin, West Texas, followed by a field demonstration in one of the fields. The fields being investigated are Geraldine Ford and Ford West fields in Reeves and Culberson Counties, Texas. Project objectives are divided into two major phases, reservoir characterization and implementation. The objectives of the reservoir characterization phase of the project were to provide a detailed understanding of the architecture and heterogeneity of the two fields, the Ford Geraldine unit and Ford West field. Reservoir characterization utilized 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once reservoir characterized was completed, a pilot area of approximately 1 mi{sup 2} at the northern end of the Ford Geraldine unit was chosen for reservoir simulation. This report summarizes the results of the second year of reservoir characterization.

  3. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, Shirley P.; Flanders, William A.

    2001-11-04

    The objective of this Class III project was demonstrate that reservoir characterization and enhanced oil recovery (EOR) by CO2 flood can increase production from slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico. Phase 1 of the project, reservoir characterization, focused on Geraldine Ford and East Ford fields, which are Delaware Mountain Group fields that produce from the upper Bell Canyon Formation (Ramsey sandstone). The demonstration phase of the project was a CO2 flood conducted in East Ford field, which is operated by Orla Petco, Inc., as the East Ford unit.

  4. Elastic and Electrical Properties Evaluation of Low Resistivity Pays in Malay Basin Clastics Reservoirs

    Science.gov (United States)

    Almanna Lubis, Luluan; Ghosh, Deva P.; Hermana, Maman

    2016-07-01

    The elastic and electrical properties of low resistivity pays clastics reservoirs in Malay Basin are strongly dependent on the complex nature of the clay content, either dispersed or laminated/layered. Estimating the hydrocarbon pore volume from conventional electrical log, i.e. resistivity log, is quite a challenge. The low elastic impedance contrast also found as one of the challenge thus create a problem to map the distribution of the low resistivity reservoirs. In this paper, we evaluate the electrical properties and elastic rock properties to discriminate the pay from the adjacent cap rock or shale. Forward modeling of well log responses including electrical properties are applied to analyze the nature of the possible pays on laminated reservoir rocks. In the implementation of rock properties analysis, several conventional elastic properties are comparatively analyzed for the sensitivity and feasibility analysis on each elastic parameters. Finally, we discussed the advantages of each elastic parameters in detail. In addition, cross-plots of elastic and electrical properties attributes help us in the clear separation of anomalous zone and lithologic properties of sand and shale facies over conventional elastic parameter crossplots attributes. The possible relationship on electrical and elastic properties are discussed for further studies.

  5. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin), Class III

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, Shirley P.; Flanders, William A.; Zirczy, Helena H.

    2000-05-24

    The objective of this Class 3 project was to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Phase 1 of the project, reservoir characterization, was completed this year, and Phase 2 began. The project is focused on East Ford field, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 1960, is operated by Oral Petco, Inc., as the East Ford unit. A CO{sub 2} flood is being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  6. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    International Nuclear Information System (INIS)

    Dutton, Shirley P.

    1999-01-01

    The objective of this Class 3 project was demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two main phases. The original objectives of the reservoir-characterization phase of the project were (1) to provide a detailed understanding of the architecture and heterogeneity of two representative fields of the Delaware Mountain Group, Geraldine Ford and Ford West, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, (2) to chose a demonstration area in one of the fields, and (3) to simulate a CO 2 flood in the demonstration area

  7. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin), Class III

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, Shirley P.; Flanders, William A.; Mendez, Daniel L.

    2001-05-08

    The objective of this Class 3 project was demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstone's of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover oil more economically through geologically based field development. This project was focused on East Ford field, a Delaware Mountain Group field that produced from the upper Bell Canyon Formation (Ramsey sandstone). The field, discovered in 9160, is operated by Oral Petco, Inc., as the East Ford unit. A CO2 flood was being conducted in the unit, and this flood is the Phase 2 demonstration for the project.

  8. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, NM

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Mark B.

    1999-02-24

    The Nash Draw Brushy Canyon Pool in Eddy County New Mexico is a cost-shared field demonstration project in the US Department of Energy Class II Program. A major goal of the Class III Program is to stimulate the use of advanced technologies to increase ultimate recovery from slope-basin clastic reservoirs. Advanced characterization techniques are being used at the Nash Draw project to develop reservoir management strategies for optimizing oil recovery from this Delaware reservoir. Analysis, interpretation, and integration of recently acquired geologic, geophysical, and engineering data revealed that the initial reservoir characterization was too simplistic to capture the critical features of this complex formation. Contrary to the initial characterization, a new reservoir description evolved that provided sufficient detail regarding the complexity of the Brushy Canyon interval at Nash Draw. This new reservoir description is being used as a risk reduction tool to identify ''sweet spots'' for a development drilling program as well as to evaluate pressure maintenance strategies. The reservoir characterization, geological modeling, 3-D seismic interpretation, and simulation studies have provided a detailed model of the Brushy Canyon zones. This model was used to predict the success of different reservoir management scenarios and to aid in determining the most favorable combination of targeted drilling, pressure maintenance, well simulation, and well spacing to improve recovery from this reservoir.

  9. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S.P.; Flanders, W.A.; Guzman, J.I.; Zirczy, H.

    1999-06-08

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover a higher percentage of the original oil in place through geologically based field development. This year the project focused on reservoir characterization of the East Ford unit, a representative Delaware Mountain Group field that produces from the upper Bell Canyon Formation (Ramsey Sandstone). The field, discovered in 1960, is operated by Orla Petco, Inc., as the East Ford unit; it contained an estimated 19.8 million barrels (MMbbl) of original oil in place. Petrophysical characterization of the East Ford unit was accomplished by integrating core and log data and quantifying petrophysical properties from wireline logs. Most methods of petrophysical analysis that had been developed during an earlier study of the Ford Geraldine unit were successfully transferred to the East Ford unit. The approach that was used to interpret water saturation from resistivity logs, however, had to be modified because in some East Ford wells the log-calculated water saturation was too high and inconsistent with observations made during the actual production. Log-porosity to core-porosity transforms and core-porosity to core-permeability transforms were derived from the East Ford reservoir. The petrophysical data were used to map porosity, permeability, net pay, water saturation, mobil-oil saturation, and other reservoir properties.

  10. Application of Advanced Reservoir Characterization, Simulation, and Production Optimization Strategies to Maximize Recovery in Slope and Basin Clastic Reservoirs, West Texas (Delaware Basin)

    Energy Technology Data Exchange (ETDEWEB)

    Andrew G. Cole; George B. Asquith; Jose I. Guzman; Mark D. Barton; Mohammad A. Malik; Shirley P. Dutton; Sigrid J. Clift

    1998-04-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based enhanced oil recovery. The study focused on the Ford Geraldine unit, which produces from the upper Bell Canyon Formation (Ramsey sandstone). Reservoirs in this and other Delaware Mountain Group fields have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Outcrop analogs were studied to better interpret the depositional processes that formed the reservoirs at the Ford Geraldine unit and to determine the dimensions of reservoir sandstone bodies. Facies relationships and bedding architecture within a single genetic unit exposed in outcrop in Culberson County, Texas, suggest that the sandstones were deposited in a system of channels and levees with attached lobes that initially prograded basinward, aggraded, and then turned around and stepped back toward the shelf. Channel sandstones are 10 to 60 ft thick and 300 to 3,000 ft wide. The flanking levees have a wedge-shaped geometry and are composed of interbedded sandstone and siltstone; thickness varies from 3 to 20 ft and length from several hundred to several thousands of feet. The lobe sandstones are broad lens-shaped bodies; thicknesses range up to 30 ft with aspect ratios (width/thickness) of 100 to 10,000. Lobe sandstones may be interstratified with laminated siltstones.

  11. The Controls of Pore-Throat Structure on Fluid Performance in Tight Clastic Rock Reservoir: A Case from the Upper Triassic of Chang 7 Member, Ordos Basin, China

    Directory of Open Access Journals (Sweden)

    Yunlong Zhang

    2018-01-01

    Full Text Available The characteristics of porosity and permeability in tight clastic rock reservoir have significant difference from those in conventional reservoir. The increased exploitation of tight gas and oil requests further understanding of fluid performance in the nanoscale pore-throat network of the tight reservoir. Typical tight sandstone and siltstone samples from Ordos Basin were investigated, and rate-controlled mercury injection capillary pressure (RMICP and nuclear magnetic resonance (NMR were employed in this paper, combined with helium porosity and air permeability data, to analyze the impact of pore-throat structure on the storage and seepage capacity of these tight oil reservoirs, revealing the control factors of economic petroleum production. The researches indicate that, in the tight clastic rock reservoir, largest throat is the key control on the permeability and potentially dominates the movable water saturation in the reservoir. The storage capacity of the reservoir consists of effective throat and pore space. Although it has a relatively steady and significant proportion that resulted from the throats, its variation is still dominated by the effective pores. A combination parameter (ε that was established to be as an integrated characteristic of pore-throat structure shows effectively prediction of physical capability for hydrocarbon resource of the tight clastic rock reservoir.

  12. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, NM

    Energy Technology Data Exchange (ETDEWEB)

    Mark B. Murphy

    2005-09-30

    The Nash Draw Brushy Canyon Pool in Eddy County New Mexico was a cost-shared field demonstration project in the U.S. Department of Energy Class III Program. A major goal of the Class III Program was to stimulate the use of advanced technologies to increase ultimate recovery from slope-basin clastic reservoirs. Advanced characterization techniques were used at the Nash Draw Pool (NDP) project to develop reservoir management strategies for optimizing oil recovery from this Delaware reservoir. The objective of the project was to demonstrate that a development program, which was based on advanced reservoir management methods, could significantly improve oil recovery at the NDP. Initial goals were (1) to demonstrate that an advanced development drilling and pressure maintenance program can significantly improve oil recovery compared to existing technology applications and (2) to transfer these advanced methodologies to other oil and gas producers. Analysis, interpretation, and integration of recently acquired geological, geophysical, and engineering data revealed that the initial reservoir characterization was too simplistic to capture the critical features of this complex formation. Contrary to the initial characterization, a new reservoir description evolved that provided sufficient detail regarding the complexity of the Brushy Canyon interval at Nash Draw. This new reservoir description was used as a risk reduction tool to identify 'sweet spots' for a development drilling program as well as to evaluate pressure maintenance strategies. The reservoir characterization, geological modeling, 3-D seismic interpretation, and simulation studies have provided a detailed model of the Brushy Canyon zones. This model was used to predict the success of different reservoir management scenarios and to aid in determining the most favorable combination of targeted drilling, pressure maintenance, well stimulation, and well spacing to improve recovery from this reservoir. An

  13. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, west Texas (Delaware Basin). Annual progress report, March 31, 1995--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S.P.; Hovorka, S.D.; Cole, A.G.

    1996-08-01

    The objective of this Class III project is to demonstrate that detailed reservoir characterization of clastic reservoirs in basinal sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost-effective way to recover more of the original oil in place by strategic infill-well placement and geologically based field development. Reservoirs in the Delaware Mountain Group have low producibility (average recovery <14 percent of the original oil in place) because of a high degree of vertical and lateral heterogeneity caused by depositional processes and post-depositional diagenetic modification. Detailed correlations of the Ramsey sandstone reservoirs in Geraldine Ford field suggest that lateral sandstone continuity is less than interpreted by previous studies. The degree of lateral heterogeneity in the reservoir sandstones suggests that they were deposited by eolian-derived turbidites. According to the eolian-derived turbidite model, sand dunes migrated across the exposed shelf to the shelf break during sea-level lowstands and provided well sorted sand for turbidity currents or grain flows into the deep basin.

  14. Application of advanced reservoir characterization, simulation, and production optimization strategies to maximize recovery in slope and basin clastic reservoirs, West Texas (Delaware Basin). Quarterly report, October 1 - December 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Dutton, S.P.

    1997-01-01

    The objective of this project is to demonstrate that detailed reservoir characterization of slope and basin clastic reservoirs in sandstones of the Delaware Mountain Group in the Delaware Basin of West Texas and New Mexico is a cost effective way to recover a higher percentage of the original oil in place through strategic placement of infill wells and geologically based field development. Project objectives are divided into two major phases. The objectives of the reservoir characterization phase of the project are to provide a detailed understanding of the architecture and heterogeneity of two fields, the Ford Geraldine unit and Ford West field, which produce from the Bell Canyon and Cherry Canyon Formations, respectively, of the Delaware Mountain Group and to compare Bell Canyon and Cherry Canyon reservoirs. Reservoir characterization will utilize 3-D seismic data, high-resolution sequence stratigraphy, subsurface field studies, outcrop characterization, and other techniques. Once the reservoir-characterization study of both fields is completed, a pilot area of approximately 1 mi{sup 2} in one of the fields will be chosen for reservoir simulation. The objectives of the implementation phase of the project are to (1) apply the knowledge gained from reservoir characterization and simulation studies to increase recovery from the pilot area, (2) demonstrate that economically significant unrecovered oil remains in geologically resolvable untapped compartments, and (3) test the accuracy of reservoir characterization and flow simulation as predictive tools in resource preservation of mature fields. A geologically designed, enhanced-recovery program (CO{sub 2} flood, waterflood, or polymer flood) and well-completion program will be developed, and one to three infill wells will be drilled and cored. Technical progress is summarized for: geophysical characterization; reservoir characterization; outcrop characterization; and recovery technology identification and analysis.

  15. Sequence stratigraphy simulations of carbonate, clastics, and mixed basin margins

    Energy Technology Data Exchange (ETDEWEB)

    Kendall, C.G.St.C.; Moore, P.; Birdwell, B.A.; Rouchie, L.; Cannon, R. (Univ. of South Carolina, Columbia (United States)); Biswas, G. (Vanderbilt Univ., Nashville, TN (United States)); Bezdek, J. (Univ. of West Florida, Pensacola (United States))

    1991-03-01

    Clastics, carbonates, and their mixtures have different depositional and post-depositional behavior that produces the different margin characteristics seen in seismic sequences. Carbonates undergo early cementation while maintaining higher angles of repose, while clays and sands accumulate at lower-angle slopes whose inclination is proportional to the grain size and post-depositional cohesive behavior. In higher energy regimes, waves or currents winnow less cohesive finer material that is transported downdip to from slope sediments rimming the basin. Simulations of mixed carbonate-clastic sediment accumulation, tectonism, and eustasy for settings in the Permian basin of west Texas and New Mexico show that sharp differentiation of clastics from carbonates is a product of higher angles of repose that carbonates maintain and the higher rates of clastic input at lowstands in sea level. In contrast, simulation of mixed grain-size margins like the Exmouth Plateau of Western Australia, the Baltimore Canyon, and the Gulf Coast Tertiary indicate that muds are winnowed preferentially from shelf-margin crests but accumulate on slopes, while sands accumulate on higher energy shelves. When they bypass at lowstands in sea level, they accumulate in the near slope basin but not on the slope. Simulation of pure carbonate systems like that of the Bahamian platform suggests that progradation is greatest in areas of low wave and current energy while backstepping and cliffed margins occur in high energy settings. The ability to accurately simulate mixed carbonate-clastic slopes is a key to development of exploration and production models of these systems.

  16. Advanced oil recovery technologies for improved recovery from slope basin clastic reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, NM. Quarterly technical progress report, April 1, 1996--June 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.B.

    1996-07-26

    The overall objective of this project is to demonstrate that a development program based on advanced reservoir management methods can significantly improve oil recovery. The demonstration plan includes developing a control area using standard reservoir management techniques and comparing the performance of the control area with an area developed using advanced reservoir management methods. Specific goals to attain the objective are: (1) to demonstrate that a development drilling program and pressure maintenance program, based on advanced reservoir management methods, can significantly improve oil recovery compared with existing technology applications, and (2) to transfer the advanced methodologies to oil and gas producers in the Permian Basin and elsewhere in the U.S. oil and gas industry.

  17. An innovative technique for estimating water saturation from capillary pressure in clastic reservoirs

    Science.gov (United States)

    Adeoti, Lukumon; Ayolabi, Elijah Adebowale; James, Logan

    2017-11-01

    A major drawback of old resistivity tools is the poor vertical resolution and estimation of hydrocarbon when applying water saturation (Sw) from historical resistivity method. In this study, we have provided an alternative method called saturation height function to estimate hydrocarbon in some clastic reservoirs in the Niger Delta. The saturation height function was derived from pseudo capillary pressure curves generated using modern wells with complete log data. Our method was based on the determination of rock type from log derived porosity-permeability relationship, supported by volume of shale for its classification into different zones. Leverette-J functions were derived for each rock type. Our results show good correlation between Sw from resistivity based method and Sw from pseudo capillary pressure curves in wells with modern log data. The resistivity based model overestimates Sw in some wells while Sw from the pseudo capillary pressure curves validates and predicts more accurate Sw. In addition, the result of Sw from pseudo capillary pressure curves replaces that of resistivity based model in a well where the resistivity equipment failed. The plot of hydrocarbon pore volume (HCPV) from J-function against HCPV from Archie shows that wells with high HCPV have high sand qualities and vice versa. This was further used to predict the geometry of stratigraphic units. The model presented here freshly addresses the gap in the estimation of Sw and is applicable to reservoirs of similar rock type in other frontier basins worldwide.

  18. Advanced oil recovery technologies for improved recovery from slope basin clastic reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico. Annual report, September 25, 1995--September 24, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.B.

    1997-08-01

    The basic driver for this project is the low recovery observed in Delaware reservoirs, such as the Nash Draw Pool (NDP). This low recovery is caused by low reservoir energy, less than optimum permeabilities and porosities, and inadequate reservoir characterization and reservoir management strategies which are typical of projects operated by independent producers. Rapid oil decline rates and high gas/oil ratios are typically observed in the first year of primary production. Based on the production characteristics that have been observed in similar Delaware fields, pressure maintenance is a likely requirement at the Nash Pool. Three basic constraints to producing the Nash Draw Brushy Canyon Reservoir are: (1) limited areal and interwell geologic knowledge, (2) lack of an engineering tool to evaluate the various producing strategies, and (3) limited surface access prohibiting development with conventional drilling. The limited surface access is caused by the proximity of underground potash mining and surface playa lakes. The objectives of this project are: (1) to demonstrate that a development drilling program and pressure maintenance program, based on advanced reservoir management methods, can significantly improve oil recovery compared with existing technology applications and (2) to transfer these advanced methodologies to oil and gas producers, especially in the Permian Basin.

  19. The high-resolution stratigraphic architecture and evolution of the Burdigalian carbonate-silici-clastic sedimentary systems on the Mut Basin, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Bassant, Ph.

    1999-06-01

    The subject of this doctorate study are the Lower Miocene (Burdigalian) carbonate systems in the Mut basin, in south central Turkey. This area is chosen because it presents extraordinary large (seismic) scale 3D outcrops showing depositional geometries. In addition, these carbonates are considered as good outcrop analogues for time equivalent carbonate buildups in the Far East, that are oil and gas bearing. The carbonates were deposited in a complex relict topography, following a tectonically active phase in the Oligocene. During the Burdigalian transgression shallow platform carbonates were deposited in a variety of settings, locally accompanied by some silici-clastic input. Observations on the strata geometries and the facies were combined into a high resolution sequence stratigraphic framework controlled by bio-stratigraphy. With the help of relative sea level curves constructed for the three studied sites, a basin-wide correlation scheme is proposed. This chronostratigraphic framework permits the recognition of condensation and omission surfaces in the basinal and platform settings, to identify basin-wide variations in sedimentation pattern, and to evaluate the relative influence of tectonism, eustatism and the environment. The exceptional quality of the outcrops with its variety of environments, and its location at the Tethys margin, make this a good candidate for a reference model for Burdigalian reef and platform architectures. Examples of a quantitative approach of the geometries of potential carbonate reservoir bodies are given in the annex. The data-files are incorporated in the carbonate reservoir body database CARABAS. (author)

  20. Characteristics of volcanic reservoirs and distribution rules of effective reservoirs in the Changling fault depression, Songliao Basin

    Directory of Open Access Journals (Sweden)

    Pujun Wang

    2015-11-01

    Full Text Available In the Songliao Basin, volcanic oil and gas reservoirs are important exploration domains. Based on drilling, logging, and 3D seismic (1495 km2 data, 546 sets of measured physical properties and gas testing productivity of 66 wells in the Changling fault depression, Songliao Basin, eruptive cycles and sub-lithofacies were distinguished after lithologic correction of the 19,384 m volcanic well intervals, so that a quantitative analysis was conducted on the relation between the eruptive cycles, lithologies and lithofacies and the distribution of effective reservoirs. After the relationship was established between lithologies, lithofacies & cycles and reservoir physical properties & oil and gas bearing situations, an analysis was conducted on the characteristics of volcanic reservoirs and the distribution rules of effective reservoirs. It is indicated that 10 eruptive cycles of 3 sections are totally developed in this area, and the effective reservoirs are mainly distributed at the top cycles of eruptive sequences, with those of the 1st and 3rd Members of Yingcheng Formation presenting the best reservoir properties. In this area, there are mainly 11 types of volcanic rocks, among which rhyolite, rhyolitic tuff, rhyolitic tuffo lava and rhyolitic volcanic breccia are the dominant lithologies of effective reservoirs. In the target area are mainly developed 4 volcanic lithofacies (11 sub-lithofacies, among which upper sub-lithofacies of effusive facies and thermal clastic sub-lithofacies of explosion lithofacies are predominant in effective reservoirs. There is an obvious corresponding relationship between the physical properties of volcanic reservoirs and the development degree of effective reservoirs. The distribution of effective reservoirs is controlled by reservoir physical properties, and the formation of effective reservoirs is influenced more by porosity than by permeability. It is concluded that deep volcanic gas exploration presents a good

  1. Geochemical elements mobility during the history of a paleo-Proterozoic clastic sedimentary basin, the Athabasca Basin (Saskatchewan, Canada)

    International Nuclear Information System (INIS)

    Kister, P.

    2003-10-01

    In order to understand the mechanisms of migration and deposition of ore elements, it is essential to determine the timing, source, and destination of the geochemical element mass transfers and/or transportation on a scale encompassing the great sedimentary. The purpose of this study was to trace and to date the element migrations that occurred during the history of a Paleo-proterozoic clastic sedimentary basin, the Athabasca Basin, which hosts the world's largest and richest uranium deposits. As this geological environment was proved to be efficient to preserve high grade ore deposits for over more than one billion years, it provides an opportunity to study the mobility of some elements in a context that shows analogies with deep geological nuclear waste disposals. The natural analogies of interest include (i) uranium oxide and spent nuclear fuel; (ii) clay alteration halo and near field barrier, (iii) Athabasca sandstone cover and far-field barrier. Five research axis: (1) 3D modelling of the distribution of the main minerals and of some trace elements (U, Pb, Zr, Th, REE, Y, Rb, Sr) on a basin-wide scale and in the U mineralized zones, using the Gocad software. The models have been compared with detailed mineralogical studies performed on selected samples. (2) Pb-Pb and Rb-Sr systematics by TIMS (3) Mass balance calculation of the average Pb/U ratio at the scale of the deposit to evaluate whether the present day amount of radiogenic lead is sufficient to explain a U deposition in one or several episodes (geostatistical tools on Gocad) (4) Thermodynamic modelling of the mineralogical evolution of the Athabasca basin, considering the main mineral present in the sandstone (Phreeqc and Supcrt softwares) (5) U-Pb geochronology of uranium oxides using a 3 step approach: (i) optical and scanning electron microscopy; (ii) electron microprobe; (iii) ion microprobe (SIMS). The purpose was to study the long term stability of the uranium oxides and to characterise the

  2. Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt.

    Science.gov (United States)

    Al-Alfy, I M; Nabih, M A; Eysa, E A

    2013-03-01

    Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  3. Gamma ray spectrometry logs as a hydrocarbon indicator for clastic reservoir rocks in Egypt

    International Nuclear Information System (INIS)

    Al-Alfy, I.M.; Nabih, M.A.; Eysa, E.A.

    2013-01-01

    Petroleum oil is an important source for the energy in the world. The Gulf of Suez, Nile Delta and South Valley are important regions for studying hydrocarbon potential in Egypt. A thorium normalization technique was applied on the sandstone reservoirs in the three regions to determine the hydrocarbon potentialities zones using the three spectrometric radioactive gamma ray-logs (eU, eTh and K% logs). The conventional well logs (gamma-ray, deep resistivity, shallow resistivity, neutron, density and sonic logs) are analyzed to determine the net pay zones in these wells. Indices derived from thorium normalized spectral logs indicate the hydrocarbon zones in petroleum reservoirs. The results of this technique in the three regions (Gulf of Suez, Nile Delta and South Valley) are in agreement with the results of the conventional well log analyses by ratios of 82%, 78% and 71% respectively. - Highlights: ► The positive DRAD values indicate the hydrocarbon zones in petroleum reservoirs. ► Thorium normalization was applied to determine the hydrocarbon potentialities. ► The conventional well logs are analyzed to determine the net pay zones in wells. ► Determining hydrocarbon potentialities zones using spectrometric gamma-ray logs

  4. Evidence of clastic evaporites in the canyons of the Levant basin (Israel): implications for the Messinian salinity crisis

    Science.gov (United States)

    Lugli, Stefano; Schreiber, B. Charlotte; Gvirtzman, Zohar; Manzi, Vinicio; Roveri, Marco

    2013-04-01

    The recognition of widespread and thick evaporite deposits below the floor of the Mediterranean Sea has boosted a long standing controversy concerning their depositional setting (shallow versus deep) and their correlation with the onshore sequences. Until a new scientific campaign might be launched to cross those deposits, the discussion is still open to speculation. Many Messinian evaporitic deposits have been interpreted as primary precipitates in very shallow-water or coastal environments, thus favouring the idea of a desiccated Mediterranean basin (Hsu et al., 1973). Recent studies have questioned this interpretation (Hardie and Lowenstein, 2004) and widespread, thick, clastic evaporite facies have been identified in the Mediterranean (Manzi et al., 2005). These clastic deposits are not compatible with a desiccation model as they were clearly emplaced by fully subaqueous, deep-water processes, ranging from submarine slides, to high- and low-density gravity flows. One of the most relevant areas for the understanding of the salinity crisis is the Levant basin where the Messinian evaporites partially fill some of the erosional features (canyons) considered to have formed as a consequence of significant drawdown related to the desiccation of the Mediterranean Sea (up to - 850 m, Druckman et al., 1995). Our complete revisitation of the available cores from onshore Israel cutting through the sedimentary filling of the Messinian canyons (Afiq 1, Ashdod 2, Be'eri Sh1, Be'eri Sh4, Jaffa 1 and Talme-Yaffe 3) revealed exclusively clastic sulfate facies. This is the first direct evidence that the Lower Evaporite Unit offshore Israel may actually consist of deep-water resedimented evaporites that were originally deposited on the margin of the Levant Basin. References Druckman Y., Buchbinder B., Martinotti G.M., Tov R.S., Aharon P., 1995. The buried Afiq Canyon (eastern Mediterranean, Israel): a case study of a Tertiary submarine canyon exposed in Late Messinian times

  5. Architecture and quantitative assessment of channeled clastic deposits, Shihezi sandstone (Lower Permian, Ordos Basin, China

    Directory of Open Access Journals (Sweden)

    Chengye Jia

    2017-02-01

    Full Text Available Lower Permian Shihezi sandstone in Ordos Basin is the largest gas reservoir in China. Architecture elements of channel, overbank and floodplain facies of braided channel deposits were identified through an outcrops survey, and their proportion of channel facies have been quantitatively estimated from well logging. Characteristics of architecture elements, such as sand thickness, bounding surfaces and lithofacies were investigated through outcrops and core. Petrology of Shihezi sandstone has also been studied in detail. Analysis on sandstone components shows that monocrystalline quartz with approximately 76% bulk volume, and lithic up to 5%–45% bulk volume, are the two main components. Litharenite and lithic quartz sandstone are the main rock types. Compaction is concluded by former researchers as the control factor of low permeability. Examination through thin section reveals that secondary pores developed well in coarse sand. Inter-granular dissolution is included as the positive effect to increasing porosity, and is concluded as the control factor to the generation of net pay. Scale of coarse grained channel fills and channel bar sandstone bodies are quantitatively estimated. Strike-oriented, dip-oriented, and vertical distribution of channel fills and channel bar sandstone bodies have been investigated. The geometry of sand bodies can be depicted as an elongated lens. Subsurface mapping reveals that channel sandstone bodies distribute widely from both lateral and longitudinal cross section profiles, and are poorly connected.

  6. Reservoir compartmentalization and management strategies: Lessons learned in the Illinois basin

    Energy Technology Data Exchange (ETDEWEB)

    Grube, J.P.; Crockett, J.E.; Huff, B.G. [and others

    1997-08-01

    A research project jointly sponsored by the US Department of Energy and the Illinois State Geological Survey focused on the Cypress and Aux Vases Formations (Mississippian), major clastic reservoirs in the Illinois Basin. Results from the research showed that understanding the nature and distribution of reservoir compartments, and using effective reservoir management strategies, can significantly improve recovery efficiencies from oil fields in this mature basin. Compartments can be most effectively drained where they are geologically well defined and reservoir management practices are coordinated through unified, compartment-wide, development programs. Our studies showed that the Cypress and Aux Vases reservoirs contain lateral and vertical permeability barriers forming compartments that range in size from isolated, interlaminated sandstone and shale beds to sandstone bodies tens of feet in thickness and more than a mile in length. Stacked or shingled, genetically similar sandstone bodies are commonly separated by thin impermeable intervals that can be difficult to distinguish on logs and can, therefore, cause correlation problems, even between wells drilled on spacing of less than ten acres. Lateral separation of sandstone bodies causes similar problems. Reservoir compartmentalization reduces primary and particularly secondary recovery by trapping pockets of by-passed or banked oil. Compartments can be detected by comparing recovery factors of genetically similar sandstone bodies within a field; using packers to separate commingled intervals and analyzing fluid recoveries and pressures; making detailed core-to-log calibrations that identify compartment boundaries; and analyzing pressure data from waterflood programs.

  7. Upper Hiwassee River Basin reservoirs 1989 water quality assessment

    International Nuclear Information System (INIS)

    Fehring, J.P.

    1991-08-01

    The water in the Upper Hiwassee River Basin is slightly acidic and low in conductivity. The four major reservoirs in the Upper Hiwassee River Basin (Apalachia, Hiwassee, Chatuge, and Nottely) are not threatened by acidity, although Nottely Reservoir has more sulfates than the other reservoirs. Nottely also has the highest organic and nutrient concentrations of the four reservoirs. This results in Nottely having the poorest water clarity and the most algal productivity, although clarity as measured by color and secchi depths does not indicate any problem with most water use. However, chlorophyll concentrations indicate taste and odor problems would be likely if the upstream end of Nottely Reservoir were used for domestic water supply. Hiwassee Reservoir is clearer and has less organic and nutrient loading than either of the two upstream reservoirs. All four reservoirs have sufficient algal activity to produce supersaturated dissolved oxygen conditions and relatively high pH values at the surface. All four reservoirs are thermally stratified during the summer, and all but Apalachia have bottom waters depleted in oxygen. The very short residence time of Apalachia Reservoir, less than ten days as compared to over 100 days for the other three reservoirs, results in it being more riverine than the other three reservoirs. Hiwassee Reservoir actually develops three distinct water temperature strata due to the location of the turbine intake. The water quality of all of the reservoirs supports designated uses, but water quality complaints are being received regarding both Chatuge and Nottely Reservoirs and their tailwaters

  8. Routing of terrigenous clastics to oceanic basins in the southern Gulf of California, inherited from features of the pre-spreading protogulf

    Science.gov (United States)

    Lonsdale, P.; Kluesner, J. W.

    2010-12-01

    The southern protogulf was a Miocene belt of continental rupture bounded on the northeast by the Sierra Madre Occidental (SMO) volcanic plateau, and on the southeast by the Main Gulf Escarpment of the Baja California (BC) rift shoulder. Since no later than 8-9Ma, before the depression became a deep inlet of the Pacific, the southern protogulf has hosted the principal shear zone between the Pacific and North American plates. As BC gradually acquired Pacific-plate motion, its vector wrt North America rotated and made the shear zone transtensional, leading to the development of several types of pull-apart basins. Some of them, at right steps between en echelon faults, evolved into the oceanic basins that are now the principal Gulf depocenters. Recent geophysical mapping and geologic sampling in the southern Gulf has clarified the location, structures, and composition of the oceanic/continental crustal boundary, and the mechanisms and routes by which terrigenous clastics reach the intracontinental and oceanic basins.Longitudinal (northwest-southeast) thermohaline and tidal currents transport significant volumes of hemipelagic sediment across the floors of gulf basins, but most of the coarser terrigenous clastics arrive there in density flows, primarily turbidity currents that have built channeled deep-sea fans at the mouths of canyons in the continental slopes. Mapped patterns of submarine canyons, channels and fans confirm that turbidity-current transport has primarily been from the northeast margin, which has permanent mainland rivers with large catchments in the SMO. Most of the arid BC peninsula, with ephemeral-stream drainage directed toward the Pacific, contributes little terrigenous input to the deep-water gulf basins, except in the far south: more than a third of the elevated Cabo Block drains into the gulf, building a large fan on the northwest side of Alarcon Basin. The canyons feeding this fan, cut through crystalline rock and probably subaerial in origin

  9. Gas accumulations in Oligocene-Miocene reservoirs in the Alpine Foreland Basin (Austria): evidence for gas mixing and gas degradation

    Science.gov (United States)

    Pytlak, L.; Gross, D.; Sachsenhofer, R. F.; Bechtel, A.; Linzer, H.-G.

    2017-09-01

    Two petroleum systems are present in the eastern (Austrian) sector of the Alpine Foreland Basin. Whereas oil and thermogenic gas in Mesozoic and Eocene reservoir rocks have been generated beneath the Alps in Lower Oligocene source rocks, relative dry gas in Oligocene-Miocene clastic rocks deposited in the deep marine basin-axial channel system (Puchkirchen Channel) is interpreted as microbial in origin. Detailed investigations of the molecular and isotope composition of 87 gas samples from 86 wells, representing all producing fields with Oligocene and Miocene reservoir rocks, suggest that the presence of pure microbial gas is rare and limited mainly to the northern basin flank (e.g., KK field). All other fields contain varying amounts of thermogenic gas, which has been generated from a source rock with oil-window maturity. A relation with the underlying thermogenic petroleum system is obvious. Upward migration occurred along discrete fault zones (e.g., H field) or through low-permeability caprocks. Local erosion of Lower Oligocene sediments, the principal seal for the thermogenic petroleum system, as well as a high percentage of permeable rocks within the Puchkirchen Channel favored upward migration and mixing of thermogenic and microbial gas. All gas samples in Oligocene-Miocene reservoirs are biodegraded. Biodegradation and the formation of secondary microbial gas resulted in gas drying. Therefore, the gas samples analyzed in this study are relative dry, despite significant contributions of thermogenic hydrocarbons. Biodegradation probably continues at present time. The degree of biodegradation, however, decreases with depth.

  10. Relationship between fluvial clastic sediment and source rock abundance in Rapti river basin of central Nepal Himalayas

    International Nuclear Information System (INIS)

    Tamrakar Naresh Kazi; Shresth Madhusudan Bhakta

    2008-01-01

    Many tributaries from carbonate sedimentary, metamorphic and igneous rocks of the Lesser Himalayan and clastic sedimentary rocks of the Sub-Himalayan Ranges carry gravelly sediments to the Rapti River. River bar sediments were analyzed for composition and texture to evaluate downstream changes in properties, and to establish relationship between proportion of clasts and the abundance of rock types in the source areas. Percent quartzite clast or granite clast increases whereas that of carbonate, schist or slate decreases along downstream. The largest grain size decreases downstream, whereas fatness index and sphericity tend to increase. Despite of little diminish in relative abundance of rock types in source areas along the river, the relative proportion of corresponding clast type shows rapid reduction (e.g. slate or phyllite or carbonate clasts) or rapid enhancement (e.g. granite clast). The relationships of quartzite clast and schist clasts with their corresponding source rocks are statistically significant suggesting that these clasts can provide clue to source rock abundance. About 85 to 94% of the gravel clasts represent rock types of the Lesser Himalayan Range suggesting that this range has been contributing enormous amount of sediments.

  11. Facies sedimentology, mineralogy and genetic stratigraphy of the lower-Lias silici-clastic reservoirs of Cere-La-Ronde; Sedimentologie de facies, mineralogie et stratigraphie genetique des reservoirs silicoclastiques du Lias inferieur de Cere-La-Ronde

    Energy Technology Data Exchange (ETDEWEB)

    Geiller, M.

    1997-11-21

    Some sandstone reservoirs in the South West of the Parisian Basin (Sologne) are used for gas storage in the underground aquifer by GDF. The study aims to reconstruct the geometry of these reservoirs and to establish the factors controlling their deposition in the Sologne basin during Rhaetian and Hettangian times. This study combines palynological, sedimentological, mineralogical and sequential analyses. It is applied to channel deposits as well as to flood-plain and over-bank deposits which are rarely considered. The formations are deposited in a continental transgressive context associated to a decreasing subsidence. The different depositional environments varied from the alluvial fan to the coastal plain with different intermediate alluvial plains. They get organized in three depositional profiles which are emphasized by hydrodynamic discontinuities due to irreversible modifications in depositional conditions. The clayey associations change with each depositional profile according to detrital source modifications. They characterize discontinuities due to geodynamic events affecting the Sologne basin (depositional profile changes, pedogenesis). In this continental context, the genetic sequences record a cycle of variation of the river longitudinal profile slope. They determine the sediments geometry which results from the relative sea-level variations. Local tectonics creates an heterogenous subsidence and consequently controls the distribution of the sediments. During tectonic instability periods, the subsiding areas migrate while they do not during tectonic stability periods. The latter end with irreversible change in depositional profile. (author) 135 refs.

  12. Seismic attributes characterization for Albian reservoirs in shallow Santos Basin

    Energy Technology Data Exchange (ETDEWEB)

    Vincentelli, Maria Gabriela C.; Barbosa, Mauro [HRT Petroleum, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The Santos basin southwest area is characterized by gas production, but it shows an exploratory problem due to the lack of good reservoirs facies. The main reservoirs are the Albian calcarenites, which show low porosities values (about 2%) in the northwest portion of the study area. From wire log analysis, it was interpreted that the porosity values can reach 15% at the south-west portion, both in the Caravela, Cavalo Marinho and Tubarao oil/gas fields and in the neighborhood of these fields. In order to find the best places to drill exploration wells at Shallow Santos, it is recommended to apply analyses of seismic attributes including: main average amplitude, energy, RMS, main amplitude, etc. Once the application of this methodology is restricted to 3D seismic data, in this study, a pseudo-3D seismic volume was built from 9,635 km of seismic lines, and 13 wells were used for reservoir facies control. As a result, the presence of good facies reservoirs in this area of the basin is restricted to trends with a NE-SW direction, and their presence is not only associated with the structural highs, this fact explains the dry wells over rollover structures. (author)

  13. Unlocking the hydrocarbon potential of the eastern Black Sea basin. Prospectivity of middle Miocene submarine fan reservoirs by seismic sequence stratigraphy

    International Nuclear Information System (INIS)

    Gundogan, Coskun; Galip, Ozbek; Ali, Demirer

    2002-01-01

    Full text : The objective of this paper is to present present depositional characteristics and hydrocarbon prospectivity of the middle Miocene submarine basin floor fan deposits from the exploration stand point of view by using seismic data available in the offshore eastern Black Sea basin. This basin is a Tertiary trough formed as a continuation of the Mesozoic oceanic basin. The hydrocarbon potential of the basin is believed to be high in the Tertiary section because of the existence of the elements necessary for generation, migration and entrapment of hydrocarbon. A sequence stratigraphic study has been carried out by using 2-d seismic data in the Turkish portion of the eastern Black Sea basin. The objective of the study was to determine periods of major clastic sediment influxes which might lead to identify good reservoir intervals and their spatial distribution in this basin. All basic seismic sequence stratigraphic interpretation techniques and seismic facies analysis were used to identify times of these sand rich deposition periods. Sequence stratigraphy and seismic facies analysis indicate that the basinal areas of the middle Miocene sequences were dominated mainly by submarine fan complexes introduced in the lowstand stages and pelagic sediments deposited during the transgressive and highstand stages. It was proposed that Turkish portion of this basin which is one of the best frontier exploration area with its high potential left in the world, is glimpsing to those looking for good future exploration opportunities.

  14. Fan-delta and interdeltaic shoreline sediments of Middle Devonian Granite Wash and Keg River clastics, Red Earth field, north Alberta basin, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Sabry, H.

    1989-03-01

    A detailed sedimentological investigation of over 4000 ft of core and 500 well logs of the Middle Devonian granite wash and Keg River clastics in the Red Earth field, North Alberta basin, Canada, has led to the recognition of a granite wash subaerial fan-delta system that is laterally continuous with a Keg River subaqueous delta component along an eastern shoreline of the ancestral Peace River arch. The subaerial fan delta includes alluvial fan facies, sheet wash and mud flows, and playa lakes. The subaqueous delta component includes lower shoreface, upper shoreface, beach-foreshore, eolian sand dunes, lagoon, washover sands, tidal channels and flats, and supratidal carbonates and anhydrites. Within this system, six mappable units are defined. A conceptual depositional model for the sequence depicts four main events. (1) Erosion of Peach River arch uplifted fault blocks, which produced coarse-grained fan-delta sediments in an adjacent fault-bounded margin. Subsequent fluvial reworking resulted in the deposition of thick, lenticular, wedge-shaped alluvial fans of granite wash. (2) Progradation of alluvial fans seaward into the Keg River Sea. (3) Transgression by Middle Devonian seas from the east, which reworked alluvial fans and led to deposition of discontinuous linear sand bodies represented by the Keg River regressive shoreline sediments. (4) Restriction of the sea by the Presqu'ile barrier reef to the north, which deposited evaporites of the Muskeg Formation over the whole sequence. Modern analog to this fan-delta system is the coastal fans of the Gulf of Aqaba, Red Sea. Red Earth field contains over 27 million bbl of recoverable oil, related to a combination structural-stratigraphic trap.

  15. 3D Sedimentological and geophysical studies of clastic reservoir analogs: Facies architecture, reservoir properties, and flow behavior within delta front facies elements of the Cretaceous Wall Creek Member, Frontier Formation, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Christopher D. White

    2009-12-21

    rock types (\\Eg sandstones and mudstones) and the variation of transport properties (\\Eg permeability and porosity) within bodies of a particular rock type. Both basin-wide processes such as sea-level change and the autocyclicity of deltaic processes commonly cause deltaic reservoirs to have large variability in rock properties; in particular, alternations between mudstones and sandstones may form baffles and trends in rock body permeability can influence productivity and recovery efficiency. In addition, diagenetic processes such as compaction, dissolution, and cementation can alter the spatial pattern of flow properties. A better understanding of these properties, and improved methods to model the properties and their effects, will allow improved reservoir development planning and increased recovery of oil and gas from deltaic reservoirs. Surface exposures of ancient deltaic rocks provide a high resolution, low uncertainty view of subsurface variability. Patterns and insights gleaned from these exposures can be used to model analogous reservoirs, for which data is much sparser. This approach is particularly attractive when reservoir formations are exposed at the surface. The Frontier Formation in central Wyoming provides an opportunity for high resolution characterization. The same rocks exposed in the vicinity of the Tisdale anticline are productive in nearby oil fields, including Salt Creek. Many kilometers of good-quality exposure are accessible, and the common bedding-plane exposures allow use of shallow-penetration, high-resolution electromagnetic methods known as ground-penetrating radar. This study combined geologic interpretations, maps, vertical sections, core data, and ground-penetrating radar to construct high-resolution geostatistical and flow models for the Wall Creek Member of the Frontier Formation. Stratal-conforming grids were use to reproduce the progradational and aggradational geometries observed in outcrop and radar data. A new, Bayesian method

  16. Sedimentological and geophysical studies of clastic reservoir analogs: Methods, applications and developments of ground-penetrating radar for determination of reservoir geometries in near-surface settings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, G.A.; Soegaard, K.

    1998-05-25

    An integrated sedimentologic and GPR investigation has been carried out on a fluvial channel sandstone in the mid-Cretaceous Ferron Sandstone at Coyote Basin along the southwestern flank of the San Rafael Uplift in east-central Utah. This near-surface study, which covers a area of 40 {times} 16.5 meters to a depth of 15 meters, integrates detailed stratigraphic data from outcrop sections and facies maps with multi-frequency 3-D GPR surveys. The objectives of this investigation are two-fold: (1) to develop new ground-penetrating radar (GPR) technology for imaging shallow subsurface sandstone bodies, and (2) to construct an empirical three-dimensional sandstone reservoir model suitable for hydrocarbon flow-simulation by imaging near-surface sandstone reservoir analogs with the use of GPR. The sedimentological data base consists of a geologic map of the survey area and a detailed facies map of the cliff face immediately adjacent to the survey area. Five vertical sections were measured along the cliff face adjacent to the survey area. In addition, four wells were cored within the survey area from which logs were recorded. In the sections and well logs primary sedimentary structures were documented along with textural information and permeability data. Gamma-ray profiles were also obtained for all sections and core logs. The sedimentologic and stratigraphic information serves as the basis from which much of the processing and interpretation of the GPR data was made. Three 3-D GPR data sets were collected over the survey area at frequencies of 50 MHZ, 100 MHZ, and 200 MHZ.

  17. Characterization of the Qishn sandstone reservoir, Masila Basin-Yemen, using an integrated petrophysical and seismic structural approach

    Science.gov (United States)

    Lashin, Aref; Marta, Ebrahim Bin; Khamis, Mohamed

    2016-03-01

    This study presents an integrated petrophysical and seismic structural analysis that is carried out to evaluate the reservoir properties of Qishn sandstone as well as the entrapment style of the hydrocarbons at Sharyoof field, Sayun-Masila Basin that is located at the east central of Yemen. The reservoir rocks are dominated by clean porous and permeable sandstones zones usually intercalated with some clay stone interbeds. As identified from well logs, Qishn sandstone is classified into subunits (S1A, S1B, S1C and S2) with different reservoir characteristics and hydrocarbon potentiality. A number of qualitative and quantitative well logging analyses are used to characterize the different subunits of the Qishn reservoir and identify its hydrocarbon potentiality. Dia-porosity, M-N, Pickett, Buckles plots, petrophysical analogs and lateral distribution maps are used in the analysis. Shale volume, lithology, porosity, and fluid saturation are among the most important deduced parameters. The analysis revealed that S1A and S1C are the main hydrocarbon-bearing units. More specifically, S1A unit is the best, as it attains the most prolific hydrocarbon saturations (oil saturation "SH″ up to 65) and reservoir characteristics. An average petrophysical ranges of 4-21%, 16-23%, 11-19%, 0-65%, are detected for S1A unit, regarding shale volume, total and effective porosity, and hydrocarbon saturation, respectively. Meanwhile, S1B unit exhibits less reservoir characteristics (Vsh>30%, ϕEff<15% and SH< 15%). The lateral distribution maps revealed that most of the hydrocarbons (for S1A and S1C units) are indicated at the middle of the study area as NE-SW oriented closures. The analysis and interpretation of seismic data had clarified that the structure of study area is represented by a big middle horst bounded by a group of step-like normal faults at the extreme boundaries (faulted anticlinal-structure). In conclusion, the entrapment of the encountered hydrocarbon at Sharyoof oil

  18. Reservoir characterization of the Mt. Simon Sandstone, Illinois Basin, USA

    Science.gov (United States)

    Frailey, S.M.; Damico, J.; Leetaru, H.E.

    2011-01-01

    The integration of open hole well log analyses, core analyses and pressure transient analyses was used for reservoir characterization of the Mt. Simon sandstone. Characterization of the injection interval provides the basis for a geologic model to support the baseline MVA model, specify pressure design requirements of surface equipment, develop completion strategies, estimate injection rates, and project the CO2 plume distribution.The Cambrian-age Mt. Simon Sandstone overlies the Precambrian granite basement of the Illinois Basin. The Mt. Simon is relatively thick formation exceeding 800 meters in some areas of the Illinois Basin. In the deeper part of the basin where sequestration is likely to occur at depths exceeding 1000 m, horizontal core permeability ranges from less than 1 ?? 10-12 cm 2 to greater than 1 ?? 10-8 cm2. Well log and core porosity can be up to 30% in the basal Mt. Simon reservoir. For modeling purposes, reservoir characterization includes absolute horizontal and vertical permeability, effective porosity, net and gross thickness, and depth. For horizontal permeability, log porosity was correlated with core. The core porosity-permeability correlation was improved by using grain size as an indication of pore throat size. After numerous attempts to identify an appropriate log signature, the calculated cementation exponent from Archie's porosity and resistivity relationships was used to identify which porosity-permeability correlation to apply and a permeability log was made. Due to the relatively large thickness of the Mt. Simon, vertical permeability is an important attribute to understand the distribution of CO2 when the injection interval is in the lower part of the unit. Only core analyses and specifically designed pressure transient tests can yield vertical permeability. Many reservoir flow models show that 500-800 m from the injection well most of the CO2 migrates upward depending on the magnitude of the vertical permeability and CO2 injection

  19. DHI evaluation by combining rock physics simulation and statistical techniques for fluid identification of Cambrian-to-Cretaceous clastic reservoirs in Pakistan

    Science.gov (United States)

    Ahmed, Nisar; Khalid, Perveiz; Shafi, Hafiz Muhammad Bilal; Connolly, Patrick

    2017-10-01

    The use of seismic direct hydrocarbon indicators is very common in exploration and reservoir development to minimise exploration risk and to optimise the location of production wells. DHIs can be enhanced using AVO methods to calculate seismic attributes that approximate relative elastic properties. In this study, we analyse the sensitivity to pore fluid changes of a range of elastic properties by combining rock physics studies and statistical techniques and determine which provide the best basis for DHIs. Gassmann fluid substitution is applied to the well log data and various elastic properties are evaluated by measuring the degree of separation that they achieve between gas sands and wet sands. The method has been applied successfully to well log data from proven reservoirs in three different siliciclastic environments of Cambrian, Jurassic, and Cretaceous ages. We have quantified the sensitivity of various elastic properties such as acoustic and extended elastic (EEI) impedances, elastic moduli ( K sat and K sat- μ), lambda-mu-rho method ( λρ and μρ), P-to-S-wave velocity ratio ( V P/ V S), and Poisson's ratio ( σ) at fully gas/water saturation scenarios. The results are strongly dependent on the local geological settings and our modeling demonstrates that for Cambrian and Cretaceous reservoirs, K sat- μ, EEI, V P/ V S, and σ are more sensitive to pore fluids (gas/water). For the Jurassic reservoir, the sensitivity of all elastic and seismic properties to pore fluid reduces due to high overburden pressure and the resultant low porosity. Fluid indicators are evaluated using two metrics: a fluid indicator coefficient based on a Gaussian model and an overlap coefficient which makes no assumptions about a distribution model. This study will provide a potential way to identify gas sand zones in future exploration.

  20. Electrofacies vs. lithofacies sandstone reservoir characterization Campanian sequence, Arshad gas/oil field, Central Sirt Basin, Libya

    Science.gov (United States)

    Burki, Milad; Darwish, Mohamed

    2017-06-01

    The present study focuses on the vertically stacked sandstones of the Arshad Sandstone in Arshad gas/oil field, Central Sirt Basin, Libya, and is based on the conventional cores analysis and wireline log interpretation. Six lithofacies types (F1 to F6) were identified based on the lithology, sedimentary structures and biogenic features, and are supported by wireline log calibration. From which four types (F1-F4) represent the main Campanian sandstone reservoirs in the Arshad gas/oil field. Lithofacies F5 is the basal conglomerates at the lower part of the Arshad sandstones. The Paleozoic Gargaf Formation is represented by lithofacies F6 which is the source provenance for the above lithofacies types. Arshad sediments are interpreted to be deposited in shallow marginal and nearshore marine environment influenced by waves and storms representing interactive shelf to fluvio-marine conditions. The main seal rocks are the Campanian Sirte shale deposited in a major flooding events during sea level rise. It is contended that the syn-depositional tectonics controlled the distribution of the reservoir facies in time and space. In addition, the post-depositional changes controlled the reservoir quality and performance. Petrophysical interpretation from the porosity log values were confirmed by the conventional core measurements of the different sandstone lithofacies types. Porosity ranges from 5 to 20% and permeability is between 0 and 20 mD. Petrophysical cut-off summary of the lower part of the clastic dominated sequence (i. e. Arshad Sandstone) calculated from six wells includes net pay sand ranging from 19.5‧ to 202.05‧, average porosity from 7.7 to 15% and water saturation from 19 to 58%.

  1. Reservoir Space Evolution of Volcanic Rocks in Deep Songliao Basin, China

    Science.gov (United States)

    Zheng, M.; Wu, X.; Zheng, M.; HU, J.; Wang, S.

    2015-12-01

    Recent years, large amount of natural gas has been discovered in volcanic rock of Lower Crataceous of Songliao basin. Volcanic reservoirs have become one of the important target reservoir types of eastern basin of China. In order to study the volcanic reservoirs, we need to know the main factors controlling the reservoir space. By careful obsercation on volcanic drilling core, casting thin sections and statistical analysis of petrophysical properties of volcanic reservoir in Songliao basin, it can be suggested that the igneous rock reservoir in Yingcheng formation of Lower Crataceous is composed of different rock types, such ad rohylite, rohylitic crystal tuff, autoclastic brecciation lava and so on. There are different reservoirs storage space in in various lithological igneous rocks, but they are mainly composed of primary stoma, secondary solution pores and fractures.The evolution of storage space can be divided into 3 stage: the pramary reservoir space,exogenic leaching process and burial diagenesis.During the evolution process, the reservoir space is effected by secondary minerals, tectonic movement and volcanic hydrothermal solution. The pore of volcanic reservoirs can be partially filled by secondary minerals, but also may be dissoluted by other chemical volcanic hydrothermal solution. Therefore, the favorable places for better-quality volcanic reservoirs are the near-crater facies of vocanic apparatus and dissolution zones on the high position of paleo-structures.

  2. Applications of the SWOT Mission to Reservoirs in the Mekong River Basin

    Science.gov (United States)

    Bonnema, M.; Hossain, F.

    2017-12-01

    The forthcoming Surface Water and Ocean Topography (SWOT) mission has the potential to significantly improve our ability to observe artificial reservoirs globally from a remote sensing perspective. By providing simultaneous estimates of reservoir water surface extent and elevation with near global coverage, reservoir storage changes can be estimated. Knowing how reservoir storage changes over time is critical for understanding reservoir impacts on river systems. In data limited regions, remote sensing is often the only viable method of retrieving such information about reservoir operations. When SWOT launches in 2021, it will join an array of satellite sensors with long histories of reservoir observation and monitoring capabilities. There are many potential synergies in the complimentary use of future SWOT observations with observations from current satellite sensors. The work presented here explores the potential benefits of utilizing SWOT observations over 20 reservoirs in the Mekong River Basin. The SWOT hydrologic simulator, developed by NASA Jet Propulsion Laboratory, is used to generate realistic SWOT observations, which are then inserted into a previously established remote sensing modeling framework of the 20 Mekong Basin reservoirs. This framework currently combines data from Landsat missions, Jason radar altimeters, and the Shuttle Radar and Topography Mission (SRTM), to provide monthly estimates of reservoir storage change. The incorporation of SWOT derived reservoir surface area and elevation into the model is explored in an effort to improve both accuracy and temporal resolution of observed reservoir operations.

  3. Forming mechanism of the Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin

    Directory of Open Access Journals (Sweden)

    Heng Fu

    2017-07-01

    Full Text Available The Ordovician karst carbonate reservoirs on the northern slope of central Tarim Basin are important oil and gas exploration targets in the basin, but their dissolution mechanisms are in controversy. In this paper, based on the integrated study of sedimentation, sequence and reservoir, together with microscopic analysis and macroscopic seismic data analysis, the carbonate karst reservoirs in the study area were divided into three types: dissolved pore-cavity limestone reservoir, pore-cavity dolomite reservoir and fracture-cavity siliceous reservoir, and their forming mechanisms were discussed respectively. Some findings were obtained. First, dissolved pore-cavity limestone reservoirs are distributed in the upper Yingshan Fm and Yijianfang Fm of the Ordovician vertically, while pore-cavity dolomite reservoirs are mainly developed in the Penglai Fm and lower Yingshan Fm of the Ordovician with great thickness. Second, dissolved pore-cavity limestone reservoirs were formed by karstification on the third-order sequence boundary (lowstand tract, while pore-cavity dolomite reservoirs were formed by deep burial dolomitization controlled by karstification on the third-order sequence boundary, both of which are distributed in the highstand tract below the third-order sequence boundary. Third, siliceous reservoirs are developed under the control of faulting, as a result of reworking of deep hydrothermal fluids along faults to the limestone, and the siliceous reservoirs and their hydrothermal solution fracture-cavity systems are distributed near faults. It is further predicted that, in addition to the three types of reservoir above, platform-margin reef-flat reservoirs are developed in the Ordovician on the northern slope of central Tarim Basin.

  4. Reservoir Performance Under Future Climate For Basins With Different Hydrologic Sensitivities

    Science.gov (United States)

    Mateus, M. C.; Tullos, D. D.

    2013-12-01

    In addition to long-standing uncertainties related to variable inflows and market price of power, reservoir operators face a number of new uncertainties related to hydrologic nonstationarity, changing environmental regulations, and rapidly growing water and energy demands. This study investigates the impact, sensitivity, and uncertainty of changing hydrology on hydrosystem performance across different hydrogeologic settings. We evaluate the performance of reservoirs in the Santiam River basin, including a case study in the North Santiam Basin, with high permeability and extensive groundwater storage, and the South Santiam Basin, with low permeability, little groundwater storage and rapid runoff response. The modeling objective is to address the following study questions: (1) for the two hydrologic regimes, how does the flood management, water supply, and environmental performance of current reservoir operations change under future 2.5, 50 and 97.5 percentile streamflow projections; and (2) how much change in inflow is required to initiate a failure to meet downstream minimum or maximum flows in the future. We couple global climate model results with a rainfall-runoff model and a formal Bayesian uncertainty analysis to simulate future inflow hydrographs as inputs to a reservoir operations model. To evaluate reservoir performance under a changing climate, we calculate reservoir refill reliability, changes in flood frequency, and reservoir time and volumetric reliability of meeting minimum spring and summer flow target. Reservoir performance under future hydrology appears to vary with hydrogeology. We find higher sensitivity to floods for the North Santiam Basin and higher sensitivity to minimum flow targets for the South Santiam Basin. Higher uncertainty is related with basins with a more complex hydrologeology. Results from model simulations contribute to understanding of the reliability and vulnerability of reservoirs to a changing climate.

  5. Controlling factors of volcanic hydrocarbon reservoirs in Bohai Bay Basin, China

    Directory of Open Access Journals (Sweden)

    Chun Yang

    2017-12-01

    Full Text Available Volcanic hydrocarbon reservoirs are developed in the Mesozoic and Cenozoic strata in Bohai Bay Basin in China. There is more than one hundred million tons of proven oil reserves in the said reservoir. They performed different actors for oil and gas accumulation in the basin. Faults controlled the distribution and accumulation of oil and gas related to volcanic rocks in Bohai Bay Basin. Not to mention, the zone near the faults is favorable for the development of good reservoirs. Volcanic rocks and volcanism can serve several roles during the course of hydrocarbon generation and accumulation. Volcanism can promote hydrocarbon generation from source rocks. Simultaneously, volcanic activity can damage petroleum reservoirs. Volcanic rocks can be both the reservoirs and the cap-rocks or obscured layer in the basin. The occurrence of volcanic rocks in source rocks can form fractures more easily compared to that in sandstones. Finally, volcanic rocks also control the distribution of mantle-derived CO2 gas reservoirs in the basin.

  6. Evaluation of reservoir operation strategies for irrigation in the Macul Basin, Ecuador

    Directory of Open Access Journals (Sweden)

    Vicente Tinoco

    2016-03-01

    Full Text Available Study focus: An irrigation project is planned in the study basin for developing the agriculture as the main income in the region. The proposed water system comprises three large reservoirs damming the rivers Macul and Maculillo. The river basin planning and operation were investigated by modelling alternative reservoir operation strategies aiming at a sustainable balance between irrigation and river ecology by integrated reservoir/river management. New hydrological insights for the region: After simulation of long-term meteorological series in a model of the integrated water system, covering several historical extreme events, results indicate that the planned irrigation volumes are higher than the available water for a sustainable irrigation strategy. Two lines of action are suggested for reaching the target irrigation demands: design of a deficit irrigation system, and modifications to the reservoir's spillway height. Keywords: Reservoir operation, Conceptual model, Irrigation

  7. Hydrocarbon accumulation characteristics and enrichment laws of multi-layered reservoirs in the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guang Yang

    2017-03-01

    Full Text Available The Sichuan Basin represents the earliest area where natural gas is explored, developed and comprehensively utilized in China. After over 50 years of oil and gas exploration, oil and gas reservoirs have been discovered in 24 gas-dominant layers in this basin. For the purpose of predicting natural gas exploration direction and target of each layer in the Sichuan Basin, the sedimentary characteristics of marine and continental strata in this basin were summarized and the forms of multi-cycled tectonic movement and their controlling effect on sedimentation, diagenesis and hydrocarbon accumulation were analyzed. Based on the analysis, the following characteristics were identified. First, the Sichuan Basin has experienced the transformation from marine sedimentation to continental sedimentation since the Sinian with the former being dominant. Second, multiple source–reservoir assemblages are formed based on multi-rhythmed deposition, and multi-layered reservoir hydrocarbon accumulation characteristics are vertically presented. And third, multi-cycled tectonic movement appears in many forms and has a significant controlling effect on sedimentation, diagenesis and hydrocarbon accumulation. Then, oil and gas reservoir characteristics and enrichment laws were investigated. It is indicated that the Sichuan Basin is characterized by coexistence of conventional and unconventional oil and gas reservoirs, multi-layered reservoir hydrocarbon supply, multiple reservoir types, multiple trap types, multi-staged hydrocarbon accumulation and multiple hydrocarbon accumulation models. Besides, its natural gas enrichment is affected by hydrocarbon source intensity, large paleo-uplift, favorable sedimentary facies belt, sedimentary–structural discontinuity plane and structural fracture development. Finally, the natural gas exploration and research targets of each layer in the Sichuan Basin were predicted according to the basic petroleum geologic conditions

  8. Reservoir heterogeneity in Carboniferous sandstone of the Black Warrior basin. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

    1994-04-01

    Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

  9. Reservoir heterogeneity in carboniferous sandstone of the Black Warrior basin. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

    1994-06-01

    Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

  10. Depositional setting and diagenetic evolution of some Tertiary unconventional reservoir rocks, Uinta Basin, Utah.

    Science.gov (United States)

    Pitman, Janet K.; Fouch, T.D.; Goldhaber, M.B.

    1982-01-01

    The Douglas Creek Member of the Tertiary Green River Formation underlies much of the Uinta basin, Utah, and contains large volumes of oil and gas trapped in a complex of fractured low-permeability sandstone reservoirs. In the SE part of the basin at Pariette Bench, the Eocene Douglas Creek Member is a thick sequence of fine- grained alluvial sandstone complexly intercalated with lacustrine claystone and carbonate rock. Sediments were deposited in a subsiding intermontane basin along the shallow fluctuating margin of ancient Lake Uinta. Although the Uinta basin has undergone postdepositional uplift and erosion, the deepest cored rocks at Pariette Bench have never been buried more than 3000m.-from Authors

  11. FRACTURED RESERVOIR E&P IN ROCKY MOUNTAIN BASINS: A 3-D RTM MODELING APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    P. Ortoleva; J. Comer; A. Park; D. Payne; W. Sibo; K. Tuncay

    2001-11-26

    Key natural gas reserves in Rocky Mountain and other U.S. basins are in reservoirs with economic producibility due to natural fractures. In this project, we evaluate a unique technology for predicting fractured reservoir location and characteristics ahead of drilling based on a 3-D basin/field simulator, Basin RTM. Recommendations are made for making Basin RTM a key element of a practical E&P strategy. A myriad of reaction, transport, and mechanical (RTM) processes underlie the creation, cementation and preservation of fractured reservoirs. These processes are often so strongly coupled that they cannot be understood individually. Furthermore, sedimentary nonuniformity, overall tectonics and basement heat flux histories make a basin a fundamentally 3-D object. Basin RTM is the only 3-D, comprehensive, fully coupled RTM basin simulator available for the exploration of fractured reservoirs. Results of Basin RTM simulations are presented, that demonstrate its capabilities and limitations. Furthermore, it is shown how Basin RTM is a basis for a revolutionary automated methodology for simultaneously using a range of remote and other basin datasets to locate reservoirs and to assess risk. Characteristics predicted by our model include reserves and composition, matrix and fracture permeability, reservoir rock strength, porosity, in situ stress and the statistics of fracture aperture, length and orientation. Our model integrates its input data (overall sedimentation, tectonic and basement heat flux histories) via the laws of physics and chemistry that describe the RTM processes to predict reservoir location and characteristics. Basin RTM uses 3-D, finite element solutions of the equations of rock mechanics, organic and inorganic diagenesis and multi-phase hydrology to make its predictions. As our model predicts reservoir characteristics, it can be used to optimize production approaches (e.g., assess the stability of horizontal wells or vulnerability of fractures to

  12. Geothermal prospection in the Greater Geneva Basin (Switzerland and France): Structural and reservoir quality assessment

    Science.gov (United States)

    Rusillon, Elme; Clerc, Nicolas; Makhloufi, Yasin; Brentini, Maud; Moscariello, Andrea

    2017-04-01

    A reservoir assessment was performed in the Greater Geneva Basin to evaluate the geothermal resources potential of low to medium enthalpy (Moscariello, 2016). For this purpose, a detail structural analysis of the basin was performed (Clerc et al., 2016) simultaneously with a reservoir appraisal study including petrophysical properties assessment in a consistent sedimentological and stratigraphical frame (Brentini et al., 2017). This multi-disciplinary study was organised in 4 steps: (1) investigation of the surrounding outcrops to understand the stratigraphy and lateral facies distribution of the sedimentary sequence from Permo-Carboniferous to Lower Cretaceous units; (2) development of 3D geological models derived from 2D seismic and well data focusing on the structural scheme of the basin to constrain better the tectonic influence on facies distribution and to assess potential hydraulic connectivity through faults between reservoir units ; (3) evaluation of the distribution, geometry, sedimentology and petrophysical properties of potential reservoir units from well data; (4) identification and selection of the most promising reservoir units for in-depth rock type characterization and 3D modeling. Petrophysical investigations revealed that the Kimmeridgian-Tithonian Reef Complex and the underlying Calcaires de Tabalcon units are the most promising geothermal reservoir targets (porosity range 10-20%; permeability to 1mD). Best reservoir properties are measured in patch reefs and high-energy peri-reefal depositional environments, which are surrounded by synchronous tight lagoonal deposits. Associated highly porous dolomitized intervals reported in the western part of the basin also provide enhanced reservoir quality. The distribution and geometry of best reservoir bodies is complex and constrained by (1) palaeotopography, which can be affected by synsedimentary fault activity during Mesozoic times, (2) sedimentary factors such as hydrodynamics, sea level variations

  13. Reservoir Characterization of the Lower Green River Formation, Southwest Uinta Basin, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Craig D.; Chidsey, Jr., Thomas C.; McClure, Kevin P.; Bereskin, S. Robert; Deo, Milind D.

    2002-12-02

    The objectives of the study were to increase both primary and secondary hydrocarbon recovery through improved characterization (at the regional, unit, interwell, well, and microscopic scale) of fluvial-deltaic lacustrine reservoirs, thereby preventing premature abandonment of producing wells. The study will encourage exploration and establishment of additional water-flood units throughout the southwest region of the Uinta Basin, and other areas with production from fluvial-deltaic reservoirs.

  14. Sedimentological reservoir characteristics of the Paleocene fluvial/lacustrine Yabus Sandstone, Melut Basin, Sudan

    Science.gov (United States)

    Mahgoub, M. I.; Padmanabhan, E.; Abdullatif, O. M.

    2016-11-01

    Melut Basin in Sudan is regionally linked to the Mesozoic-Cenozoic Central and Western African Rift System (CWARS). The Paleocene Yabus Formation is the main oil producing reservoir in the basin. It is dominated by channel sandstone and shales deposited in fluvial/lacustrine environment during the third phase of rifting in the basin. Different scales of sedimentological heterogeneities influenced reservoir quality and architecture. The cores and well logs analyses revealed seven lithofacies representing fluvial, deltaic and lacustrine depositional environments. The sandstone is medium to coarse-grained, poorly to moderately-sorted and sub-angular to sub-rounded, arkosic-subarkosic to sublitharenite. On the basin scale, the Yabus Formation showed variation in sandstone bodies, thickness, geometry and architecture. On macro-scale, reservoir quality varies vertically and laterally within Yabus Sandstone where it shows progressive fining upward tendencies with different degrees of connectivity. The lower part of the reservoir showed well-connected and amalgamated sandstone bodies, the middle to the upper parts, however, have moderate to low sandstone bodies' connectivity and amalgamation. On micro-scale, sandstone reservoir quality is directly affected by textures and diagenetic changes such as compaction, cementation, alteration, dissolution and kaolinite clays pore fill and coat all have significantly reduced the reservoir porosity and permeability. The estimated porosity in Yabus Formation ranges from 2 to 20% with an average of 12%; while permeability varies from 200 to 500 mD and up to 1 Darcy. The understanding of different scales of sedimentological reservoir heterogeneities might contribute to better reservoir quality prediction, architecture, consequently enhancing development and productivity.

  15. Global surveys of reservoirs and lakes from satellites and regional application to the Syrdarya river basin

    International Nuclear Information System (INIS)

    Jean-François, Crétaux; Adalbert, Arsen; Muriel, Bergé-Nguyen; Sylvain, Biancamaria; Mélanie, Becker

    2015-01-01

    Large reservoirs along rivers regulate downstream flows to generate hydropower but may also store water for irrigation and urban sectors. Reservoir management therefore becomes critical, particularly for transboundary basins, where coordination between riparian countries is needed. Reservoir management is even more important in semiarid regions where downstream water users may be totally reliant on upstream reservoir releases. If the water resources are shared between upstream and downstream countries, potentially opposite interests arise as is the case in the Syrdarya river in Central Asia. In this case study, remote sensing data (radar altimetry and optical imagery) are used to highlight the potential of satellite data to monitor water resources: water height, areal extent and storage variations. New results from 20 years of monitoring using satellites over the Syrdarya basin are presented. The accuracy of satellite data is 0.6 km 3 using a combination of MODIS data and satellite altimetry, and only 0.2 km 3 with Landsat images representing 2–4% of average annual reservoir volume variations in the reservoirs in the Syrdarya basin. With future missions such as Sentinel-3A (S3A), Sentinel-3B (S3B) and surface water and ocean topography (SWOT), significant improvement is expected. The SWOT mission’s main payload (a radar interferometer in Ka band) will furthermore provide 2D maps of water height, reservoirs, lakes, rivers and floodplains, with a temporal resolution of 21 days. At the global scale, the SWOT mission will cover reservoirs with areal extents greater than 250  ×  250 m with 20 cm accuracy. (letter)

  16. Global surveys of reservoirs and lakes from satellites and regional application to the Syrdarya river basin

    Science.gov (United States)

    Jean-François, Crétaux; Sylvain, Biancamaria; Adalbert, Arsen; Muriel, Bergé-Nguyen; Mélanie, Becker

    2015-01-01

    Large reservoirs along rivers regulate downstream flows to generate hydropower but may also store water for irrigation and urban sectors. Reservoir management therefore becomes critical, particularly for transboundary basins, where coordination between riparian countries is needed. Reservoir management is even more important in semiarid regions where downstream water users may be totally reliant on upstream reservoir releases. If the water resources are shared between upstream and downstream countries, potentially opposite interests arise as is the case in the Syrdarya river in Central Asia. In this case study, remote sensing data (radar altimetry and optical imagery) are used to highlight the potential of satellite data to monitor water resources: water height, areal extent and storage variations. New results from 20 years of monitoring using satellites over the Syrdarya basin are presented. The accuracy of satellite data is 0.6 km3 using a combination of MODIS data and satellite altimetry, and only 0.2 km3 with Landsat images representing 2-4% of average annual reservoir volume variations in the reservoirs in the Syrdarya basin. With future missions such as Sentinel-3A (S3A), Sentinel-3B (S3B) and surface water and ocean topography (SWOT), significant improvement is expected. The SWOT mission’s main payload (a radar interferometer in Ka band) will furthermore provide 2D maps of water height, reservoirs, lakes, rivers and floodplains, with a temporal resolution of 21 days. At the global scale, the SWOT mission will cover reservoirs with areal extents greater than 250 × 250 m with 20 cm accuracy.

  17. Structural controls on fractured coal reservoirs in the southern Appalachian Black Warrior foreland basin

    Energy Technology Data Exchange (ETDEWEB)

    Groshong, R.H.; Pashin, J.C.; McIntyre, M.R. [University of Alabama, Tuscaloosa, AL (United States). Dept. of Geological Science

    2009-09-15

    Coal is a nearly impermeable rock type for which the production of fluids requires the presence of open fractures. Basin-wide controls on the fractured coal reservoirs of the Black Warrior foreland basin are demonstrated by the variability of maximum production rates from coalbed methane wells. Reservoir behavior depends on distance from the thrust front. Far from the thrust front, normal faults are barriers to fluid migration and compartmentalize the reservoirs. Close to the thrust front, rates are enhanced along some normal faults, and a new trend is developed. The two trends have the geometry of conjugate strike-slip faults with the same sigma(1) direction as the Appalachian fold-thrust belt and are inferred to be the result of late pure-shear deformation of the foreland. Face cleat causes significant permeability anisotropy in some shallow coal seams but does not produce a map-scale production trend.

  18. Structural controls on fractured coal reservoirs in the southern Appalachian Black Warrior foreland basin

    Science.gov (United States)

    Groshong, Richard H., Jr.; Pashin, Jack C.; McIntyre, Marcella R.

    2009-09-01

    Coal is a nearly impermeable rock type for which the production of fluids requires the presence of open fractures. Basin-wide controls on the fractured coal reservoirs of the Black Warrior foreland basin are demonstrated by the variability of maximum production rates from coalbed methane wells. Reservoir behavior depends on distance from the thrust front. Far from the thrust front, normal faults are barriers to fluid migration and compartmentalize the reservoirs. Close to the thrust front, rates are enhanced along some normal faults, and a new trend is developed. The two trends have the geometry of conjugate strike-slip faults with the same σ1 direction as the Appalachian fold-thrust belt and are inferred to be the result of late pure-shear deformation of the foreland. Face cleat causes significant permeability anisotropy in some shallow coal seams but does not produce a map-scale production trend.

  19. Cross-fault pressure depletion, Zechstein carbonate reservoir, Weser-Ems area, Northern German Gas Basin

    Energy Technology Data Exchange (ETDEWEB)

    Corona, F.V.; Brauckmann, F.; Beckmann, H.; Gobi, A.; Grassmann, S.; Neble, J.; Roettgen, K. [ExxonMobil Production Deutschland GmbH (EMPG), Hannover (Germany)

    2013-08-01

    A cross-fault pressure depletion study in Upper Permian Zechstein Ca2 carbonate reservoir was undertaken in the Weser-Ems area of the Northern German Gas Basin. The primary objectives are to develop a practical workflow to define cross-fault pressures scenarios for Zechstein Ca2 reservoir drillwells, to determine the key factors of cross-fault pressure behavior in this platform carbonate reservoir, and to translate the observed cross-fault pressure depletion to fault transmissibility for reservoir simulation models. Analysis of Zechstein Ca2 cross-fault pressures indicates that most Zechstein-cutting faults appear to act as fluid-flow baffles with some local occurrences of fault seal. Moreover, there appears to be distinct cross-fault baffling or pressure depletion trends that may be related to the extent of the separating fault or fault system, degree of reservoir flow-path tortuosity, and quality of reservoir juxtaposition. Based on the above observations, a three-part workflow was developed consisting of (1) careful interpretation and mapping of faults and fault networks, (2) analysis of reservoir juxtaposition and reservoir juxtaposition quality, and (3) application of the observed cross-fault pressure depletion trends. This approach is field-analog based, is practical, and is being used currently to provide reliable and supportable pressure prediction scenarios for subsequent Zechstein fault-bounded drill-well opportunities.

  20. Discovery and reservoir-forming geological characteristics of the Shenmu Gas Field in the Ordos Basin

    Directory of Open Access Journals (Sweden)

    Hua Yang

    2015-10-01

    Full Text Available By the end of 2014, the giant Shenmu Gas Field had been found in the Ordos Basin with an explored gas-bearing area of 4069 km2 and the proved geological gas reserves of 333.4 billion m3. This paper aims to review the exploration history of this field and discusses its reservoir-forming mechanism and geological characteristics, which may guide the further discovery and exploration of such similar gas fields in this basin and other basins. The following research findings were concluded. (1 There are typical tight sand gas reservoirs in this field primarily with the pay zones of the Upper Paleozoic Taiyuan Fm, and secondly with those of the Shanxi and Shihezi Fms. (2 Gas types are dominated by coal gas with an average methane content of 88% and no H2S content. (3 The gas reservoirs were buried 1700–2800 m deep underneath with multiple pressure systems and an average pressure coefficient of 0.87. (4 The reservoir strata are composed of fluvial delta facies sandstones with an average porosity of 7.8% and permeability of 0.63 mD, having high pressure sensibility and a strong water-locking effect because the pore throat radius are mostly less than 1 μm. (5 There are different dynamics at various stages in the gas reservoir-forming process. The abnormal well-developed strata pressure was the main reservoir-forming force at the Early Cretaceous setting stage while the fluid expansibility became the main gas-migrating force at the uplift and denudation stage after the Early Cretaceous period. (6 Gas reservoirs with ultra-low water saturation are mainly controlled by many factors such as changes of high temperature and high pressure fields in the Late Jurassic and Early Cretaceous periods, the charging of dry gas at the highly-mature stage, and the gas escape and dissipation at the post-reservoir-forming periods. (7 Natural gas migrated and accumulated vertically in a shortcutting path to form gas reservoirs. At such areas near the source rocks

  1. Sedimentary features and exploration targets of Middle Permian reservoirs in the SW Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guoming Xu

    2015-11-01

    Full Text Available The exploration direction and targets for the large-scale Middle Permian gas reservoirs in the Sichuan Basin are hot spots and challenges in current exploration researches. The exploration successes of large gas field of Cambrian Longwangmiao Formation in Gaoshiti-Moxi region, Central Sichuan Basin, indicated that prospective sedimentary facies belt was the basis for the formation of large gas fields. In this paper, based on seismic data, outcrop data and drilling data, the tectonic framework and sedimentary features of the Middle Permian in the SW Sichuan Basin were comprehensively studied. The following conclusions were reached from the perspective of sedimentary facies control: (1 during the Middle Permian, this region was in shallow water gentle slope belts with high energy, where thick reef flat facies were deposited; (2 the basement was uplifted during Middle Permian, resulting in the unconformity weathering crust at the top of Maokou Formation due to erosion; the SW Sichuan Basin was located in the karst slope belt, where epigenic karstification was intense; and (3 reef flat deposits superimposed by karst weathering crust was favorable for the formation of large-scale reef flat karst reservoirs. Based on the combination of the resources conditions and hydrocarbon accumulation conditions in this region, it was pointed out that the Middle Permian has great potential of large-scale reef flat karst gas reservoir due to its advantageous geological conditions; the Middle Permian traps with good hydrocarbon accumulation conditions were developed in the Longmen Mountain front closed structural belt in the SW Sichuan Basin and Western Sichuan Basin depression slope belt, which are favorable targets for large-scale reef flat karst reservoirs.

  2. Hydrocarbon origin and reservoir forming model research of Longwangmiao Formation, Moxi-Gaoshiti area, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Mindong Jin

    2016-06-01

    Full Text Available This paper focuses on the Longwangmiao gas reservoir in Moxi-Gaoshiti area, Sichuan Basin. Starting from the tectonic evolution perspective, though comparing biological marker compound and analyzing fluid inclusions, the oil & gas origin and accumulation evolution of Longwangmiao Formation are systematic studied with reference to the burial-thermal evolution of single well geological history in the study area. It is suggested that the oil & gas reservoir is generally characterized by early accumulation, multi-stage filling, late cracking and later adjustment. The oil and gas were mainly sourced from lower Cambrian Qiongzhusi Formation, partly from the Permian source rock. During the geological period, 3 major oil & gas fillings occurred in the Longwangmiao Formation, namely Caledonian-Hercynian filling that was small in scale and produced the first phase of paleo-oil reservoir that soon destroyed by Caledonian movement uplift, large-scale Permian filling that gave rise to the second-phase of paleo-oil reservoir and the Triassic-Jurassic filling that enriched the second phase of paleo-oil reservoir. Finally, the paleo-oil reservoir experienced an in-situ cracking during the cretaceous period that gave rise to a natural gas reservoir and left behind carbonaceous bitumen and oily bitumen in the holes of the Longwangmiao Formation.

  3. Towards an optimal integrated reservoir system management for the Awash River Basin, Ethiopia

    Directory of Open Access Journals (Sweden)

    R. Müller

    2016-05-01

    Full Text Available Recently, the Kessem–Tendaho project is completed to bring about socioeconomic development and growth in the Awash River Basin, Ethiopia. To support reservoir Koka, two new reservoirs where built together with extensive infrastructure for new irrigation projects. For best possible socioeconomic benefits under conflicting management goals, like energy production at three hydropower stations and basin wide water supply at various sites, an integrated reservoir system management is required. To satisfy the multi-purpose nature of the reservoir system, multi-objective parameterization-simulation-optimization model is applied. Different Pareto-optimal trade-off solutions between water supply and hydro-power generation are provided for two scenarios (i recent conditions and (ii future planned increases for Tendaho and Upper Awash Irrigation projects. Reservoir performance is further assessed under (i rule curves with a high degree of freedom – this allows for best performance, but may result in rules curves to variable for real word operation and (ii smooth rule curves, obtained by artificial neuronal networks. The results show no performance penalty for smooth rule curves under future conditions but a notable penalty under recent conditions.

  4. Hydrothermal dolomite reservoir facies in the Sinian Dengying Fm, central Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Yuqiang Jiang

    2017-07-01

    Full Text Available The Upper Sinian Dengying Fm is the focus of natural gas exploration in the central part of the Sichuan Basin (central Sichuan Basin in recent years. Especially, epigenic karstification and its resulted reservoir-seepage spaces have always been the focal points in researches. Based on the petrographic characteristics of drilling cuttings and core samples, and through experimental analysis by using trace elements, isotopes, and cathodoluminescence, the Dengying Fm dolomite was demonstrated to have matrix recrystallized dolomite (MRD, filled saddle dolomite (FSD (the mean homogenization temperature of inclusion: 178.5 °C, high concentrations of Fe & Mn, slightly positive 87Sr/86Sr value and hydrothermal minerals combination (including sphalerite, galena, pyrite, and quartz, etc.. Thus, it was proposed that hydrothermal dolomite reservoir facies (HDRF exist in the Dengying Fm dolomite, in other words, the dolomite reservoir is composed of hydrothermal dissolved pores, intercrystalline pores of hydrothermal origin, hydrothermal caverns and expanded fractures, and was formed due to the reworking of hydrothermal fluid on tight matrix dolomite. Identification marks are presented in terms of petrography and geochemistry so that hydrothermal dolomite reservoir facies can be effectively recognized and identified. It is concluded that the development of hydrothermal dolomite reservoir facies in this area are preliminary controlled by deep and large basement faults and the strength of hydrothermal fluids.

  5. Towards an optimal integrated reservoir system management for the Awash River Basin, Ethiopia

    Science.gov (United States)

    Müller, Ruben; Gebretsadik, Henok Y.; Schütze, Niels

    2016-05-01

    Recently, the Kessem-Tendaho project is completed to bring about socioeconomic development and growth in the Awash River Basin, Ethiopia. To support reservoir Koka, two new reservoirs where built together with extensive infrastructure for new irrigation projects. For best possible socioeconomic benefits under conflicting management goals, like energy production at three hydropower stations and basin wide water supply at various sites, an integrated reservoir system management is required. To satisfy the multi-purpose nature of the reservoir system, multi-objective parameterization-simulation-optimization model is applied. Different Pareto-optimal trade-off solutions between water supply and hydro-power generation are provided for two scenarios (i) recent conditions and (ii) future planned increases for Tendaho and Upper Awash Irrigation projects. Reservoir performance is further assessed under (i) rule curves with a high degree of freedom - this allows for best performance, but may result in rules curves to variable for real word operation and (ii) smooth rule curves, obtained by artificial neuronal networks. The results show no performance penalty for smooth rule curves under future conditions but a notable penalty under recent conditions.

  6. Simpson reservoirs in Arkoma basin and Ouachita Mountains, Oklahoma and Arkansas

    Energy Technology Data Exchange (ETDEWEB)

    Suhm, R.W.

    1983-08-01

    The Simpson Group and its equivalents are shown to have reservoir potential in the Arkoma basin and Ouachita overthrust region of Oklahoma and Arkansas. The Simpson in Oklahoma, the Everton/St. Peter in Arkansas, and the Crystal Mountain/Mazarn/Blakely of the Ouachitas were studied in outcrop, and from well cuttings and logs to derive an understanding of 1) their stratigraphic relationships, 2) the nature and distribution of Simpson reservoir sands, 3) depositional and source environments, and 4) geologic history. Regional cross sections, sand distribution maps, and paleogeographic maps are used to illustrate these ideas and to point out areas favorable for oil and gas exploration.

  7. Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies, Class III

    Energy Technology Data Exchange (ETDEWEB)

    City of Long Beach; Tidelands Oil Production Company; University of Southern California; David K. Davies and Associates

    2002-09-30

    The objective of this project was to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California through the testing and application of advanced reservoir characterization and thermal production technologies. It was hoped that the successful application of these technologies would result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs.

  8. Reservoir diagenesis research of Silurian Longmaxi Formation in Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Lingming Kong

    2016-06-01

    Full Text Available The reservoir diagenesis of Silurian Longmaxi Formation in Sichuan Basin was studied based on a large number of thin section identification, scanning electron microscopy analysis, X-ray diffraction tests, and some other experiments. Seven diagenetic processes were identified, including compaction, cementation, clay mineral transformation, replacement, dissolution, organic matter thermal maturation, and tectonic disruption. Three kinds of cements (quartz, carbonate and sulfide were recognized, while the source material of quartz cements and the main factor of forming abundant carbonate cements were summed up. According to the single well analysis of the Well N3, it shows that the best, the suboptimal and the none shale reservoir sections were subjected to different diagenetic transformations. As to best shale reservoir, except for compaction, all the main inorganic diagenesis were significantly related to organic matter maturation. Through comprehensive analysis of diagenetic indicators, it is observed that the reservoir has already been in period B of middle diagenetic stage to late diagenetic stage. The inorganic diagenesis has a significant impact on shale reservoir, because it not only controls the conservation, development, and evolution of porosity, but also the mechanical property and the adsorption capacity of rocks. The organic diagenesis is the source material of shale gas, and it generates a large number of nanoporosity in organic matter, which increases the total porosity and the adsorption capacity of the reservoir.

  9. Paleogeographic evolution of carbonate reservoirs: geological and geophysical analysis at the Albian Campos Basin, Brazil

    Science.gov (United States)

    Castillo Vincentelli, Maria Gabriela; Favoreto, Julia; Roemers-Oliveira, Eduardo

    2018-02-01

    An integrated geophysical and geological analysis of a carbonate reservoir can offer an effective method to better understand the paleogeographical evolution and distribution of a geological reservoir and non-reservoir facies. Therefore, we propose a better method for obtaining geological facies from geophysical facies, helping to characterize the permo-porous system of this kind of play. The goal is to determine the main geological phases from a specific hydrocarbon producer (Albian Campos Basin, Brazil). The applied method includes the use of a petrographic and qualitative description from the integrated reservoir with seismic interpretation of an attribute map (energy, root mean square, mean amplitude, maximum negative amplitude, etc), all calculated at the Albian level for each of the five identified phases. The studied carbonate reservoir is approximately 6 km long with a main direction of NE-SW, and it was sub-divided as follows (from bottom to top): (1) the first depositional sequence of the bank was composed mainly of packstone, indicating that the local structure adjacent to the main bank is protected from environmental conditions; (2) characterized by the presence of grainstone developed at the higher structure; (3) the main sequence of the peloidal packstone with mudstones oncoids; (4) corresponds to the oil production of carbonate reservoirs formed by oolitic grainstone deposited at the top of the carbonate bank; at this phase, rising sea levels formed channels that connected the open sea shelf with the restricted circulation shelf; and (5) mudstone and wackestone represent the system’s flooding phase.

  10. Asphalt features and gas accumulation mechanism of Sinian reservoirs in the Tongwan Palaeo-uplift, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-10-01

    Full Text Available Breakthroughs have been made in natural gas exploration in Sinian reservoirs in the Tongwan Palaeo-uplift, Sichuan Basin, recently. However, there are disputes with regard to the genetic mechanisms of natural gas reservoirs. The development law of asphalts in the Sinian reservoirs may play an extremely important role in the study of the relationships between palaeo oil and gas reservoirs. Accordingly, researches were conducted on the features and development patterns of asphalts in the Sinian reservoirs in this area. The following research results were obtained. (1 Asphalts in the Sinian reservoirs were developed after the important hydrothermal event in the Sichuan Basin, namely the well-known Emei Taphrogeny in the mid-late Permian Period. (2 Distribution of asphalts is related to palaeo oil reservoirs under the control of palaeo-structures of Indosinian-Yanshanian Period, when the palaeo-structures contained high content of asphalts in the high positions of the palaeo-uplift. (3 Large-scale oil and gas accumulations in the Sinian reservoirs occurred in the Indosinian-Yanshanian Period to generate the Leshan-Ziyang and Gaoshiti-Moxi-Guang'an palaeo oil reservoirs. Cracking of crude oil in the major parts of these palaeo oil reservoirs controlled the development of the present natural gas reservoirs. (4 The development of asphalts in the Sinian reservoirs indicates that hydrocarbons in the Dengying Formation originated from Cambrian source rocks and natural gas accumulated in the Sinian reservoirs are products of late-stage cracking of the Sinian reservoirs. (5 The Sinian palaeo-structures of Indosinian-Yanshanian Period in the Sichuan Basin are favorable regions for the development of the Sinian reservoirs, where discoveries and exploration practices will play an important role in the era of Sinian natural gas development in China.

  11. Hydrodynamic analysis of clastic injection and hydraulic fracturing structures in the Jinding Zn-Pb deposit, Yunnan, China

    Directory of Open Access Journals (Sweden)

    Guoxiang Chi

    2012-01-01

    Full Text Available The Jinding Zn-Pb deposit has been generally considered to have formed from circulating basinal fluids in a relatively passive way, with fluid flow being controlled by structures and sedimentary facies, similar to many other sediments-hosted base metal deposits. However, several recent studies have revealed the presence of sand injection structures, intrusive breccias, and hydraulic fractures in the open pit of the Jinding deposit and suggested that the deposit was formed from explosive release of overpressured fluids. This study reports new observations of fluid overpressure-related structures from underground workings (Paomaping and Fengzishan, which show clearer crosscutting relationships than in the open pit. The observed structures include: 1 sand (±rock fragment dikes injecting into fractures in solidified rocks; 2 sand (±rock fragment bodies intruding into unconsolidated or semi-consolidated sediments; 3 disintegrated semi-consolidated sand bodies; and 4 veins and breccias formed from hydraulic fracturing of solidified rocks followed by cementation of hydrothermal minerals. The development of ore minerals (sphalerite in the cement of the various clastic injection and hydraulic fractures indicate that these structures were formed at the same time as mineralization. The development of hydraulic fractures and breccias with random orientation indicates small differential stress during mineralization, which is different from the stress field with strong horizontal shortening prior to mineralization. Fluid flow velocity may have been up to more than 11 m/s based on calculations from the size of the fragments in the clastic dikes. The clastic injection and hydraulic fracturing structures are interpreted to have formed from explosive release of overpressured fluids, which may have been related to either magmatic intrusions at depth or seismic activities that episodically tapped an overpressured fluid reservoir. Because the clastic injection

  12. Thermo-hydrodynamical modelling of a flooded deep mine reservoir - Case of the Lorraine Coal Basin

    International Nuclear Information System (INIS)

    Reichart, Guillaume

    2015-01-01

    Since 2006, cessation of dewatering in Lorraine Coal Basin (France) led to the flooding of abandoned mines, resulting in a new hydrodynamic balance in the area. Recent researches concerning geothermal exploitation of flooded reservoirs raised new questions, which we propose to answer. Our work aimed to understand the thermos-hydrodynamic behaviour of mine water in a flooding or flooded system. Firstly, we synthesized the geographical, geological and hydrogeological contexts of the Lorraine Coal Basin, and we chose a specific area for our studies. Secondly, temperature and electric conductivity log profiles were measured in old pits of the Lorraine Coal Basin, giving a better understanding of the water behaviour at a deep mine shaft scale. We were able to build a thermos-hydrodynamic model and simulate water behaviour at this scale. Flow regime stability is also studied. Thirdly, a hydrodynamic spatialized meshed model was realized to study the hydrodynamic behaviour of a mine reservoir as a whole. Observed water-table rise was correctly reproduced: moreover, the model can be used in a predictive way after the flooding. Several tools were tested, improved or developed to ease the study of flooded reservoirs, as three-dimensional up-scaling of hydraulic conductivities and a coupled spatialized meshed model with a pipe network. (author) [fr

  13. Development of a Reservoir System Operation Model for Water Sustainability in the Yaqui River Basin

    Science.gov (United States)

    Mounir, A.; Che, D.; Robles-Morua, A.; Kauneckis, D.

    2017-12-01

    The arid state of Sonora, Mexico underwent the Sonora SI project to provide additional water supply to the capital of Hermosillo. The main component of the project involves an interbasin transfer from the Yaqui River Basin (YRB) to the Sonora River Basin via the Independencia aqueduct. This project has generated conflicts over water among different social sectors in the YRB. To improve the management of the Yaqui reservoir system, we developed a daily watershed model. This model allowed us to predict the amount of water available in different regions of the basin. We integrated this simulation to an optimization model which calculates the best water allocation according to water rights established in Mexico's National Water Law. We compared different precipitation forcing scenarios: (1) a network of ground observations from Mexican water agencies during the historical period of 1980-2013, (2) gridded fields from the North America Land Data Assimilation System (NLDAS) at 12 km resolution, and (3) we will be studying a future forecast scenario. The simulation results were compared to historical observations at the three reservoirs existing in the YRB to generate confidence in the simulation tools. Our results are presented in the form of flow duration, reliability and exceedance frequency curves that are commonly used in the water management agencies. Through this effort, we anticipate building confidence among regional stakeholders in utilizing hydrological models in the development of reservoir operation policies.

  14. Rationale for finding and exploiting fractured reservoirs, based on the MWX/SHCT-Piceance basin experience

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, J.C.; Warpinski, N.R.; Teufel, L.W.

    1993-08-01

    The deliverability of a reservoir depends primarily on its permeability, which, in many reservoirs, is controlled by a combination of natural fractures and the in situ stresses. Therefore it is important to be able to predict which parts of a basin are most likely to contain naturally fractured strata, what the characteristics of those fractures might be, and what the most likely in situ stresses are at a given location. This paper presents a set of geologic criteria that can be superimposed onto factors, such as levels of maturation and porosity development, in order to predict whether fractures are present once the likelihood of petroleum presence and reservoir development have been determined. Stress causes fracturing, but stresses are not permanent. A natural-fracture permeability pathway opened by one system of stresses may be held open by those stresses, or narrowed or even closed by changes of the stress to an oblique or normal orientation. The origin of stresses and stress anisotropies in a basin, the potential for stress to create natural fractures, and the causes of stress reorientation are examined in this paper. The appendices to this paper present specific techniques for exploiting and characterizing natural fractures, for measuring the present-day in situ stresses, and for reconstructing a computerized stress history for a basin.

  15. Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin

    Science.gov (United States)

    Wu, Yiping; Liu, Shu-Guang

    2012-01-01

    Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (~78%) and nutrients (~30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices.

  16. Modeling of land use and reservoir effects on nonpoint source pollution in a highly agricultural basin.

    Science.gov (United States)

    Wu, Yiping; Liu, Shuguang

    2012-09-01

    Nonpoint source (NPS) pollution is tightly linked to land use activities that determine the sources and magnitudes of pollutant loadings to stream water. The pollutant loads may also be alleviated within reservoirs because of the physical interception resulting from changed hydrological regimes and other biochemical processes. It is important but challenging to assess the NPS pollution processes with human effects due to the measurement limitations. The objective of this study is to evaluate the effects of human activities such as land uses and reservoir operation on the hydrological and NPS pollution processes in a highly agricultural area-the Iowa River Basin-using the Soil and Water Assessment Tool (SWAT). The evaluation of model performance at multiple sites reveals that SWAT can consistently simulate the daily streamflow, and monthly/annual sediment and nutrient loads (nitrate nitrogen and mineral phosphorus) in the basin. We also used the calibrated model to estimate the trap efficiencies of sediment (∼78%) and nutrients (∼30%) in the Coralville Reservoir within the basin. These non-negligible effects emphasize the significance of incorporating the sediment and nutrient removal mechanisms into watershed system studies. The spatial quantification of the critical NPS pollution loads can help identify hot-spot areas that are likely locations for the best management practices.

  17. Diagenetic history of the Swan Hills Simonette Oil Reservoir (Givetian-Frasnian), deep basin of west-central Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Duggan, J.P.; Mountjoy, E.W. [McGill Univ., Montreal, PQ (Canada). Dept. of Earth and Planetary Sciences

    1997-05-01

    The geology and diagenetic history of the Swan Hills Simonette oil field of west-central Alberta basin was described. Present-day burial depth is 3900 m; formation temperature is 93 degrees C. Highest porosites (20 per cent) occur in dolostones of the lagoon, ref, and fore-reef depositional environments but limestones still retain porosities up to five per cent. Hydrocarbons are present in saddle dolomite fluid inclusions. Oxygen isotopes for replacement dolomites and late calcite suggest that the carbonate-precipitating fluids were derived from the Precambrian basement or Paleozoic clastics sourced from the basement. Faults may have acted as vertical conduits for fluid migration.

  18. Characterization of petroleum reservoirs in the Eocene Green River Formation, Central Uinta Basin, Utah

    Science.gov (United States)

    Morgan, C.D.; Bereskin, S.R.

    2003-01-01

    The oil-productive Eocene Green River Formation in the central Uinta Basin of northeastern Utah is divided into five distinct intervals. In stratigraphically ascending order these are: 1) Uteland Butte, 2) Castle Peak, 3) Travis, 4) Monument Butte, and 5) Beluga. The reservoir in the Uteland Butte interval is mainly lacustrine limestone with rare bar sandstone beds, whereas the reservoirs in the other four intervals are mainly channel and lacustrine sandstone beds. The changing depositional environments of Paleocene-Eocene Lake Uinta controlled the characteristics of each interval and the reservoir rock contained within. The Uteland Butte consists of carbonate and rare, thin, shallow-lacustrine sandstone bars deposited during the initial rise of the lake. The Castle Peak interval was deposited during a time of numerous and rapid lake-level fluctuations, which developed a simple drainage pattern across the exposed shallow and gentle shelf with each fall and rise cycle. The Travis interval records a time of active tectonism that created a steeper slope and a pronounced shelf break where thick cut-and-fill valleys developed during lake-level falls and rises. The Monument Butte interval represents a return to a gentle, shallow shelf where channel deposits are stacked in a lowstand delta plain and amalgamated into the most extensive reservoir in the central Uinta Basin. The Beluga interval represents a time of major lake expansion with fewer, less pronounced lake-level falls, resulting in isolated single-storied channel and shallow-bar sandstone deposits.

  19. Remotely Sensed Based Lake/Reservoir Routing in Congo River Basin

    Science.gov (United States)

    Raoufi, R.; Beighley, E.; Lee, H.

    2017-12-01

    Lake and reservoir dynamics can influence local to regional water cycles but are often not well represented in hydrologic models. One challenge that limits their inclusion in models is the need for detailed storage-discharge behavior that can be further complicated in reservoirs where specific operation rules are employed. Here, the Hillslope River Routing (HRR) model is combined with a remotely sensed based Reservoir Routing (RR) method and applied to the Congo River Basin. Given that topographic data are often continuous over the entire terrestrial surface (i.e., does not differentiate between land and open water), the HRR-RR model integrates topographic derived river networks and catchment boundaries (e.g., HydroSHEDs) with water boundary extents (e.g., Global Lakes and Wetlands Database) to develop the computational framework. The catchments bordering lakes and reservoirs are partitioned into water and land portions, where representative flowpath characteristics are determined and vertical water balance and lateral routings is performed separately on each partition based on applicable process models (e.g., open water evaporation vs. evapotranspiration). To enable reservoir routing, remotely sensed water surface elevations and extents are combined to determine the storage change time series. Based on the available time series, representative storage change patterns are determined. Lake/reservoir routing is performed by combining inflows from the HRR-RR model and the representative storage change patterns to determine outflows. In this study, a suite of storage change patterns derived from remotely sensed measurements are determined representative patterns for wet, dry and average conditions. The HRR-RR model dynamically selects and uses the optimal storage change pattern for the routing process based on these hydrologic conditions. The HRR-RR model results are presented to highlight the importance of lake attenuation/routing in the Congo Basin.

  20. Sequence Stratigraphy of the Dakota Sandstone, Eastern San Juan Basin, New Mexico, and its Relationship to Reservoir Compartmentalization

    Energy Technology Data Exchange (ETDEWEB)

    Varney, Peter J.

    2002-04-23

    This research established the Dakota-outcrop sequence stratigraphy in part of the eastern San Juan Basin, New Mexico, and relates reservoir quality lithologies in depositional sequences to structure and reservoir compartmentalization in the South Lindrith Field area. The result was a predictive tool that will help guide further exploration and development.

  1. Application of sequence stratigraphy to carbonate reservoir prediction, Early Palaeozoic eastern Warburton basin, South Australia

    Energy Technology Data Exchange (ETDEWEB)

    Xiaowen S.; Stuart, W.J.

    1996-12-31

    The Early Palaeozoic Warburton Basin underlies the gas and oil producing Cooper and Eromanga Basins. Postdepositional tectonism created high potential fracture porosities, complicating the stratigraphy and making reservoir prediction difficult. Sequence stratigraphy integrating core, cuttings, well-log, seismic and biostratigraphic data has recognized a carbonate-dominated to mixed carbonate/siliciclastic supersequence comprising several depositional sequences. Biostratigraphy based on trilobites and conodonts ensures reliable well and seismic correlations across structurally complex areas. Lithofacies interpretation indicates sedimentary environments ranging from carbonate inner shelf, peritidal, shelf edge, deep outer shelf and slope to basin. Log facies show gradually upward shallowing trends or abrupt changes indicating possible sequence boundaries. With essential depositional models and sequence analysis from well data, seismic facies suggest general reflection configurations including parallel-continuous layered patterns indicating uniform neuritic shelf, and mounded structures suggesting carbonate build-ups and pre-existing volcanic relief. Seismic stratigraphy also reveals inclined slope and onlapping margins of a possibly isolated platform geometry. The potential reservoirs are dolomitized carbonates containing oomoldic, vuggy, intercrystalline and fracture porosities in lowstand systems tracts either on carbonate mounds and shelf crests or below shelf edge. The source rock is a deep basinal argillaceous mudstone, and the seal is fine-grained siltstone/shale of the transgressive system tract.

  2. Application of sequence stratigraphy to carbonate reservoir prediction, Early Palaeozoic eastern Warburton basin, South Australia

    Energy Technology Data Exchange (ETDEWEB)

    Xiaowen S.; Stuart, W.J.

    1996-01-01

    The Early Palaeozoic Warburton Basin underlies the gas and oil producing Cooper and Eromanga Basins. Postdepositional tectonism created high potential fracture porosities, complicating the stratigraphy and making reservoir prediction difficult. Sequence stratigraphy integrating core, cuttings, well-log, seismic and biostratigraphic data has recognized a carbonate-dominated to mixed carbonate/siliciclastic supersequence comprising several depositional sequences. Biostratigraphy based on trilobites and conodonts ensures reliable well and seismic correlations across structurally complex areas. Lithofacies interpretation indicates sedimentary environments ranging from carbonate inner shelf, peritidal, shelf edge, deep outer shelf and slope to basin. Log facies show gradually upward shallowing trends or abrupt changes indicating possible sequence boundaries. With essential depositional models and sequence analysis from well data, seismic facies suggest general reflection configurations including parallel-continuous layered patterns indicating uniform neuritic shelf, and mounded structures suggesting carbonate build-ups and pre-existing volcanic relief. Seismic stratigraphy also reveals inclined slope and onlapping margins of a possibly isolated platform geometry. The potential reservoirs are dolomitized carbonates containing oomoldic, vuggy, intercrystalline and fracture porosities in lowstand systems tracts either on carbonate mounds and shelf crests or below shelf edge. The source rock is a deep basinal argillaceous mudstone, and the seal is fine-grained siltstone/shale of the transgressive system tract.

  3. Geochemical characteristics and reservoir continuity of Silurian Acacus in Ghadames Basin, Southern Tunisia

    Science.gov (United States)

    Mahmoudi, S.; Mohamed, A. Belhaj; Saidi, M.; Rezgui, F.

    2017-11-01

    The present work is dealing with the study of lateral and vertical continuity of the multi-layers Acacus reservoir (Ghadames Basin-Southern Tunisia) using the distribution of hydrocarbon fraction. For this purpose, oil-oil and source rock-oil correlations as well as the composition of the light fractions and a number of saturate and aromatic biomarkers parameters, including C35/C34 hopanes and DBT/P, have been investigated. Based on the ratios of light fraction and their fingerprints, the Acacus reservoir from Well1 and Well2 have found to be laterally non-connected although the hydrocarbons they contain have the same source rock. Moreover, the two oil samples from two different Acacus reservoir layers crossed by Well3-A3 and A9, display a similar hydrocarbons distribution, suggesting vertical reservoir continuity. On the other hand, the biomarker distributions of the oils samples and source rocks assess a Silurian ;Hot shale; that is the source rock feeding the Acacus reservoir. The biomarker distribution is characterized by high tricyclic terpanes contents compared to hopanes for the Silurian source rock and the two crude oils. This result is also confirmed by the dendrogram that precludes the Devonian source rocks as a source rock in the study area.

  4. Diagenesis and porosity evolution of tight sand reservoirs in Carboniferous Benxi Formation, Southeast Ordos Basin

    Science.gov (United States)

    Hu, Peng; Yu, Xinghe; Shan, Xin; Su, Dongxu; Wang, Jiao; Li, Yalong; Shi, Xin; Xu, Liqiang

    2016-04-01

    The Ordos Basin, situated in west-central China, is one of the oldest and most important fossil-fuel energy base, which contains large reserves of coal, oil and natural gas. The Upper Palaeozoic strata are widely distributed with rich gas-bearing and large natural gas resources, whose potential is tremendous. Recent years have witnessed a great tight gas exploration improvement of the Upper Paleozoic in Southeastern Ordos basin. The Carboniferous Benxi Formation, mainly buried more than 2,500m, is the key target strata for hydrocarbon exploration, which was deposited in a barrier island and tidal flat environment. The sandy bars and flats are the favorable sedimentary microfacies. With an integrated approach of thin-section petrophysics, constant velocity mercury injection test, scanning electron microscopy and X-ray diffractometry, diagenesis and porosity evolution of tight sand reservoirs of Benxi Formation were analyzed in detail. The result shows that the main lithology of sandstone in this area is dominated by moderately to well sorted quartz sandstone. The average porosity and permeability is 4.72% and 1.22mD. The reservoirs of Benxi Formation holds a variety of pore types and the pore throats, with obvious heterogeneity and poor connection. Based on the capillary pressure curve morphological characteristics and parameters, combined with thin section and phycical property data, the reservoir pore structure of Benxi Formation can be divided into 4 types, including mid pore mid throat type(I), mid pore fine throat type(II), small pore fine throat type(III) and micro pro micro throat type(Ⅳ). The reservoirs primarily fall in B-subsate of middle diagenesis and late diagenesis, which mainly undergo compaction, cmentation, dissolution and fracturing process. Employing the empirical formula of different sorting for unconsolideated sandstone porosity, the initial sandstone porosity is 38.32% on average. Quantitative evaluation of the increase and decrease of

  5. Low permeability Neogene lithofacies in Northern Croatia as potential unconventional hydrocarbon reservoirs

    Science.gov (United States)

    Malvić, Tomislav; Sučić, Antonija; Cvetković, Marko; Resanović, Filip; Velić, Josipa

    2014-06-01

    We present two examples of describing low permeability Neogene clastic lithofacies to outline unconventional hydrocarbon lithofacies. Both examples were selected from the Drava Depression, the largest macrostructure of the Pannonian Basin System located in Croatia. The first example is the Beničanci Field, the largest Croatian hydrocarbon reservoir discovered in Badenian coarse-grained clastics that consists mostly of breccia. The definition of low permeability lithofacies is related to the margins of the existing reservoir, where the reservoir lithology changed into a transitional one, which is mainly depicted by the marlitic sandstones. However, calculation of the POS (probability of success of new hydrocarbons) shows critical geological categories where probabilities are lower than those in the viable reservoir with proven reserves. Potential new hydrocarbon volumes are located in the structural margins, along the oil-water contact, with a POS of 9.375%. These potential reserves in those areas can be classified as probable. A second example was the Cremušina Structure, where a hydrocarbon reservoir was not proven, but where the entire structure has been transferred onto regional migration pathways. The Lower Pontian lithology is described from well logs as fine-grained sandstones with large sections of silty or marly clastics. As a result, the average porosity is low for conventional reservoir classification (10.57%). However, it is still an interesting case for consideration as a potentially unconventional reservoir, such as the "tight" sandstones.

  6. Increasing Heavy Oil in the Wilmington Oil Fiel Through Advanced Reservoir Characterization and Thermal Production Technologies. Annual Report, March 30, 1995--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Edith

    1996-12-01

    The objective of this project is to increase heavy oil reserves in a portion of the Wilmington Oil Field, near Long Beach, California, by implementing advanced reservoir characterization and thermal production technologies. Based on the knowledge and experience gained with this project, these technologies are intended to be extended to other sections of the Wilmington Oil Field, and, through technology transfer, will be available to increase heavy oil reserves in other slope and basin clastic (SBC) reservoirs.

  7. Increasing Heavy Oil in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies. Annual Report, March 30, 1995--March 31, 1996

    International Nuclear Information System (INIS)

    Allison, Edith

    1996-12-01

    The objective of this project is to increase heavy oil reserves in a portion of the Wilmington Oil Field, near Long Beach, California, by implementing advanced reservoir characterization and thermal production technologies. Based on the knowledge and experience gained with this project, these technologies are intended to be extended to other sections of the Wilmington Oil Field, and, through technology transfer, will be available to increase heavy oil reserves in other slope and basin clastic (SBC) reservoirs

  8. Reservoir characterization of the Mississippian Ratcliffe, Richland County, Montana, Williston Basin. Topical report, September 1997

    Energy Technology Data Exchange (ETDEWEB)

    Sippel, M.; Luff, K.D.; Hendricks, M.L.

    1998-07-01

    This topical report is a compilation of characterizations by different disciplines of the Mississippian Ratcliffe in portions of Richland County, MT. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity and methods for improved recovery. The report covers investigations of geology, petrography, reservoir engineering and seismic. The Ratcliffe is a low permeability oil reservoir which appears to be developed across much of the study area and occurs across much of the Williston Basin. The reservoir has not been a primary drilling target in the study area because average reserves have been insufficient to payout the cost of drilling and completion despite the application of hydraulic fracture stimulation. Oil trapping does not appear to be structurally controlled. For the Ratcliffe to be a viable drilling objective, methods need to be developed for (1) targeting better reservoir development and (2) better completions. A geological model is presented for targeting areas with greater potential for commercial reserves in the Ratcliffe. This model can be best utilized with the aid of 3D seismic. A 3D seismic survey was acquired and is used to demonstrate a methodology for targeting the Ratcliffe. Other data obtained during the project include oriented core, special formation-imaging log, pressure transient measurements and oil PVT. Although re-entry horizontal drilling was unsuccessfully tested, this completion technology should improve the economic viability of the Ratcliffe. Reservoir simulation of horizontal completions with productivity of three times that of a vertical well suggested two or three horizontal wells in a 258-ha (640-acre) area could recover sufficient reserves for profitable drilling.

  9. Seasonal Forecasting of Reservoir Inflow for the Segura River Basin, Spain

    Science.gov (United States)

    de Tomas, Alberto; Hunink, Johannes

    2017-04-01

    A major threat to the agricultural sector in Europe is an increasing occurrence of low water availability for irrigation, affecting the local and regional food security and economies. Especially in the Mediterranean region, such as in the Segura river basin (Spain), drought epidodes are relatively frequent. Part of the irrigation water demand in this basin is met by a water transfer from the Tagus basin (central Spain), but also in this basin an increasing pressure on the water resources has reduced the water available to be transferred. Currently, Drought Management Plans in these Spanish basins are in place and mitigate the impact of drought periods to some extent. Drought indicators that are derived from the available water in the storage reservoirs impose a set of drought mitigation measures. Decisions on water transfers are dependent on a regression-based time series forecast from the reservoir inflows of the preceding months. This user-forecast has its limitations and can potentially be improved using more advanced techniques. Nowadays, seasonal climate forecasts have shown to have increasing skill for certain areas and for certain applications. So far, such forecasts have not been evaluated in a seasonal hydrologic forecasting system in the Spanish context. The objective of this work is to develop a prototype of a Seasonal Hydrologic Forecasting System and compare this with a reference forecast. The reference forecast in this case is the locally used regression-based forecast. Additionally, hydrological simulations derived from climatological reanalysis (ERA-Interim) are taken as a reference forecast. The Spatial Processes in Hydrology model (SPHY - http://www.sphy.nl/) forced with the ECMWF- SFS4 (15 ensembles) Seasonal Forecast Systems is used to predict reservoir inflows of the upper basins of the Segura and Tagus rivers. The system is evaluated for 4 seasons with a forecasting lead time of 3 months. First results show that only for certain initialization

  10. Diagenetic Evolution and Reservoir Quality of Sandstones in the North Alpine Foreland Basin: A Microscale Approach.

    Science.gov (United States)

    Gross, Doris; Grundtner, Marie-Louise; Misch, David; Riedl, Martin; Sachsenhofer, Reinhard F; Scheucher, Lorenz

    2015-10-01

    Siliciclastic reservoir rocks of the North Alpine Foreland Basin were studied focusing on investigations of pore fillings. Conventional oil and gas production requires certain thresholds of porosity and permeability. These parameters are controlled by the size and shape of grains and diagenetic processes like compaction, dissolution, and precipitation of mineral phases. In an attempt to estimate the impact of these factors, conventional microscopy, high resolution scanning electron microscopy, and wavelength dispersive element mapping were applied. Rock types were established accordingly, considering Poro/Perm data. Reservoir properties in shallow marine Cenomanian sandstones are mainly controlled by the degree of diagenetic calcite precipitation, Turonian rocks are characterized by reduced permeability, even for weakly cemented layers, due to higher matrix content as a result of lower depositional energy. Eocene subarkoses tend to be coarse-grained with minor matrix content as a result of their fluvio-deltaic and coastal deposition. Reservoir quality is therefore controlled by diagenetic clay and minor calcite cementation.Although Eocene rocks are often matrix free, occasionally a clay mineral matrix may be present and influence cementation of pores during early diagenesis. Oligo-/Miocene deep marine rocks exhibit excellent quality in cases when early cement is dissolved and not replaced by secondary calcite, mainly bound to the gas-water contact within hydrocarbon reservoirs.

  11. Carbonate reservoirs modified by magmatic intrusions in the Bachu area, Tarim Basin, NW China

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    Kang Xu

    2015-09-01

    Full Text Available Oil and gas exploration in carbonate rocks was extremely successful in recent years in the Ordovician in Tarim Basin, NW China. Here, we investigate the carbonate reservoirs in the Bachu area of the Tarim Basin through petrological and geochemical studies combined with oil and gas exploration data. Geochemical analysis included the major, trace, and rare earth elements; fluid inclusion thermometry; clay mineral characterization; and carbon and oxygen isotopes of the carbonate rocks. Homogenization temperatures of the fluid inclusions of Well He-3 in the Bachu area indicate three groups, 60–80 °C, 90–130 °C, and 140–170 °C, and suggest that the carbonate rocks experienced modification due to heating events. The porosity in the reservoir is defined by fractures and secondary pores, and there is a notable increase in the porosity of the carbonate reservoirs in proximity to magmatic intrusion, particularly approximately 8–10 m from the intrusive rocks. The development of secondary pores was controlled by lithofacies and corrosion by various fluids. We identify supercritical fluids with high density (138.12–143.97 mg/cm3 in the Bachu area. The negative correlations of δ13C (−2.76‰ to −0.97‰ and δ18O (−7.91‰ to −5.07‰ suggest that the carbonate rocks in the study area were modified by high-salinity hydrothermal fluid. The formation of clay minerals, such as illite and montmorillonite, caused a decrease in porosity. Our study demonstrates the effect of magmatic intrusions in modifying the reservoir characteristics of carbonate rocks and has important implications for oil and gas exploration.

  12. ADVANCED CHARACTERIZATION OF FRACTURED RESERVOIRS IN CARBONATE ROCKS: THE MICHIGAN BASIN

    Energy Technology Data Exchange (ETDEWEB)

    James R. Wood; William B. Harrison

    2002-12-01

    The purpose of the study was to collect and analyze existing data on the Michigan Basin for fracture patterns on scales ranging form thin section to basin. The data acquisition phase has been successfully concluded with the compilation of several large digital databases containing nearly all the existing information on formation tops, lithology and hydrocarbon production over the entire Michigan Basin. These databases represent the cumulative result of over 80 years of drilling and exploration. Plotting and examination of these data show that contrary to most depictions, the Michigan Basin is in fact extensively faulted and fractured, particularly in the central portion of the basin. This is in contrast to most of the existing work on the Michigan Basin, which tends to show relatively simple structure with few or minor faults. It also appears that these fractures and faults control the Paleozoic sediment deposition, the subsequent hydrocarbon traps and very likely the regional dolomitization patterns. Recent work has revealed that a detailed fracture pattern exists in the interior of the Central Michigan Basin, which is related to the mid-continent gravity high. The inference is that early Precambrian, ({approx}1 Ga) rifting events presumed by many to account for the gravity anomaly subsequently controlled Paleozoic sedimentation and later hydrocarbon accumulation. There is a systematic relationship between the faults and a number of gas and oil reservoirs: major hydrocarbon accumulations consistently occur in small anticlines on the upthrown side of the faults. The main tools used in this study to map the fault/fracture patterns are detailed, close-interval (CI = 10 feet) contouring of the formation top picks accompanied by a new way of visualizing the data using a special color spectrum to bring out the third dimension. In addition, recent improvements in visualization and contouring software were instrumental in the study. Dolomitization is common in the

  13. Hydrogeology and hydrogeochemistry at a site of strategic importance: the Pareja Limno-reservoir drainage basin (Guadalajara, central Spain)

    Science.gov (United States)

    Molina-Navarro, Eugenio; Sastre-Merlín, Antonio; Vicente, Rosa; Martínez-Pérez, Silvia

    2014-08-01

    A small calcareous basin in central Spain was studied to establish the role of groundwater in the Pareja Limno-reservoir. Limno-reservoirs aim to preserve a constant water level in the riverine zone of large reservoirs to mitigate the impacts arising from their construction. Groundwater flow contribution (mean 60 %) was derived by recharge estimation. In situ measurements (spring discharge, electrical conductivity and sulfate) were undertaken and spring discharge was compared with a drought index. Twenty-eight springs were monitored and three hydrogeological units (HGUs) were defined: a carbonate plateau (HGU1), the underlying aquitard (HGU2), and the gypsum-enriched HGU3. HGU1 is the main aquifer and may play a role in the preservation of the limno-reservoir water level. Hydrogeochemical sampling was conducted and the code PHREEQC used to describe the main geochemical processes. Weathering and dissolution of calcite and gypsum seem to control the hydrogeochemical processes in the basin. Water progresses from Ca2+-HCO3 - in the upper basin to Ca2+-SO4 2- in the lower basin, where HGU3 outcrops. A clear temporal pattern was observed in the limno-reservoir, with salinity decreasing in winter and increasing in summer. This variation was wider at the river outlet, but the mixing of the river discharge with limno-reservoir water buffered it.

  14. From obc seismic to porosity volume: A pre-stack analysis of a turbidite reservoir, deepwater Campos Basin, Brazil

    Science.gov (United States)

    Martins, Luiz M. R.

    The Campos Basin is the best known and most productive of the Brazilian coastal basins. Turbidites are, by far, the main oil-bearing reservoirs. Using a four component (4-C) ocean-bottom-cable (OBC) seismic survey I set out to improve the reservoir characterization in a deep-water turbidite field in the Campos Basin. In order to achieve my goal, pre-stack angle gathers were derived and PP and PS inversion were performed. The inversion was used as an input to predict the petrophysical properties of the reservoir. Converting seismic reflection amplitudes into impedance profiles not only maximizes vertical resolution but also minimizes tuning effects. Mapping the porosity is extremely important in the development of a hydrocarbon reservoirs. Combining seismic attributes derived from the P-P data and porosity logs I use linear multi-regression and neural network geostatistical tools to predict porosity between the seismic attributes and porosity logs at the well locations. After predicting porosity in well locations, those relationships were applied to the seismic attributes to generate a 3-D porosity volume. The predicted porosity volume highlighted the best reservoir facies in the reservoir. The integration of elastic impedance, shear impedance and porosity improved the reservoir characterization.

  15. Stimulation technologies for Longwangmiao Fm gas reservoirs in the Sichuan Basin and their application results

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    Fu Yongqiang

    2014-10-01

    Full Text Available The Longwangmiao Fm group gas reservoirs in the Moxi structure in central Sichuan Basin feature high temperature, high pressure and high H2S content. The thickness of such high permeable reservoirs with great homogeneity is a geologic basis for a high-productivity gas well, and good match of natural fractures and vugs is the key factor to high well productivity. Overbalance drilling is likely to cause the opening-up of natural fractures, which will lead to the leakage of drilling fluid and severe damage to the reservoir. Experimental evaluation results show that the damage rate of the drilling fluid to the rock sample is between 82.2% and 89.2%, which severely restricts the productivity of gas wells. Therefore, it is necessary to deepen the experimental evaluation technologies and methods to promote the design pertinence of technical parameters. The study shows: first, the optimized gelling acid and steering acid are effective in slowing down speed and removing blockage, forming acidizing wormholes and effectively eliminating the blockage effect caused by drilling liquid pollution; second, the self-developed fiber steering agent and soluble temporary blocking ball can divert the acid, increasing the processing pressure at the well bottom by 5–15 MPa, realizing the even stimulation of heterogeneous reservoirs; third, based on experimental evaluation such as the acid penetration and acid rock reaction, it is recommended that the pumping rate be 3.0–3.5 m3/min in acidizing treatment and the acid intensity for blockage removal be 3.0–5.0 m3/m; fourth, the established blockage removal and steering acidizing technology have been applied in more than 20 wells with a remarkable productivity-increase effect, which gives full play to the natural productivity of gas wells and decreases the acid application scale. All these technologies and measures effectively enhance the development quality and profit of the gas reservoir.

  16. Sedimentology and Reservoir Characteristics of Early Cretaceous Fluvio-Deltaic and Lacustrine Deposits, Upper Abu Gabra Formation, Sufyan Sub-basin, Muglad Rift Basin, Sudan

    Science.gov (United States)

    Yassin, Mohamed; Abdullatif, Osman; Hariri, Mustafa

    2017-04-01

    Sufyan Sub-basin is an East-West trending Sub-basin located in the northwestern part of the Muglad Basin (Sudan), in the eastern extension of the West and Central Africa Rift System (WCARS). The Early Cretaceous Abu Gabra Formation considered as the main source rock in the Muglad Basin. In Sufyan Sub-basin the Early Cretaceous Upper Abu Gabra Formation is the main oil-producing reservoir. It is dominated by sandstone and shales deposited in fluvio-deltaic and lacustrine environment during the first rift cycle in the basin. Depositional and post-depositional processes highly influenced the reservoir quality and architecture. This study investigates different scales of reservoir heterogeneities from macro to micro scale. Subsurface facies analysis was analyzed based on the description of six conventional cores from two wells. Approaches include well log analysis, thin sections and scanning electron microscope (SEM) investigations, grain-size, and X-ray diffraction (XRD) analysis of the Abu Gabra sandstone. The cores and well logs analyses revealed six lithofacies representing fluvio-deltaic and lacustrine depositional environment. The sandstone is medium to coarse-grained, poorly to moderately sorted and sub-angular to subrounded, Sub-feldspathic arenite to quartz arenite. On macro-scale, reservoir quality varies within Abu Gabra reservoir where it shows progressive coarsening upward tendencies with different degrees of connectivity. The upper part of the reservoir showed well connected and amalgamated sandstone bodies, the middle to lower parts, however, have moderate to low sandstone bodies' connectivity and amalgamation. On micro-scale, sandstone reservoir quality is directly affected by textures and diagenesis.The XRD and SEM analyses show that kaolinite and chlorite clay are the common clay minerals in the studied samples. Clay matrix and quartz overgrowth have significantly reduced the reservoir porosity and permeability, while the dissolution of feldspars

  17. Technical difficulties of logging while drilling in carbonate reservoirs and the countermeasures: A case study from the Sichuan Basin

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    Shudong Zhang

    2015-12-01

    Full Text Available In the Sichuan Basin, carbonate reservoirs are characterized by deep burial depth and strong heterogeneity, so it is difficult to conduct structure steering, pore space reservoir tracking and trajectory control in the process of geosteering logging while drilling. In this paper, a series of corresponding techniques for structure, reservoir and formation tracking were proposed after analysis was conducted on multiple series of carbonate strata in terms of their geologic and logging response characteristics. And investigation was performed on the adaptabilities of the following logging technologies to geosteering while drilling, including gamma ray imaging while drilling, resistivity imaging while drilling, density imaging while drilling, gamma ray logging while drilling, resistivity logging while drilling, neutron logging while drilling and density logging while drilling. After while drilling information was thoroughly analyzed, the logging suites for four common types of complicated reservoirs (thin layered reservoirs, thick massive reservoirs, denuded karst reservoirs and shale gas reservoirs were optimized, and five logging combinations suitable for different formations and reservoirs were proposed, including gamma ray logging + porosity + resistivity imaging, gamma ray logging + resistivity imaging, gamma ray logging + porosity + resistivity logging, gamma ray imaging + resistivity logging, and gamma ray logging. Field application indicates that it is of great reference and application value to use this method for the first time to summarize logging while drilling combinations for different types of carbonate reservoirs.

  18. The future of the reservoirs in the Siret River Basin considering the sediment transport of rivers (ROMANIA

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    Petru OLARIU

    2015-02-01

    Full Text Available The Siret River Basin is characterized by an important use of hydro potential, resulted in the number of reservoirs constructed and operational. The cascade power stage of the reservoirs on Bistrita and Siret rivers indicate the anthropic interventions with different purposes (hydro energy, water supply, irrigation etc. in the Siret River Basin. In terms of the capacity in the Siret River Basin there is a dominance of the small capacity reservoirs, which is given by the less than 20 mil m³ volumes. Only two lakes have capacities over 200 mil m³: Izvoru Muntelui on Bistrita River and Siriu on Buzau River. Based on the monitoring of the alluvial flow at the hydrometric stations, from the Siret River Basin, there have been analysed the sediment yield formation and the solid transit dimensions in order to obtain typical values for the geographical areas of this territory. The silting of these reservoirs was monitored by successive topobatimetric measurements performed by the Bureau of Prognosis, Hydrology and Hydrogeology and a compartment within Hidroelectrica S.A. Piatra Neamt Subsidiary. The quantities of the deposited sediments are very impressive. The annual rates range betwee3 000 – 2 000 000 t/year, depending on the size of the hydrographical basin, the capacity of the reservoirs, the liquid flow and many other factors which may influence the upstream transport of sediments. These rates of sedimentation lead to a high degree of silting in the reservoirs. Many of them are silted over 50% of the initial capacity and the others even more. The effects of the silting have an important impact when analysing the effective exploitation of the reservoirs

  19. Application of Simultaneous Inversion Characterizing Reservoir Properties in X Field, Sabah Basin

    Science.gov (United States)

    Xiang, Lee Ming; Almanna Lubis, Luluan

    2017-10-01

    X field located between the East Baram Delta and Southern Inboard Belt, which is elongated northwest to southeast direction in Middle Miocene Sabah Basin. Previous studies were unable to differentiate the lithology and fluid distribution in the field by using conventional reservoir characterization approaches for example amplitude versus offset (AVO) analysis and post-stack deterministic inversion due to the low contrast in P-impedance between gas sand and shale. Thus, the goal of this approach is to obtain a reliable estimation of P wave velocity (VP). S-wave velocity (Vs), and density (ƿ). From these parameters, we predict the fluid and lithology properties for better reservoir characterization. A feasibility analysis was conducted and the results show that prediction of the hydrocarbon reservoir in X field is feasible using P-impedance and Vp/Vs. Consequently, the simultaneous inversion is carried out to derive the rock properties such as density, P-impedance, S-impedance, Lambda-rho (λƿ) (Incompressibility), and Mu-rho (µƿ) (Rigidity). The results from this study demonstrate the effectiveness of simultaneous inversion and the best parameters for enhancing the resolution and characterizing the hydrocarbon sand layer of the prospect.

  20. Relationships between water and gas chemistry in mature coalbed methane reservoirs of the Black Warrior Basin

    Science.gov (United States)

    Pashin, Jack C.; McIntyre-Redden, Marcella R.; Mann, Steven D.; Kopaska-Merkel, David C.; Varonka, Matthew S.; Orem, William H.

    2014-01-01

    Water and gas chemistry in coalbed methane reservoirs of the Black Warrior Basin reflects a complex interplay among burial processes, basin hydrodynamics, thermogenesis, and late-stage microbial methanogenesis. These factors are all important considerations for developing production and water management strategies. Produced water ranges from nearly potable sodium-bicarbonate water to hypersaline sodium-chloride brine. The hydrodynamic framework of the basin is dominated by structurally controlled fresh-water plumes that formed by meteoric recharge along the southeastern margin of the basin. The produced water contains significant quantities of hydrocarbons and nitrogen compounds, and the produced gas appears to be of mixed thermogenic-biogenic origin.Late-stage microbial methanogenesis began following unroofing of the basin, and stable isotopes in the produced gas and in mineral cements indicate that late-stage methanogenesis occurred along a CO2-reduction metabolic pathway. Hydrocarbons, as well as small amounts of nitrate in the formation water, probably helped nourish the microbial consortia, which were apparently active in fresh to hypersaline water. The produced water contains NH4+ and NH3, which correlate strongly with brine concentration and are interpreted to be derived from silicate minerals. Denitrification reactions may have generated some N2, which is the only major impurity in the coalbed gas. Carbon dioxide is a minor component of the produced gas, but significant quantities are dissolved in the formation water. Degradation of organic compounds, augmented by deionization of NH4+, may have been the principal sources of hydrogen facilitating late-stage CO2 reduction.

  1. Pore characteristics of shale gas reservoirs from the Lower Paleozoic in the southern Sichuan Basin, China

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    Xianqing Li

    2016-06-01

    Full Text Available Data was acquired from both the drillings and core samples of the Lower Paleozoic Qiongzhusi and Longmaxi Formations' marine shale gas reservoirs in the southern Sichuan Basin by means of numerous specific experimental methods such as organic geochemistry, organic petrology, and pore analyses. Findings helped determine the characteristics of organic matter, total porosity, microscopic pore, and pore structure. The results show that the Lower Paleozoic marine shale in the south of the Sichuan Basin are characterized by high total organic carbon content (most TOC>2.0%, high thermal maturity level (RO = 2.3%–3.8%, and low total porosity (1.16%–6.87%. The total organic carbon content and thermal maturity level of the Qiongzhusi Formation shale are higher than those of the Longmaxi Formation shale, while the total porosity of the Qiongzhusi Formation shale is lower than that of the Longmaxi Formation shale. There exists intergranular pore, dissolved pore, crystal particle pore, particle edge pore, and organic matter pore in the Lower Paleozoic Qiongzhusi Formation and Longmaxi Formation shale. There are more micro-nano pores developed in the Longmaxi Formation shales than those in the Qiongzhusi Formation shales. Intergranular pores, dissolved pores, as well as organic matter pores, are the most abundant, these are primary storage spaces for shale gas. The microscopic pores in the Lower Paleozoic shales are mainly composed of micropores, mesopores, and a small amount of macropores. The micropore and mesopore in the Qiongzhusi Formation shale account for 83.92% of the total pore volume. The micropore and mesopore in the Longmaxi Formation shale accounts for 78.17% of the total pore volume. Thus, the micropores and mesopores are the chief components of microscopic pores in the Lower Paleozoic shale gas reservoirs in the southern Sichuan Basin.

  2. Effect of pore structure on the seepage characteristics of tight sandstone reservoirs: A case study of Upper Jurassic Penglaizhen Fm reservoirs in the western Sichuan Basin

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    Liqiang Sima

    2017-01-01

    Full Text Available Tight sandstone reservoirs are characterized by complex pore structures and strong heterogeneity, and their seepage characteristics are much different from those of conventional sandstone reservoirs. In this paper, the tight sandstone reservoirs of Upper Jurassic Penglaizhen Fm in western Sichuan Basin were analyzed in terms of their pore structures by using the data about physical property, mercury injection and nuclear magnetic resonance (NMR tests. Then, the seepage characteristics and the gas–water two-phase migration mechanisms and distribution of tight sandstone reservoirs with different types of pore structures in the process of hydrocarbon accumulation and development were simulated by combining the relative permeability experiment with the visual microscopic displacement model. It is shown that crotch-like viscous fingering occurs in the process of gas front advancing in reservoirs with different pore structures. The better the pore structure is, the lower the irreducible water saturation is; the higher the gas-phase relative permeability of irreducible water is, the more easily the gas reservoir can be developed. At the late stage of development, the residual gas is sealed in reservoirs in the forms of bypass, cutoff and dead end. In various reservoirs, the interference between gas and water is stronger, so gas and water tends to be produced simultaneously. The sealed gas may reduce the production rate of gas wells significantly, and the existence of water phase may reduce the gas permeability greatly; consequently, the water-bearing low-permeability tight sandstone gas reservoirs reveal serious water production, highly-difficult development and low-recovery percentage at the late stage, which have adverse impacts on the effective production and development of gas wells.

  3. RESERVOIR CHARACTERIZATION OF THE LOWER GREEN RIVER FORMATION, SOUTHWEST UINTA BASIN, UTAH

    Energy Technology Data Exchange (ETDEWEB)

    S. Robert Bereskin

    2003-02-11

    Anastamosing, low gradient distributary channels produce {approx}30 gravity, paraffinic oils from the Middle Member of the lacustrine Eocene Green River Formation in the south-central portion of the Uinta Basin. This localized depocenter was situated along the fluctuating southern shoreline of Lake Uinta, where complex deposits of marginal-lacustrine to lower delta plain accumulations are especially characteristic. The Middle Member contains several fining-upward parasequences that can be recognized in outcrop, core, and downhole logs. Each parasequence is about 60 to 120 feet thick and consists of strata deposited during multiple lake level fluctuations that approach 30 to 35 feet in individual thickness. Such parasequences represent 300,000-year cycles based on limited absolute age dating. The subaerial to subaqueous channels commonly possess an erosional base and exhibit a fining upward character. Accordingly, bedding features commonly range from large-scale trough and planar cross bedding or lamination at the base, to a nonreservoir, climbing ripple assemblage near the uppermost reservoir boundary. The best reservoir quality occurs within the laminated to cross-stratified portions, and the climbing ripple phase usually possesses more deleterious micas and/or detrital clays. Diagenesis also exerts a major control on reservoir quality. Certain sandstones were cemented by an early, iron-poor calcite cement, which can be subsequently leached. Secondary intergranular porosity (up to 20%) is largely responsible for the 10 -100 millidarcy rock, which represents petrophysical objectives for both primary and secondary production. Otherwise, intense compaction, silicic and iron-rich carbonate cements, and authigenic clays serve to reduce reservoir quality to marginal economic levels.

  4. Quantifying the potential for reservoirs to secure future surface water yields in the world’s largest river basins

    Science.gov (United States)

    Liu, Lu; Parkinson, Simon; Gidden, Matthew; Byers, Edward; Satoh, Yusuke; Riahi, Keywan; Forman, Barton

    2018-04-01

    Surface water reservoirs provide us with reliable water supply, hydropower generation, flood control and recreation services. Yet reservoirs also cause flow fragmentation in rivers and lead to flooding of upstream areas, thereby displacing existing land-use activities and ecosystems. Anticipated population growth and development coupled with climate change in many regions of the globe suggests a critical need to assess the potential for future reservoir capacity to help balance rising water demands with long-term water availability. Here, we assess the potential of large-scale reservoirs to provide reliable surface water yields while also considering environmental flows within 235 of the world’s largest river basins. Maps of existing cropland and habitat conservation zones are integrated with spatially-explicit population and urbanization projections from the Shared Socioeconomic Pathways to identify regions unsuitable for increasing water supply by exploiting new reservoir storage. Results show that even when maximizing the global reservoir storage to its potential limit (∼4.3–4.8 times the current capacity), firm yields would only increase by about 50% over current levels. However, there exist large disparities across different basins. The majority of river basins in North America are found to gain relatively little firm yield by increasing storage capacity, whereas basins in Southeast Asia display greater potential for expansion as well as proportional gains in firm yield under multiple uncertainties. Parts of Europe, the United States and South America show relatively low reliability of maintaining current firm yields under future climate change, whereas most of Asia and higher latitude regions display comparatively high reliability. Findings from this study highlight the importance of incorporating different factors, including human development, land-use activities, and climate change, over a time span of multiple decades and across a range of different

  5. Sedimentary mode and reservoir distribution of the Cambrian carbonate & evaporate paragenesis system in the Sichuan Basin

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    Anna Xu

    2016-11-01

    Full Text Available The Cambrian carbonate & evaporite paragenesis system in the Sichuan Basin is made up of the Longwangmiao, Gaotai and Xixiangchi Fms. So far, great breakthrough has been made only in the Longwangmiao Fm instead of the latter two, and the Anyue Gasfield was discovered in the center of this basin. In this paper, therefore, the Cambrian carbonate & evaporite paragenesis system in the Sichuan Basin was analyzed in terms of its structural–sedimentary setting, sequence stratigraphic framework, sedimentary facies and the distribution of evaporites by using various geologic, logging and seismic data. Then, the geological model of sedimentary facies was established and the distribution range of favorable reservoirs was predicted. Based on these studies, the following results are obtained. Firstly, the palaeotectonic framework is characterized by the style of “one depression between two uplifts” in the setting of a large SE dipping slope, and the stratigraphic filling is in the structure of “onlapping at the bottom and truncation at the top” which is thin in the west and thick in the east. Secondly, three third-order sequence cycles which, on the whole, become shallow upward are developed from bottom to top, and gypsum-salt rocks are mainly located at the high system tract (HST of third-order sequences and concentrated in the Wanzhou–Yibin sag. Thirdly, the geological model of sedimentary facies is composed of three major sedimentary structural layers from bottom to top, namely the evaporative carbonate ramp, the evaporative diamictic restricted platform and the evaporative restricted platform. The sedimentary environment changes from the open to the closed and the penesaline for a long time, and then back to the open. The distribution of shoals changes from the pattern of “dual banks” in a large area to more scattered shoals and banded shoals, while the evaporative lagoon and tidal flat shrink. Fourthly, the reservoir distribution is

  6. Low flows and reservoir management for the Durance River basin (Southern France) in the 2050s

    Science.gov (United States)

    Sauquet, Eric

    2015-04-01

    . A model of water management similar to the tools used by Electricité De France was calibrated to simulate the behavior of the three reservoirs Serre-Ponçon, Castillon, Sainte-Croix on present-day conditions. This model simulates water releases from reservoir under constraints imposed by rule curves, ecological flows downstream to the dams and water levels in summer for recreational purposes. The results demonstrate the relatively good performance of this simplified model and its ability to represent the influence of reservoir operations on the natural hydrological river flow regime, the decision-making involved in water management and the interactions at regional scale. Four territorial socio-economic scenarios have been also elaborated with the help of stake holders to project water needs in the 2050s for the area supplied with water from the Durance River basin. This presentation will focus on the specific tools developed within the project to simulate water management and water abstractions. The main conclusions related to the risk of water shortage in the 2050s and the level of satisfaction for each water use will be also discussed.

  7. Shallow Miocene basaltic magma reservoirs in the Bahia de Los Angeles basin, Baja California, Mexico

    Science.gov (United States)

    Delgado-Argote, Luis A.; García-Abdeslem, Juan

    1999-01-01

    The basement in the Bahía de Los Angeles basin consists of Paleozoic metamorphic rocks and Cretaceous granitoids. The Neogene stratigraphy overlying the basement is formed, from the base to the top, by andesitic lava flows and plugs, sandstone and conglomeratic horizons, and Miocene pyroclastic flow units and basaltic flows. Basaltic dikes also intrude the whole section. To further define its structure, a detailed gravimetric survey was conducted across the basin about 1 km north of the Sierra Las Flores. In spite of the rough and lineal topography along the foothills of the Sierra La Libertad, we found no evidence for large-scale faulting. Gravity data indicates that the basin has a maximum depth of 120 m in the Valle Las Tinajas and averages 75 m along the gravimetric profile. High density bodies below the northern part of the Sierra Las Flores and Valle Las Tinajas are interpreted to be part of basaltic dikes. The intrusive body located north of the Sierra Las Flores is 2.5 km wide and its top is about 500 m deep. The lava flows of the top of the Sierra Las Flores, together with the distribution of basaltic activity north of this sierra, suggests that this intrusive body continues for 20 km along a NNW-trending strike. Between the sierras Las Flores and Las Animas, a 0.5-km-wide, 300-m-thick intrusive body is interpreted at a depth of about 100 m. This dike could be part of the basaltic activity of the Cerro Las Tinajas and the small mounds along the foothills of western Sierra Las Animas. The observed local normal faulting in the basin is inferred to be mostly associated with the emplacement of the shallow magma reservoirs below Las Flores and Las Tinajas.

  8. Reservoir characteristics and control factors of Carboniferous volcanic gas reservoirs in the Dixi area of Junggar Basin, China

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    Ji'an Shi

    2017-02-01

    Full Text Available Field outcrop observation, drilling core description, thin-section analysis, SEM analysis, and geochemistry, indicate that Dixi area of Carboniferous volcanic rock gas reservoir belongs to the volcanic rock oil reservoir of the authigenic gas reservoir. The source rocks make contact with volcanic rock reservoir directly or by fault, and having the characteristics of near source accumulation. The volcanic rock reservoir rocks mainly consist of acidic rhyolite and dacite, intermediate andesite, basic basalt and volcanic breccia: (1 Acidic rhyolite and dacite reservoirs are developed in the middle-lower part of the structure, have suffered strong denudation effect, and the secondary pores have formed in the weathering and tectonic burial stages, but primary pores are not developed within the early diagenesis stage. Average porosity is only at 8%, and the maximum porosity is at 13.5%, with oil and gas accumulation showing poor performance. (2 Intermediate andesite and basic basalt reservoirs are mainly distributed near the crater, which resembles the size of and suggests a volcanic eruption. Primary pores are formed in the early diagenetic stage, secondary pores developed in weathering and erosion transformation stage, and secondary fractures formed in the tectonic burial stage. The average porosity is at 9.2%, and the maximum porosity is at 21.9%: it is of the high-quality reservoir types in Dixi area. (3 The volcanic breccia reservoir has the same diagenetic features with sedimentary rocks, but also has the same mineral composition with volcanic rock; rigid components can keep the primary porosity without being affected by compaction during the burial process. At the same time, the brittleness of volcanic breccia reservoir makes it easily fracture under the stress; internal fracture was developmental. Volcanic breccia developed in the structural high part and suffered a long-term leaching effect. The original pore-fracture combination also made

  9. Long-term trend analysis of reservoir water quality and quantity at the landscape scale in two major river basins of Texas, USA.

    Science.gov (United States)

    Patino, Reynaldo; Asquith, William H.; VanLandeghem, Matthew M.; Dawson, D.

    2016-01-01

    Trends in water quality and quantity were assessed for 11 major reservoirs of the Brazos and Colorado river basins in the southern Great Plains (maximum period of record, 1965–2010). Water quality, major contributing-stream inflow, storage, local precipitation, and basin-wide total water withdrawals were analyzed. Inflow and storage decreased and total phosphorus increased in most reservoirs. The overall, warmest-, or coldest-monthly temperatures increased in 7 reservoirs, decreased in 1 reservoir, and did not significantly change in 3 reservoirs. The most common monotonic trend in salinity-related variables (specific conductance, chloride, sulfate) was one of no change, and when significant change occurred, it was inconsistent among reservoirs. No significant change was detected in monthly sums of local precipitation. Annual water withdrawals increased in both basins, but the increase was significant (P quality data due to the presence of high- and low-salinity reservoirs in both basins. These observations present a landscape in the Brazos and Colorado river basins where, in the last ∼40 years, reservoir inflow and storage generally decreased, eutrophication generally increased, and water temperature generally increased in at least 1 of 3 temperature indicators evaluated. Because local precipitation remained generally stable, observed reductions in reservoir inflow and storage during the study period may be attributable to other proximate factors, including increased water withdrawals (at least in the Colorado River basin) or decreased runoff from contributing watersheds.

  10. The Baltic Basin: structure, properties of reservoir rocks, and capacity for geological storage of CO2

    Directory of Open Access Journals (Sweden)

    Vaher, Rein

    2009-12-01

    Full Text Available Baltic countries are located in the limits of the Baltic sedimentary basin, a 700 km long and 500 km wide synclinal structure. The axis of the syneclise plunges to the southwest. In Poland the Precambrian basement occurs at a depth of 5 km. The Baltic Basin includes the Neoproterozoic Ediacaran (Vendian at the base and all Phanerozoic systems. Two aquifers, the lower Devonian and Cambrian reservoirs, meet the basic requirements for CO2 storage. The porosity and permeability of sandstone decrease with depth. The average porosity of Cambrian sandstone at depths of 80–800, 800–1800, and 1800–2300 m is 18.6, 14.2, and 5.5%, respectively. The average permeability is, respectively, 311, 251, and 12 mD. Devonian sandstone has an average porosity of 26% and permeability in the range of 0.5–2 D. Prospective Cambrian structural traps occur only in Latvia. The 16 largest ones have CO2 storage capacity in the range of 2–74 Mt, with total capacity exceeding 400 Mt. The structural trapping is not an option for Lithuania as the uplifts there are too small. Another option is utilization of CO2 for enhanced oil recovery (EOR. The estimated total EOR net volume of CO2 (part of CO2 remaining in the formation in Lithuania is 5.6 Mt. Solubility and mineral trapping are a long-term option. The calculated total solubility trapping capacity of the Cambrian reservoir is as high as 11 Gt of CO2 within the area of the supercritical state of carbon dioxide.

  11. Sedimentary tectonic evolution and reservoir-forming conditions of the Dazhou–Kaijiang paleo-uplift, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Yueming Yang

    2016-12-01

    Full Text Available Great breakthrough recently achieved in the Sinian–Lower Paleozoic gas exploration in the Leshan–Longnüsi paleo-uplift, Sichuan Basin, has also made a common view reached, i.e., large-scale paleo-uplifts will be the most potential gas exploration target in the deep strata of this basin. Apart from the above-mentioned one, the other huge paleo-uplifts are all considered to be the ones formed in the post-Caledonian period, the impact of which, however, has rarely ever been discussed on the Sinian–Lower Paleozoic oil and gas reservoir formation. In view of this, based on outcrops, drilling and geophysical data, we analyzed the Sinian–Lower Paleozoic tectonic setting and sedimentary background in the East Sichuan Basin, studied the distribution rules of reservoirs and source rocks under the control of paleo-uplifts, and finally discussed, on the basis of structural evolution analysis, the conditions for the formation of Sinian–Lower Paleozoic gas reservoirs in this study area. The following findings were achieved. (1 The Dazhou–Kaijiang inherited uplift in NE Sichuan Basin which was developed before the Middle Cambrian controlled a large area of Sinian and Cambrian beach-facies development. (2 Beach-facies reservoirs were developed in the upper part of the paleo-uplift, while in the peripheral depression belts thick source rocks were developed like the Upper Sinian Doushantuo Fm and Lower Cambrian Qiongzhusi Fm, so there is a good source–reservoir assemblage. (3 Since the Permian epoch, the Dazhou–Kaijiang paleo-uplift had gradually become elevated from the slope zone, where the Permian oil generation peak occurred in the slope or lower and gentle uplift belts, while the Triassic gas generation peak occurred in the higher uplift belts, both with a favorable condition for hydrocarbon accumulation. (4 The lower structural layers, including the Lower Cambrian and its underlying strata, in the East Sichuan Basin, are now equipped with a

  12. Coupling relationship between reservoir diagenesis and gas accumulation in Xujiahe Formation of Yuanba–Tongnanba area, Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Jun Li

    2016-10-01

    Full Text Available The relationship between reservoir tightening time and gas charge period are the key subjects that have not been well solved considering the studies on the tight sand gas accumulation mechanism and enrichment regularity. The diagenetic evolution history, interaction sequence of organic–inorganic in aquiferous rock, gas charge history, the tightening mechanism of tight sandstone reservoir and the relationship between reservoir tightening time and gas accumulation period of the Xujiahe Formation have been analyzed in the Yuanba–Tongnanba area of the Sichuan Basin. It has been confirmed that the main reason for the tight sandstone reservoir formation is the intensive mechanical compaction which has dramatically reduced the sandstone reservoir quality, and it resulted to a semi-closed to a closed diagenetic fluid system formation at the early diagenetic stage. In the semi-closed to a closed diagenetic fluid system, at the later part of the diagenetic stage, the fluid circulation is not smooth, and the migration of the dissolution products are blocked, hence, the dissolution products mainly undergo the in situ precipitation and cementation. Such dissolution products block the dissolution pores and the residual primary pores; and the stronger the dissolution is, the higher the cement content is, which makes the reservoir further tightened. The hydrocarbon generation and expulsion history of source rocks and reservoir fluid inclusion characteristics in the Xujiahe Formation show that the charge of natural gas occurs in the Middle Jurassic–Early Cretaceous (mainly Early Cretaceous. A comprehensive analysis of the reservoir tightening history, gas charge history, and interaction sequence of organic–inorganic aquiferous in rock indicate that the sandstone reservoir experienced a tightening process when gas charging took place in the Xujiahe Formation in the Yuanba–Tongnanba area of the Sichuan Basin.

  13. Seismic fracture detection of shale gas reservoir in Longmaxi formation, Sichuan Basin, China

    Science.gov (United States)

    Lu, Yujia; Cao, Junxing; Jiang, Xudong

    2017-11-01

    In the shale reservoirs, fractures play an important role, which not only provide space for the oil and gas, but also offer favorable petroleum migration channel. Therefore, it is of great significance to study the fractures characteristics in shale reservoirs for the exploration and development of shale gas. In this paper, four analysis technologies involving coherence, curvature attribute, structural stress field simulation and pre-stack P-wave azimuthal anisotropy have been applied to predict the fractures distribution in the Longmaxi formation, Silurian, southeast of Sichuan Basin, China. By using the coherence and curvature attribute, we got the spatial distribution characteristics of fractures in the study area. Structural stress field simulation can help us obtain distribution characteristics of structural fractures. And using the azimuth P-wave fracture detection technology, we got the characteristics about the fracture orientation and density of this region. Application results show that there are NW and NE fractures in the study block, which is basically consistent with the result of log interpretation. The results also provide reliable geological basis for shale gas sweet spots prediction.

  14. Prospect evaluation of shallow I-35 reservoir of NE Malay Basin offshore, Terengganu, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Janjua, Osama Akhtar, E-mail: janjua945@hotmail.com; Wahid, Ali, E-mail: ali.wahid@live.com; Salim, Ahmed Mohamed Ahmed, E-mail: mohamed.salim@petronas.com.my [Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 32610 Tronoh, Perak (Malaysia); Rahman, M. Nasir B. A., E-mail: nasirr@petronas.com.my [Petroleum Engineering Division, PETRONAS Carigali Sdn Bhd, Kuala Lumpur (Malaysia)

    2016-02-01

    A potential accumulation of hydrocarbon that describes significant and conceivable drilling target is related to prospect. Possibility of success estimation, assuming discovery of hydrocarbons and the potential recoverable quantities range under a commercial development program are the basis of Prospect evaluation activities. The objective was to find the new shallow prospects in reservoir sandstone of I –Formation in Malay basin. The prospects in the study area are mostly consisting of faulted structures and stratigraphic channels. The methodology follows seismic interpretation and mapping, attribute analysis, evaluation of nearby well data i.e., based on well – log correlation. The petrophysical parameters analogue to nearby wells was used as an input parameter for volumetric assessment. Based on analysis of presence and effectiveness, the prospect has a complete petroleum system. Two wells have been proposed to be drilled near the major fault and stratigraphic channel in I-35 reservoir that is O-1 and O-2 prospects respectively. The probability of geological success of prospect O-1 is at 35% while for O-2 is 24%. Finally, for hydrocarbon in place volumes were calculated which concluded the best estimate volume for oil in O-1 prospect is 4.99 MMSTB and O-2 prospect is 28.70 MMSTB while for gas is 29.27 BSCF and 25.59 BSCF respectively.

  15. ANALYSIS OF FAULT SEAL POTENTIAL FOR KNOX RESERVOIRS IN THE SOUTHERN ILLINOIS BASIN

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, John; Leetaru, Hannes

    2014-09-30

    The presence of known faults near potential geologic CO2 sequestration sites significantly raises the uncertainty of having a sufficient seal to prevent leakage along the fault plane from the intended reservoir. In regions where relocating a large sequestration project a considerable distance away from any known faults is impractical, a detailed analysis of the sealing potential of any faults within the projected future injection plume must be performed. In order to estimate the sealing potential of faults within the Late Cambrian-Early Ordovician Knox Supergroup in the Illinois Basin, two well-based cross sections were produced across two different regional fault systems (Rough Creek Fault Zone in Kentucky, and the unnamed core fault of the LaSalle Anticlinorium in Illinois) to calculate subsurface stratigraphic juxtapositions across each fault zone. Using this stratigraphic and lithologic data, three different algorithms were used to calculate the sealing potential of a theoretical Knox reservoir at each section location. These results indicate a high probability for sealing within the Rough Creek Fault Zone, but a much lower probability for a continuous seal within the LaSalle Anticlinorium.

  16. Prospect evaluation of shallow I-35 reservoir of NE Malay Basin offshore, Terengganu, Malaysia

    Science.gov (United States)

    Janjua, Osama Akhtar; Wahid, Ali; Salim, Ahmed Mohamed Ahmed; Rahman, M. Nasir B. A.

    2016-02-01

    A potential accumulation of hydrocarbon that describes significant and conceivable drilling target is related to prospect. Possibility of success estimation, assuming discovery of hydrocarbons and the potential recoverable quantities range under a commercial development program are the basis of Prospect evaluation activities. The objective was to find the new shallow prospects in reservoir sandstone of I -Formation in Malay basin. The prospects in the study area are mostly consisting of faulted structures and stratigraphic channels. The methodology follows seismic interpretation and mapping, attribute analysis, evaluation of nearby well data i.e., based on well - log correlation. The petrophysical parameters analogue to nearby wells was used as an input parameter for volumetric assessment. Based on analysis of presence and effectiveness, the prospect has a complete petroleum system. Two wells have been proposed to be drilled near the major fault and stratigraphic channel in I-35 reservoir that is O-1 and O-2 prospects respectively. The probability of geological success of prospect O-1 is at 35% while for O-2 is 24%. Finally, for hydrocarbon in place volumes were calculated which concluded the best estimate volume for oil in O-1 prospect is 4.99 MMSTB and O-2 prospect is 28.70 MMSTB while for gas is 29.27 BSCF and 25.59 BSCF respectively.

  17. SWOT data assimilation for operational reservoir management on the upper Niger River Basin

    Science.gov (United States)

    Munier, S.; Polebistki, A.; Brown, C.; Belaud, G.; Lettenmaier, D. P.

    2015-01-01

    The future Surface Water and Ocean Topography (SWOT) satellite mission will provide two-dimensional maps of water elevation for rivers with width greater than 100 m globally. We describe a modeling framework and an automatic control algorithm that prescribe optimal releases from the Selingue dam in the Upper Niger River Basin, with the objective of understanding how SWOT data might be used to the benefit of operational water management. The modeling framework was used in a twin experiment to simulate the "true" system state and an ensemble of corrupted model states. Virtual SWOT observations of reservoir and river levels were assimilated into the model with a repeat cycle of 21 days. The updated state was used to initialize a Model Predictive Control (MPC) algorithm that computed the optimal reservoir release that meets a minimum flow requirement 300 km downstream of the dam. The data assimilation results indicate that the model updates had a positive effect on estimates of both water level and discharge. The "persistence," which describes the duration of the assimilation effect, was clearly improved (greater than 21 days) by integrating a smoother into the assimilation procedure. We compared performances of the MPC with SWOT data assimilation to an open-loop MPC simulation. Results show that the data assimilation resulted in substantial improvements in the performances of the Selingue dam management with a greater ability to meet environmental requirements (the number of days the target is missed falls to zero) and a minimum volume of water released from the dam.

  18. Quantifying quagga mussel veliger abundance and distribution in Copper Basin Reservoir (California) using acoustic backscatter.

    Science.gov (United States)

    Anderson, Michael A; Taylor, William D

    2011-11-01

    Quagga mussels (Dreissena bugensis) have been linked to oligotrophication of lakes, alteration of aquatic food webs, and fouling of infrastructure associated with water supply and power generation, causing potentially billions of dollars in direct and indirect damages. Understanding their abundance and distribution is key in slowing their advance, assessing their potential impacts, and evaluating effectiveness of control strategies. Volume backscatter strength (Sv) measurements at 201- and 430-kHz were compared with quagga mussel veliger and zooplankton abundances determined from samples collected using a Wisconsin closing net from the Copper Basin Reservoir on the Colorado River Aqueduct. The plankton within the lower portion of the water column (>18 m depth) was strongly dominated by D-shaped quagga mussel veligers, comprising up to 95-99% of the community, and allowed direct empirical measurement of their mean backscattering cross-section. The upper 0-18 m of the water column contained a smaller relative proportion of veligers based upon net sampling. The difference in mean volume backscatter strength at these two frequencies was found to decrease with decreasing zooplankton abundance (r(2) = 0.94), allowing for correction of Sv due to the contribution of zooplankton and the determination of veliger abundance in the reservoir. Hydroacoustic measurements revealed veligers were often present at high abundances (up to 100-200 ind L(-1)) in a thin 1-2 m layer at the thermocline, with considerable patchiness in their distribution observed along a 700 m transect on the reservoir. Under suitable conditions, hydroacoustic measurements can rapidly provide detailed information on the abundance and distribution of quagga mussel veligers over large areas with high horizontal and vertical resolution. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Tectonic characteristics and distribution of Putaohua oil Reservoir in Changchang area of Songliao basin

    Science.gov (United States)

    Chang, Yan; Liu, Dameng

    2018-01-01

    Since the Late Jurassic in the Songliao Basin, the tectonic movement of Yanshan and Heshan has experienced a lot of tectonic movement. The tectonic activity has a clearer display on the seismic profile. The tectonic deformation is generally weak in the east, Features. The regional structure of the Chaochang area is located on the Chaoyangou terrace and Changchunling anticline belt in the central depression of the northern part of the Songliao Basin, and across the two tectonic units of the Chaoyanggou terrace and Changchunling anticline. The study area is characterized by a low tectonic pattern in the southwest and northwest. The highest point is located near the Chang72 well in the Changchunling anticline. The elevation is about -100 m, and the lowest point is the Zhou50 Well near the depth of about - 1750 m. Based on the technical means such as splicing, closed difference correction, horizon calibration, seismic interpretation and attribute extraction of 9 seismic blocks in the study area, the seismic interpretation of the top of the Putaohua reservoir is completed, and the next step Style, tectonic evolution characteristics, oil and gas accumulation law and other research work to lay the foundation.

  20. OIL RESERVOIR CHARACTERIZATION AND CO2 INJECTION MONITORING IN THE PERMIAN BASIN WITH CROSSWELL ELECTROMAGNETIC IMAGING

    Energy Technology Data Exchange (ETDEWEB)

    Michael Wilt

    2004-02-01

    Substantial petroleum reserves exist in US oil fields that cannot be produced economically, at current prices, unless improvements in technology are forthcoming. Recovery of these reserves is vital to US economic and security interests as it lessens our dependence on foreign sources and keeps our domestic petroleum industry vital. Several new technologies have emerged that may improve the situation. The first is a series of new flooding techniques to re-pressurize reservoirs and improve the recovery. Of these the most promising is miscible CO{sub 2} flooding, which has been used in several US petroleum basins. The second is the emergence of new monitoring technologies to track and help manage this injection. One of the major players in here is crosswell electromagnetics, which has a proven sensitivity to reservoir fluids. In this project, we are applying the crosswell EM technology to a CO{sub 2} flood in the Permian Basin oil fields of New Mexico. With our partner ChevronTexaco, we are testing the suitability of using EM for tracking the flow of injected CO{sub 2} through the San Andreas reservoir in the Vacuum field in New Mexico. The project consisted of three phases, the first of which was a preliminary field test at Vacuum, where a prototype system was tested in oil field conditions including widely spaced wells with steel casing. The results, although useful, demonstrated that the older technology was not suitable for practical deployment. In the second phase of the project, we developed a much more powerful and robust field system capable of collecting and interpreting field data through steel-cased wells. The final phase of the project involved applying this system in field tests in the US and overseas. Results for tests in steam and water floods showed remarkable capability to image between steel wells and provided images that helped understand the geology and ongoing flood and helped better manage the field. The future of this technology is indeed bright

  1. Nutrient dynamics in five off-stream reservoirs in the lower South Platte River basin, March-September 1995

    Science.gov (United States)

    Sprague, Lori A.

    2002-01-01

    In 1995, the U.S. Geological Survey conducted a study to characterize nutrient concentrations in five off-stream reservoirs in the lower South Platte River Basin?Riverside, Jackson, Prewitt, North Sterling, and Julesburg. These reservoirs are critical sources of irrigation water for agricultural areas, and several also are used for fishing, boating, swimming, hunting, and camping. Data collected for this study include depth profiles of water temperature, dissolved oxygen, pH, and specific conductance; nutrient species concentrations in the water column, bottom sediment, and inflow and outflow canals; and chlorophyll-a concentrations in the water column. Data were collected during the irrigation season from March through September 1995 at five sites each in Riverside, Jackson, Prewitt, and Julesburg Reservoirs and at six sites in North Sterling Reservoir. The five reservoirs studied are located in similar geographic, climatic, and land-use areas and, as a result, have a number of similarities in their internal nutrient dynamics. Nitrogen concentrations in the reservoirs were highest in March and decreased through September as a result of dilution from river inflows and biological activity. From March through June, decreases in nitrogen concentrations in the river and biological activity contributed to decreases in reservoir concentrations. From July through September, inflows from the river were cut off, and biological activity in the reservoirs led to further decreases in nitrate concentrations, which fell to near or below detectable levels. Phosphorus concentrations in the reservoirs did not show the same consistent decrease from March through September. Phosphorus likely was recycled continuously back to algae during the study period through processes such as excretion from fish, decay of aquatic plants and animals, and release of orthophosphate from bottom sediment during periods of low oxygen. With the exception of phosphorus in Jackson Reservoir, the

  2. Multi-scale reservoir modeling as an integrated assessment tool for geo-sequestration in the San Juan Basin

    Science.gov (United States)

    Young, G.; Haerer, D.; Bromhal, G.; Reeves, S.

    2007-01-01

    The Southwestern Regional Partnership on CO2 Sequestration conducted an Enhanced Coalbed Methane (ECBM)/Carbon Storage Pilot in the San Juan Basin as part of the ongoing DOE/NETL Carbon Capture and Storage Program. The primary goal of this pilot is to demonstrate the efficacy of using CO2 to enhance coalbed methane recovery particularly near reservoir abandonment pressure while also evaluating the suitability of coal seams for longer-term carbon storage. Basic geologic models of the coal seams were developed from well logs in the area. Production histories from several surrounding CBM wells were shown. To monitor the injection of up to 75,000 ton of CO2 beginning September 2007, seismic surveys and tiltmeter arrays were utilized. Larger-scale geo-hydrodynamic simulations were used to develop a regional model for the fluid dynamics of the northern San Juan Basin. Smaller-scale reservoir simulations, incorporating available laboratory and field data, were used to develop an improved understanding of reservoir dynamics within the specific 640-acre pilot area. Both modeling scales were critical to assessing the suitability of deploying commercial carbon storage programs throughout the basin. Reservoir characterization results on the optimization of total CO2 injection volume, injection rate over time, and how CO2 is expected to disperse after injection are presented. This is an abstract of a paper presented at the 2007 AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).

  3. Innovation-driven efficient development of the Longwangmiao Fm large-scale sulfur gas reservoir in Moxi block, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Xinhua Ma

    2016-03-01

    Full Text Available The Lower Cambrian Longwangmiao Fm gas reservoir in Moxi block of the Anyue Gas field, Sichuan Basin, is the largest single-sandbody integrated carbonate gas reservoir proved so far in China. Notwithstanding this reservoir's advantages like large-scale reserves and high single-well productivity, there are multiple complicated factors restricting its efficient development, such as a median content of hydrogen sulfide, low porosity and strong heterogeneity of fracture–cave formation, various modes of gas–water occurrences, and close relation between overpressure and stress sensitivity. Up till now, since only a few Cambrian large-scale carbonate gas reservoirs have ever been developed in the world, there still exists some blind spots especially about its exploration and production rules. Besides, as for large-scale sulfur gas reservoirs, the exploration and construction is costly, and production test in the early evaluation stage is severely limited, all of which will bring about great challenges in productivity construction and high potential risks. In this regard, combining with Chinese strategic demand of strengthening clean energy supply security, the PetroChina Southwest Oil & Gas Field Company has carried out researches and field tests for the purpose of providing high-production wells, optimizing development design, rapidly constructing high-quality productivity and upgrading HSE security in the Longwangmiao Fm gas reservoir in Moxi block. Through the innovations of technology and management mode within 3 years, this gas reservoir has been built into a modern large-scale gas field with high quality, high efficiency and high benefit, and its annual capacity is now up to over 100 × 108 m3, with a desirable production capacity and development indexes gained as originally anticipated. It has become a new model of large-scale gas reservoirs with efficient development, providing a reference for other types of gas reservoirs in China.

  4. Metal and trace element sediment assessment from Guarapiranga reservoir, Alto Tiete Basin, Sao Paulo, SP, Brazil

    International Nuclear Information System (INIS)

    Guimaraes, Guilherme Moura

    2011-01-01

    The Guarapiranga Reservoir, located in Sao Paulo metropolitan region, Brazil, is responsible for supplying about 20% of the entire population's water needs of this region or approximately 3.7 million people. However, this system has shown significant degradation in water quality, due to untreated domestic sewage and industrial effluents. In this study sediment samples were collected at five points along the reservoir and total concentration of some major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Hg, Rb, Sb, Sc, Ta, Tb, Th, U, V and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) elements were determined by instrumental neutron activation analysis (INAA). By inductively coupled plasma optical emission spectrometry (ICP OES) the concentrations of Al, Ba, Be, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Ti, V e Zn were determined after digestion procedure following US EPA 3051 methodology. The concentrations of metals Cd and Pb were determined by graphite furnace atomic absorption spectrometry (GFAAS) and total Hg by cold vapor atomic absorption spectrometry (CVAAS). Methodology validation according to precision and accuracy was performed by reference materials analyses for the three different analytical techniques used. Multielemental results obtained by INAA were compared to NASC (North American Shale Composite), Upper Continental Crust (UCC) and soil from Guarapiranga park values. The Enrichment Factor (EF) and Geo accumulation Index (Igeo) were also evaluated for these data. Metal concentration results by ICP OES and AAS in the samples were compared to the TEL and PEL oriented values established by the Canadian Council of Ministers of the Environment and also adopted by CETESB (Environmental Protection Agency of the Sao Paulo State). The results were also compared to regional reference values (VRR) of limnic sediments from the Alto Tiete Basin. From these data an assessment of metal and trace element accumulated in the sediments from the

  5. Key seismic exploration technology for the Longwangmiao Fm gas reservoir in Gaoshiti–Moxi area, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Guangrong Zhang

    2016-10-01

    Full Text Available The dolomite reservoirs of the Lower Cambrian Longwangmiao Fm in the Gaoshiti–Moxi area, Sichuan Basin, are deeply buried (generally 4400–4900 m, with high heterogeneity, making reservoir prediction difficult. In this regard, key seismic exploration technologies were developed through researches. Firstly, through in-depth analysis on the existing geologic, drilling, seismic data and available research findings, basic surface and subsurface structures and geologic conditions within the study area were clarified. Secondly, digital seismic data acquisition technologies with wide azimuth, wide frequency band and minor bins were adopted to ensure even distribution of coverage of target formations through optimization of the 3D seismic geometry. In this way, high-accuracy 3D seismic data can be acquired through shallow, middle and deep formations. Thirdly, well-control seismic data processing technologies were applied to enhance the signal-to-noise ratio (SNR of seismic data for deep formations. Fourthly, a seismic response model was established specifically for the Longwangmiao Fm reservoir. Quantitative prediction of the reservoir was performed through pre-stack geo-statistics. In this way, plan distribution of reservoir thicknesses was mapped. Fifthly, core tests and logging data analysis were conducted to determine gas-sensitive elastic parameters, which were then used in pre-stack hydrocarbon detection to eliminate the multiple solutions in seismic data interpretation. It is concluded that application of the above-mentioned key technologies effectively promote the discovery of largescale marine carbonate gas reservoirs of the Longwangmiao Fm.

  6. Drought propagation in the Paraná Basin, Brazil: from rainfall deficits to impacts on reservoir storage

    Science.gov (United States)

    Melo, D. D.; Wendland, E.

    2017-12-01

    The sensibility and resilience of hydrologic systems to climate changes are crucial for estimating potential impacts of droughts, responsible for major economic and human losses globally. Understanding how droughts propagate is a key element to develop a predictive understanding for future management and mitigation strategies. In this context, this study investigated the drought propagation in the Paraná Basin (PB), Southeast Brazil, a major hydroelectricity producing region with 32 % (60 million people) of the country's population. Reservoir storage (RESS), river discharge (Q) and rainfall (P) data were used to assess the linkages between meteorological and hydrological droughts, characterized by the Standard Precipitation Index (SPI) and Streamflow Drought Index (SDI), respectively. The data are from 37 sub-basins within the PB, consisting of contributing areas of 37 reservoirs (250 km3 of stored water) within the PB for the period between 1995 and 2015. The response time (RT) of the hydrologic system to droughts, given as the time lag between P, Q and RESS, was quantified using a non-parametric statistical method that combines cumulative sums and Bootstrap resampling technique. Based on our results, the RTs of the hydrologic system of the PB varies from 0 to 6 months, depending on a number of aspects: lithology, topography, dam operation, etc. Linkages between SPI and SDI indicated that the anthropogenic control (dam operation) plays an important role in buffering drought impacts to downstream sub-basins: SDI decreased from upstream to downstream despite similar SPI values over the whole area. Comparisons between sub-basins, with variable drainage sizes (5,000 - 50,000 km2), confirmed the benefice of upstream reservoirs in reducing hydrological droughts. For example, the RT for a 4,800 km2 basin was 6 months between P and Q and 9 months between Q and RESS, under anthropogenic control. Conversely, the RT to precipitation for a reservoir subjected to natural

  7. Fault assessment for basement reservoir compartmentalization: Case study at Northeast Betara gas field, South Sumatra Basin

    Science.gov (United States)

    Risyad, M.; Suta, I. N.; Haris, A.

    2017-07-01

    Northeast Betara field is situated on the northern part of prolific South Sumatra Basin. It has produced gas from Lower Talang Akar Formation sandstone and over 90 wells have been drilled. A 3D seismic data was acquired in 2000 and reprocessed in 2012 to enhance the subsurface image. In 2013 an exploratory well NEB Base-1 was drilled and made gas and condensate discovery from the subsequent pre-tertiary basement which is confirmed as granite. The well proved fractured basement reservoir play on paleo high of the structure. The absence of full-diameter conventional core prompts well logs and seismic data analysis by using a workstation. Main methods for fracture prediction have been seismic attributes extraction and structural geology studies of basement provided by image logs on a few exploration wells. Ant tracking attribute is widely employed to image seismic event discontinuities due to extensive faults which generated the natural fractures. Delineations well NEB Base-2 was drilled on second paleo high and unfortunately, it did not find any gas indication from pre-tertiary basement target. Seismic structural interpretation and seismic attributes are conducted to image distribution of event discontinuities related to faults or fracture. We found that compartmentalization on basement involved old faults and both paleo high have undergone different structural history and stress character which resulted in separated fractures distribution.

  8. Spatio-Temporal Variations and Source Apportionment of Water Pollution in Danjiangkou Reservoir Basin, Central China

    Directory of Open Access Journals (Sweden)

    Pan Chen

    2015-05-01

    Full Text Available Understanding the spatio-temporal variation and the potential source of water pollution could greatly improve our knowledge of human impacts on the environment. In this work, data of 11 water quality indices were collected during 2012–2014 at 10 monitoring sites in the mainstream and major tributaries of the Danjiangkou Reservoir Basin, Central China. The fuzzy comprehensive assessment (FCA, the cluster analysis (CA and the discriminant analysis (DA were used to assess the water pollution status and analyze its spatio-temporal variation. Ten sites were classified by the high pollution (HP region and the low pollution (LP region, while 12 months were divided into the wet season and the dry season. It was found that the HP region was mainly in the small tributaries with small drainage areas and low average annual discharges, and it was also found that most of these rivers went through urban areas with industrial and domestic sewages input into the water body. Principal component analysis/factor analysis (PCA/FA was applied to reveal potential pollution sources, whereas absolute principal component score-multiple linear regression (APCS-MLR was used to identify their contributions to each water quality variable. The study area was found as being generally affected by industrial and domestic sewage. Furthermore, the HP region was polluted by chemical industries, and the LP region was influenced by agricultural and livestock sewage.

  9. Palaeofluid evolution in a fractured basalt hosted reservoir in the Ulles-Ruzsa-Bordany area, southern sector of the Pannonian Basin

    Czech Academy of Sciences Publication Activity Database

    Szabó, B.; Schubert, F.; Toth, T.M.; Steinbach, Gabor

    2016-01-01

    Roč. 69, č. 3 (2016), s. 281-293 ISSN 1330-030X Institutional support: RVO:61388971 Keywords : fractured basalt reservoir * Pannonian Basin * zeolite minerals Subject RIV: EE - Microbiology, Virology Impact factor: 0.595, year: 2016

  10. APPLICATION OF WELL LOG ANALYSIS IN ASSESSMENT OF PETROPHYSICAL PARAMETERS AND RESERVOIR CHARACTERIZATION OF WELLS IN THE “OTH” FIELD, ANAMBRA BASIN, SOUTHERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Eugene URORO

    2014-12-01

    Full Text Available Over the past years, the Anambra basin one of Nigeria’s inland basins has recorded significant level of hydrocarbon exploration activities. The basin has been confirmed by several authors from source rock analyses to have the potential for generating hydrocarbon. For the hydrocarbon to be exploited, it is imperative to have a thorough understanding of the reservoir. Computer-assisted log analyses were employed to effectively evaluate the petrophysical parameters such as the shale volume (Vsh, total porosity (TP, effective porosity (EP, water saturation (Sw, and hydrocarbon saturation (Sh. Cross-plots of the petrophysical parameters versus depth were illustrated. Five hydrocarbon bearing reservoirs were delineated in well 1, four in well 2. The reservoirs in well 3 do not contain hydrocarbon. The estimated reservoir porosity varies from 10% to 21% while their permeability values range from 20md to 1400md. The porosity and permeability values suggest that reservoirs are good enough to store and also permit free flow of fluid. The volume of shale (0.05% to 0.35% analysis reveals that the reservoirs range from shaly sand to slightly shaly sand to clean sand reservoir. On the basis of petrophysics data, the reservoirs are interpreted a good quality reservoir rocks which has been confirmed with high effective porosity range between 20% and high hydrocarbon saturation exceeding 55% water saturation in well 1 and well 2. Water saturation 3 is nearly 100% although the reservoir properties are good.  

  11. Unconformity structures controlling stratigraphic reservoirs in the north-west margin of Junggar basin, North-west China

    Science.gov (United States)

    Wu, Kongyou; Paton, Douglas; Zha, Ming

    2013-03-01

    Tectonic movements formed several unconformities in the north-west margin of the Junggar basin. Based on data of outcrop, core, and samples, the unconformity is a structural body whose formation associates with weathering, leaching, and onlap. At the same time, the structural body may be divided into three layers, including upper layer, mid layer, and lower layer. The upper layer with good primary porosity serves as the hydrocarbon migration system, and also accumulates the hydrocarbon. The mid layer with compactness and ductility can play a role as cap rock, the strength of which increases with depth. The lower layer with good secondary porosity due to weathering and leaching can form the stratigraphic truncation traps. A typical stratigraphic reservoir lying in the unconformity between the Jurassic and Triassic in the north-west margin of the Junggar basin was meticulously analyzed in order to reveal the key controlling factors. The results showed that the hydrocarbon distribution in the stratigraphic onlap reservoirs was controlled by the onlap line, the hydrocarbon distribution in the stratigraphic truncation reservoirs was confined by the truncation line, and the mid layer acted as the key sealing rock. So a conclusion was drawn that "two lines (onlap line and truncation line) and a body (unconformity structural body)" control the formation and distribution of stratigraphic reservoirs.

  12. Petrophysical Analysis and Geographic Information System for San Juan Basin Tight Gas Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Martha Cather; Robert Lee; Robert Balch; Tom Engler; Roger Ruan; Shaojie Ma

    2008-10-01

    The primary goal of this project is to increase the availability and ease of access to critical data on the Mesaverde and Dakota tight gas reservoirs of the San Juan Basin. Secondary goals include tuning well log interpretations through integration of core, water chemistry and production analysis data to help identify bypassed pay zones; increased knowledge of permeability ratios and how they affect well drainage and thus infill drilling plans; improved time-depth correlations through regional mapping of sonic logs; and improved understanding of the variability of formation waters within the basin through spatial analysis of water chemistry data. The project will collect, integrate, and analyze a variety of petrophysical and well data concerning the Mesaverde and Dakota reservoirs of the San Juan Basin, with particular emphasis on data available in the areas defined as tight gas areas for purpose of FERC. A relational, geo-referenced database (a geographic information system, or GIS) will be created to archive this data. The information will be analyzed using neural networks, kriging, and other statistical interpolation/extrapolation techniques to fine-tune regional well log interpretations, improve pay zone recognition from old logs or cased-hole logs, determine permeability ratios, and also to analyze water chemistries and compatibilities within the study area. This single-phase project will be accomplished through four major tasks: Data Collection, Data Integration, Data Analysis, and User Interface Design. Data will be extracted from existing databases as well as paper records, then cleaned and integrated into a single GIS database. Once the data warehouse is built, several methods of data analysis will be used both to improve pay zone recognition in single wells, and to extrapolate a variety of petrophysical properties on a regional basis. A user interface will provide tools to make the data and results of the study accessible and useful. The final deliverable

  13. Scoping Summary Report: Development of Lower Basin Shortage Guidelines and Coordinated Management Strategies for Lake Powell and Lake Mead, Particularly Under Low Reservoir Conditions

    OpenAIRE

    U.S. Department of the Interior, Bureau of Reclamation

    2006-01-01

    The Bureau of Reclamation (Reclamation) acting on behalf of the Secretary of the Department of the Interior (Secretary) proposes to take action to adopt specific Colorado River Lower Basin shortage guidelines and coordinated reservoir management strategies to address operations of Lake Powell and Lake Mead, particularly under low reservoir conditions. This proposed Action will provide a greater degree of certainty to all water users and managers in the Colorado River Basin by providing more d...

  14. Hydrologic modeling in a small mediterranean basin as a tool to assess the feasibility of a limno-reservoir.

    Science.gov (United States)

    Molina-Navarro, Eugenio; Martínez-Pérez, Silvia; Sastre-Merlín, Antonio; Bienes-Allas, Ramón

    2014-01-01

    The SWAT model was applied to the Ompólveda River Basin (Guadalajara, central Spain) to assess the hydrological feasibility of the Pareja Limno-reservoir. A limno-reservoir is a water management infrastructure designed to counteract some negative impacts caused by large reservoirs under Mediterranean climate. Highly detailed inputs were selected to set up the model. Its performance was evaluated by graphical and statistical techniques and compared with the previous knowledge of the basin. An overall good performance was obtained during the calibration and validation periods (monthly and annual NSE values of 0.67 and 0.60, respectively, for calibration and 0.70 and 0.83, respectively, for validation). Total discharge was well simulated, and flow components prediction was acceptable. However, the model is not accurate at predicting evapotranspiration. Once evaluated, the model was used to simulate the water discharge into the Pareja Limno-reservoir during 2008 and 2009, establishing a water balance and assessing its hydrologic feasibility. The water balance predicted the absence of surplus during summer (2008 and 2009) and autumn (2009), matching up with the decrease of water level and demonstrating the usefulness of SWAT as a tool to evaluate the hydrologic feasibility of the Pareja Limno-reservoir. Very low discharges from the Ompólveda River after a sequence of normal and dry years are the main factors responsible of this phenomenon, whereas the effect of the wastewater flow redirection in the Pareja village is negligible. These results question the usefulness of the Pareja Limno-reservoir during summer, the most favorable season for recreational activities. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Genesis Analysis of High-Gamma Ray Sandstone Reservoir and Its Log Evaluation Techniques: A Case Study from the Junggar Basin, Northwest China

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2013-01-01

    Full Text Available In the Junggar basin, northwest China, many high gamma-ray (GR sandstone reservoirs are found and routinely interpreted as mudstone non-reservoirs, with negative implications for the exploration and exploitation of oil and gas. Then, the high GR sandstone reservoirs’ recognition principles, genesis, and log evaluation techniques are systematically studied. Studies show that the sandstone reservoirs with apparent shale content greater than 50% and GR value higher than 110API can be regarded as high GR sandstone reservoir. The high GR sandstone reservoir is mainly and directly caused by abnormally high uranium enrichment, but not the tuff, feldspar or clay mineral. Affected by formation’s high water sensitivity and poor borehole quality, the conventional logs can not recognize reservoir and evaluate the physical property of reservoirs. Then, the nuclear magnetic resonance (NMR logs is proposed and proved to be useful in reservoir recognition and physical property evaluation.

  16. The formation of giant clastic extrusions at the end of the Messinian Salinity Crisis

    Science.gov (United States)

    Kirkham, Christopher; Cartwright, Joe; Hermanrud, Christian; Jebsen, Christopher

    2018-01-01

    This paper documents the discovery of five multi-km scale lensoid bodies that directly overlie the upper surface of the thick (>1 km) Messinian Evaporite sequence. They were identified through the analysis of 3D seismic data from the western Nile Cone. The convergence of the upper and lower bounding reflections of these lensoid bodies, their external and internal reflection configuration, the positive 'depositional' relief at their upper surface, and the stratal relationship with underlying and overlying deposits supports the interpretation that these are giant clastic extrusions. The interpretations combined with the stratal position of these clastic extrusions demonstrate a prior unsuspected link between periods of major environment change and basin hydrodynamics on a plate scale. All five lensoid bodies were extruded onto a single, seismically resolvable marker horizon correlatable with the end of the Messinian Salinity Crisis (Horizon M). It is argued that the source of these clastic extrusions is pre-Messinian in origin, which implies massive sediment remobilisation at depth in the pre-evaporitic succession and intrusion through the thick evaporite layer. We propose that the scale and timing of this dramatic event was primed and triggered by near-lithostatic overpressure in the pre-evaporitic sediments generated through (1) their rapid burial and loading during the Messinian Salinity Crisis and (2) catastrophic re-flooding during its immediate aftermath. The largest of these clastic extrusions has a volume of over c. 116 km3, making it amongst the largest extruded sedimentary bodies described on Earth. The findings extend the understanding of the upper scale of other analogous clastic extrusions such as mud volcanoes and sediment-hosted hydrothermal systems. Following the 2006 eruption of the Lusi sediment-hosted hydrothermal system in Indonesia, an understanding of the upper scale limit of clastic extrusions has even greater societal relevance, in order to

  17. Lacustrine Environment Reservoir Properties on Sandstone Minerals and Hydrocarbon Content: A Case Study on Doba Basin, Southern Chad

    Science.gov (United States)

    Sumery, N. F. Mohd; Lo, S. Z.; Salim, A. M. A.

    2017-10-01

    The contribution of lacustrine environment as the hydrocarbon reservoir has been widely known. However, despite its growing importance, the lacustrine petroleum geology has received far less attention than marine due to its sedimentological complexity. This study therefore aims in developing an understanding of the unique aspects of lacustrine reservoirs which eventually impacts the future exploration decisions. Hydrocarbon production in Doba Basin, particularly the northern boundary, for instance, has not yet succeeded due to the unawareness of its depositional environment. The drilling results show that the problems were due to the: radioactive sand and waxy oil/formation damage, which all are related to the lacustrine depositional environment. Detailed study of geological and petrophysical integration on wireline logs and petrographic thin sections analysis of this environment helps in distinguishing reservoir and non-reservoir areas and determining the possible mechanism causing the failed DST results. The interpretations show that the correlation of all types> of logs and rho matrix analysis are capable in identifying sand and shale bed despite of the radioactive sand present. The failure of DST results were due to the presence of arkose in sand and waxy oil in reservoir bed. This had been confirmed by the petrographic thin section analysis where the arkose has mineral twinning effect indicate feldspar and waxy oil showing bright colour under fluorescent light. Understanding these special lacustrine environment characteristics and features will lead to a better interpretation of hydrocarbon prospectivity for future exploration.

  18. Play Analysis and Digital Portfolio of Major Oil Reservoirs in the Permian Basin: Application and Transfer of Advanced Geological and Engineering Technologies for Incremental Production Opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; Caroline L. Breton; William D. Raatz; Stephen C. Ruppel; Charles Kerans

    2004-01-13

    A play portfolio is being constructed for the Permian Basin in west Texas and southeast New Mexico, the largest onshore petroleum-producing basin in the United States. Approximately 1,300 reservoirs in the Permian Basin have been identified as having cumulative production greater than 1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of oil through 2000. Of these significant-sized reservoirs, approximately 1,000 are in Texas and 300 in New Mexico. There are 32 geologic plays that have been defined for Permian Basin oil reservoirs, and each of the 1,300 major reservoirs was assigned to a play. The reservoirs were mapped and compiled in a Geographic Information System (GIS) by play. The final reservoir shapefile for each play contains the geographic location of each reservoir. Associated reservoir information within the linked data tables includes RRC reservoir number and district (Texas only), official field and reservoir name, year reservoir was discovered, depth to top of the reservoir, production in 2000, and cumulative production through 2000. Some tables also list subplays. Play boundaries were drawn for each play; the boundaries include areas where fields in that play occur but are smaller than 1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of cumulative production. Oil production from the reservoirs in the Permian Basin having cumulative production of >1 MMbbl (1.59 x 10{sup 5} m{sup 3}) was 301.4 MMbbl (4.79 x 10{sup 7} m{sup 3}) in 2000. Cumulative Permian Basin production through 2000 was 28.9 Bbbl (4.59 x 10{sup 9} m{sup 3}). The top four plays in cumulative production are the Northwest Shelf San Andres Platform Carbonate play (3.97 Bbbl [6.31 x 10{sup 8} m{sup 3}]), the Leonard Restricted Platform Carbonate play (3.30 Bbbl [5.25 x 10{sup 8} m{sup 3}]), the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play (2.70 Bbbl [4.29 x 10{sup 8} m{sup 3}]), and the San Andres Platform Carbonate play (2.15 Bbbl [3.42 x 10{sup 8} m{sup 3}]). Detailed studies of three reservoirs

  19. Creating an Erosion Vulnerability Map for the Columbia River Basin to Determine Reservoir Susceptibility to Sedimentation Before and After Wildfires

    Science.gov (United States)

    Ren, J.; Robichaud, P. J. L.; Adam, J. C.

    2017-12-01

    Sedimentation is important issue to most rivers and reservoirs especially in watersheds with extensive agricultural or wildfire activity. These human and natural induced disturbances have the potential to increase runoff-induced erosion and sediment load to rivers; downstream sedimentation can decrease the life expectancy of reservoir and consequently the dam. This is particularly critical in snowmelt-dominant regions because, as rising temperatures reduce snowpack as a natural reservoir, humans will become more reliant on reservoir storage. In the Northwest U.S., the Columbia River Basin (CRB) has more than 60 dams, which were built for irrigation, hydropower, and flood control, all of which are affected by sediment to varying degrees. Determining what dams are most likely to be affected by sedimentation caused by post-fire erosion is important for future management of reservoirs, especially as climate change is anticipated to exacerbate wildfire and its impacts. The objective of this study is to create a sedimentation vulnerability map for reservoirs in the CRB. There are four attributes of a watershed that determine erosion potential; soil type, topography, vegetation (such as forests, shrubs, and grasslands), and precipitation (although precipitation was excluded in this analysis). In this study, a rating system was developed on a scale of 0-90 (with 90 having the greatest erosion potential). The different layers in a Graphical Information System were combined to create an erosion vulnerability map. Results suggest that areas with agriculture have more erosion without a wildfire but that forested areas are most vulnerable to erosion rates following a fire, particularly a high severity fire. Sedimentation in dams is a growing problem that needs to be addressed especially with the likely reduction in snowpack, this vulnerability map will help determine which reservoirs in the CRB are prone to high sedimentation. This information can inform managers where post

  20. INCREASED OIL PRODUCTION AND RESERVES UTILIZING SECONDARY/TERTIARY RECOVERY TECHNIQUES ON SMALL RESERVOIRS IN THE PARADOX BASIN, UTAH

    Energy Technology Data Exchange (ETDEWEB)

    Thomas C. Chidsey, Jr.

    2002-11-01

    The Paradox Basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from shallow-shelf carbonate buildups or mounds within the Desert Creek zone of the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to four wells with primary production ranging from 700,000 to 2,000,000 barrels (111,300-318,000 m{sup 3}) of oil per field at a 15 to 20 percent recovery rate. Five fields in southeastern Utah were evaluated for waterflood or carbon-dioxide (CO{sub 2})-miscible flood projects based upon geological characterization and reservoir modeling. Geological characterization on a local scale focused on reservoir heterogeneity, quality, and lateral continuity as well as possible compartmentalization within each of the five project fields. The Desert Creek zone includes three generalized facies belts: (1) open-marine, (2) shallow-shelf and shelf-margin, and (3) intra-shelf, salinity-restricted facies. These deposits have modern analogs near the coasts of the Bahamas, Florida, and Australia, respectively, and outcrop analogs along the San Juan River of southeastern Utah. The analogs display reservoir heterogeneity, flow barriers and baffles, and lithofacies geometry observed in the fields; thus, these properties were incorporated in the reservoir simulation models. Productive carbonate buildups consist of three types: (1) phylloid algal, (2) coralline algal, and (3) bryozoan. Phylloid-algal buildups have a mound-core interval and a supra-mound interval. Hydrocarbons are stratigraphically trapped in porous and permeable lithotypes within the mound-core intervals of the lower part of the buildups and the more heterogeneous supramound intervals. To adequately represent the observed spatial heterogeneities in reservoir properties, the phylloid-algal bafflestones of the mound-core interval and the dolomites of the overlying supra-mound interval were subdivided into ten architecturally distinct lithotypes, each of which

  1. The tight reservoir microscopic classification of southern part of Qijia area in Songliao Basin

    Science.gov (United States)

    Hang, Fu

    2018-02-01

    With the decreasing of the conventional oil and gas reserves, the unconventional tight oil and gas are gradually becoming the focus of the study. The casting thin section, conventional mercury injection, constant velocity and pressure mercury and other experimental methods, tight reservoir microscopic characteristics in southern part of Qijia area were studied in this paper. Based on the above conditions, combined with the parameters of pore type, pore throat radius, the reservoir is divided into two types, conventional reservoir and low permeability tight reservoir. Reservoir conventional reservoir permeability values are greater than 1mD, low permeability tight reservoirs are classified into IIa type and IIb type, which provides some reference value for the actual exploration and development.

  2. [Surface physicochemical and fractal characteristics of sediments in desilting basin from Yellow River diversion reservoir].

    Science.gov (United States)

    Hu, Kang-Bo; Wang, Yi-Li; Li, Jun-Qing; Gui, Ping; Jiang, Yan-Ling

    2011-07-01

    Surface morphology and pore surface fractal characteristics of the sediment in the desilting basin of Queshan Reservoir were studied. Six sediment samples were collected and particle size, morphology, pore structure and fractal characteristics, surface elements distribution were analyzed as well. The objectives of this study were to investigate the reason for the differences among the pore surface fractal dimensions and fractal scales on the basis of different models, and discuss the effect of surface morphology of these sediment particles on their surface elements distribution. The results showed that these sediment particles with average diameter of 18-83 microm were mainly composed of clay, silt and fine sand. Their complex surface morphology and pore size distribution were reflected by wide range of the BET surface area (8.248-31.60 m2/g), average pore diameter (3.977-7.850 nm) and pore-size distribution (1.870-60.78 nm). Although the pore surface fractal dimensions (D(s)), based on fractal FHH or thermodynamic models, were 2.67-2.89, and their fractal scales generally ranged from several nanometers to tens of nanometers, the differences were still observed in D(s) values calculated from above two models because of inhomogeneity in surface pore size distribution. Therefore, the D(s) based on pore-size distribution were 2.12-2.60, these values close to D(s) calculated from fractal FHH models revealed that pore-size distribution could contribute significantly to D(s) calculation. In addition, the heterogeneous surface adsorption sites of these sediment particles caused by much complex surface morphology had strong influence on the each element distribution on the particle surface.

  3. An Integrated Rock Typing Approach for Unraveling the Reservoir Heterogeneity of Tight Sands in the Whicher Range Field of Perth Basin, Western Australia

    DEFF Research Database (Denmark)

    Ilkhchi, Rahim Kadkhodaie; Rezaee, Reza; Harami, Reza Moussavi

    2014-01-01

    between pore system properties and depositional and diagenetic characteristics in each sand type, reservoir rock types were extracted. The identified reservoir rock types are in fact a reflection of internal reservoir heterogeneity related to pore system properties. All reservoir rock types...... are characterized by a compacted fabric and cemented framework. But distribution and dominance of diagenetic products in each of them depend on primary depositional composition and texture. The results show that reservoir rock typing based on three aspects of reservoir sandstones (depositional properties......Tight gas sands in Whicher Range Field of Perth Basin show large heterogeneity in reservoir characteristics and production behavior related to depositional and diagenetic features. Diagenetic events (compaction and cementation) have severely affected the pore system. In order to investigate...

  4. PLAY ANALYSIS AND DIGITAL PORTFOLIO OF MAJOR OIL RESERVOIRS IN THE PERMIAN BASIN: APPLICATION AND TRANSFER OF ADVANCED GEOLOGICAL AND ENGINEERING TECHNOLOGIES FOR INCREMENTAL PRODUCTION OPPORTUNITIES

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; William Raatz; Cari Breton; Stephen C. Ruppel; Charles Kerans; Mark H. Holtz

    2003-04-01

    A play portfolio is being constructed for the Permian Basin in west Texas and southeast New Mexico, the largest petroleum-producing basin in the US. Approximately 1300 reservoirs in the Permian Basin have been identified as having cumulative production greater than 1 MMbbl of oil through 2000. Of these major reservoirs, approximately 1,000 are in Texas and 300 in New Mexico. On a preliminary basis, 32 geologic plays have been defined for Permian Basin oil reservoirs and assignment of each of the 1300 major reservoirs to a play has begun. The reservoirs are being mapped and compiled in a Geographic Information System (GIS) by play. Detailed studies of three reservoirs are in progress: Kelly-Snyder (SACROC unit) in the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play, Fullerton in the Leonardian Restricted Platform Carbonate play, and Barnhart (Ellenburger) in the Ellenburger Selectively Dolomitized Ramp Carbonate play. For each of these detailed reservoir studies, technologies for further, economically viable exploitation are being investigated.

  5. Hydrocarbon Potential in Sandstone Reservoir Isolated inside Low Permeability Shale Rock (Case Study: Beruk Field, Central Sumatra Basin)

    Science.gov (United States)

    Diria, Shidqi A.; Musu, Junita T.; Hasan, Meutia F.; Permono, Widyo; Anwari, Jakson; Purba, Humbang; Rahmi, Shafa; Sadjati, Ory; Sopandi, Iyep; Ruzi, Fadli

    2018-03-01

    Upper Red Bed, Menggala Formation, Bangko Formation, Bekasap Formation and Duri Formationare considered as the major reservoirs in Central Sumatra Basin (CSB). However, Telisa Formation which is well-known as seal within CSB also has potential as reservoir rock. Field study discovered that lenses and layers which has low to high permeability sandstone enclosed inside low permeability shale of Telisa Formation. This matter is very distinctive and giving a new perspective and information related to the invention of hydrocarbon potential in reservoir sandstone that isolated inside low permeability shale. This study has been conducted by integrating seismic data, well logs, and petrophysical data throughly. Facies and static model are constructed to estimate hydrocarbon potential resource. Facies model shows that Telisa Formation was deposited in deltaic system while the potential reservoir was deposited in distributary mouth bar sandstone but would be discontinued bedding among shale mud-flat. Besides, well log data shows crossover between RHOB and NPHI, indicated that distributary mouth bar sandstone is potentially saturated by hydrocarbon. Target area has permeability ranging from 0.01-1000 mD, whereas porosity varies from 1-30% and water saturation varies from 30-70%. The hydrocarbon resource calculation approximates 36.723 MSTB.

  6. Electrolyte CPA equation of state for very high temperature and pressure reservoir and basin applications

    Science.gov (United States)

    Courtial, Xavier; Ferrando, Nicolas; de Hemptinne, Jean-Charles; Mougin, Pascal

    2014-10-01

    In this work, an electrolyte version of the Cubic Plus Association (eCPA) equation of state has been adapted to systems containing CH4, CO2, H2O and NaCl (up to 5 molal) at pressures up to 200 MPa and temperatures up to 773 K for salt-free systems and 573 K for salt-containing systems. Its purpose is to represent the phase behavior (including salting-out effect and critical point) and the phase densities in a range of temperature and pressure encountered in deep reservoirs and basins. The goal of the parameterization proposed is not to reach a very high accuracy for phase equilibrium and volumetric properties, but rather to develop a semi-predictive approach to model the phase and volumetric behavior of this system while allowing an easy extension to other compounds. Without salt, predictions for pure component vapor pressures and liquid molar volumes present an average absolute deviation (AAD) lower than 3% compared to experimental reference values. The pure component molar volumes out of saturation show an AAD lower than 4%. The highest deviations in densities are observed as expected in the vicinity of the critical coordinates of pure water and this effect increases when gases or salts are added to the system. For each binary system, CH4 + CO2, CH4 + H2O and CO2 + H2O, binary interaction parameters have been fitted to correctly represent the shape of the fluid phase envelopes (including all critical points) in the entire temperature and pressure range considered (219 K to 633 K and up to 250 MPa). The methane concentration in both phases of the CH4 + CO2 binary system is represented with an AAD lower than 9%. The methane solubility in water is represented within 16% and 8% for the methane content of the vapor. The CO2 solubility in water is within 26%, while the CO2 in the vapor phase shows an average deviation of 12%. All molar volumes are represented with an AAD lower than 3%. The few VLE experimental data for the CH4 + CO2 + H2O ternary system are fairly well

  7. Reservoir storage and hydrologic responses to droughts in the Paraná River basin, south-eastern Brazil

    Directory of Open Access Journals (Sweden)

    D. D. C. D. Melo

    2016-11-01

    Full Text Available Droughts are particularly critical for Brazil because of impacts on water supply and because most (70 % of its electricity is derived from hydroelectric generation. The Paraná basin (PB, a major hydroelectric producing region with 32 % (60 million people of Brazil's population, recently experienced the most severe drought since the 1960s, compromising the water supply for 11 million people in São Paulo. The objective of this study is to quantify linkages between meteorological and hydrological droughts based on remote sensing, modelling, and monitoring data using the Paraná River basin in south-eastern Brazil as a case study. Two major meteorological droughts were identified in the early 2000s and 2014, with precipitation 20–50 % below the long-term mean. Total water storage change estimated from the Gravity Recovery and Climate Experiment (GRACE satellites declined by 150 km3 between April 2011 and April 2015. Simulated soil moisture storage declined during the droughts, resulting in decreased runoff into reservoirs. As a result, reservoir storage decreased by 30 % relative to the system's maximum capacity, with negative trends ranging from 17 (May 1997–April 2001 to 25 km3 yr−1 (May 2011–April 2015. Storage in upstream reservoirs is mostly controlled by natural climate forcing, whereas storage in downstream reservoirs also reflects dam operations. This study emphasizes the importance of integrating remote sensing, modelling, and monitoring data to evaluate droughts and to establish a preliminary understanding of the linkages between a meteorological and hydrological drought for future management.

  8. Development of a segmentation method for analysis of Campos basin typical reservoir rocks

    Energy Technology Data Exchange (ETDEWEB)

    Rego, Eneida Arendt; Bueno, Andre Duarte [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Macae, RJ (Brazil). Lab. de Engenharia e Exploracao de Petroleo (LENEP)]. E-mails: eneida@lenep.uenf.br; bueno@lenep.uenf.br

    2008-07-01

    This paper represents a master thesis proposal in Exploration and Reservoir Engineering that have the objective to development a specific segmentation method for digital images of reservoir rocks, which produce better results than the global methods available in the bibliography for the determination of rocks physical properties as porosity and permeability. (author)

  9. Reservoir characterisation using process-response simulations : The Lower Cretaceous Rijn Field, West Netherlands Basin

    NARCIS (Netherlands)

    Alberts, L.J.H.; Geel, C.R.; Klasen, J.J.

    2003-01-01

    Petroleum geologists always need to deal with large gaps in data resolution and coverage during reservoir characterisation. Seismic data shows only large geological structures, whereas small-scale structures and reservoir properties can be observed only at well locations. In the area between wells,

  10. Estimation of small reservoir storage capacities in the São Francisco, Limpopo, Bandama and Volta river basins using remotely sensed surface areas

    Science.gov (United States)

    Rodrigues, Lineu; Senzanje, Aidan; Cecchi, Philippe; Liebe, Jens

    2010-05-01

    People living in areas with highly variable rainfall, experience droughts and floods and often have insecure livelihoods. Small multi-purpose reservoirs (SR) are a widely used form of infrastructures to provide people in such areas with water during the dry season, e.g. in the basins of São Francisco, Brazil, Limpopo, Zimbabwe, Bandama, Ivory Coast and Volta, Ghana. In these areas, the available natural flow in the streams is sometimes less than the flow required for water supply or irrigation, however water can be stored in times of surplus, for example, from a wet season to a dry season. Efficient water management and sound reservoir planning are hindered by the lack of information about the functioning of these reservoirs. Reservoirs in these regions were constructed in a series of projects funded by different agencies, at different times, with little or no coordination among the implementing partners. Poor record keeping and the lack of appropriate institutional support result in deficiencies of information on the capacity, operation, and maintenance of these structures. Estimating the storage capacity of dams is essential to the responsible management of water diversion. Most of SR in these basins have never been evaluated, possibly because the tools currently used for such measurement are labor-intensive, costly and time-consuming. The objective of this research was to develop methodology to estimate small reservoir capacities as a function of their remotely sensed surface areas in the São Francisco, Limpopo, Bandama and Volta basins, as a way to contribute to improve the water resource management in those catchments. Remote sensing was used to identify, localize and characterize small reservoirs. The surface area of each was calculated from satellite images. A sub-set of reservoirs was selected. For each reservoir in the sub-set, the surface area was estimated from field surveys, and storage capacity was estimated using information on reservoir surface

  11. Sediment transport and capacity change in three reservoirs, Lower Susquehanna River Basin, Pennsylvania and Maryland, 1900-2012

    Science.gov (United States)

    Langland, Michael J.

    2015-01-01

    The U.S. Geological Survey (USGS) has conducted numerous sediment transport studies in the Susquehanna River and in particular in three reservoirs in the Lower Susquehanna River Basin to determine sediment transport rates over the past century and to document changes in storage capacity. The Susquehanna River is the largest tributary to Chesapeake Bay and transports about one-half of the total freshwater input and substantial amounts of sediment and nutrients to the bay. The transported loads are affected by deposition in reservoirs (Lake Clarke, Lake Aldred, and Conowingo Reservoir) behind three hydropower dams. The geometry and texture of the deposited sediments in each reservoir upstream from the three dams has been a subject of research in recent decades. Particle size deposition and sediment scouring processes are part of the reservoir dynamics. A Total Maximum Daily Load (TMDL) for nitrogen, phosphorus, and sediment was established for Chesapeake Bay to attain water-quality standards. Six states and the District of Columbia agreed to reduce loads to the bay and to meet load allocation goals for the TMDL. The USGS has been estimating annual sediment loads at the Susquehanna River at Marietta, Pennsylvania (above Lake Clarke), and Susquehanna River at Conowingo, Maryland (below Conowingo Reservoir), since the mid-1980s to predict the mass balance of sediment transport through the reservoir system. Using streamflow and sediment data from the Susquehanna River at Harrisburg, Pennsylvania (upstream from the reservoirs), from 1900 to 1981, sediment loads were greatest in the early to mid-1900s when land disturbance activities from coal production and agriculture were at their peak. Sediment loads declined in the 1950s with the introduction of agricultural soil conservation practices. Loads were dominated by climatic factors in the 1960s (drought) and 1970s (very wet) and have been declining since the 1980s through 2012. The USGS developed a regression equation to

  12. Increased Oil Production and Reserves Utilizing Secondary/Tertiary Recovery Techniques on Small Reservoirs in the Paradox Basin, Utah

    International Nuclear Information System (INIS)

    Chidsey Jr., Thomas C.

    2003-01-01

    The primary objective of this project was to enhance domestic petroleum production by field demonstration and technology transfer of an advanced-oil-recovery technology in the Paradox Basin, southeastern Utah. If this project can demonstrate technical and economic feasibility, the technique can be applied to approximately 100 additional small fields in the Paradox Basin alone, and result in increased recovery of 150 to 200 million barrels (23,850,000-31,800,000 m3) of oil. This project was designed to characterize five shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation and choose the best candidate for a pilot demonstration project for either a waterflood or carbon-dioxide-(CO2-) miscible flood project. The field demonstration, monitoring of field performance, and associated validation activities will take place within the Navajo Nation, San Juan County, Utah

  13. Iodine-129 chronological study of brines from an Ordovician paleokarst reservoir in the Lunnan oilfield, Tarim Basin

    International Nuclear Information System (INIS)

    Chen, Jian; Liu, Dayong; Peng, Ping'an; Ning, Chen; Xiaolin, Hou; Baoshou, Zhang; Zhongyao, Xiao

    2016-01-01

    Previous studies have shown that brines in an Ordovician paleokarst reservoir of the Lunnan oilfield in the Tarim Basin, China, are the product of mixing of paleo-evaporated seawater in the east with paleometeoric waters in the west. In order to put time constraints on the brine and related hydrocarbons in this field, 10 brine samples were collected, for which the iodine concentrations and 129 I/I ratios were measured and discussed. The iodine concentration (3.70–31.2 mg/L) and the 129 I/I ratio (189–897 × 10 −15 ) show that the iodine in the paleoseawater and meteoric water (MW) had different origins and 129 I characteristics. The paleoseawater has a high iodine content (∼31 mg/L), indicating that iodine was introduced into the reservoir along with thermally generated hydrocarbons, possibly in the Cretaceous, from the Caohu Sag in the eastern area. Based on consideration of all possible origins of iodine and 129 I in the brines, it is suggested that the meteoric water maintained its initial iodine content (0.01 mg/L) and 129 I/I ratio (1500 × 10 −15 ), whereas the iodine-enriched paloseawater (IPSW) exhibited a secular 129 I equilibrium (N sq  = 39 atom/μL) as a result of fissiogenic 129 I input in the reservoir over a long period of time. The model of brine evolution developed on that basis confirmed that meteoric water entered the reservoir in the Miocene at about 10 Ma, and partially mixed with the iodine-enriched paleoseawater. The movement of meteoric water was facilitated by faults created during the Himalayan orogeny, then became more dense after dissolving Paleogene halite and infiltrated into the reservoir at high pressure. The iodine and 129 I concentration in the brine contains information about the path and history of the fluid in the reservoir. This may be useful in oil exploration, since the movement of water was, to some extent, related to hydrocarbon migration. - Highlights: • A 129 I chronological study of deep oilfield

  14. An Integrated Rock Typing Approach for Unraveling the Reservoir Heterogeneity of Tight Sands in the Whicher Range Field of Perth Basin, Western Australia

    DEFF Research Database (Denmark)

    Ilkhchi, Rahim Kadkhodaie; Rezaee, Reza; Harami, Reza Moussavi

    2014-01-01

    Tight gas sands in Whicher Range Field of Perth Basin show large heterogeneity in reservoir characteristics and production behavior related to depositional and diagenetic features. Diagenetic events (compaction and cementation) have severely affected the pore system. In order to investigate...... the petrophysical characteristics, reservoir sandstone facies were correlated with core porosity and permeability and their equivalent well log responses to describe hydraulic flow units and electrofacies, respectively. Thus, very tight, tight, and sub-tight sands were differentiated. To reveal the relationship......, diagenetic features and petrophysical characteristics) is a suitable technique for depiction of reservoir heterogeneity, recognition of reservoir units and identifying factors controlling reservoir quality of tight sandstones. This methodology can be used for the other tight reservoirs....

  15. Increased oil production and reserves utilizing secondary/tertiary recovery techniques on small reservoirs in the Paradox basin, Utah. Annual report, February 9, 1996--February 8, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Chidsey, T.C. Jr.

    1997-08-01

    The Paradox basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from carbonate buildups or mounds within the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to four wells with primary production ranging from 700,000 to 2,000,000 barrels of oil per field at a 15 to 20% recovery rate. At least 200 million barrels of oil is at risk of being unrecovered in these small fields because of inefficient recovery practices and undrained heterogeneous reservoirs. Five fields (Anasazi, Mule, Blue Hogan, Heron North, and Runway) within the Navajo Nation of southeastern Utah are being evaluated for waterflood or carbon-dioxide-miscible flood projects based upon geological characterization and reservoir modeling. The results can be applied to other fields in the Paradox basin and the Rocky Mountain region, the Michigan and Illinois basins, and the Midcontinent. The Anasazi field was selected for the initial geostatistical modeling and reservoir simulation. A compositional simulation approach is being used to model primary depletion, waterflood, and CO{sub 2}-flood processes. During this second year of the project, team members performed the following reservoir-engineering analysis of Anasazi field: (1) relative permeability measurements of the supra-mound and mound-core intervals, (2) completion of geologic model development of the Anasazi reservoir units for use in reservoir simulation studies including completion of a series of one-dimensional, carbon dioxide-displacement simulations to analyze the carbon dioxide-displacement mechanism that could operate in the Paradox basin system of reservoirs, and (3) completion of the first phase of the full-field, three-dimensional Anasazi reservoir simulation model, and the start of the history matching and reservoir performance prediction phase of the simulation study.

  16. Lithofacies paleogeography mapping and reservoir prediction in tight sandstone strata: A case study from central Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Yuan Zhong

    2017-09-01

    Full Text Available Sand-rich tight sandstone reservoirs are potential areas for oil and gas exploration. However, the high ratio of sandstone thickness to that of the strata in the formation poses many challenges and uncertainties to traditional lithofacies paleogeography mapping. Therefore, the prediction of reservoir sweet spots has remained problematic in the field of petroleum exploration. This study provides new insight into resolving this problem, based on the analyses of depositional characteristics of a typical modern sand-rich formation in a shallow braided river delta of the central Sichuan Basin, China. The varieties of sand-rich strata in the braided river delta environment include primary braided channels, secondary distributary channels and the distribution of sediments is controlled by the successive superposed strata deposited in paleogeomorphic valleys. The primary distributary channels have stronger hydrodynamic forces with higher proportions of coarse sand deposits than the secondary distributary channels. Therefore, lithofacies paleogeography mapping is controlled by the geomorphology, valley locations, and the migration of channels. We reconstructed the paleogeomorphology and valley systems that existed prior to the deposition of the Xujiahe Formation. Following this, rock-electro identification model for coarse skeletal sand bodies was constructed based on coring data. The results suggest that skeletal sand bodies in primary distributary channels occur mainly in the valleys and low-lying areas, whereas secondary distributary channels and fine deposits generally occur in the highland areas. The thickness distribution of skeletal sand bodies and lithofacies paleogeography map indicate a positive correlation in primary distributary channels and reservoir thickness. A significant correlation exists between different sedimentary facies and petrophysical properties. In addition, the degree of reservoir development in different sedimentary facies

  17. Temporal and basin-specific population trends of quagga mussels on soft sediment of a multi-basin reservoir

    Science.gov (United States)

    Caldwell, Timothy J; Rosen, Michael R.; Chandra, Sudeep; Acharya, Kumud; Caires, Andrea M; Davis, Clinton J.; Thaw, Melissa; Webster, Daniel M.

    2015-01-01

    Invasive quagga (Dreissena bugnesis) and zebra (Dreissena ploymorpha) mussels have rapidly spread throughout North America. Understanding the relationships between environmental variables and quagga mussels during the early stages of invasion will help management strategies and allow researchers to predict patterns of future invasions. Quagga mussels were detected in Lake Mead, NV/AZ in 2007, we monitored early invasion dynamics in 3 basins (Boulder Basin, Las Vegas Bay, Overton Arm) bi-annually from 2008-2011. Mean quagga density increased over time during the first year of monitoring and stabilized for the subsequent two years at the whole-lake scale (8 to 132 individuals·m-2, geometric mean), in Boulder Basin (73 to 875 individuals·m-2), and in Overton Arm(2 to 126 individuals·m-2). In Las Vegas Bay, quagga mussel density was low (9 to 44 individuals·m-2), which was correlated with high sediment metal concentrations and warmer (> 30°C) water temperatures associated with that basin. Carbon content in the sediment increased with depth in Lake Mead and during some sampling periods quagga density was also positively correlated with depth, but more research is required to determine the significance of this interaction. Laboratory growth experiments suggested that food quantity may limit quagga growth in Boulder Basin, indicating an opportunity for population expansion in this basin if primary productivity were to increase, but was not the case in Overton Arm. Overall quagga mussel density in Lake Mead is highly variable and patchy, suggesting that temperature, sediment size, and sediment metal concentrations, and sediment carbon content all contribute to mussel distribution patterns. Quagga mussel density in the soft sediment of Lake Mead expanded during initial colonization, and began to stabilize approximately 3 years after the initial invasion.

  18. Data for "Controls on nitrous oxide production and consumption in reservoirs of the Ohio River Basin"

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dissolved oxygen, dissolved nitrous oxide, and water temperature in reservoirs. This dataset is associated with the following publication: Beaulieu , J., C. Nietch ,...

  19. Effects of a regional décollement level for gravity tectonics on late Neogene-Quaternary deep-sea clastic sedimentation in the Foz do Amazonas Basin, Brazil

    Science.gov (United States)

    Cruz, A. M.; Gorini, C.

    2015-12-01

    Sets of 2D multi-channel seismic and chronostratigraphic data allowed us to undertake analyses of source to sink processes and triggering mechanisms of the gigantic megaslides previously documented off the NW and SE steep slope settings of the Foz do Amazonas basin. These megaslides comprise two sets of stacked allochthonous masses within the Upper Miocene-Quaternary sedimentary record, now described as Mass-Transport Complexes (MTCs): the Amapá Megaslide Complex (AMC) and the Pará-Maranhão Megaslide Complex (PMMC). Individual megaslides of both MTCs can mobilize to deep waters up to kilometer thick sedimentary series as allochthonous masses with different flow directions, degrees of sediment disruption and internal coherence. Megaslides spread downslope over areas as large as thousands of km2, attaining dimensions comparable to the world's largest mass-transport deposits. The basal and largest megaslide of the AMC (AM1 megaslide) is a quite unique example of mass-transport deposit, since it is interpreted as a dominant carbonate allochthonous mass sourced from a mixed carbonate-siliciclastic platform. According to stratigraphic correlations with global sea-level positions, platform instability would have been triggered between the late Miocene and the end of the Early Pliocene by gravitational collapse of the mixed platform under its own weight, after successive subaerial exposures which were able to generate karstification processes. Siliciclastic-type megaslides, on the other hand, are all sourced from large upslope slide and/or rotated blocks (up to 60 km large in the case of the PMMC).Stratigraphic correlations evidenced that horizon equally acts as the upper décollement level for the gravity tectonic system that operates in the regional scale of the Foz do Amazonas basin. In such a context, results of this work evidence complex links between variable modes of gravity deformation (gravity tectonics and mass wasting), all induced by instability created from

  20. Geochemical characteristics of crude oil from a tight oil reservoir in the Lucaogou Formation, Jimusar Sag, Junggar Basin

    Science.gov (United States)

    Cao, Z.

    2015-12-01

    Jimusar Sag, which lies in the Junggar Basin,is one of the most typical tight oil study areas in China. However, the properties and origin of the crude oil and the geochemical characteristics of the tight oil from the Lucaogou Formation have not yet been studied. In the present study, 23 crude oilsfrom the Lucaogou Formation were collected for analysis, such as physical properties, bulk composition, saturated hydrocarbon gas chromatography-mass spectrometry (GC-MS), and the calculation of various biomarker parameters. In addition,source rock evaluation and porosity permeability analysis were applied to the mudstones and siltstones. Biomarkers of suitable source rocks (TOC>1, S1+S2>6mg/g, 0.7%basin modeling was performed. The oil-filling history was also defined by means of basin modeling and microthermometry. The results indicated the presence of low maturity to mature crude oils originating from the burial of terrigenous organic matter beneath a saline lake in the source rocks of mainly type II1kerogen. In addition, a higher proportion of bacteria and algae was shown to contribute to the formation of crude oil in the lower section when compared with the upper section of the Lucaogou Formation. Oil-source correlations demonstrated that not all mudstones within the Lucaogou Formation contributed to oil accumulation.Crude oil from the upper and lower sections originated from thin-bedded mudstones interbedded within sweet spot sand bodies. A good coincidence of filling history and hydrocarbon generation history indicated that the Lucaogou reservoir is a typical in situ reservoir. The mudstones over or beneath the sweet spot bodies consisted of natural caprocks and prevented the vertical movement of oil by capillary forces. Despite being thicker, the thick-bedded mudstone between the upper and lower sweet spots had no obvious contribution to

  1. Liquid-Rich Shale Potential of Utah’s Uinta and Paradox Basins: Reservoir Characterization and Development Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Vanden Berg, Michael [Utah Geological Survey, Salt Lake City, UT (United States); Morgan, Craig [Utah Geological Survey, Salt Lake City, UT (United States); Chidsey, Thomas [Utah Geological Survey, Salt Lake City, UT (United States); McLennan, John [Univ. of Utah, Salt Lake City, UT (United States). Energy & Geoscience Inst.; Eby, David [Eby Petrography & Consulting, Littleton, CO (United States); Machel, Hans [Univ. of Alberta, Edmonton, AB (Canada); Schamel, Steve [GeoX Consulting, Salt Lake City, UT (United States); Birdwell, Justin [U.S. Geological Survey, Boulder, CO (United States); Johnson, Ron [U.S. Geological Survey, Boulder, CO (United States); Sarg, Rick [Colorado School of Mines, Golden, CO (United States)

    2017-08-31

    The enclosed report is the culmination of a multi-year and multi-faceted research project investigating Utah’s unconventional tight oil potential. From the beginning, the project team focused efforts on two different plays: (1) the basal Green River Formation’s (GRF) Uteland Butte unconventional play in the Uinta Basin and (2) the more established but understudied Cane Creek shale play in the Paradox Basin. The 2009-2014 high price of crude oil, coupled with lower natural gas prices, generated renewed interest in exploration and development of liquid hydrocarbon reserves. Following the success of the mid-2000s shale gas boom and employing many of the same well completion techniques, petroleum companies started exploring for liquid petroleum in shale formations. In fact, many shales targeted for natural gas include areas in which the shale is more prone to liquid production. In Utah, organic-rich shales in the Uinta and Paradox Basins have been the source of significant hydrocarbon generation, with companies traditionally targeting the interbedded sands or carbonates for their conventional resource recovery. Because of the advances in horizontal drilling and hydraulic fracturing techniques, operators in these basins started to explore the petroleum production potential of the shale units themselves. The GRF in the Uinta Basin has been studied for over 50 years, since the first hydrocarbon discoveries. However, those studies focused on the many conventional sandstone reservoirs currently producing oil and gas. In contrast, less information was available about the more unconventional crude oil production potential of thinner carbonate/shale units, most notably the basal Uteland Butte member. The Cane Creek shale of the Paradox Basin has been a target for exploration periodically since the 1960s and produces oil from several small fields. The play generated much interest in the early 1990s with the successful use of horizontal drilling. Recently, the USGS assessed

  2. PLAY ANALYSIS AND DIGITAL PORTFOLIO OF MAJOR OIL RESERVOIRS IN THE PERMIAN BASIN: APPLICATION AND TRANSFER OF ADVANCED GEOLOGICAL AND ENGINEERING TECHNOLOGIES FOR INCREMENTAL PRODUCTION OPPORTUNITIES

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; Caroline L. Breton; William D. Raatz; Stephen C. Ruppel; Charles Kerans

    2004-05-01

    The Permian Basin of west Texas and southeast New Mexico has produced >30 Bbbl (4.77 x 10{sup 9} m{sup 3}) of oil through 2000, most of it from 1,339 reservoirs having individual cumulative production >1 MMbbl (1.59 x 10{sup 5} m{sup 3}). These significant-sized reservoirs are the focus of this report. Thirty-two Permian Basin oil plays were defined, and each of the 1,339 significant-sized reservoirs was assigned to a play. The reservoirs were mapped and compiled in a Geographic Information System (GIS) by play. Associated reservoir information within linked data tables includes Railroad Commission of Texas reservoir number and district (Texas only), official field and reservoir name, year reservoir was discovered, depth to top of the reservoir, production in 2000, and cumulative production through 2000. Some tables also list subplays. Play boundaries were drawn for each play; the boundaries include areas where fields in that play occur but are <1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of cumulative production. This report contains a summary description of each play, including key reservoir characteristics and successful reservoir-management practices that have been used in the play. The CD accompanying the report contains a pdf version of the report, the GIS project, pdf maps of all plays, and digital data files. Oil production from the reservoirs in the Permian Basin having cumulative production >1 MMbbl (1.59 x 10{sup 5} m{sup 3}) was 301.4 MMbbl (4.79 x 10{sup 7} m{sup 3}) in 2000. Cumulative Permian Basin production through 2000 from these significant-sized reservoirs was 28.9 Bbbl (4.59 x 10{sup 9} m{sup 3}). The top four plays in cumulative production are the Northwest Shelf San Andres Platform Carbonate play (3.97 Bbbl [6.31 x 10{sup 8} m{sup 3}]), the Leonard Restricted Platform Carbonate play (3.30 Bbbl 5.25 x 10{sup 8} m{sup 3}), the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play (2.70 Bbbl [4.29 x 10{sup 8} m{sup 3}]), and the San Andres

  3. Identifying sources of groundwater recharge in the Merguellil basin (Tunisia) using isotopic methods: implication of dam reservoir water accounting

    Science.gov (United States)

    Dassi, Lassaad; Zouari, Kamel; Faye, Serigne

    2005-11-01

    Thirty-two groundwater samples collected from the Merguellil Wadi basin (central Tunisia) complemented by the Haouareb dam reservoir water samples have been isotopically analysed in order to investigate the implication of the reservoir water to recharging the aquifer, and also to infer the sources, relative ages and mixing processes in the aquifer system. Plots of the stable isotopes data against the local meteoric lines of Tunis-Carthage and Sfax indicate a strong implication of the dam water noticeable up to a distance of 6-7 km. A contribution as much as 80% of the pumped water has been evidenced using isotopic mass balance. In addition, poorly distinguished water clusters in the stable isotope plots, but clearly identified in the diagrams δ18O versus 3H and 3H versus 14C, indicate various water types related to sources and timing of recharge. The isotopic signatures of the dam accounting water, the “old” and “native” recharged waters, have been evidenced in relation to their geographical distribution and also to their radiogenic isotopes (3H and 14C) contents. In the south-western part of the aquifer, mixing process occurs between the dam reservoir water and both the “old” and “native” water components.

  4. Rational Rock Physics for Improved Velocity Prediction and Reservoir Properties Estimation for Granite Wash (Tight Sands in Anadarko Basin, Texas

    Directory of Open Access Journals (Sweden)

    Muhammad Z. A. Durrani

    2014-01-01

    Full Text Available Due to the complex nature, deriving elastic properties from seismic data for the prolific Granite Wash reservoir (Pennsylvanian age in the western Anadarko Basin Wheeler County (Texas is quite a challenge. In this paper, we used rock physics tool to describe the diagenesis and accurate estimation of seismic velocities of P and S waves in Granite Wash reservoir. Hertz-Mindlin and Cementation (Dvorkin’s theories are applied to analyze the nature of the reservoir rocks (uncemented and cemented. In the implementation of rock physics diagnostics, three classical rock physics (empirical relations, Kuster-Toksöz, and Berryman models are comparatively analyzed for velocity prediction taking into account the pore shape geometry. An empirical (VP-VS relationship is also generated calibrated with core data for shear wave velocity prediction. Finally, we discussed the advantages of each rock physics model in detail. In addition, cross-plots of unconventional attributes help us in the clear separation of anomalous zone and lithologic properties of sand and shale facies over conventional attributes.

  5. Accounting for geochemical alterations of caprock fracture permeability in basin-scale models of leakage from geologic CO2 reservoirs

    Science.gov (United States)

    Guo, B.; Fitts, J. P.; Dobossy, M.; Bielicki, J. M.; Peters, C. A.

    2012-12-01

    Climate mitigation, public acceptance and energy, markets demand that the potential CO2 leakage rates from geologic storage reservoirs are predicted to be low and are known to a high level of certainty. Current approaches to predict CO2 leakage rates assume constant permeability of leakage pathways (e.g., wellbores, faults, fractures). A reactive transport model was developed to account for geochemical alterations that result in permeability evolution of leakage pathways. The one-dimensional reactive transport model was coupled with the basin-scale Estimating Leakage Semi-Analytical (ELSA) model to simulate CO2 and brine leakage through vertical caprock pathways for different CO2 storage reservoir sites and injection scenarios within the Mt. Simon and St. Peter sandstone formations of the Michigan basin. Mineral dissolution in the numerical reactive transport model expands leakage pathways and increases permeability as a result of calcite dissolution by reactions driven by CO2-acidified brine. A geochemical model compared kinetic and equilibrium treatments of calcite dissolution within each grid block for each time step. For a single fracture, we investigated the effect of the reactions on leakage by performing sensitivity analyses of fracture geometry, CO2 concentration, calcite abundance, initial permeability, and pressure gradient. Assuming that calcite dissolution reaches equilibrium at each time step produces unrealistic scenarios of buffering and permeability evolution within fractures. Therefore, the reactive transport model with a kinetic treatment of calcite dissolution was coupled to the ELSA model and used to compare brine and CO2 leakage rates at a variety of potential geologic storage sites within the Michigan basin. The results are used to construct maps based on the susceptibility to geochemically driven increases in leakage rates. These maps should provide useful and easily communicated inputs into decision-making processes for siting geologic CO2

  6. Petroleum geology and resources of the West Siberian Basin, Russia

    Science.gov (United States)

    Ulmishek, Gregory F.

    2003-01-01

    during Neocomian time. The clastic material was transported by a system of rivers dominantly from the eastern provenance. Sandstones within the Neocomian clinoforms contain the principal oil reservoirs. The thick continental Aptian?Cenomanian Pokur Formation above the Neocomian sequence contains giant gas reserves in the northern part of the basin. Three total petroleum systems are identified in the West Siberian basin. Volumes of discovered hydrocarbons in these systems are 144 billion barrels of oil and more than 1,300 trillion cubic feet of gas. The assessed mean undiscovered resources are 55.2 billion barrels of oil, 642.9 trillion cubic feet of gas, and 20.5 billion barrels of natural gas liquids. The largest known oil reserves are in the Bazhenov-Neocomian total petroleum system that includes Upper Jurassic and younger rocks of the central and southern parts of the basin. Oil reservoirs are mainly in Neocomian and Upper Jurassic clastic strata. Source rocks are organic-rich siliceous shales of the Bazhenov Formation. Most discovered reserves are in structural traps, but stratigraphic traps in the Neocomian clinoform sequence are pro-ductive and are expected to contain much of the undiscovered resources. Two assessment units are identified in this total petroleum system. The first assessment unit includes all conventional reservoirs in the stratigraphic interval from the Upper Jurassic to the Cenomanian. The second unit includes unconventional (or continuous), self-sourced, fractured reservoirs in the Bazhenov Formation. This unit was not assessed quantitatively. The Togur-Tyumen total petroleum system covers the same geographic area as the Bazhenov-Neocomian system, but it includes older, Lower?Middle Jurassic strata and weathered rocks at the top of the pre-Jurassic sequence. A Callovian regional shale seal of the Abalak and lower Vasyugan Formations separates the two systems. The Togur-Tyumen system is oil-prone; gas reserves are insignificant. The principal o

  7. Design philosophy and practice of asymmetrical 3D fracturing and random fracturing: A case study of tight sand gas reservoirs in western Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Jianchun Guo

    2015-03-01

    Full Text Available At present two technical models are commonly taken in tight gas reservoir stimulation: conventional massive fracturing and SRV fracturing, but how to select a suitable fracturing model suitable for reservoir characteristics is still a question waiting to be answered. In this paper, based on the analysis of geological characteristics and seepage mechanism of tight gas and shale gas reservoirs, the differences between stimulation philosophy of tight gas reservoirs and shale reservoirs are elucidated, and the concept that a suitable stimulation model should be selected based on reservoir geological characteristics and seepage mechanism aiming at maximally improving the seepage capability of a reservoir. Based on this concept, two fracturing design methods were proposed for two tight gas reservoirs in western Sichuan Basin: asymmetrical 3D fracturing design (A3DF for the middle-shallow Upper Jurassic Penglaizhen Fm stacked reservoirs in which the hydraulic fractures can well match the sand spatial distribution and seepage capability of the reservoirs; SRV fracturing design which can increase fracture randomness in the sandstone and shale laminated reservoirs for the 5th Member of middle-deep Upper Triassic Xujiahe Fm. Compared with that by conventional fracturing, the average production of horizontal wells fractured by A3DF increased by 41%, indicating that A3DF is appropriate for gas reservoir development in the Penglaizhen Fm; meanwhile, the average production per well of the 5th Member of the Xujiahe Fm was 2.25 × 104 m3/d after SRV fracturing, showing that the SRV fracturing is a robust technical means for the development of this reservoir.

  8. Key technologies for well drilling and completion in ultra-deep sour gas reservoirs, Yuanba Gasfield, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Jiaxiang Xia

    2016-12-01

    Full Text Available The Yuanba Gasfield is a large gas field discovered by Sinopec in the Sichuan Basin in recent years, and another main exploration area for natural gas reserves and production increase after the Puguang Gasfield. The ultra-deep sour gas reservoir in the Yuanba Gasfield is characterized by complicated geologic structure, deep reservoirs and complex drilled formation, especially in the continental deep strata which are highly abrasive with low ROP (rate of penetration and long drilling period. After many years of drilling practice and technical research, the following six key drilling and completion technologies for this type reservoir are established by introducing new tools and technologies, developing specialized drill bits and optimizing drilling design. They are: casing program optimization technology for ROP increasing and safe well completion; gas drilling technology for shallow continental strata and high-efficiency drilling technology for deep high-abrasion continental strata; drilling fluid support technologies of gas–liquid conversion, ultra-deep highly-deviated wells and horizontal-well lubrication and drag reduction, hole stability control and sour gas contamination prevention; well cementing technologies for gas medium, deep-well long cementing intervals and ultra-high pressure small space; horizontal-well trajectory control technologies for measuring instrument, downhole motor optimization and bottom hole assembly design; and liner completion modes and completion string optimization technologies suitable for this gas reservoir. Field application shows that these key technologies are contributive to ROP increase and efficiency improvement of 7000 m deep horizontal wells and to significant operational cycle shortening.

  9. Model identification and control of development of deeply buried paleokarst reservoir in the central Tarim Basin, northwest China

    Science.gov (United States)

    Yu, Jingbo; Li, Zhong; Yang, Liu; Han, Yinxue

    2018-04-01

    The paleokarst reservoirs of the Ordovician Yingshan formation, rich in oil and gas, are deeply buried in the central Tarim Basin, northwest China. Dozens of imaging well-logs in this region reveal five typical paleokarst features, including solution vugs, solution-enlarged fractures, filled caves, unfilled caves and collapsed caves, as well as two typical paleokarst structures located in different paleotopographic sites, including paleokarst vadose and phreatic zones. For seismic data, the large wave impedance contrast between the paleocave system and the surrounding rocks leads to a strong seismic reflection, which is highlighted as a bead-like ‘bright spot’ in a seismic section. By quantitatively estimating the seismic resolution limits of deep seismic reflections, a single paleocave cannot be identified from a seismic profile, and the bead-like reflection represents an entire paleocave complex. The spectral decomposition technique was employed to depict the planar shape and semi-quantitatively measure the size of the paleocave complexes. The results indicate that the sizes of the paleokarst caves are all small, and most of the karst caves are nearly completely filled by clay and calcite. The small cave size and the effective support of cave fills for the overlying strata mean that some individual paleocaves in a paleocave complex are preserved at a burial depth of more than 6000 m. Paleotopography and faults strongly impact the distribution of paleokarst reservoirs. Well-developed paleokarst reservoirs are generally located in paleotopographic highlands and on slopes, and for a specific paleotopographic site, the distribution of paleokarst reservoirs is obviously controlled by NW-SE trending faults. The most favorable area for paleokarst development is the Tazhong No. 10 fault zone, a faulted anticline bounded by two NW-SE trending back thrusts.

  10. Reservoir characterization of the Ordovician Red River Formation in southwest Williston Basin Bowman County, ND and Harding County, SD

    Energy Technology Data Exchange (ETDEWEB)

    Sippel, M.A.; Luff, K.D.; Hendricks, M.L.; Eby, D.E.

    1998-07-01

    This topical report is a compilation of characterizations by different disciplines of the Red River Formation in the southwest portion of the Williston Basin and the oil reservoirs which it contains in an area which straddles the state line between North Dakota and South Dakota. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity, and methods for improved recovery. The report is divided by discipline into five major sections: (1) geology, (2) petrography-petrophysical, (3) engineering, (4) case studies and (5) geophysical. Interwoven in these sections are results from demonstration wells which were drilled or selected for special testing to evaluate important concepts for field development and enhanced recovery. The Red River study area has been successfully explored with two-dimensional (2D) seismic. Improved reservoir characterization utilizing 3-dimensional (3D) and has been investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Targeted drilling from predictions using 3D seismic for porosity development were successful in developing significant reserves at close distances to old wells. Short-lateral and horizontal drilling technologies were tested for improved completion efficiency. Lateral completions should improve economics for both primary and secondary recovery where low permeability is a problem and higher density drilling is limited by drilling cost. Low water injectivity and widely spaced wells have restricted the application of waterflooding in the past. Water injection tests were performed in both a vertical and a horizontal well. Data from these tests were used to predict long-term injection and oil recovery.

  11. Evaluation on the effectiveness of natural fractures in Changxing Fm reef-flat facies reservoirs, Yuanba area, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Xiangyuan Zhao

    2017-07-01

    Full Text Available Study on the effectiveness of fractures is of great significance for understanding reservoir types and properties, identifying reservoir seepage mechanisms and delineating the reasonable development technologies and policies. In this paper, the Changxing reef-flat facies reservoirs in the Yuanba area, Sichuan Basin, was taken as an example. After the characteristics of natural fractures were evaluated, the effectiveness of different types of fractures was investigated by using core, thin section, imaging logging and production performance data. Then, the main geological factors that influence fracture effectiveness were analyzed, and the development significance of effective fractures was illustrated. The following results are obtained. (1 Structural fractures and diagenetic fractures are mainly developed in Changxing Fm carbonate reservoirs in Yuanba area. Structural fractures include shear fractures and extensional fractures, and diagenetic fractures include dissolution fractures, structural-dissolution fractures and pressure-solution fractures. (2 High-angle structural fractures are the most effective, followed by horizontal fractures and then oblique fractures, and pressure-solution fractures are the least effective. (3 Among structural fractures, those of NW–SE and nearly E–W oriented are more effective than those of the NE–SW oriented. (4 The earlier the fractures are formed, the more likely they are to be filled with calcite or dolomite and become invalid. (5 The fractures which are formed before or during the oil and gas charging tend to be filled with organic matters and become invalid. The late fractures which are formed after oil and gas charging are mostly effective and their contribution to the reservoir is the greatest. (6 The fractures nearly parallel to the maximum principal stress direction of current ground stress present good effectiveness with large opening. It is concluded that the opening and filling features of

  12. Optimized reservoir operation model of regional wind and hydro power integration case study: Zambezi basin and South Africa

    International Nuclear Information System (INIS)

    Gebretsadik, Yohannes; Fant, Charles; Strzepek, Kenneth; Arndt, Channing

    2016-01-01

    Highlights: • The study introduced reliability assessment method of integrated wind–hydropower operation. • The method identifies optimum target power operations that maximizes the firm generation. • We test the proposed method on interconnected system of reservoirs in Southern Africa region. • Results indicate that higher penetration of wind power can be achieved through the proposed frame work of operation. - Abstract: The present study develops a reliability assessment method of wind resource using optimum reservoir target power operations that maximizes the firm generation of integrated wind and hydropower. A combination of water resources model for a system of reservoirs that implements a demand–priority based linear programing algorithm and a single node power grid system model is implemented on hourly time step. This model was accompanied by a global genetic algorithm solver to determine optimum operation targets for each storage reservoir aiming at maximizing the 90th percentile power generation produced by the integration of wind and hydro over the entire simulation period. This model was applied on the reservoir storages and hydropower system in the Zambezi river basin to test if the storage reservoirs could be efficiently be used to offset wind power intermittence in South Africa subjected to the different physical and policy constraints. Based on the optimized target operation and hourly annual real data for the year 2010, the water resources system and power interconnection system were simulated together to assess the maximum firm generation of power as a result of the new wind and hydro combination target for storage hydropower plants. The result obtained indicates that high regulation of wind and hydro can be achieved as a result of combined operation and showed 45% increase in the level of wind penetration in South Africa’s power system over the reference scenario. The result also indicated a reduced level of coal power utilization and

  13. Geochemistry of formation waters from the Wolfcamp and “Cline” shales: Insights into brine origin, reservoir connectivity, and fluid flow in the Permian Basin, USA

    Science.gov (United States)

    Engle, Mark A.; Reyes, Francisco R.; Varonka, Matthew S.; Orem, William H.; Lin, Ma; Ianno, Adam J.; Westphal, Tiffani M.; Xu, Pei; Carroll, Kenneth C.

    2016-01-01

    Despite being one of the most important oil producing provinces in the United States, information on basinal hydrogeology and fluid flow in the Permian Basin of Texas and New Mexico is lacking. The source and geochemistry of brines from the basin were investigated (Ordovician- to Guadalupian-age reservoirs) by combining previously published data from conventional reservoirs with geochemical results for 39 new produced water samples, with a focus on those from shales. Salinity of the Ca–Cl-type brines in the basin generally increases with depth reaching a maximum in Devonian (median = 154 g/L) reservoirs, followed by decreases in salinity in the Silurian (median = 77 g/L) and Ordovician (median = 70 g/L) reservoirs. Isotopic data for B, O, H, and Sr and ion chemistry indicate three major types of water. Lower salinity fluids (Saline (>100 g/L), isotopically heavy (O and H) water in Leonardian [Permian] to Pennsylvanian reservoirs (2–3.2 km depth) is evaporated, Late Permian seawater. Water from the Permian Wolfcamp and Pennsylvanian “Cline” shales, which are isotopically similar but lower in salinity and enriched in alkalis, appear to have developed their composition due to post-illitization diffusion into the shales. Samples from the “Cline” shale are further enriched with NH4, Br, I and isotopically light B, sourced from the breakdown of marine kerogen in the unit. Lower salinity waters (3 km depth), which plot near the modern local meteoric water line, are distinct from the water in overlying reservoirs. We propose that these deep meteoric waters are part of a newly identified hydrogeologic unit: the Deep Basin Meteoric Aquifer System. Chemical, isotopic, and pressure data suggest that despite over-pressuring in the Wolfcamp shale, there is little potential for vertical fluid migration to the surface environment via natural conduits.

  14. Controls on nitrous oxide production and consumption in reservoirs of the Ohio River Basin

    Science.gov (United States)

    Aquatic ecosystems are a globally significant source of nitrous oxide (N2O), a potent greenhouse gas, but estimates are largely based on studies conducted in streams and rivers with relatively less known about N2O dynamics in lakes and reservoirs. Due to long water residence tim...

  15. Experiments with Interaction between the National Water Model and the Reservoir System Simulation Model: A Case Study of Russian River Basin

    Science.gov (United States)

    Kim, J.; Johnson, L.; Cifelli, R.; Chandra, C. V.; Gochis, D.; McCreight, J. L.; Yates, D. N.; Read, L.; Flowers, T.; Cosgrove, B.

    2017-12-01

    NOAA National Water Center (NWC) in partnership with the National Centers for Environmental Prediction (NCEP), the National Center for Atmospheric Research (NCAR) and other academic partners have produced operational hydrologic predictions for the nation using a new National Water Model (NWM) that is based on the community WRF-Hydro modeling system since the summer of 2016 (Gochis et al., 2015). The NWM produces a variety of hydrologic analysis and prediction products, including gridded fields of soil moisture, snowpack, shallow groundwater levels, inundated area depths, evapotranspiration as well as estimates of river flow and velocity for approximately 2.7 million river reaches. Also included in the NWM are representations for more than 1,200 reservoirs which are linked into the national channel network defined by the USGS NHDPlusv2.0 hydrography dataset. Despite the unprecedented spatial and temporal coverage of the NWM, many known deficiencies exist, including the representation of lakes and reservoirs. This study addresses the implementation of a reservoir assimilation scheme through coupling of a reservoir simulation model to represent the influence of managed flows. We examine the use of the reservoir operations to dynamically update lake/reservoir storage volume states, characterize flow characteristics of river reaches flowing into and out of lakes and reservoirs, and incorporate enhanced reservoir operating rules for the reservoir model options within the NWM. Model experiments focus on a pilot reservoir domain-Lake Mendocino, CA, and its contributing watershed, the East Fork Russian River. This reservoir is modeled using United States Army Corps of Engineers (USACE) HEC-ResSim developed for application to examine forecast informed reservoir operations (FIRO) in the Russian River basin.

  16. Increased oil production and reserves utilizing secondary/tertiary recovery techniques on small reservoirs in the Paradox basin, Utah. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Chidsey, T.C. Jr.

    1997-02-01

    The Paradox basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from carbonate buildups or mounds within the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to four wells with primary production ranging from 700,000 to 2,000,000 barrels of oil per field at a 15 to 20% recovery rate. At least 200 million barrels of oil is at risk of being unrecovered in these small fields because of inefficient recovery practices and undrained heterogeneous reservoirs. Five fields (Anasazi, mule, Blue Hogan, heron North, and Runway) within the Navajo Nation of southeastern utah are being evaluated for waterflood or carbon-dioxide-miscible flood projects based upon geological characterization and reservoir modeling. The results can be applied to other fields in the Paradox basin and the Rocky Mountain region, the Michigan and Illinois basins, and the Midcontinent. The reservoir engineering component of the work completed to date included analysis of production data and well tests, comprehensive laboratory programs, and preliminary mechanistic reservoir simulation studies. A comprehensive fluid property characterization program was completed. Mechanistic reservoir production performance simulation studies were also completed.

  17. Application of multi-agent simulation to evaluate the influence of reservoir operation strategies on the distribution of water availability in the semi-arid Jaguaribe basin, Brazil

    NARCIS (Netherlands)

    van Oel, P.R.; Krol, Martinus S.; Hoekstra, Arjen Ysbert

    2012-01-01

    Studying the processes responsible for the distribution of water resources in a river basin over space and time is of great importance for spatial planning. In this study a multi-agent simulation approach is applied for exploring the influence of alternative reservoir operation strategies on water

  18. Monitoring Impacts of Long-Term Drought on Surface Water Quantity and Quality in Middle Rio Grande Basin Reservoirs Using Multispectral Remote Sensing and Geographic Information Systems

    Science.gov (United States)

    Mubako, S. T.; Hargrove, W. L.

    2017-12-01

    The Elephant Butte and Caballo dams form the largest surface water reservoirs in the Middle Rio Grande basin. The basin supports more than 2 million people, including the major urban centers of Ciudad Juárez, Chihuahua, Mexico, El Paso, Texas, and Las Cruces, New Mexico, plus more than 70,000 ha of land with water rights for irrigated agriculture. However, this region has experienced severe droughts and growing water demand over the past few decades. This study applied GIS and remote sensing techniques to (1) quantify the shrinking and expansion of the reservoirs for the 44-year period 1973-2017; (2) demonstrate the use of multispectral satellite imagery for qualitative assessment of reservoir water turbidity; and (3) investigate and compare annual and seasonal variability of reservoir temperature. Our preliminary results show apparent shrinkage and recovery cycles of both reservoirs, depending on annual inflow and diversion cycles. For example, the period 1981 to 1993 was unusually `wet' on average, in contrast to the period around September 2002 when the Elephant Butte reservoir shrinked to less than 11 percent of its capacity due to drought. Water in the reservoirs appears more turbid in the fall compared to the summer season, and satellite images showed distinctive zones of deep and shallow water, with evident sedimentation near the in-flow of each reservoir. Examination of image digital numbers revealed the following three distinct temperature zones: scrub environment around the reservoirs, very shallow water around reservoir edges, and deeper reservoir water. The zones were represented by a higher range of digital numbers in the summer in comparison to the fall season, indicating greater surface temperature variability in the summer season. The distinction between high summer temperatures and low fall temperatures was especially prominent along the shallow edges of each reservoir. The fluctuating thermal patterns can be explained by variations in depth

  19. A study of CO2 flooding on wave velocities in the Naharkatiya oil reservoir of Upper Assam Basin

    Directory of Open Access Journals (Sweden)

    Subrata Borgohain Gogoi

    2017-03-01

    Full Text Available This paper studies the compressional-wave and shear-wave velocities in the laboratory in six conventional core plugs. These plugs were obtained from a depth of more than 3000 m from the producing horizons of Naharkatiya oil reservoir of Upper Assam Basin, India. The porosities of the conventional core plugs were from 9.67 to 25.8% and that of unconsolidated sand pack was 47%. These plugs and sand pack were saturated with n-hexadecane before CO2 flooding. It was observed that during flooding compressional-wave velocities decreased more than the shear wave velocities. These decreases in wave velocity depend on confining pressure, pore pressure, porosity and temperature of the plugs. Increasing pore pressure at constant confining pressure not only keeps the pores and cracks open but also reduces the confining pressure effect and increases the CO2 density. Higher pore pressures causes larger decrease in both compressional and shear wave velocities. In case of conventional core plugs which are consolidated, having lower porosities tends to decrease the CO2 effect. In unconsolidated sand pack the flooding effect is large even though porosity is high because the bulk modulus of the sand is low. The experimental and the theoretical analyses in this paper show that the decrease in compressional-wave velocities caused by CO2 flooding makes it possible to track CO2 front movements and monitor CO2 flooding process in the reservoir.

  20. Fault seal analysis to predict the compartmentalization of gas reservoir: Case study of Steenkool formation Bintuni Basin

    Science.gov (United States)

    Ginanjar, W. C. B.; Haris, A.; Riyanto, A.

    2017-07-01

    This study is aimed to analyze the mechanism of hydrocarbons trapping in the field on a relatively new play in the Bintuni basin particularly Steenkool formation. The first well in this field has been drilled with a shallow target in the Steenkool formation and the drilling is managed to find new gas reserves in the shale-sandstone layer. In the structure of this gas discovery, there is the potential barrier for compartmentalization that draws attention to analyze how the patterns of structural of fault become a part of reservoir compartment. In order to measure the risk associated with prospects on a field bounded by faults, it is important to understand the processes that contribute to fault seal. The method of Fault Seal Analysis (FSA) is one of the methods used for the analysis of the nature of a fault whether the fault is sealing or leaking the fluid flow in the reservoir. Trapping systems that are limited by faults play an important role in creating a trap of hydrocarbon. The ability of a fault to seal fluid is quantitatively reflected by the value of Shale Gouge Ratio (SGR). SGR is the calculation of the amount of fine-grained material that fills fault plane (fault gouge) as a result of the movement mechanism of fault. The result of this study is a valuable resource for the systematic evaluation of the analysis of hydrocarbon prospects in the field.

  1. Negotiating designs of multi-purpose reservoir systems in international basins

    Science.gov (United States)

    Geressu, Robel; Harou, Julien

    2016-04-01

    Given increasing agricultural and energy demands, coordinated management of multi-reservoir systems could help increase production without further stressing available water resources. However, regional or international disputes about water-use rights pose a challenge to efficient expansion and management of many large reservoir systems. Even when projects are likely to benefit all stakeholders, agreeing on the design, operation, financing, and benefit sharing can be challenging. This is due to the difficulty of considering multiple stakeholder interests in the design of projects and understanding the benefit trade-offs that designs imply. Incommensurate performance metrics, incomplete knowledge on system requirements, lack of objectivity in managing conflict and difficulty to communicate complex issue exacerbate the problem. This work proposes a multi-step hybrid multi-objective optimization and multi-criteria ranking approach for supporting negotiation in water resource systems. The approach uses many-objective optimization to generate alternative efficient designs and reveal the trade-offs between conflicting objectives. This enables informed elicitation of criteria weights for further multi-criteria ranking of alternatives. An ideal design would be ranked as best by all stakeholders. Resource-sharing mechanisms such as power-trade and/or cost sharing may help competing stakeholders arrive at designs acceptable to all. Many-objective optimization helps suggests efficient designs (reservoir site, its storage size and operating rule) and coordination levels considering the perspectives of multiple stakeholders simultaneously. We apply the proposed approach to a proof-of-concept study of the expansion of the Blue Nile transboundary reservoir system.

  2. Reservoir uncertainty, Precambrian topography, and carbon sequestration in the Mt. Simon Sandstone, Illinois Basin

    Science.gov (United States)

    Leetaru, H.E.; McBride, J.H.

    2009-01-01

    Sequestration sites are evaluated by studying the local geological structure and confirming the presence of both a reservoir facies and an impermeable seal not breached by significant faulting. The Cambrian Mt. Simon Sandstone is a blanket sandstone that underlies large parts of Midwest United States and is this region's most significant carbon sequestration reservoir. An assessment of the geological structure of any Mt. Simon sequestration site must also include knowledge of the paleotopography prior to deposition. Understanding Precambrian paleotopography is critical in estimating reservoir thickness and quality. Regional outcrop and borehole mapping of the Mt. Simon in conjunction with mapping seismic reflection data can facilitate the prediction of basement highs. Any potential site must, at the minimum, have seismic reflection data, calibrated with drill-hole information, to evaluate the presence of Precambrian topography and alleviate some of the uncertainty surrounding the thickness or possible absence of the Mt. Simon at a particular sequestration site. The Mt. Simon is thought to commonly overlie Precambrian basement granitic or rhyolitic rocks. In places, at least about 549 m (1800 ft) of topographic relief on the top of the basement surface prior to Mt. Simon deposition was observed. The Mt. Simon reservoir sandstone is thin or not present where basement is topographically high, whereas the low areas can have thick Mt. Simon. The paleotopography on the basement and its correlation to Mt. Simon thickness have been observed at both outcrops and in the subsurface from the states of Illinois, Ohio, Wisconsin, and Missouri. ?? 2009. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  3. The reproductive strategy of Leporinus friderici (Characiformes, Anostomidae) in the Paraná River basin: the effect of reservoirs.

    Science.gov (United States)

    Lopes; Benedito-Cecilio; Agostinho

    2000-05-01

    The reproductive strategy of a species depends upon the interaction between intrinsic and extrinsic factors. Examining the population of Leporinus friderici in two reservoirs of the Upper Paraná River basin in reference to first gonadal maturation and breeding season and sites, the present investigation tested whether the environment formed by damming promoted spatial and temporal changes in the reproductive strategy of this species. Analyses of sex ratios showed that females significantly predominated in Itaipu, while in Corumbá the sexes were about equal with a slight predominance of males. Size-associated sexual dimorphism was observed, that is females dominated the longer length categories, and males the shorter. The minimum size at which L. friderici initiated reproduction varied from year to year, and was larger in the periods soon after formation of both reservoirs. In Itaipu, stabilization between the maximum and minimum lengths at first maturation was also noted after year 6 following closure and continuing until year 15. In general, the breeding season lasted from October through April, although cyclic changes in the duration and intensity of this season were evident. Young individuals predominated during the entire study period in Corumbá. The formation of Itaipu Reservoir had a greater effect on the reproduction of L. friderici, where a gradual adaptation of the reproductive strategy of this species may possibly have been occurring. It is also possible that some of the characteristics of the Itaipu population will in the future be shown by the Corumbá population. It was concluded that reproductive strategies constitute ecological adaptations that are temporally and spatially altered and are fitted to resource availability and environmental pressure.

  4. Salinity management in river basins : modelling and management of the salt-affected Jarreh Reservoir (Iran)

    NARCIS (Netherlands)

    Shiati, K.

    1991-01-01

    The sources and origin of salts in the basin of the two salt- affected Shapur and Dalaki rivers (Southern Iran) and the processes involved in salinization have been studied. The extent of water deterioration have been identified by examining spatial changes in the rivers water

  5. Airborne Snow Observatory: measuring basin-wide seasonal snowpack with LiDAR and an imaging spectrometer to improve runoff forecasting and reservoir operation (Invited)

    Science.gov (United States)

    McGurk, B. J.; Painter, T. H.

    2013-12-01

    The Airborne Snow Observatory (ASO) NASA-JPL demonstration mission collected detailed snow information for portions of the Tuolumne Basin in California and the Uncompahgre Basin in Colorado in spring of 2013. The ASO uses an imaging spectrometer and LiDAR sensors mounted in an aircraft to collect snow depth and extent data, and snow albedo. By combining ground and modeled density fields, the ~weekly flights over the Tuolumne produced both basin-wide and detailed sub-basin snow water equivalent (SWE) estimates that were used in a hydrologic simulation model to improve the accuracy and timing of runoff forecasting tools used to manage Hetch Hetchy Reservoir, the source of 85% of the water supply for 2.5 million people on the San Francisco Peninsula. The USGS PRMS simulation model was calibrated to the 459 square mile basin and was updated with both weather forecast data and distributed snow information from ASO flights to inform the reservoir operators of predicted inflow volumes and timing. Information produced by the ASO data collection was used to update distributed SWE and albedo state variables in the PRMS model and improved inflow forecasts for Hetch Hetchy. Data from operational ASO programs is expected to improve the ability of reservoir operators to more efficiently allocate the last half of the recession limb of snowmelt inflow and be more assured of meeting operational mandates. This presentation will provide results from the project after its first year.

  6. Geochemical characteristics of natural gas in the hydrocarbon accumulation history, and its difference among gas reservoirs in the Upper Triassic formation of Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Peng Wang

    2016-08-01

    Full Text Available The analysis of hydrocarbon generation, trap formation, inclusion homogenization temperature, authigenic illite dating, and ESR dating were used to understand the history of hydrocarbon accumulation and its difference among gas reservoirs in the Upper Triassic formation of Sichuan Basin. The results show the hydrocarbon accumulation mainly occurred during the Jurassic and Cretaceous periods; they could also be classified into three stages: (1 early hydrocarbon generation accumulation stage, (2 mass hydrocarbon generation accumulation stage before the Himalayan Epoch, (3 and parts of hydrocarbon adjustment and re-accumulation during Himalayan Epoch. The second stage is more important than the other two. The Hydrocarbon accumulation histories are obviously dissimilar in different regions. In western Sichuan Basin, the gas accumulation began at the deposition period of member 5 of Xujiahe Formation, and mass accumulation occurred during the early Middle Jurassic up to the end of the Late Cretaceous. In central Sichuan Basin, the accumulation began at the early Late Jurassic, and the mass accumulation occurred from the middle Early Cretaceous till the end of the Late Cretaceous. In southern Sichuan Basin, the accumulation began at the middle Late Jurassic, and the mass accumulation occurred from the middle of the Late Cretaceous to the end of the Later Cretaceous. The accumulation history of the western Sichuan Basin is the earliest, and the southern Sichuan Basin is the latest. This paper will help to understand the accumulation process, accumulation mechanism, and gas reservoir distribution of the Triassic gas reservoirs in the Sichuan Basin better. Meanwhile, it is found that the authigenic illite in the Upper Triassic formation of Sichuan Basin origin of deep-burial and its dating is a record of the later accumulation. This suggests that the illite dating needs to fully consider illite origin; otherwise the dating results may not accurately

  7. Study of the relation between soil use, vegetation coverage, and the discharge of sediments from artificial reservoirs using MSS/LANDSAT images. Example: The Tres Marias reservoir and its supply basin

    Science.gov (United States)

    Dejesusparada, N. (Principal Investigator); Sausen, T. M.

    1981-01-01

    The land use and types of vegetation in the region of the upper Sao Francisco River, Brazil, are identified. This region comprises the supply basin of the Tres Marias reservoir. Imagery from channels 5 and 7 of the LANDSAT multispectral band scanner during wet and rainy seasons and ground truth data were employed to characterize and map the vegetation, land use, and sedimentary discharges from the reservoir. Agricultural and reforested lands, meadows, and forests are identified. Changes in land use due to human activity are demonstrated.

  8. The role of deformation bands controlling reservoir quality in a salt-walled mini-basin, Central North Sea, UK

    Science.gov (United States)

    Davies, Philip; Jones, Stuart; Imber, Jonathan

    2017-04-01

    At shallow burial depths, sediments are typically poorly consolidated and subject to low confining pressure and differential stress. Fractures that form in poorly consolidated and therefore non-lithified sediments would be unable to remain open. However, the large amount of pore space present would allow for processes such as grain sliding and grain rolling, resulting in the formation of deformation bands. The structure and style of the resulting deformation bands would depend on the size, shape and sorting of the grains, as well as early cementation, porosity and the orientation and magnitude of the local stresses. Previous studies on deformation bands in general have shown that they produce an anisotropy that can affect fluid flow. Early deformation band formation near the surface may also influence later diagenesis at greater burial depths, and thus have a further impact on fluid flow in sandstone. Dilatant (deformation) bands are commonly reported for poorly consolidated sandstones at surface or near-surface conditions (fractures, faults and deformation bands create a complex system of permeable fluid pathways and cemented baffles at deeper burial. The results presented highlight the importance of constraining the occurrence of dilation and dilatant shear bands along the margins of salt-walled mini-basins to better understand the kinematics of the salt movement and additional loading on adjacent sediments. Furthermore, this research identifies the importance of early formed deformation bands in controlling meteoric water influx and governing later reservoir quality for spatially and temporally complex sedimentary fills of salt-walled mini-basins.

  9. Predicting the downstream impact of ensembles of small reservoirs with special reference to the Volta Basin, West Africa

    Science.gov (United States)

    van de Giesen, N.; Andreini, M.; Liebe, J.; Steenhuis, T.; Huber-Lee, A.

    2005-12-01

    After a strong reduction in investments in water infrastructure in Sub-Saharan Africa, we now see a revival and increased interest to start water-related projects. The global political willingness to work towards the UN millennium goals are an important driver behind this recent development. Large scale irrigation projects, such as were constructed at tremendous costs in the 1970's and early 1980's, are no longer seen as the way forward. Instead, the construction of a large number of small, village-level irrigation schemes is thought to be a more effective way to improve food production. Such small schemes would fit better in existing and functioning governance structures. An important question now becomes what the cumulative (downstream) impact is of a large number of small irrigation projects, especially when they threaten to deplete transboundary water resources. The Volta Basin in West Africa is a transboundary river catchment, divided over six countries. Of these six countries, upstream Burkina Faso and downstream Ghana are the most important and cover 43% and 42% of the basin, respectively. In Burkina Faso (and also North Ghana), small reservoirs and associated irrigation schemes are already an important means to improve the livelihoods of the rural population. In fact, over two thousand such schemes have already been constructed in Burkina Faso and further construction is to be expected in the light of the UN millennium goals. The cumulative impact of these schemes would affect the Akosombo Reservoir, one of the largest manmade lakes in the world and an important motor behind the economic development in (South) Ghana. This presentation will put forward an analytical framework that allows for the impact assessment of (large) ensembles of small reservoirs. It will be shown that despite their relatively low water use efficiencies, the overall impact remains low compared to the impact of large dams. The tools developed can be used in similar settings elsewhere

  10. Zonation of shale reservoir stimulation modes: a conceptual model based on hydraulic fracturing data from the Baltic Basin (Poland).

    Science.gov (United States)

    Jarosiński, Marek; Pachytel, Radomir

    2017-04-01

    Depending on the pressure distribution within Stimulated Reservoir Volume (SRV), a different modes of hydraulic fracturing or tectonic fracture reactivation are active. Hydraulic pressure-driven shortening or expansion of reservoir produces changes in stress field that results in decrease of differential stress either by increasing of horizontal stress minimum (Shmin) or/and by decreasing of horizontal stress maximum (SHmax). For further considerations we assume initial strike-slip stress regime which prevails in the Polish part of the Lower Paleozoic Baltic Basin (BB), as well as in majority of the USA shale basins. The data come from vertical and horizontal shale gas exploration wells drilled from one pad located in the middle of the BB. Structural survey of a long core interval combined with stress analysis based on microfrac tests and fracturing tests allow to reconstruct the initial structural and geomechanical state of reservoir. Further geomechanical evolution of the SRV depends on the hydraulic pressure bubble growth, which is in general unknown. However, the state of pressure can be determined close to the injection borehole and in the front of the SRV migrating in time. In our case, we are able to distinguish four stimulation zones characterized by increasingly diverse stimulation modes and successively closer to the borehole injection zone: (1) shear on preexisting fractures generates microseismic events that produce open fractures propped by their natural asperities being impenetrable for proppant grains; (2) above + initial hydraulic opening of natural fractures that are preferentially oriented to the Shmin, which favors microseismic events triggered by secondary shear on bedding planes and produces open spaces supported by natural fracture asperities and fine-grained proppant; (3) above + failure of primary hydraulic fractures, which increases extensional component of the microseismic events and opens space for coarse-grained proppant; (4) above

  11. Secondary natural gas recovery: Targeted applications for infield reserve growth in midcontinent reservoirs, Boonsville Field, Fort Worth Basin, Texas. Topical report, May 1993--June 1995

    Energy Technology Data Exchange (ETDEWEB)

    Hardage, B.A.; Carr, D.L.; Finley, R.J.; Tyler, N.; Lancaster, D.E.; Elphick, R.Y.; Ballard, J.R.

    1995-07-01

    The objectives of this project are to define undrained or incompletely drained reservoir compartments controlled primarily by depositional heterogeneity in a low-accommodation, cratonic Midcontinent depositional setting, and, afterwards, to develop and transfer to producers strategies for infield reserve growth of natural gas. Integrated geologic, geophysical, reservoir engineering, and petrophysical evaluations are described in complex difficult-to-characterize fluvial and deltaic reservoirs in Boonsville (Bend Conglomerate Gas) field, a large, mature gas field located in the Fort Worth Basin of North Texas. The purpose of this project is to demonstrate approaches to overcoming the reservoir complexity, targeting the gas resource, and doing so using state-of-the-art technologies being applied by a large cross section of Midcontinent operators.

  12. Comparison of Three Key Marine Shale Reservoirs in the Southeastern Margin of the Sichuan Basin, SW China

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2017-09-01

    Full Text Available This study performs a comprehensive comparison of three key marine shale reservoirs in the southeastern margin of the Sichuan Basin, and explains why commercial gas production was only achieved in the Lower Silurian Longmaxi (LSL and Upper Ordovician Wufeng (UOW formations, but not in the Lower Cambrian Niutitang (LCN formation. The experimental methods included in situ gas content and gas composition tests, methane adsorption analysis, low-pressure N2 adsorption, field emission scanning electron microscopy (FE-SEM, and total organic carbon (TOC and vitrinite reflectance (Ro analyses to evaluate the lithology, mineralogy, physical properties of the reservoir, organic geochemistry, in situ gas content and methane adsorption capacity characteristics of the three shales. The LCN shale has lower quartz and clay mineral contents and a low brittleness index, but higher contents of feldspar, pyrite and carbonate minerals than the LSL and UOW shales. The porosity and permeability of the LSL and UOW shales are higher than those of the LCN shale. The primary contributions to the high permeability in the LSL shale are its well-developed fractures and organic matter pores. In contrast, the over-mature LCN shale is unfavorable for the development of organic pores and fractures. Although the LCN shale has a higher methane sorption capacity than the LSL and UOW shales, the gas content and methane saturation of the LCN shale are distinctly lower than those of the LSL and UOW shales. This is primarily due to gas migration from the LCN shale, resulting from the activities of tectonic uplift and the unconformable contact between the LCN shale and the Dengying formation. When compared with gas shale in North America, the LSL shale is the most favorable shale reservoir out of the three Sichuan shales, while the combination of the LSL and UOW shales is also potentially productive. However, the individual single layer production of the UOW or LCN shales is still

  13. Designing multi-reservoir system designs via efficient water-energy-food nexus trade-offs - Selecting new hydropower dams for the Blue Nile and Nepal's Koshi Basin

    Science.gov (United States)

    Harou, J. J.; Hurford, A.; Geressu, R. T.

    2015-12-01

    Many of the world's multi-reservoir water resource systems are being considered for further development of hydropower and irrigation aiming to meet economic, political and ecological goals. Complex river basins serve many needs so how should the different proposed groupings of reservoirs and their operations be evaluated? How should uncertainty about future supply and demand conditions be factored in? What reservoir designs can meet multiple goals and perform robustly in a context of global change? We propose an optimized multi-criteria screening approach to identify best performing designs, i.e., the selection, size and operating rules of new reservoirs within multi-reservoir systems in a context of deeply uncertain change. Reservoir release operating rules and storage sizes are optimized concurrently for each separate infrastructure design under consideration across many scenarios representing plausible future conditions. Outputs reveal system trade-offs using multi-dimensional scatter plots where each point represents an approximately Pareto-optimal design. The method is applied to proposed Blue Nile River reservoirs in Ethiopia, where trade-offs between capital costs, total and firm energy output, aggregate storage and downstream irrigation and energy provision for the best performing designs are evaluated. The impact of filling period for large reservoirs is considered in a context of hydrological uncertainty. The approach is also applied to the Koshi basin in Nepal where combinations of hydropower storage and run-of-river dams are being considered for investment. We show searching for investment portfolios that meet multiple objectives provides stakeholders with a rich view on the trade-offs inherent in the nexus and how different investment bundles perform differently under plausible futures. Both case-studies show how the proposed approach helps explore and understand the implications of investing in new dams in a global change context.

  14. A new, fully coupled, reaction-transport-mechanical approach to modeling the evolution of natural gas reservoirs in the Piceance Basin

    Science.gov (United States)

    Payne, Dorothy Frances

    The Piceance Basin is highly compartmented, and predicting the location and characteristics of producible reservoirs is difficult. Gas generation is an important consideration in quality and size of natural gas reserves, but it also may contribute to fracturing, and hence the creation of the reservoirs in which it is contained. The purpose of this dissertation is to use numerical modeling to study the evolution of these unconventional natural gas reservoirs in the Piceance Basin. In order to characterize the scale and structure of compartmentation in the Piceance Basin, a set of in-situ fluid pressure data were interpolated across the basin and the resulting fluid pressure distribution was analyzed. Results show complex basin- and field-scale compartmentation in the Upper Cretaceous units. There are no simple correlations between compartment location and such factors as stratigraphy, basin structure, or coal thickness and maturity. To account for gas generation in the Piceance Basin, a new chemical kinetic approach to modeling lignin maturation is developed, based primarily on structural transformations of the lignin molecule observed in naturally matured samples. This model calculates mole fractions of all species, functional group fractions, and elemental weight percents. Results show reasonable prediction of maturities at other sites in the Piceance Basin for vitrinite reflectance up to about 1.7 %Ro. The flexible design of the model allows it to be modified to account for compositionally heterogeneous source material. To evaluate the role of gas generation in this dynamical system, one-dimensional simulations have been performed using the CIRFB reaction-transport-mechanical (RTM) simulator. CIRFB accounts for compaction, fracturing, hydrocarbon generation, and multi-phase flow. These results suggest that by contributing to overpressure, gas generation has two important implications: (1) gas saturation in one unit affects fracturing in other units, thereby

  15. Advanced reservoir characterization for improved oil recovery in a New Mexico Delaware basin project

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.D.; Kendall, R.P.; Whitney, E.M. [Dave Martin and Associates, Inc., Socorro, NM (United States)] [and others

    1997-08-01

    The Nash Draw Brushy Canyon Pool in Eddy County, New Mexico is a field demonstration site in the Department of Energy Class III program. The basic problem at the Nash Draw Pool is the low recovery typically observed in similar Delaware fields. By comparing a control area using standard infill drilling techniques to a pilot area developed using advanced reservoir characterization methods, the goal of the project is to demonstrate that advanced technology can significantly improve oil recovery. During the first year of the project, four new producing wells were drilled, serving as data acquisition wells. Vertical seismic profiles and a 3-D seismic survey were acquired to assist in interwell correlations and facies prediction. Limited surface access at the Nash Draw Pool, caused by proximity of underground potash mining and surface playa lakes, limits development with conventional drilling. Combinations of vertical and horizontal wells combined with selective completions are being evaluated to optimize production performance. Based on the production response of similar Delaware fields, pressure maintenance is a likely requirement at the Nash Draw Pool. A detailed reservoir model of pilot area was developed, and enhanced recovery options, including waterflooding, lean gas, and carbon dioxide injection, are being evaluated.

  16. Study Of Rock Physics And Seismic Attributes Of Hydrocarbon Reservoirs In Sabah Basin

    Science.gov (United States)

    anak Penguang, Adelynna Shirley; Almanna Lubis, Luluan; Hermana, Maman; Deva Prasad Ghosh, Dr., Prof.

    2017-10-01

    Elastic moduli are known to discriminate fluid and lithology for effective reservoir characterization. However, in some cases, the elastic modulus can also show the same response for different type of fluid and lithology. In our study area, a few elastic moduli were used to evaluate the hydrocarbon sands, water sand and shale as identified based on well log response. Seismic attributes such as Relative Acoustic Impedance attribute and RMS amplitude attribute are also applied to confirm the well log analysis and investigate the seismic response. Based on the results, the effective elastic moduli for our study area is the Lambda-Mu-Rho, Velocity Ratio (Vp/Vs), Poisson's ratio and Scaled Inverse Quality (Q) Ratio. The seismic attributes such as the Relative Acoustic Impedance highlights the impedance difference between the formations while RMS amplitude shows the hydrocarbon presence. The workflow of this study is applicable for other areas for effective fluid and lithology delineation.

  17. Characterization of gas hydrate reservoirs by integration of core and log data in the Ulleung Basin, East Sea

    Science.gov (United States)

    Bahk, J.-J.; Kim, G.-Y.; Chun, J.-H.; Kim, J.-H.; Lee, J.Y.; Ryu, B.-J.; Lee, J.-H.; Son, B.-K.; Collett, Timothy S.

    2013-01-01

    Examinations of core and well-log data from the Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) drill sites suggest that Sites UBGH2-2_2 and UBGH2-6 have relatively good gas hydrate reservoir quality in terms of individual and total cumulative thicknesses of gas-hydrate-bearing sand (HYBS) beds. In both of the sites, core sediments are generally dominated by hemipelagic muds which are intercalated with turbidite sands. The turbidite sands are usually thin-to-medium bedded and mainly consist of well sorted coarse silt to fine sand. Anomalies in infrared core temperatures and porewater chlorinity data and pressure core measurements indicate that “gas hydrate occurrence zones” (GHOZ) are present about 68–155 mbsf at Site UBGH2-2_2 and 110–155 mbsf at Site UBGH2-6. In both the GHOZ, gas hydrates are preferentially associated with many of the turbidite sands as “pore-filling” type hydrates. The HYBS identified in the cores from Site UBGH2-6 are medium-to-thick bedded particularly in the lower part of the GHOZ and well coincident with significant high excursions in all of the resistivity, density, and velocity logs. Gas-hydrate saturations in the HYBS range from 12% to 79% with an average of 52% based on pore-water chlorinity. In contrast, the HYBS from Site UBGH2-2_2 are usually thin-bedded and show poor correlations with both of the resistivity and velocity logs owing to volume averaging effects of the logging tools on the thin HYBS beds. Gas-hydrate saturations in the HYBS range from 15% to 65% with an average of 37% based on pore-water chlorinity. In both of the sites, large fluctuations in biogenic opal contents have significant effects on the sediment physical properties, resulting in limited usage of gamma ray and density logs in discriminating sand reservoirs.

  18. Occurrence and distribution characteristics of fluids in tight sandstone reservoirs in the Shilijiahan zone, northern Ordos Basin

    Directory of Open Access Journals (Sweden)

    Gongqiang Li

    2017-05-01

    Full Text Available High-yield gas layers, low-yield gas layers and (gas bearing water layers of Upper Paleozoic coexist in the Shilijiahan zone in the northern Ordos Basin, but gas–water distribution characteristics, laws and influence factors are not understood well, so the exploration and development of natural gas in this zone are restricted. In this paper, statistical analysis was carried out on the data of Upper Paleozoic formation water in this zone, e.g. salinity, pH value and ion concentration. It is shown that the formation water in this zone is of CaCl2 type. Then, the origin, types, controlling factors and spatial distribution characteristics of formation water were figured out by using core, mud logging, well logging and testing data, combined with the classification and evaluation results of geochemical characteristics of formation water. Besides, the logging identification chart of gas, water and dry layers in this zone was established. Finally, the occurrence and distribution laws of reservoir fluids were defined. The formation water of CaCl2 type indicates a good sealing capacity in this zone, which is favorable for natural gas accumulation. It is indicated that the reservoir fluids in this zone exist in the state of free water, capillary water and irreducible water. Free water is mainly distributed in the west of this zone, irreducible water in the east, and capillary water in the whole zone. The logging identification chart has been applied in many wells in this zone like Well Jin 86. The identification result is basically accordant with the gas testing result. It is verified that gas and water layers can be identified effectively based on this logging identification chart.

  19. Petroleum geology and resources of the North Caspian Basin, Kazakhstan and Russia

    Science.gov (United States)

    Ulmishek, Gregory F.

    2001-01-01

    on the Kashagan structure offshore in the Caspian Sea is probably also of the supergiant status. Major oil and gas reserves are located in carbonate reservoirs in reefs and structural traps of the subsalt sequence. Substantially smaller reserves are located in numerous fields in the suprasalt sequence. These suprasalt fields are largely in shallow Jurassic and Cretaceous clastic reservoirs in salt dome-related traps. Petroleum source rocks are poorly identified by geochemical methods. However, geologic data indicate that the principal source rocks are Upper Devonian to Lower Permian deep-water black-shale facies stratigraphically correlative to shallow-shelf carbonate platforms on the basin margins. The main stage of hydrocarbon generation was probably in Late Permian and Triassic time, during deposition of thick orogenic clastics. Generated hydrocarbons migrated laterally into adjacent subsalt reservoirs and vertically, through depressions between Kungurian salt domes where the salt is thin or absent, into suprasalt clastic reservoirs. Six assessment units have been identified in the North Caspian basin. Four of them include Paleozoic subsalt rocks of the basin margins, and a fifth unit, which encompasses the entire total petroleum system area, includes the suprasalt sequence. All five of these assessment units are underexplored and have significant potential for new discoveries. Most undiscovered petroleum resources are expected in Paleozoic subsalt carbonate rocks. The assessment unit in subsalt rocks with the greatest undiscovered potential occupies the south basin margin. Petroleum potential of suprasalt rocks is lower; however, discoveries of many small to medium size fields are expected. The sixth identified assessment unit embraces subsalt rocks of the central basin areas. The top of subsalt rocks in these areas occurs at depths ranging from 7 to 10 kilometers and has not been reached by wells. Undiscovered resources of this unit did not rec

  20. Major factors controlling fracture development in the Middle Permian Lucaogou Formation tight oil reservoir, Junggar Basin, NW China

    Science.gov (United States)

    Zhang, Chen; Zhu, Deyu; Luo, Qun; Liu, Luofu; Liu, Dongdong; Yan, Lin; Zhang, Yunzhao

    2017-09-01

    Natural fractures in seven wells from the Middle Permian Lucaogou Formation in the Junggar Basin were evaluated in light of regional structural evolution, tight reservoir geochemistry (including TOC and mineral composition), carbon and oxygen isotopes of calcite-filled fractures, and acoustic emission (AE). Factors controlling the development of natural fractures were analyzed using qualitative and/or semi-quantitative techniques, with results showing that tectonic factors are the primary control on fracture development in the Middle Permian Lucaogou Formation of the Junggar Basin. Analyses of calcite, dolomite, and TOC show positive correlations with the number of fractures, while deltaic lithofacies appear to be the most favorable for fracture development. Mineral content was found to be a major control on tectonic fracture development, while TOC content and sedimentary facies mainly control bedding fractures. Carbon and oxygen isotopes vary greatly in calcite-filled fractures (δ13C ranges from 0.87‰ to 7.98‰, while δ18O ranges from -12.63‰ to -5.65‰), indicating that fracture development increases with intensified tectonic activity or enhanced diagenetic alteration. By analyzing the cross-cutting relationships of fractures in core, as well as four Kaiser Effect points in the acoustic emission curve, we observed four stages of tectonic fracture development. First-stage fractures are extensional, and were generated in the late Triassic, with calcite fracture fills formed between 36.51 °C and 56.89 °C. Second-stage fractures are shear fractures caused by extrusion stress from the southwest to the northeast, generated by the rapid uplift of the Tianshan in the Middle and Late Jurassic; calcite fracture fills formed between 62.91 °C and 69.88 °C. Third-stage fractures are NNW-trending shear fractures that resulted from north-south extrusion and thrusting in a foreland depression along the front of the Early Cretaceous Bogda Mountains. Calcite fracture

  1. Characteristics and origin of the relatively high-quality tight reservoir in the Silurian Xiaoheba Formation in the southeastern Sichuan Basin

    Science.gov (United States)

    Gong, Xiaoxing; Shi, Zejin; Wang, Yong; Tian, Yaming; Li, Wenjie; Liu, Lei

    2017-01-01

    A mature understanding of the sandstone gas reservoir in the Xiaoheba Formation in the southeastern Sichuan Basin remains lacking. To assess the reservoir characteristics and the origin of the high-quality reservoir in the Xiaoheba Formation, this paper uses systematic field investigations, physical property analysis, thin section identification, scanning electron microscopy and electron microprobe methods. The results indicate that the Xiaoheba sandstone is an ultra-tight and ultra-low permeability reservoir, with an average porosity of 2.97% and an average permeability of 0.56×10−3 μm2. This promising reservoir is mainly distributed in the Lengshuixi and Shuangliuba regions and the latter has a relatively high-quality reservoir with an average porosity of 5.28% and average permeability of 0.53×10−3 μm2. The reservoir space comprises secondary intergranular dissolved pores, moldic pores and fractures. Microfacies, feldspar dissolution and fracture connectivity control the quality of this reservoir. The relatively weak compaction and cementation in the interbedded delta front distal bar and interdistributary bay microfacies indirectly protected the primary intergranular pores and enhanced late-stage dissolution. Late-stage potassium feldspar dissolution was controlled by the early-stage organic acid dissolution intensity and the distance from the hydrocarbon generation center. Early-stage fractures acted as pathways for organic acid migration and were therefore important factors in the formation of the reservoir. Based on these observations, the area to the west of the Shuangliuba and Lengshuixi regions has potential for gas exploration. PMID:28686735

  2. Characteristics and origin of the relatively high-quality tight reservoir in the Silurian Xiaoheba Formation in the southeastern Sichuan Basin.

    Directory of Open Access Journals (Sweden)

    Xiaoxing Gong

    Full Text Available A mature understanding of the sandstone gas reservoir in the Xiaoheba Formation in the southeastern Sichuan Basin remains lacking. To assess the reservoir characteristics and the origin of the high-quality reservoir in the Xiaoheba Formation, this paper uses systematic field investigations, physical property analysis, thin section identification, scanning electron microscopy and electron microprobe methods. The results indicate that the Xiaoheba sandstone is an ultra-tight and ultra-low permeability reservoir, with an average porosity of 2.97% and an average permeability of 0.56×10-3 μm2. This promising reservoir is mainly distributed in the Lengshuixi and Shuangliuba regions and the latter has a relatively high-quality reservoir with an average porosity of 5.28% and average permeability of 0.53×10-3 μm2. The reservoir space comprises secondary intergranular dissolved pores, moldic pores and fractures. Microfacies, feldspar dissolution and fracture connectivity control the quality of this reservoir. The relatively weak compaction and cementation in the interbedded delta front distal bar and interdistributary bay microfacies indirectly protected the primary intergranular pores and enhanced late-stage dissolution. Late-stage potassium feldspar dissolution was controlled by the early-stage organic acid dissolution intensity and the distance from the hydrocarbon generation center. Early-stage fractures acted as pathways for organic acid migration and were therefore important factors in the formation of the reservoir. Based on these observations, the area to the west of the Shuangliuba and Lengshuixi regions has potential for gas exploration.

  3. National Dam Safety Program. Hillburn Reservoir Dam (Inventory Number NY 974), Passaic River Basin, Rockland County, New York. Phase I Inspection Report.

    Science.gov (United States)

    1981-06-30

    Ieupcoemar an Identify by block rnumber) Natna S fet eyyrora Hilburn ’Reservoir*Dam Vioal n s aetyiPgr- Rockland County Visul Ispecion saic River Basin...o the 1dan a3 bit the report dae Information and F~nlj is ara based CKI .pIr:ial .0 inspecti&i of the darn ’ii:’ t*,., performing o-:Zizaton...196A-934 PASSAIC RIVER BASIN ROCKLAND COUNTY, NEW YORK TABLE OF CONTENTS PAGE NO. ASSESSMENT OVERVIEW PHOTOGRAPH PROJECT INFORMATION 1 1.1 GENERAL 1

  4. Integrated techniques for rapid and highly-efficient development and production of ultra-deep tight sand gas reservoirs of Keshen 8 Block in the Tarim Basin

    Directory of Open Access Journals (Sweden)

    Tongwen Jiang

    2017-01-01

    Full Text Available The unusually ultra-deep and ultra-high-pressure gas reservoirs in the Keshen 8 Block on the Kelasu structural belt of the Tarim Basin are also featured by high temperature, well-developed fault fissures, huge thickness, tight matrix, complex oil–water distribution, etc., which brings about great difficulties to reserves evaluation and further development. In view of this, an overall study was made on the fine description of reservoir fractures and their seepage mechanism, technical problems were being tackled on seismic data processing and interpretation of complex and high & steep structural zones, optimal development design, safe & rapid drilling and completion wells, reservoir stimulation, dynamic monitoring, etc. to promote the development level of such ultra-deep tight gas reservoirs, and 22 complete sets of specific techniques were formulated in the fields of high-efficiency well spacing, safe and fast drilling, recovery enhancement by well completion transformation, efficient development of optimization design, and so on. Through the technical progress and innovative management of integrated exploration & development, reserves evaluation and productivity construction have been completed on the Keshen 8 Block in the last three years of the 12th Five-Year Plan period (2011–2015, as a result, rapid and high-efficiency productivity construction is realized, and a new area is explored in the development of ultra-deep and ultra-high-pressure fractured tight sand gas reservoirs. This study is of great reference to the development of similar gas reservoirs at home and abroad.

  5. ENHANCING RESERVOIR MANAGEMENT IN THE APPALACHIAN BASIN BY IDENTIFYING TECHNICAL BARRIER AND PREFERRED PRACTICES

    Energy Technology Data Exchange (ETDEWEB)

    Ronald R. McDowell; Khashayar Aminian; Katharine L. Avary; John M. Bocan; Michael Ed. Hohn; Douglas G. Patchen

    2003-09-01

    The Preferred Upstream Management Practices (PUMP) project, a two-year study sponsored by the United States Department of Energy (USDOE), had three primary objectives: (1) the identification of problems, problematic issues, potential solutions and preferred practices related to oil production; (2) the creation of an Appalachian Regional Council to oversee and continue this investigation beyond the end of the project; and (3) the dissemination of investigative results to the widest possible audience, primarily by means of an interactive website. Investigation and identification of oil production problems and preferred management practices began with a Problem Identification Workshop in January of 2002. Three general issues were selected by participants for discussion: Data Management; Reservoir Engineering; and Drilling Practices. At the same meeting, the concept of the creation of an oversight organization to evaluate and disseminated preferred management practices (PMP's) after the end of the project was put forth and volunteers were solicited. In-depth interviews were arranged with oil producers to gain more insight into problems and potential solutions. Project members encountered considerable reticence on the part of interviewees when it came to revealing company-specific production problems or company-specific solutions. This was the case even though interviewees were assured that all responses would be held in confidence. Nevertheless, the following production issues were identified and ranked in order of decreasing importance: Water production including brine disposal; Management of production and business data; Oil field power costs; Paraffin accumulation; Production practices including cementing. An number of secondary issues were also noted: Problems associated with Enhanced Oil Recovery (EOR) and Waterflooding; Reservoir characterization; Employee availability, training, and safety; and Sale and Purchase problems. One item was mentioned both in

  6. Allozyme relationships in hypostomines (Teleostei: Loricariidae) from the Itaipu Reservoir, Upper Rio Paraná basin, Brazil.

    Science.gov (United States)

    Zawadzki, Cláudio Henrique; Renesto, Erasmo; dos Reis, Roberto Esser; Moura, Maurício Osvaldo; Mateus, Rogério Pincela

    2005-03-01

    In an allozyme electrophoresis survey of 15 hypostomine species from the Itaipu Hydroelectric Reservoir, 25 loci from 14 enzyme systems were scored. Allozyme data allowed recording diagnostic genetic markers for all species analyzed and for some species groups within Hypostomus, a taxon which is taxonomically still unresolved in the Upper Rio Paraná basin. The mean expected heterozygosity of the species was considerably variable and hypotheses to tentatively explain this variation are discussed. A cladogram based upon the allelic frequencies of the species analyzed was produced by the continuous maximum likelihood method: Rhinelepis aspera and M. parananus were separated from the species of Hypostominae by a long branch length. Pterygoplichthys anisitsi was the sister of all the representatives of the genus Hypostomus. Within Hypostomus, two main clades were produced: in the first, H. cochliodon was the sister of the species comprising the H. plecostomus group, and in the second, the tree showed the following relationships: (H. albopunctatus (H. regani + Hypostomus sp. 3) + (H. margaritifer (H. microstomus (Hypostomus sp. 1 (H. ternetzi + Hypostomus sp. 2)). Hypostomus ternetzi and Hypostomus sp. 2 are referred to here as representatives of the H. ternetzi group.

  7. Landsat-based long–term LUCC mapping in Xinlicheng Reservoir Basin using object-based classification

    Science.gov (United States)

    Su, Wei; Liang, Dongmei; Tang, Gula; Xiao, Zundong; Li, Jingxin; Wan, Zhengyu; Li, Ping

    2017-05-01

    Rapid urbanization dramatically changes the local environment around Xinlicheng Reservoir Basin. Landsat images are suitable for the land use change caused by human impact. In order to obtain consistent land cover products, a hybrid classification method combining object-based classification and pre-classification alteration detection method was developed and applied to long-term multi-temporal Landsat images to obtain land cover change information. Object-based classification method was combined with Random forest (RF) classifier to classify the Landsat image in 2008. Then the changed areas in 2000, 2004, 2012, and 2016 were identified by comparing with the images in 2008 via the re–weighted multivariate alteration detection transformation method. The images in 2000, 2004, 2012 and 2016 were classified by RF classifier. Land cover maps for 2000, 2004, 2012, and 2016 were produced by combining the unchanged area in 2008 with the new classes of the changed areas in 2000, 2004, 2012 and 2016. According to the accuracy assessment, the overall accuracy of the land covers of the four periods are all greater than 93%. The accuracy assessment indicates that this hybrid method can produce consistent land cover datasets for a long time period.

  8. Accumulation conditions and enrichment patterns of natural gas in the Lower Cambrian Longwangmiao Fm reservoirs of the Leshan-Longnǚsi Palaeohigh, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Xu Chunchun

    2014-10-01

    Full Text Available As several major new gas discoveries have been made recently in the Lower Cambrian Longwangmiao Fm reservoirs in the Leshan-Longnǚsi Palaeohigh of the Sichuan Basin, a super-huge gas reservoir group with multiple gas pay zones vertically and cluster reservoirs laterally is unfolding in the east segment of the palaeohigh. Study shows that the large-scale enrichment and accumulation of natural gas benefits from the good reservoir-forming conditions, including: (1 multiple sets of source rocks vertically, among which, the high-quality Lower Paleozoic source rocks are widespread, and have a hydrocarbon kitchen at the structural high of the Palaeohigh, providing favorable conditions for gas accumulation near the source; (2 three sets of good-quality reservoirs, namely, the porous-vuggy dolomite reservoirs of mound-shoal facies in the 2nd and 4th members of the Sinian Dengying Fm as well as the porous dolomite reservoirs of arene-shoal facies in the Lower Cambrian Longwangmiao Fm, are thick and wide in distribution; (3 structural, lithological and compound traps developed in the setting of large nose-like uplift provide favorable space for hydrocarbon accumulation. It is concluded that the inheritance development of the Palaeohigh and its favorable timing configuration with source rock evolution are critical factors for the extensive enrichment of gas in the Lower Cambrian Longwangmiao Fm reservoirs. The structural high of the Palaeohigh is the favorable area for gas accumulation. The inherited structural, stratigraphic and lithological traps are the favorable sites for gas enrichment. The areas where present structures and ancient structures overlap are the sweet-spots of gas accumulation.

  9. Types and characteristics of carbonate reservoirs and their implication on hydrocarbon exploration: A case study from the eastern Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Shiwei Huang

    2017-02-01

    Full Text Available Carbonate rocks are deposited in the Ordovician, Cambrian, and Sinian of eastern Tarim Basin with a cumulative maximum thickness exceeding 2000 m. They are the main carriers of oil and gas, and a great deal of natural gas has been found there in the past five years. Based on lithofacies and reservoir differences, natural gas exploration domains of eastern Tarim Basin can be classified into five types: Ordovician platform limestone; Ordovician platform dolomite; Cambrian platform margin mound shoal; Cambrian slope gravity flow deposits, and; Sinian dolomite. Carbonate reservoir characteristics of all the types were synthetically analyzed through observation on drilling core and thin sections, porosity and permeability measurement, and logging data of over 10 drilling wells. We find distribution of part of good fracture and cave reservoir in carbonate platform limestone of Ordovician. In the Ordovician, platform facies dolomite is better than limestone, and in the Cambrian, platform margin mound shoal dolomite has large stacking thickness. Good quality and significantly thick carbonate gravity deposit flow can be found in the Cambrian slope, and effective reservoir has also been found in Sinian dolomite. Commercial gas has been found in the limestone and dolomite of Ordovician in Shunnan and Gucheng areas. Exploration experiences from these two areas are instructive, enabling a deeper understanding of this scene.

  10. Reservoir formation mechanism analysis and deep high-quality reservoir prediction in Yingcheng Formation in Longfengshan area of Songliao Basin, China

    Directory of Open Access Journals (Sweden)

    Yongmei Zhang

    2016-12-01

    Full Text Available Although commercial gas flow was produced in several wells with recent years' exploration of Longfengshan area in Changling fault sag, the formation mechanism and controlling factors for high-quality reservoirs still remained undefined. Here, the Yingcheng tight gas reservoirs of Longfengshan area are used as an example to characterize high-quality reservoir formation mechanism and distribution rules. Based on the thin section, SEM, X-ray diffraction, computed tomography (CT scanning, burial history, constant-rate mercury penetration and physical properties testing, formation mechanism and controlling factors for high-quality reservoirs were analyzed. Results show the following characteristics. First, the reservoir is dominated by chlorite and laumontite cements, and compaction is the most important factor to control reservoir physical properties. According to this, the reservoir can be divided into compacted tight sandstones, chlorite-cemented sandstones and laumontite-cemented sandstones. Second, the high-quality reservoirs are formed due to early extensive laumontite precipitation and the later dissolution of laumontite by organic acid. Meanwhile, it is found that the distribution of cementation and dissolution exhibits some regulations in sedimentary facies, and the distribution is mainly effected and controlled by the lake water and charging of fresh water. Besides, the distribution model of various types of sandstones was established. Studies over diagenesis and sedimentary facies reveal that the high-quality laumontite-cemented sandstones exist in the outside subaqueous fan-delta of the deep sag in Longfengshan area. These findings have been validated by recent exploration wells which obtained high industrial gas flow.

  11. Petroleum geology and resources of the Dnieper-Donets Basin, Ukraine and Russia

    Science.gov (United States)

    Ulmishek, Gregory F.

    2001-01-01

    the Dnieper-Donets basin. Discovered reserves of the system are 1.6 billion barrels of oil and 59 trillion cubic feet of gas. More than one-half of the reserves are in Lower Permian rocks below the salt seal. Most of remaining reserves are in upper Visean-Serpukhovian (Lower Carboniferous) strata. The majority of discovered fields are in salt-cored anticlines or in drapes over Devonian horst blocks; little exploration has been conducted for stratigraphic traps. Synrift Upper Devonian carbonate reservoirs are almost unexplored. Two identified source-rock intervals are the black anoxic shales and carbonates in the lower Visean and Devonian sections. However, additional source rocks possibly are present in the deep central area of the basin. The role of Carboniferous coals as a source rock for gas is uncertain; no coal-related gas has been identified by the limited geochemical studies. The source rocks are in the gas-generation window over most of the basin area; consequently gas dominates over oil in the reserves. Three assessment units were identified in the Dnieper-Donets Paleozoic total petroleum system. The assessment unit that contains all discovered reserves embraces postrift Carboniferous and younger rocks. This unit also contains the largest portion of undiscovered resources, especially gas. Stratigraphic and combination structural and stratigraphic traps probably will be the prime targets for future exploration. The second assessment unit includes poorly known synrift Devonian rocks. Carbonate reef reservoirs along the basin margins probably will contain most of the undiscovered resources. The third assessment unit is an unconventional, continuous, basin-centered gas accumulation in Carboniferous low-permeability clastic rocks. The entire extent of this accumulation is unknown, but it occupies much of the basin area. Resources of this assessment unit were not estimated quantitatively.

  12. Lower permian reef-bank bodies’ characterization in the pre-caspian basin

    Science.gov (United States)

    Wang, Zhen; Wang, Yankun; Yin, Jiquan; Luo, Man; Liang, Shuang

    2018-02-01

    Reef-bank reservoir is one of the targets for exploration of marine carbonate rocks in the Pre-Caspian Basin. Within this basin, the reef-bank bodies were primarily developed in the subsalt Devonian-Lower Permian formations, and are dominated by carbonate platform interior and margin reef-banks. The Lower Permian reef-bank present in the eastern part of the basin is considered prospective. This article provides a sequence and sedimentary facies study utilizing drilling and other data, as well as an analysis and identification of the Lower Permian reef-bank features along the eastern margin of the Pre-Caspian Basin using sub-volume coherence and seismic inversion techniques. The results indicate that the sub-volume coherence technique gives a better reflection of lateral distribution of reefs, and the seismic inversion impedance enables the identification of reef bodies’ development phases in the vertical direction, since AI (impedance) is petrophysically considered a tool for distinguishing the reef limestone and the clastic rocks within the formation (limestone exhibits a relatively high impedance than clastic rock). With this method, the existence of multiple phases of the Lower Permian reef-bank bodies along the eastern margin of the Pre-Caspian Basin has been confirmed. These reef-bank bodies are considered good subsalt exploration targets due to their lateral connectivity from south to north, large distribution range and large scale.

  13. Controlling effect of fractures on gas accumulation and production within the tight sandstone: A case study on the Jurassic Dibei gas reservoir in the eastern part of the Kuqa foreland basin, China

    OpenAIRE

    Lu, Hui; Lu, Xuesong; Fan, Junjia; Zhao, Mengjun; Wei, Hongxing; Zhang, Baoshou; Lu, Yuhong

    2016-01-01

    Using Dibei tight sandstone gas reservoir in the eastern part of the Kuqa foreland basin as an example, this paper discusses tight sandstone reservoir fractures characterization, its effect on storage space and gas flow capacity, and its contribution to gas accumulation, enrichment and production in tight sandstone reservoir by using laser scanning confocal microscope (LSCM) observation, mercury intrusion capillary pressure (MICP) testing, and gas-water two-phase relative permeability testing...

  14. Fault features and enrichment laws of narrow-channel distal tight sandstone gas reservoirs: A case study of the Jurassic Shaximiao Fm gas reservoir in the Zhongjiang Gas Field, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Zhongping Li

    2016-11-01

    Full Text Available The Jurassic Shaximiao Fm gas reservoir in the Zhongjiang Gas Field, Sichuan Basin, is the main base of Sinopec Southwest Oil & Gas Company for gas reserves and production increase during the 12th Five-Year Plan. However, its natural gas exploration and development process was restricted severely, since the exploration wells cannot be deployed effectively in this area based on the previous gas accumulation and enrichment pattern of “hydrocarbon source fault + channel sand body + local structure”. In this paper, the regional fault features and the gas accumulation and enrichment laws were discussed by analyzing the factors like fault evolution, fault elements, fault-sand body configuration (the configuration relationship between hydrocarbon source faults and channel sand bodies, trap types, and reservoir anatomy. It is concluded that the accumulation and enrichment of the Shaximiao Fm gas reservoir in this area is controlled by three factors, i.e., hydrocarbon source, sedimentary facies and structural position. It follows the accumulation laws of source controlling region, facies controlling zone and position controlling reservoir, which means deep source and shallow accumulation, fault-sand body conductivity, multiphase channel, differential accumulation, adjusted enrichment and gas enrichment at sweet spots. A good configuration relationship between hydrocarbon source faults and channel sand bodies is the basic condition for the formation of gas reservoirs. Natural gas accumulated preferentially in the structures or positions with good fault-sand body configuration. Gas reservoirs can also be formed in the monoclinal structures which were formed after the late structural adjustment. In the zones supported by multiple faults or near the crush zones, no gas accumulation occurs, but water is dominantly produced. The gas-bearing potential is low in the area with undeveloped faults or being 30 km away from the hydrocarbon source faults. So

  15. Estimating the combined effects of road-induced landslides and reservoir sediment trapping on the regional sediment budget in the Lancang Basin.

    Science.gov (United States)

    Rubin, Z.; Zhao, Y.; Schmitt, R. J. P.; Kondolf, G. M.; Huang, Y.; Xie, Q.

    2016-12-01

    Roads are essential for rural development, but road construction can also increase hillslope erosion rates, disconnect ecosystems, and disrupt social structures. Moreover, we identify a feedback between road-induced landslides and reservoirs: Dam construction commonly requires road construction for access, and the new roads themselves can accelerate rural development, which induces further road construction. Poorly sited or constructed roads on steep slopes increase risks of landslides, which increase sediment loads, and thus increase the rate of sediment accumulation in downstream reservoirs, which can damage turbines and shorten reservoir life. However, landslide-generated sediment reaching rivers downstream of dams could compensate for reduced sediment loads from sediment trapping in reservoirs. We quantified the combined effects ofroad and reservoir development on river sediment transport and reservoir sedimentation rates in the Chinese Lancang Basin (165,000 km2). We mapped landslides along all highways, national roads, and provincial roads (total length 4845 km), as well as on slopes opposite of roads (as control sites to estimate ambient landslide rates). We determined the relative increase in landslide risks due to road construction, estimated slide volumes, and classified landslide connectivity to the fluvial system. From this inventory, we quantified the spatial and temporal distribution of road-induced landslides and estimated sediment inputs to the Lancang River. Our findings indicate that road-induced landslides significantly exceed naturally occurring landslides both in frequency and area, and are changing the regional sediment budget, though overall, sediment transport in the Lancang is reduced due to the larger alteration- sediment trapping in reservoirs.Our results highlight links between resource management and geomorphic change, and the need to consider human impacts on regional scales and from interacting processes.

  16. Assessment of spatial distribution of soil loss over the upper basin of Miyun reservoir in China based on RS and GIS techniques.

    Science.gov (United States)

    Chen, Tao; Niu, Rui-qing; Wang, Yi; Li, Ping-xiang; Zhang, Liang-pei; Du, Bo

    2011-08-01

    Soil conservation planning often requires estimates of the spatial distribution of soil erosion at a catchment or regional scale. This paper applied the Revised Universal Soil Loss Equation (RUSLE) to investigate the spatial distribution of annual soil loss over the upper basin of Miyun reservoir in China. Among the soil erosion factors, which are rainfall erosivity (R), soil erodibility (K), slope length (L), slope steepness (S), vegetation cover (C), and support practice factor (P), the vegetative cover or C factor, which represents the effects of vegetation canopy and ground covers in reducing soil loss, has been one of the most difficult to estimate over broad geographic areas. In this paper, the C factor was estimated based on back propagation neural network and the results were compared with the values measured in the field. The correlation coefficient (r) obtained was 0.929. Then the C factor and the other factors were used as the input to RUSLE model. By integrating the six factor maps in geographical information system (GIS) through pixel-based computing, the spatial distribution of soil loss over the upper basin of Miyun reservoir was obtained. The results showed that the annual average soil loss for the upper basin of Miyun reservoir was 9.86 t ha(-1) ya(-1) in 2005, and the area of 46.61 km(2) (0.3%) experiences extremely severe erosion risk, which needs suitable conservation measures to be adopted on a priority basis. The spatial distribution of erosion risk classes was 66.9% very low, 21.89% low, 6.18% moderate, 2.89% severe, and 1.84% very severe. Thus, by using RUSLE in a GIS environment, the spatial distribution of water erosion can be obtained and the regions which susceptible to water erosion and need immediate soil conservation planning and application over the upper watershed of Miyun reservoir in China can be identified.

  17. Consistent lithological units and its influence on geomechanical stratification in shale reservoir: case study from Baltic Basin, Poland.

    Science.gov (United States)

    Pachytel, Radomir; Jarosiński, Marek; Bobek, Kinga

    2017-04-01

    Geomechanical investigations in shale reservoir are crucial to understand rock behavior during hydraulic fracturing treatment and to solve borehole wall stability problem. Anisotropy should be considered as key mechanical parameter while trying to characterize shale properties in variety of scales. We are developing a concept of step-by-step approach to characterize and upscale the Consistent Lithological Units (CLU) at several scales of analysis. We decided that the most regional scale model, comparable to lithostratigraphic formations, is too general for hydraulic fracture propagation study thus a more detailed description is needed. The CLU's hierarchic model aims in upscale elastic properties with their anisotropy based on available data from vertical borehole. For the purpose of our study we have an access to continuous borehole core profile and full set of geophysical logging from several wells in the Pomeranian part of the Ordovician and Silurian shale complex belongs to the Baltic Basin. We are focused on shale properties that might be crucial for mechanical response to hydraulic fracturing: mineral components, porosity, density, elastic parameters and natural fracture pattern. To prepare the precise CLU model we compare several methods of determination and upscaling every single parameter used for consistent units secretion. Mineralogical data taken from ULTRA log, GEM log, X-ray diffraction and X-ray fluorescence were compared with Young modulus from sonic logs and Triaxial Compressive Strength Tests. The results showed the impact of clay content and porosity increase on Young's modulus reduction while carbonates (both calcite and dolomite) have stronger impact on elastic modulus growth, more than quartz, represented here mostly by detrital particles. Comparing the shales of similar composition in a few wells of different depths we concluded that differences in diagenesis and compaction due to variation in formation depth in a range of 1 km has negligible

  18. Microbial nitrification, denitrification and respiration in the leached cinnamon soil of the upper basin of Miyun Reservoir

    Science.gov (United States)

    Xu, Wen; Cai, Yan-Peng; Yang, Zhi-Feng; Yin, Xin-An; Tan, Qian

    2017-02-01

    Leached cinnamon soil is the main agricultural soil distributed in the North China Plain. In this research, leached cinnamon soil samples were collected in the upper basin of Miyun Reservoir (northeast of Beijing, China). The BaPS method (Barometric Process Separation) was applied to measure nitrification, denitrification and respiration rates. The rates of nitrification, denitrification and respiration were 0-120.35 μg N/kg SDW h, 0-246.86 μg N/kg SDW h and 0.17-225.85 μg C/kg SDW h (Soil Dry Weight, SDW), respectively. The emission rates of CO2 and NxOy through nitrification, denitrification and respiration were 1.00-547.80 and 6.00-4850.65 μmol/h, respectively. The analysis of relationships between nitrification, denitrification and respiration rates indicated that these three microbial processes were interacted, which posed impacts on soil nitrogen availability. As indicated by the results, C:N ratio coupled with content could be taken as the indicators of content, which is usually the predominant form of N available to plants growing in soil. Results showed that content was the highest (i.e., >62.4 mg/kg) when C:N ratio was 5.30-8.40, meanwhile content was 3.71-4.39 mg/kg. Nevertheless, content was the lowest (i.e., <6.40 mg/kg) when C:N ratio was 9.2-12.10, meanwhile content was 3.41-4.35 mg/kg.

  19. Tectono-Thermal History Modeling and Reservoir Simulation Study of the Nenana Basin, Central Alaska: Implications for Regional Tectonics and Geologic Carbon Sequestration

    Science.gov (United States)

    Dixit, Nilesh C.

    basin. Coals have significant capacity for sequestering anthropogenic CO 2 emissions and offer the benefit of enhanced coal bed methane production that can offset the costs associated with the sequestration processes. In order to do a preliminary assessment of the CO2 sequestration and coal bed methane production potential of the Nenana basin, I used available surface and subsurface data to build and simulate a reservoir model of subbituminous Healy Creek Formation coals. The petroleum exploration data were also used to estimate the state of subsurface stresses that are critical in modeling the orientation, distribution and flow behavior of natural coal fractures in the basin. The effect of uncertainties within major coal parameters on the total CO2 sequestration and coal bed methane capacity estimates were evaluated through a series of sensitivity analyses, experimental design methods and fluid flow simulations. Results suggest that the mature, unmineable Healy Creek Formation coals of the Nenana basin can sequester up to 0.41 TCF of CO2 while producing up to 0.36 TCF of CH4 at the end of 44-year forecast. However, these volumes are estimates and they are also sensitive to the well type, pattern and cap rock lithology. I used a similar workflow to evaluate the state of in situ stress in the northeastern North Slope province of Alaska. The results show two distinct stress regimes across the northeastern North Slope. The eastern Barrow Arch exhibits both strike-slip and normal stress regimes. Along the northeastern Brooks Range thrust front, an active thrust-fault regime is present at depths up to 6000 ft but changes to a strike-slip stress regime at depths greater than 6000 ft.

  20. Research on the calculation method of shale and tuff content: taking tuffaceous reservoirs of X depression in the Hailar–Tamtsag Basin as an example

    International Nuclear Information System (INIS)

    Liu, Sihui; Huang, Buzhou; Pan, Baozhi; Guo, Yuhang; Fang, Chunhui; Wang, Guiping; Sun, Fengxian; Qiu, Haibo; Jiang, Bici

    2015-01-01

    Shale content is known in reservoir evaluation as an important parameter in well logging. However, the log response characteristics are simultaneously affected by shale and tuff existing in tuffaceous sandstone reservoirs. Due to the fact that tuff content exerts an influence on the calculation of shale content, the former is equally important as the latter. Owing to the differences in the source and composition between shale and tuff, the calculation of tuff content using the same methods for shale content cannot meet the accuracy requirements of logging evaluation. The present study takes the tuffaceous reservoirs in the X depression of the Hailar–Tamtsag Basin as an example. The differences in the log response characteristics between shale and tuff are theoretically analyzed and verified using core analysis data. The tuff is then divided into fine- and coarse-grained fractions, according to the differences in the distribution of the radioactive elements, uranium, thorium and potassium. Next, a volume model suitable for tuffaceous sandstone reservoirs is established to include a sandstone matrix, shale, fine-grained tuff, coarse-grained tuff and pore. A comparison of three optimization algorithms shows that the particle swarm optimization (PSO) yields better calculation results with small mean errors. The resistivity differences among shale, fine-grained tuff and coarse-grained tuff are considered in the calculation of saturation. The water saturation of tuffaceous reservoirs is computed using the improved Poupon’s equation, which is suitable for tuffaceous sandstone reservoirs with low water salinity. The method is used in well Y, and is shown to have a good application effect. (paper)

  1. Standardizing texture and facies codes for a process-based classification of clastic sediment and rock

    Science.gov (United States)

    Farrell, K.M.; Harris, W.B.; Mallinson, D.J.; Culver, S.J.; Riggs, S.R.; Pierson, J.; ,; Lautier, J.C.

    2012-01-01

    Proposed here is a universally applicable, texturally based classification of clastic sediment that is independent from composition, cementation, and geologic environment, is closely allied to process sedimentology, and applies to all compartments in the source-to-sink system. The classification is contingent on defining the term "clastic" so that it is independent from composition or origin and includes any particles or grains that are subject to erosion, transportation, and deposition. Modifications to Folk's (1980) texturally based classification that include applying new assumptions and defining a broader array of textural fields are proposed to accommodate this. The revised ternary diagrams include additional textural fields that better define poorly sorted and coarse-grained deposits, so that all end members (gravel, sand, and mud size fractions) are included in textural codes. Revised textural fields, or classes, are based on a strict adherence to volumetric estimates of percentages of gravel, sand, and mud size grain populations, which by definition must sum to 100%. The new classification ensures that descriptors are applied consistently to all end members in the ternary diagram (gravel, sand, and mud) according to several rules, and that none of the end members are ignored. These modifications provide bases for standardizing vertical displays of texture in graphic logs, lithofacies codes, and their derivatives- hydrofacies. Hydrofacies codes are nondirectional permeability indicators that predict aquifer or reservoir potential. Folk's (1980) ternary diagram for fine-grained clastic sediments (sand, silt, and clay size fractions) is also revised to preserve consistency with the revised diagram for gravel, sand, and mud. Standardizing texture ensures that the principles of process sedimentology are consistently applied to compositionally variable rock sequences, such as mixed carbonate-siliciclastic ramp settings, and the extreme ends of depositional

  2. An Analytical Method for Deriving Reservoir Operation Curves to Maximize Social Benefits from Multiple Uses of Water in the Willamette River Basin

    Science.gov (United States)

    Moore, K. M.; Jaeger, W. K.; Jones, J. A.

    2013-12-01

    A central characteristic of large river basins in the western US is the spatial and temporal disjunction between the supply of and demand for water. Water sources are typically concentrated in forested mountain regions distant from municipal and agricultural water users, while precipitation is super-abundant in winter and deficient in summer. To cope with these disparities, systems of reservoirs have been constructed throughout the West. These reservoir systems are managed to serve two main competing purposes: to control flooding during winter and spring, and to store spring runoff and deliver it to populated, agricultural valleys during the summer. The reservoirs also provide additional benefits, including recreation, hydropower and instream flows for stream ecology. Since the storage capacity of the reservoirs cannot be used for both flood control and storage at the same time, these uses are traded-off during spring, as the most important, or dominant use of the reservoir, shifts from buffering floods to storing water for summer use. This tradeoff is expressed in the operations rule curve, which specifies the maximum level to which a reservoir can be filled throughout the year, apart from real-time flood operations. These rule curves were often established at the time a reservoir was built. However, climate change and human impacts may be altering the timing and amplitude of flood events and water scarcity is expected to intensify with anticipated changes in climate, land cover and population. These changes imply that reservoir management using current rule curves may not match future societal values for the diverse uses of water from reservoirs. Despite a broad literature on mathematical optimization for reservoir operation, these methods are not often used because they 1) simplify the hydrologic system, raising doubts about the real-world applicability of the solutions, 2) exhibit perfect foresight and assume stationarity, whereas reservoir operators face

  3. Study on the lower limits of petrophysical parameters of the Upper Paleozoic tight sandstone gas reservoirs in the Ordos Basin, China

    Directory of Open Access Journals (Sweden)

    Huiying Cui

    2017-02-01

    Full Text Available There hasn't been a clear understanding of the lower limits of petrophysical parameters of tight sandstone gas reservoirs so far. However, it is an important question directly related to exploration and development strategies. Research methods of the lower limits of petrophysical parameters are reviewed. The new minimum flow pore throat radius method is used to determine the lower limit of flow pore throat radius. The relative permeability curve method, irreducible water saturation method, and testing method, are used to determine the lower limits of porosity, permeability, and gas saturation. After the comprehensive analysis, the lower limits of petrophysical parameters of the Upper Paleozoic tight sandstone gas reservoirs in Ordos Basin are thought as follows: the minimum flow pore throat radius is 0.02 μm, the lower limits of porosity are 3%, the permeability is 0.02 × 10−3 μm2 and the gas saturation is 20%. Besides, the influence of formation pressure on porosity and permeability, the tight sandstone gas filling mechanism, and reservoir characterization petrophysical parameters of tight sandstone reservoirs are further discussed.

  4. The role of anthropogenic water reservoirs within the landscapes of mining areas – a case study from the western part of the Upper Silesian Coal Basin

    Directory of Open Access Journals (Sweden)

    Jaruchiewicz Ewelina

    2014-03-01

    Full Text Available A few thousand anthropogenic water reservoirs can be found in the area of the Upper Silesian Coal Basis (USCB located in southern Poland. In this paper the role of such anthropogenic lakes in the landscape of the western part of the USCB was presented and illustrated with the example of Knurów, a mining city, and its immediate surrounding area. The study of landscape changes in this area was carried out on the basis of archival and contemporary cartographic materials, historical sources, and interviews with inhabitants and direct field observations. It was found that the origin of the majority of the water reservoirs is related to hard coal, clay and sand mining. They were created primarily as a result of filling subsidence basins and post-mining excavations with water, as well as being the result of the construction of various hydro-technical facilities (settling ponds, fire protection water reservoirs, etc. In the study area the anthropogenic water reservoirs are of different sizes, shapes and durability and play different roles in the environment. Between 1884 and 2001 their number increased 25-fold, while at the same time their total surface area increased more than 8-fold. The role of the newly created water reservoirs in the landscape primarily involves the transformation of the existing terrestrial ecosystems into wetland ecosystems. The agro-forestry landscape of the late 19th century was transformed into a typically anthropogenic landscape with a dominant share of water reservoirs, settlement ponds and mining waste heaps. The most common species of plants around the water reservoirs are Phragmites australis, Typha latifolia, Ceratophyllum demersum, Elodea canadensis, Potamogeton natans, Lemna sp., Acorus calamus, Myriophyllum verticillatum, Sagittaria sagittifolia, Alisma plantago-aquatica and Glyceria aquatica. The most valuable elements of the flora include Trapa natans and Ruppia maritima, species recognized in Poland as threatened

  5. Elements and gas enrichment laws of sweet spots in shale gas reservoir: A case study of the Longmaxi Fm in Changning block, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Renfang Pan

    2016-05-01

    Full Text Available Identification of sweet spot is of great significance in confirming shale gas prospects to realize large-scale economic shale gas development. In this paper, geological characteristics of shale gas reservoirs were compared and analyzed based on abundant data of domestic and foreign shale gas reservoirs. Key elements of sweet spots were illustrated, including net thickness of gas shale, total organic carbon (TOC content, types and maturity (Ro of organic matters, rock matrix and its physical properties (porosity and permeability, and development characteristics of natural fractures. After the data in Changning and Weiyuan blocks, the Sichuan Basin, were analyzed, the geologic laws of shale gas enrichment were summarized based on the economic exploitation characteristics of shale gas and the correlation between the elements. The elements of favorable “sweet spots” of marine shale gas reservoirs in the Changning block and their distribution characteristics were confirmed. Firstly, the quality of gas source rocks is ensured with the continuous thickness of effective gas shale larger than 30 m, TOC > 2.0% and Ro = 2.4–3.5%. Secondly, the quality of reservoir is ensured with the brittle minerals content being 30–69%, the clay mineral content lower than 30% and a single lamination thickness being 0.1–1.0 m. And thirdly, the porosity is higher than 2.0%, the permeability is larger than 50 nD, gas content is higher than 1.45 m3/t, and formation is under normal pressure–overpressure system, which ensures the production modes and capacities. Finally, the primary and secondary elements that control the “sweet spots” of shale gas reservoirs were further analyzed and their restrictive relationships with each other were also discussed.

  6. Clastic dykes in over-consolidated tills: evidence for subglacial hydrofracturing at Killiney Bay, eastern Ireland

    Science.gov (United States)

    Rijsdijk, Kenneth F.; Owen, Geraint; Warren, William P.; McCarroll, Danny; van der Meer, Jaap J. M.

    1999-11-01

    A swarm of vertical gravel-filled dykes up to 6 m high and several decimetres wide, cut through an over-consolidated till at Killiney Bay. The dykes are rooted in a gravel layer and many display plumes of clastic debris ejected into the overlying sediments — `burst-out structures'. Such features have not previously been described. These clastic dykes are interpreted as the infillings of hydrofractures which formed when water pressures in the basal gravel layer exceeded the overburden pressure and tensile shear strength of the capping till. The burst-out structures extend up to 7 m from the tops of the dykes and provide strong evidence for forceful upward flow. Evidence suggests that the hydrofractures formed subglacially, probably during a minor re-advance. Their presence in Late Devensian (26-13 ka BP) tills with an Irish Sea provenance (`Irish Sea till') may have important implications for the subglacial hydrology of the last Irish Sea ice sheet. These hydrofractures cannot form in unconsolidated glacimarine sediment and their presence precludes a glacimarine origin for these deposits. They greatly affect the geotechnical properties of Irish Sea tills, in particular providing very permeable routes through otherwise impermeable layers, with important consequences in situations elsewhere in the Irish Sea basin, where they have been used as aquicludes in landfill and low-level nuclear waste disposal sites.

  7. Extended geothermal potential of clastic aquifers by hydraulic stimulation

    NARCIS (Netherlands)

    Veldkamp, J.G.; Pluymaekers, M.P.D.; Wees, J.D.A.M.

    2014-01-01

    We evaluated the implications of hydraulic stimulation in a Dutch context for low permeability clastic aquifers at a depth of 2000 to 4000 m, whose transmissivity has been mapped in the framework of the Dutch subsurface information system on geothermal energy in the Netherlands. For the simulation

  8. Land-use effects on erosion, sediment yields, and reservoir sedimentation: a case study in the Lago Loiza Basin, Puerto Rico

    Science.gov (United States)

    Gellis, A.C.; Webb, R.M.T.; McIntyre, S.C.; Wolfe, W.J.

    2006-01-01

     Lago Loíza impounded in 1953 to supply San Juan, Puerto Rico, with drinking water; by 1994, it had lost 47% of its capacity. To characterize sedimentation in Lago Loíza, a study combining land-use history, hillslope erosion rates, and subbasin sediment yields was conducted. Sedimentation rates during the early part of the reservoir’s operation (1953– 1963) were slightly higher than the rates during 1964–1990. In the early history of the reservoir, cropland comprised 48% of the basin and erosion rates were high. Following economic shifts during the 1960s, cropland was abandoned and replaced by forest, which increased from 7.6% in 1950 to 20.6% in 1987. These land-use changes follow a pattern similar to the northeastern United States. Population in the Lago Loíza Basin increased 77% from 1950 to 1990, and housing units increased 194%. Sheetwash erosion measured from 1991 to 1993 showed construction sites had the highest sediment concentration (61,400 ppm), followed by cropland (47,400 ppm), pasture (3510 ppm), and forest (2050 ppm). This study illustrates how a variety of tools and approaches can be used to understand the complex interaction between land use, upland erosion, fluvial sediment transport and storage, and reservoir sedimentation. 

  9. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images

    Science.gov (United States)

    Tian, Fei; Lu, Xinbian; Zheng, Songqing; Zhang, Hongfang; Rong, Yuanshuai; Yang, Debin; Liu, Naigui

    2017-06-01

    The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills) and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  10. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images

    Directory of Open Access Journals (Sweden)

    Tian Fei

    2017-06-01

    Full Text Available The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  11. Extreme hydrological events and the influence of reservoirs in a highly regulated river basin of northeastern Spain

    Directory of Open Access Journals (Sweden)

    S.M. Vicente-Serrano

    2017-08-01

    New hydrological insights: Results reveal a general reduction in the occurrence of extreme precipitation events in the Segre basin from 1950 to 2013, which corresponded to a general reduction in high flows measured at various gauged stations across the basin. While this study demonstrates spatial differences in the decrease of streamflow between the headwaters and the lower parts of the basin, mainly associated with changes in river regulation, there was no reduction in the frequency of the extraordinary floods. Changes in water management practices in the basin have significantly impacted the frequency, duration, and severity of hydrological droughts downstream of the main dams, as a consequence of the intense water regulation to meet water demands for irrigation and livestock farms. Nonetheless, the hydrological response of the headwaters to these droughts differed markedly from that of the lower areas of the basin.

  12. Role of ecosystem of reservoir basin of the Dnieper river for ensuring life standards and population’s health in Ukraine

    Directory of Open Access Journals (Sweden)

    Shapar A.G.

    2014-06-01

    Full Text Available In this article the reasons of the environment quality deterioration, inclu¬ding its component - water are considered, as well as methods to resolve this problem are offered. High quality of life provides for high economic and social standards, including public health. The share of environmental quality impact on morbidity rate reaches 25%, while the role of water is extremely important. At present medicine does not yet have data on the interactions between different types of diseases and water chemical composition. We need to know the impact of each indicator of water quality on health and human lifespan. In Ukraine about 25 million of population, as well as industrial and agricultural enterprises meet their needs of the water at the expense of the Dnieper river basin. As a result of construction of six extra-large reservoirs they overregulated flow of the river, which led to serious contamination of the water and catastrophic consequences for the ecosystem. Proportion of shallow water constantly increases due to siltation of reservoirs. One of the major challenges is to provide population with qualitative natural water resources. Nature prompts effective solutions. For example, water passes through the natural barriers and is purified from biofouling. A widespread prohibition on discharging untreated water into reservoirs and total transition to water recycling technologies may significantly reduce chemical contamination.

  13. Tectonic framework of the southern portion of the Paraná Basin based on magnetotelluric method: a contribution to the understanding of unconventional reservoirs

    Science.gov (United States)

    Rolim, S.

    2015-12-01

    The characterization of the tectonic framework of Paleozoic terrains is crucial for the investigation of unconventional fractured volcanic reservoirs. In recent years, the need for exploitation of these areas showed the value of the non-seismic methods in Brazil. Here we present the results of a magnetotelluric imaging (MT) to identify and characterize the structural framework of the southern portion of the Paraná Basin, southern Brazil. We carried out a SW-NE ,1200 km-long MT profile, with 68 stations spaced between 5-15 km on the southernmost states in Brazil. The observation of the PSI profile highlights the presence of large scale NW-SE faults and emphasize the presence of two major regional structures: (i) the Rio Grande Arc in the southern portion, and (ii) the Torres Syncline in the northern portion. The Rio Grande Arc is a horst highlighted by the basement uplift and the thicker layers of sedimentary rocks in the extremes south and north of this structure. The fault system observed along the profile suggests simultaneously uplifting of the basement and deposition of the sedimentary sequences of the Paraná Basin. This hypothesis is in agreement with stratigraphic, borehole and geochronological data, which have shown that the Rio Grande arc is contemporaneous with the deposition of the Triassic to Early Jurassic sediments. The Torres Syncline is a structure characterized by the increasing thickness of sedimentary layers in the north section of our MT profile. The continuity of the layers is interrupted by large regional fault systems, which also affect the volcanic rocks of the Serra Geral Formation, indicating that the faults were active after the Cretaceous. The results show that the MT modeling brings a distinct contribution to the understanding of the present structural architecture of the Paraná basin and the construction of a model for potential fractured volcanic reservoirs.

  14. Estimated Loads of Suspended Sediment and Selected Trace Elements Transported through Milltown Reservoir in the Upper Clark Fork Basin, Montana, Water Years 2004-07

    Science.gov (United States)

    Lambing, John H.; Sando, Steven K.

    2008-01-01

    The purpose of this report is to present estimated daily and annual loads of suspended sediment and selected trace elements for water years 2004-07 at two sites upstream and one site downstream from Milltown Reservoir. Milltown Reservoir is a National Priorities List Superfund site in the upper Clark Fork basin of western Montana where sediments enriched in trace elements from historical mining and ore processing have been deposited since the construction of Milltown Dam in 1907. The estimated loads were used to quantify annual net gains and losses (mass balance) of suspended sediment and trace elements within Milltown Reservoir before and after June 1, 2006, which was the start of Stage 1 of a permanent drawdown of the reservoir in preparation for removal of Milltown Dam. This study was done in cooperation with the U.S. Environmental Protection Agency. Daily loads of suspended sediment were estimated for water years 2004-07 by using either high-frequency sampling as part of daily sediment monitoring or regression equations relating suspended-sediment discharge to streamflow. Daily loads of unfiltered-recoverable arsenic, cadmium, copper, iron, lead, manganese, and zinc were estimated by using regression equations relating trace-element discharge to suspended-sediment discharge. Regression equations were developed from data for eriodic water-quality samples collected during water years 2004-07. The equations were applied to daily records of either streamflow or suspended-sediment discharge to produce estimated daily loads. Variations in daily suspended-sediment and trace-element loads generally coincided with variations in streamflow. For most of the period before June 1, 2006, differences in daily loads transported to and from Milltown Reservoir were minor or indicated small amounts of deposition; however, losses of suspended sediment and trace elements from the reservoir occurred during temporary drawdowns in July-August 2004 and October-December 2005. After the

  15. Challenges to and countermeasures for the production stabilization of tight sandstone gas reservoirs of the Sulige Gasfield, Ordos Basin

    Directory of Open Access Journals (Sweden)

    Tao Lu

    2015-10-01

    Full Text Available With the grade of hydrocarbon resources becoming poorer, tight sandstone gas reservoirs may serve as the key to the enhancement of both reserves and productivity. Accordingly, high efficient and sustainable development of the large and over-large tight sandstone reservoirs is very important. However, currently, there is no effective method available for macro-analysis. Based on the latest research findings from the Sulige Gasfield, the largest onshore tight sandstone gas reservoir in China, studies were conducted in five aspects, i.e. reserve scale, development scale, dynamic reserve evaluation, rules in production declines of gasfields and undeveloped resource evaluation, to identify challenges to the production stabilization of gas reservoirs. In addition, key evidences and constraints for the solutions to the difficulties in production stabilization were proposed to provide necessary technical supports for high-efficient development in later stages. Research results show that the major challenges to production stabilization include seven aspects, such as low development induced by improper allocation of well patterns, uneven declines in productivity induced by specific features of reservoir formations and fluids, difficulties in the development of some reserves due to complex gas/water correlation, and differences in production performances by using different production techniques. Finally, guided by the development principles of “promoting productivity by using innovative technologies in different spaces and time”, 13 key technologies, such as comprehensive optimization of development well patterns, multi-dimensional matrix for gas well management and “positive” water discharging and gas production technologies, were proposed to further prolong peak production time and enhance the recovery rates of tight gas reservoirs.

  16. Establishing the Relationship between Fracture-Related Dolomite and Primary Rock Fabric on the Distribution of Reservoirs in the Michigan Basin

    Energy Technology Data Exchange (ETDEWEB)

    G. Michael Grammer

    2006-09-30

    This topical report covers the year 2 of the subject 3-year grant, evaluating the relationship between fracture-related dolomite and dolomite constrained by primary rock fabric in the 3 most prolific reservoir intervals in the Michigan Basin (Ordovician Trenton-Black River Formations; Silurian Niagara Group; and the Devonian Dundee Formation). The characterization of select dolomite reservoirs has been the major focus of our efforts in Phase II/Year 2. Fields have been prioritized based upon the availability of rock data for interpretation of depositional environments, fracture density and distribution as well as thin section, geochemical, and petrophysical analyses. Structural mapping and log analysis in the Dundee (Devonian) and Trenton/Black River (Ordovician) suggest a close spatial relationship among gross dolomite distribution and regional-scale, wrench fault related NW-SE and NE-SW structural trends. A high temperature origin for much of the dolomite in the 3 studied intervals (based upon initial fluid inclusion homogenization temperatures and stable isotopic analyses,) coupled with persistent association of this dolomite in reservoirs coincident with wrench fault-related features, is strong evidence for these reservoirs being influenced by hydrothermal dolomitization. For the Niagaran (Silurian), a comprehensive high resolution sequence stratigraphic framework has been developed for a pinnacle reef in the northern reef trend where we had 100% core coverage throughout the reef section. Major findings to date are that facies types, when analyzed at a detailed level, have direct links to reservoir porosity and permeability in these dolomites. This pattern is consistent with our original hypothesis of primary facies control on dolomitization and resulting reservoir quality at some level. The identification of distinct and predictable vertical stacking patterns within a hierarchical sequence and cycle framework provides a high degree of confidence at this point

  17. Characterization and 3D reservoir modelling of fluvial sandstones of the Williams Fork Formation, Rulison Field, Piceance Basin, Colorado, USA

    International Nuclear Information System (INIS)

    Pranter, Matthew J; Vargas, Marielis F; Davis, Thomas L

    2008-01-01

    This study describes the stratigraphic characteristics and distribution of fluvial deposits of the Upper Cretaceous Williams Fork Formation in a portion of Rulison Field and addresses 3D geologic modelling of reservoir sand bodies and their associated connectivity. Fluvial deposits include isolated and stacked point-bar deposits, crevasse splays and overbank (floodplain) mudrock. Within the Williams Fork Formation, the distribution and connectivity of fluvial sandstones significantly impact reservoir productivity and ultimate recovery. The reservoir sandstones are primarily fluvial point-bar deposits interbedded with shales and coals. Because of the lenticular geometry and limited lateral extent of the reservoir sandstones (common apparent widths of ∼500–1000 ft; ∼150–300 m), relatively high well densities (e.g. 10 acre (660 ft; 200 m) spacing) are often required to deplete the reservoir. Heterogeneity of these fluvial deposits includes larger scale stratigraphic variability associated with vertical stacking patterns and structural heterogeneities associated with faults that exhibit lateral and reverse offsets. The discontinuous character of the fluvial sandstones and lack of distinct marker beds in the middle and upper parts of the Williams Fork Formation make correlation between wells tenuous, even at a 10 acre well spacing. Some intervals of thicker and amalgamated sandstones within the middle and upper Williams Fork Formation can be correlated across greater distances. To aid correlation and for 3D reservoir modelling, vertical lithology proportion curves were used to estimate stratigraphic trends and define the stratigraphic zonation within the reservoir interval. Object-based and indicator-based modelling methods have been applied to the same data and results from the models were compared. Results from the 3D modelling indicate that sandstone connectivity increases with net-to-gross ratio and, at lower net-to-gross ratios (<30%), differences exist in

  18. The Springhill Formation (Jurassic-Cretaceous) as a potential low enthalpy geothermal reservoir in the Cerro Sombrero area, Magallanes Basin, Chile.

    Science.gov (United States)

    Lagarrigue, S. C.; Elgueta, S.; Arancibia, G.; Morata, D.; Sanchez, J.; Rojas, L.

    2017-12-01

    Low enthalpy geothermal energy technologies are being developed around the world as part of policies to replace the use of conventional sources of energy by renewable ones. The reuse of abandoned oil and gas wells in sedimentary basins, whose reservoirs are saturated with water at temperatures above 120°C, is of increasing interest due to the low initial cost.In Chile, interest in applying this technology is focused on the Magallanes Basin (Austral Basin in Argentina) in the extreme south of the country, where important hydrocarbon deposits have been exploited for more than six decades with more than 3,500 wells drilled to depths of over 4,000m. Hydrocarbons have been extracted mainly from the Upper Jurassic to lowermost Cretaceous Springhill Formation, which includes sandstone lithofacies with porosities of 12% to 19% and permeability of 10mD and 1100mD. This formation has been drilled mainly at depths of 1500m to 3000m, the estimated geothermal gradient in the zone is 4.9 °C/100m with well bottom temperature measurements oscillating between 60° and 170°C, sufficient for district heating, and even, electricity generation by means of ORC technologies.To understand in detail the behavior and distribution of the different lithofacies of the Springhill Formation in the Sombrero Oil and Gas Field, sedimentological and geological 3D models have been generated from existing well logs and seismic data. To comprehend the quality of the reservoirs on the other hand, many petrophysical studies of drill core samples representative of the different lithofacies, complemented by electric well log interpretations, were carried out. Results confirm the existence of at least two quartz-rich sandstone lithofacies as potential geothermal reservoirs. In the principal settlement in this area, Cerro Sombrero township (1,800 population), the annual average temperature is 6.4°C, requiring constant domestic heating which, at present comes exclusively from natural gas. The study shows

  19. Experimental reactivity with CO2 of clayey cap-rock and carbonate reservoir of the Paris basin

    International Nuclear Information System (INIS)

    Hubert, G.

    2009-01-01

    The constant increase in the quantity of carbon dioxide in the atmosphere is regarded as being the principal cause of the current global warming. The geological sequestration of CO 2 seems to be an ideal solution to reduce the increase of greenhouse gases (of which CO 2 ) in the atmosphere but only if the reservoir's cap-rock keep its integrity for several hundreds or thousands of years. Batch experimental simulations were conducted to observe the reactivity of a cap-rock made of clay and a carbonate reservoir with CO 2 at 80 C and 150 C for a pressure of 150 bar with an equilibrated water. The analytical protocol established allowed to compare the rocks before and after experimentations finding a very low reactivity, focusing on aluminium in phyllosilicates. Textural analysis shows that CO 2 does not affect the properties of adsorption and the specific surface. The study of carbonate reservoir by confocal microscopy has revealed phenomena of dissolution-precipitation which have no significant impact on chemistry and structure of the reservoir. The numerical simulations carried out on mineral reference as calcium montmorillonite or clinochlore show a significant reaction in the presence of CO 2 not achieved experimentally, probably due to lacunas in the thermodynamic databases or the kinetics of reactions. The simulations on Bure show no reaction on the major minerals confirming the results with batch experiments. (author)

  20. Lack of inhibiting effect of oil emplacement on quartz cementation: Evidence from Cambrian reservoir sandstones, Paleozoic Baltic Basin

    DEFF Research Database (Denmark)

    Molenaar, Nicolaas; Cyziene, Jolanta; Sliaupa, Saulius

    2008-01-01

    , including sandstone architecture, i.e., distribution of shales within the sandstone bodies, and sandstone thickness. Heterogeneity is inherent to sandstone architecture and to the fact that silica for quartz cementation is derived from heterogeneously distributed local pressure solution. Models predicting...... reservoir properties should encompass facies and architecture as important independent factors....

  1. The Sirte Basin province of Libya; Sirte-Zelten total petroleum system

    Science.gov (United States)

    Ahlbrandt, Thomas S.

    2001-01-01

    The Sirte (Sirt) Basin province ranks 13th among the world?s petroleum provinces, having known reserves of 43.1 bil-lion barrels of oil equivalent (36.7 billion barrels of oil, 37.7 tril-lion cubic feet of gas, 0.1 billion barrels of natural gas liquids). It includes an area about the size of the Williston Basin of the north-ern United States and southern Canada (?490,000 square kilome-ters). The province contains one dominant total petroleum system, the Sirte-Zelten, based on geochemical data. The Upper Cretaceous Sirte Shale is the primary hydrocarbon source bed. Reservoirs range in rock type and age from fractured Precam-brian basement, clastic reservoirs in the Cambrian-Ordovician Gargaf sandstones, and Lower Cretaceous Nubian (Sarir) Sand-stone to Paleocene Zelten Formation and Eocene carbonates commonly in the form of bioherms. More than 23 large oil fields (>100 million barrels of oil equivalent) and 16 giant oil fields (>500 million barrels of oil equivalent) occur in the province. Abstract 1 Production from both clastic and carbonate onshore reservoirs is associated with well-defined horst blocks related to a triple junc-tion with three arms?an eastern Sarir arm, a northern Sirte arm, and a southwestern Tibesti arm. Stratigraphic traps in combina-tion with these horsts in the Sarir arm are shown as giant fields (for example, Messla and Sarir fields in the southeastern portion of the province). Significant potential is identified in areas marginal to the horsts, in the deeper grabens and in the offshore area. Four assessment units are defined in the Sirte Basin prov-ince, two reflecting established clastic and carbonate reservoir areas and two defined as hypothetical units. Of the latter, one is offshore in water depths greater than 200 meters, and the other is onshore where clastic units, mainly of Mesozoic age, may be res-ervoirs for laterally migrating hydrocarbons that were generated in the deep-graben areas. The Sirte Basin reflects significant rifting

  2. Multiphase Calcite Cementation and Fluids Evolution of a Deeply Buried Carbonate Reservoir in the Upper Ordovician Lianglitag Formation, Tahe Oilfield, Tarim Basin, NW China

    Directory of Open Access Journals (Sweden)

    Jiaqing Liu

    2017-01-01

    Full Text Available Oil and gas have been found in the Upper Ordovician Lianglitag Formation carbonates in the Tahe Oilfield, Tarim Basin, NW China. This study documents the origin of diagenetic fluids by using a combination of petrology, SIMS, fluid inclusion, and radiogenic isotope analysis. Six stages of calcite cements were revealed. C1-C2 formed in marine to early burial environments. C3 has relatively low δ18OVPDB values (−8.45‰ to −6.50‰ and likely has a meteoric origin. Meteoric water probably fluxed into aquifers during the Early Paleozoic and Late Paleozoic uplift. C4 has δ18OVPDB values typically 3‰ higher than those of C3, and probably formed during shallow burial. C5 displays relatively negative δ18OVPDB values (−8.26‰ to −5.12‰, and the moderate-to-high fluid-inclusion temperatures imply that it precipitated in burial environments. C6 shows homogenization temperatures (up to 200°C higher than the maximum burial and much lower salinities (<10.61 wt% NaCl, which may suggest that the fluid was deeply recycled meteoric water. The average 87Sr/86Sr ratios of fracture- and vug-filling calcite cements are much higher, indicative of incorporation of radiogenic Sr. Caves and fractures constitute the dominant reservoir spaces. A corresponding diagenesis-related reservoir evolution model was established that favors exploration and prediction.

  3. Risk and geological uncertainties in carbonate reservoirs in Santos Basin; Incertezas geologicas e risco em reservatorios carbonaticos na Bacia de Santos

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Makoto; Cortez, Marcella M.M. [Queiroz Galvao Perfuracoes S.A., Rio de Janeiro, RJ (Brazil); Mendes, Marcos Huber

    2004-07-01

    The Lower Albian in the south part of Santos Basin is composed mainly of oolitic calcarenites and calcilutites organized in shoaling upward cycles. The calcarenites from the top of the sequence constitute a package of reservoir zones and sub-zones with regional distribution along which are located mature, producing and development phase oil fields. In this work the main factors with major impact in reserves estimation are interpreted and quantified in a probabilistic approach giving support for the development plan phase of a field of the carbonatic trend. The regional stratigraphic and structural interpretations provided information about extension, external geometry, and continuity of the reservoir zones for reserves risk computation. The porosity probability density functions were defined according to stratigraphic position, seismic reflection pattern of calcarenites and also information from the discovery and the appraisal wells. The Decision Tree methodology with Monte Carlo Simulation was used to better understand the impact of geological uncertainties in reserves computation and also as a first step for risk management. The Monte Carlo simulation allows the Multivariate Sensibility and Scenario Analysis, Probabilistic Technical and Economic Evaluation and Optimal Portfolio Stochastic Simulation. (author)

  4. Depositional facies, diagenesis and their impact on the reservoir quality of Silurian sandstones from Tazhong area in central Tarim Basin, western China

    Science.gov (United States)

    Zhang, Jinliang; Qin, Lijuan; Zhang, Zhongjie

    2008-06-01

    The Silurian sandstones of the Tazhong area are an important oil exploration target in the Tarim Basin, western China. This study deals with the Lower Silurian of the Kalpingtag Formation, which was deposited in a braided delta system. Four major depositional microfacies are identified consisting of distributary channel, interdistributary bay, front bar and sand sheet. In spite of their large lateral extent, exploration of these sandstones is complicated by variation of sediment facies and intense diagenesis, which strongly affected reservoir quality. Depositional environment exerted an essential control on the reservoir quality. Higher energy, well-sorted and relatively coarser grained sandstones have better quality than low-energy fine-grained, clay-rich sandstones. Diagenesis was mainly composed of mechanical and chemical compaction and cementation by quartz overgrowths, carbonates and various clay minerals. Mechanical compaction was a significant porosity reducing agent in the Silurian sandstones. The presence of carbonate cement exerts a dominant influence on porosity and permeability in Tazhong area. Other cements are less important, but quartz cement is significant. The third significant element is clay minerals. The porosity reduction by compaction and cementation and the relative timing of them indicates that compaction was much more important than cementation in reducing porosity.

  5. Water-quality trends in the Rio Grande/Rio Bravo Basin using sediment cores from reservoirs

    Science.gov (United States)

    Van Metre, Peter C.; Mahler, B.J.; Callender, Edward C.

    1997-01-01

    Water-quality trends reflect the relation between water quality and human activities, chronicling changes in concentrations of environmental contaminants, introduction of new contaminants, and successful efforts in environmental pollution remediation. Historical data available for analyzing trends often have severe limitations, from questionable accuracy to unknown sampling and analytic methodologies. Where data are unavailable or have such limitations, water-quality trends sometimes can be reconstructed using sediment cores from lakes and reservoirs.

  6. Impact of acid mine drainage from mining exploitations on the Margajita River basin and the Hatillo reservoir (Dominican Republic)

    International Nuclear Information System (INIS)

    Grandia, F.; Salas, J.; Arcos, D.; Archambault, A.; Cottard, F.

    2009-01-01

    Mining of the Pueblo Viejo high-sulphidation epithermal deposit (Dominican Republic) leads to environmental impact due to the formation of acid mine drainage associated with the oxidative dissolution of sulphides and sulpho salts. In addition to the very low pH, the acid waters are capable of transporting away from the mining areas high concentrations of metals and metalloids in solution. In the present work, a geochemical study of sediments deposited in the Hatillo reservoir is carried out. This reservoir is fed by the Margajita and Yuna streams which transport leachates from the Pueblo Viejo and Falcondo-Bonao (Cr-Ni) mining areas, respectively. The results show that these sediments have very high concentrations of Fe, Al and sulphate, along with significant amounts of As, Zn and Te, which are of especial environmental concern. The main contributor to this metal discharge into the reservoir is the Margajita stream, whereas the Yuna stream does not transport significant amounts of metals in solution due to its neutral pH, although it is likely that metals such as Mn, Cr, Ni and Co can be mobilised as a particulate. (Author) 5 refs.

  7. Maps showing petroleum exploration intensity and production in major Cambrian to Ordovician reservoir rocks in the Anadarko Basin

    Science.gov (United States)

    Henry, Mitch; Hester, Tim

    1996-01-01

    The Anadarko basin is a large, deep, two-stage Paleozoic basin (Feinstein, 1981) that is petroleum rich and generally well explored. The Anadarko basin province, a geogrphic area used here mostly for the convenience of mapping and data management, is defined by political boundaries that include the Anadarko basin proper. The boundaries of the province are identical to those used by the U.S. Geological Survey (USGS) in the 1995 National Assessment of United Stated Oil and Gas Resources. The data in this report, also identical to those used in the national assessment, are from several computerized data bases including Nehring Research Group (NRG) Associates Inc., Significant Oil and Gas Fields of the United States (1992); Petroleum Information (PI), Inc., Well History Control System (1991); and Petroleum Information (PI), Inc., Petro-ROM: Production data on CD-ROM (1993). Although generated mostly in response to the national assessment, the data presented here arc grouped differently and arc displayed and described in greater detail. In addition, the stratigraphic sequences discussed may not necessarily correlate with the "plays" of the 1995 national assessment. This report uses computer-generated maps to show drilling intensity, producing wells, major fields, and other geologic information relevant to petroleum exploration and production in the lower Paleozoic part of the Anadarko basin province as defined for the U.S. Geological Survey's 1995 national petroleum assessment. Hydrocarbon accumulations must meet a minimum standard of 1 million barrels of oil (MMBO) or 6 billion cubic feet of gas (BCFG) estimated ultimate recovery to be included in this report as a major field or revoir. Mapped strata in this report include the Upper Cambrian to Lower Ordovician Arbuckle and Low Ordovician Ellenburger Groups, the Middle Ordovician Simpson Group, and the Middle to Upper Ordovician Viola Group.

  8. Increasing heavy oil reserves in the Wilmington Oil Field through advanced reservoir characterization and thermal production technologies. Annual report, March 30, 1995--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-09-01

    The objective of this project is to increase heavy oil reserves in a portion of the Wilmington Oil Field, near Long Beach, California, by implementing advanced reservoir characterization and thermal production technologies. Based on the knowledge and experience gained with this project, these technologies are intended to be extended to other sections of the Wilmington Oil Field, and, through technology transfer, will be available to increase heavy oil reserves in other slope and basin clastic (SBC) reservoirs. The project involves implementing thermal recovery in the southern half of the Fault Block II-A Tar zone. The existing steamflood in Fault Block II-A has been relatively inefficient due to several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery efficiency and reduce operating costs.

  9. Well-Production Data and Gas-Reservoir Heterogeneity -- Reserve Growth Applications

    Science.gov (United States)

    Dyman, Thaddeus S.; Schmoker, James W.

    2003-01-01

    Oil and gas well production parameters, including peakmonthly production (PMP), peak-consecutive-twelve month production (PYP), and cumulative production (CP), are tested as tools to quantify and understand the heterogeneity of reservoirs in fields where current monthly production is 10 percent or less of PMP. Variation coefficients, defined as VC= (F5-F95)/F50, where F5, F95, and F50 are the 5th, 95th, and 50th (median) fractiles of a probability distribution, are calculated for peak and cumulative production and examined with respect to internal consistency, type of production parameter, conventional versus unconventional accumulations, and reservoir depth. Well-production data for this study were compiled for 69 oil and gas fields in the Lower Pennsylvanian Morrow Formation of the Anadarko Basin, Oklahoma. Of these, 47 fields represent production from marine clastic facies. The Morrow data were supplemented by data from the Upper Cambrian and Lower Ordovician Arbuckle Group, Middle Ordovician Simpson Group, Middle Pennsylvanian Atoka Formation, and Silurian and Lower Devonian Hunton Group of the Anadarko Basin, one large gas field in Upper Cretaceous reservoirs of north-central Montana (Bowdoin field), and three areas of the Upper Devonian and Lower Mississippian Bakken Formation continuous-type (unconventional) oil accumulation in the Williston Basin, North Dakota and Montana. Production parameters (PMP, PYP, and CP) measure the net result of complex geologic, engineering, and economic processes. Our fundamental hypothesis is that well-production data provide information about subsurface heterogeneity in older fields that would be impossible to obtain using geologic techniques with smaller measurement scales such as petrographic, core, and well-log analysis. Results such as these indicate that quantitative measures of production rates and production volumes of wells, expressed as dimensionless variation coefficients, are potentially valuable tools for

  10. Geoprocessing techniques to evaluate the spatial distribution of natural rain erosion potential in the Hydrographic Basin of Cachoeira Dourada Reservoir – Brazil

    Directory of Open Access Journals (Sweden)

    João Batista Pereira CABRAL

    2005-12-01

    Full Text Available Natural potential erosion were defined from their main natural conditioners in the region of hydrographic basin of Cachoeira Dourada (between Goiás and Minas Gerais states −Brazil, with geoprocessing techniques and the Universal Soil Loss Equation (USLE. Upon the decision for natural erosion potential, a matrix with values of erosivity (R, erodibility (K, declivity, and ramp length (LS was elaborated, where classes of low, medium, high, very high, and extremely high natural erosion potential (NEP were established. Spatial distribution for the factors R, K, LS, and PNE was defined. The highest average R index for the rainy series was 8173.50 MJ ha mm-1 h-1 year-1. The period with data from 30 years (1973 – 2002 showed that the reservoir basin displayed areas susceptible to rill and interill erosion (69.16% of the total. There is a predominance of low erosion potential among the classes, which can be explained due to the soil predominant classes as well as to the low declivity. Areas with medium to extremely high erosion potential require the adoption of measures to avoid start and development of more severe erosion processes (ravines and gullies.

  11. How to solve the technical problems in CBM development: A case study of a CBM gas reservoir in the southern Qinshui Basin

    Directory of Open Access Journals (Sweden)

    Qingzhong Zhu

    2015-03-01

    Full Text Available The low average single-well production, resulting in low economic benefit, has become the main bottleneck of CBM development in China. In view of this issue, through case study of a CBM gas reservoir in the southern Qinshui Basin, we summarized the present status of CBM technology and development there and also pointed out some major problems in CBM development: (1 the engineering technology for the CBM development needs to adapt to the particular geological characteristics; (2 a large number of inefficient zones still exist in mature blocks in the southern Qinshui Basin; (3 single-well production can not be effectively enhanced only by increasing the fracturing scale; (4 the production of multi-lateral wells is higher, but the fulfillment rate of production capacity overall is still low; and (5 on-site management lacks scientific evidence. On this basis, we present the following suggestions for subsequent coalbed gas development: (1 the production construction mode should be changed, and the fulfillment rate of production capacity construction should be improved; (2 CBM geological research should be improved and well types and locations should be designed reasonably and scientifically; (3 main technologies should be built in a dialectical thinking mode; (4 horizontal well design should be optimized to improve the applicability of relevant technologies; (5 fracturing mode should be changed to improve single-well production; and (6 the drainage technology should be changed to improve economic efficiency.

  12. Analysis on biomass and productivity of epilithic algae and their relations to environmental factors in the Gufu River basin, Three Gorges Reservoir area, China.

    Science.gov (United States)

    Ge, Jiwen; Wu, Shuyuan; Touré, Dado; Cheng, Lamei; Miao, Wenjie; Cao, Huafen; Pan, Xiaoying; Li, Jianfeng; Yao, Minmin; Feng, Liang

    2017-12-01

    The main purpose of this study conducted from August 2010 was to find biomass and productivity of epilithic algae and their relations to environmental factors and try to explore the restrictive factors affecting the growth of algae in the Gufu River, the one of the branches of Xiangxi River located in the Three Gorges Reservoir of the Yangtze River, Hubei Province, Central China. An improved method of in situ primary productivity measurement was utilized to estimate the primary production of the epilithic algae. It was shown that in rivers, lakes, and reservoirs, algae are the main primary producers and have a central role in the ecosystem. Chlorophyll a concentration and ash-free dry mass (AFDM) were estimated for epilithic algae of the Gufu River basin in Three Gorges Reservoir area. Environmental factors in the Gufu River ecosystem highlighted differences in periphyton chlorophyll a ranging from 1.49 mg m -2 (origin) to 69.58 mg m -2 (terminal point). The minimum and maximum gross primary productivity of epilithic algae were 96.12 and 1439.89 mg C m -2  day -1 , respectively. The mean net primary productivity was 290.24 mg C m -2  day -1 . The mean autotrophic index (AFDM:chlorophyll a) was 407.40. The net primary productivity, community respiration ratio (P/R ratio) ranged from 0.98 to 9.25 with a mean of 2.76, showed that autotrophic productivity was dominant in the river. Relationship between physicochemical characteristics and biomass was discussed through cluster and stepwise regression analysis which indicated that altitude, total nitrogen (TN), NO 3 - -N, and NH 4 + -N were significant environmental factors affecting the biomass of epilithic algae. However, a negative logarithmic relationship between altitude and the chlorophyll a of epilithic algae was high. The results also highlighted the importance of epilithic algae in maintaining the Gufu River basin ecosystems health.

  13. Phase I (Year 1) Summary of Research--Establishing the Relationship between Fracture-Related Dolomite and Primary Rock Fabric on the Distribution of Reservoirs in the Michigan Basin

    Energy Technology Data Exchange (ETDEWEB)

    G. Michael Grammer

    2005-11-09

    This topical report covers the first 12 months of the subject 3-year grant, evaluating the relationship between fracture-related dolomite and dolomite constrained by primary rock fabric in the 3 most prolific reservoir intervals in the Michigan Basin (Ordovician Trenton-Black River Formations; Silurian Niagara Group; and the Devonian Dundee Formation). Phase I tasks, including Developing a Reservoir Catalog for selected dolomite reservoirs in the Michigan Basin, Characterization of Dolomite Reservoirs in Representative Fields and Technology Transfer have all been initiated and progress is consistent with our original scheduling. The development of a reservoir catalog for the 3 subject formations in the Michigan Basin has been a primary focus of our efforts during Phase I. As part of this effort, we currently have scanned some 13,000 wireline logs, and compiled in excess of 940 key references and 275 reprints that cover reservoir aspects of the 3 intervals in the Michigan Basin. A summary evaluation of the data in these publications is currently ongoing, with the Silurian Niagara Group being handled as a first priority. In addition, full production and reservoir parameter data bases obtained from available data sources have been developed for the 3 intervals in Excel and Microsoft Access data bases. We currently have an excess of 25 million cells of data for wells in the Basin. All Task 2 objectives are on time and on target for Phase I per our original proposal. Our mapping efforts to date, which have focused in large part on the Devonian Dundee Formation, have important implications for both new exploration plays and improved enhanced recovery methods in the Dundee ''play'' in Michigan--i.e. the interpreted fracture-related dolomitization control on the distribution of hydrocarbon reservoirs. In an exploration context, high-resolution structure mapping using quality-controlled well data should provide leads to convergence zones of fault

  14. THE STRUCTURE OF THE WATER CONSTRUCTIONS IN THE SEBES HYDROGRAPHIC BASIN AND THE STORAGE RESERVOIRS. EFFECT ON THE AVERAGE DISCHARGE

    Directory of Open Access Journals (Sweden)

    Stef Iulian Ioan

    2013-05-01

    Full Text Available In the upper basin of the Sebes Valley, the oldest storage lakes have been temporary artificial lakes, called haituri in Romanian. They were created within the forest exploitation areas. Inside the dams of those retention lakes, which dams are made of a wooden skeleton, filled with soil and stones, there have been weirs for the quick discharge of the water, having the purpose of creating some flood trends, capable of carrying over the logs, downstream the lake. At present, some of those temporary artificial lakes are used as trout farms, while others are damaged, or operate as basins for the sedimentation of the alluvial deposits. The difference of level between the springs of the Sebes and the Mures Rivers generates a convertible hydroelectric potential, having an average power exceeding 60,000 kW" />

  15. GestAqua.AdaPT - Mediterranean river basin modeling and reservoir operation strategies for climate change adaptation

    Science.gov (United States)

    Alexandre Diogo, Paulo; Nunes, João Pedro; Marco, Machado; Aal, Carlo; Carmona Rodrigues, António; Beça, Pedro; Casanova Lino, Rafael; Rocha, João; Carvalho Santos, Cláudia

    2016-04-01

    Climate change (CC) scenarios for the Mediterranean region include an increase in the frequency and intensity of extreme weather events such as drought periods. higher average temperatures and evapotranspiration, combined with the decrease of annual precipitation may strongly affect the sustainability of water resources. In face of these risks, improving water management actions? by anticipating necessary operational measures is required to insure water quantity and quality according to the needs of the populations and irrigation in agriculture. This is clearly the case of the Alentejo region, southern Portugal, where present climatic conditions already pose significant challenges to water resources stakeholders, mainly from the agricultural and the urban supply sectors. With this in mind, the GestAqua.AdaPT project is underway during 2015 and 2016, aiming at analyzing CC impacts until 2100 and develop operational procedures to ensure water needs are adequately satisfied in the Monte Novo and Vigia reservoirs, which supply water for the city of Évora and nearby irrigation systems. Specific project objectives include: a) defining management and operational adaptation strategies aiming to ensure resource sustainability, both quantitatively and qualitatively; b) evaluate future potential costs and available alternatives to the regional water transfer infrastructure linked with the large Alqueva reservoir implemented in 2011; c) defining CC adaptation strategies to reduce irrigation water needs and d) identification of CC adaptation strategies which can be suitable also to other similar water supply systems. The methodology is centered on the implementation of a cascade of modeling tools, allowing the integrated simulation of the multiple variables under analysis. The project is based on CC scenarios resulting from the CORDEX project for 10 combinations of Global and regional climate models (GCMs and RCMs). The study follows by using two of these combinations

  16. The Effect of Dreissena polymorpha on Bacterioplankton, Nematode Fauna and their Relations to Environmental Factors in Ogosta Reservoir (Danube Basin

    Directory of Open Access Journals (Sweden)

    Kalcheva Hristina

    2016-04-01

    Full Text Available Spatial, seasonal, and annual bacterioplankton dynamics in recently infested by the species Dreissena polymorpha Ogosta Reservoir were studied for the first time during three year period. Bacterioplankton total number was higher in spring in ecotone zones, than in summer at thermocline. NH4-N, PO4-P, turbidity, dissolved oxygen, COD and chlorophyll-a correlate positively, while transparency and Ca2+ negatively with bacteria. Nematode species composition, included 22 species studied (13 rarely found and Rhabditis brevispina new for Bulgaria belonging to nine families. The D. polymorpha impact is positive on nematodes and phytoplankton, negative on zooplankton and bacterioplankton, but weak positive on larger bacteria, rods and attached bacteria.

  17. Techniques used in the exploration of turbidite reservoirs in a frontier setting - Helland Hansen setting, Voering Basin, offshore Mid Norway

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Ferrer, F.; James, S.D.; Lak, B.; Evans, A.M.

    1998-12-31

    In the 15th Norwegian licensing round there was awarded operation of the Helland Hansen deep water license. Subsurface interpretation commenced towards the end of 1996, following completion of a 1540 km{sup 2} 3-D seismic survey. The main exploration target comprise Turonian to Coniacian turbidite sands within a large fault-bound dip closure. This presentation describes various techniques applied in the exploration of this new turbidite play, with emphasis on the study of the reservoir potential. A methodology of integrated analysis is presented. Through these efforts, a greater understanding of the lithological and depositional models in this non-calibrated area has progressively been achieved. 5 refs., 11 figs.

  18. The estimation of CO2 storage potential of gas-bearing shale complex at the early stage of reservoir characterization: the case of Baltic Basin (Poland).

    Science.gov (United States)

    Wójcicki, Adam; Jarosiński, Marek

    2017-04-01

    For the stage of shale gas production, like in the USA, prediction of the CO2 storage potential in shale reservoir can be performed by dynamic modeling. We have made an attempt to estimate this potential at an early stage of shale gas exploration in the Lower Paleozoic Baltic Basin, based on data from 3,800 m deep vertical well (without hydraulic fracking stimulation), supplemented with additional information from neighboring boreholes. Such an attempt makes a sense as a first guess forecast for company that explores a new basin. In our approach, the storage capacity is build by: (1) sorption potential of organic matter, (2) open pore space and (3) potential fracture space. the sequence. our estimation is done for 120 m long shale sequence including three shale intervals enriched with organic mater. Such an interval is possible to be fracked from a single horizontal borehole as known from hydraulic fracture treatment in the other boreholes in this region. The potential for adsorbed CO2 is determined from Langmuir isotherm parameters taken from laboratory measurements in case of both CH4 and CO2 adsorption, as well as shale density and volume. CO2 has approximately three times higher sorption capacity than methane to the organic matter contained in the Baltic Basin shales. Finally, due to low permeability of shale we adopt the common assumption for the USA shale basins that the CO2 will be able to reach effectively only 10% of theoretical total sorption volume. The pore space capacity was estimated by utilizing results of laboratory measurements of dynamic capacity for pores bigger than 10 nm. It is assumed for smaller pores adsorption prevails over free gas. Similarly to solution for sorption, we have assumed that only 10 % of the tight pore space will be reached by CO2. For fracture space we have considered separately natural (tectonic-origin) and technological (potentially produced by hydraulic fracturing treatment) fractures. From fracture density profile and

  19. Geomechanical Framework for Secure CO2 Storage in Fractured Reservoirs and Caprocks for Sedimentary Basins in theMidwest United States

    Energy Technology Data Exchange (ETDEWEB)

    Sminchak, Joel [Battelle, Columbus, OH (United States)

    2017-09-29

    This report presents final technical results for the project Geomechanical Framework for Secure CO2 Storage in Fractured Reservoirs and Caprocks for Sedimentary Basins in the Midwest United States (DE-FE0023330). The project was a three-year effort consisting of seven technical tasks focused on defining geomechanical factors for CO2 storage applications in deep saline rock formations in Ohio and the Midwest United States, because geomechancial issues have been identified as a significant risk factor for large-scale CO2 storage applications. A basin-scale stress-strain analysis was completed to describe the geomechanical setting for rock formations of Ordovician-Cambrian age in Ohio and adjacent areas of the Midwest United States in relation to geologic CO2 storage applications. The tectonic setting, stress orientation-magnitude, and geomechanical and petrophysical parameters for CO2 storage zones and caprocks in the region were cataloged. Ten geophysical image logs were analyzed for natural fractures, borehole breakouts, and drilling-induced fractures. The logs indicated mostly less than 10 fractures per 100 vertical feet in the borehole, with mostly N65E principal stress orientation through the section. Geophysical image logs and other logs were obtained for three wells located near the sites where specific models were developed for geomechanical simulations: Arches site in Boone County, Kentucky; Northern Appalachian Basin site in Chautauqua County, New York; and E-Central Appalachian Basin site in Tuscarawas County, Ohio. For these three wells, 9,700 feet of image logs were processed and interpreted to provide a systematic review of the distribution within each well of natural fractures, wellbore breakouts, faults, and drilling induced fractures. There were many borehole breakouts and drilling-induced tensile fractures but few natural fractures. Concentrated fractures were present at the Rome-basal sandstone

  20. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    Large impoundments, defined as those with surface area of 200 ha or greater, are relatively new aquatic ecosystems in the global landscape. They represent important economic and environmental resources that provide benefits such as flood control, hydropower generation, navigation, water supply, commercial and recreational fisheries, and various other recreational and esthetic values. Construction of large impoundments was initially driven by economic needs, and ecological consequences received little consideration. However, in recent decades environmental issues have come to the forefront. In the closing decades of the 20th century societal values began to shift, especially in the developed world. Society is no longer willing to accept environmental damage as an inevitable consequence of human development, and it is now recognized that continued environmental degradation is unsustainable. Consequently, construction of large reservoirs has virtually stopped in North America. Nevertheless, in other parts of the world construction of large reservoirs continues. The emergence of systematic reservoir management in the early 20th century was guided by concepts developed for natural lakes (Miranda 1996). However, we now recognize that reservoirs are different and that reservoirs are not independent aquatic systems inasmuch as they are connected to upstream rivers and streams, the downstream river, other reservoirs in the basin, and the watershed. Reservoir systems exhibit longitudinal patterns both within and among reservoirs. Reservoirs are typically arranged sequentially as elements of an interacting network, filter water collected throughout their watersheds, and form a mosaic of predictable patterns. Traditional approaches to fisheries management such as stocking, regulating harvest, and in-lake habitat management do not always produce desired effects in reservoirs. As a result, managers may expend resources with little benefit to either fish or fishing. Some locally

  1. Geothermal reservoir assessment case study, Northern Basin and Range Province. Final Report, 1 October 1978-30 September 1979

    Energy Technology Data Exchange (ETDEWEB)

    1979-10-01

    Campbell E No. 2 well in the Humboldt House geothermal field in central Pershing County, Nevada was drilled to a depth of 8061 ft in order to confirm the existence of a commercial reservoir. This well offsets the field discovery well which was drilled in 1977 and completed to a depth of only 1835 ft. Desert Peak B-23-1 well was likewise drilled in order to help evaluate a previously discovered geothermal field located in northwestern Churchill County, Nevada. The Desert Peak B-23-1 well was drilled to a depth of 9641 ft as compared to the deepest of three earlier wells drilled to 7662 ft. The drilling and completion of both these wells are described, including the daily drilling reports, drill bit records, descriptions of the casing and cementing programs, drilling fluid descriptions including methods of combating lost circulation, wellhead equipment descriptions, and logging programs.

  2. Methane in the Northern West Siberian Basin. Generation, dynamics of the reservoirs and exchange with the atmosphere

    International Nuclear Information System (INIS)

    Cramer, B.

    1997-07-01

    Based on compositional data and isotope geochemistry natural gas in northern West Siberia can be divided into three groups. These are: natural gas in Jurassic rocks, natural gas in Neocomian rocks and natural gas from the Aptian to Cenomanian Pokur Formation. Natural gas in Jurassic rocks was generated thermogenically from rocks of the Jurassic Tyumen Formation. Natural gas in Neocomian rocks is also of thermogenic origin, possibly being generated from the organic matter of Lower Cretaceous sediments. The largest accumulation of natural gas occurs in sandstone reservoirs in the Pokur Formation. This gas can be described as a mixture between thermogenic gas from deeper strata and isotopically light almost pure methane. 98.6% of this gas consists of methane with an unusual isotope signature of -51.2 permille. It is not possible to explain the existence of this methane with established concepts of gas generation. A new model was developed to examine the possibility of a thermogenic origin of the isotopically light methane in early mature rocks of the Pokur Formation. Based on pyrolysis experiments and reaction kinetic calculations the model enables the simulation of stable carbon isotope ratios of hydrocarbon components in natural gas. The temperature dependent kinetic isotope fractionation is defined by a difference in the activation energies of 12 C-and 13 C-methane generation. The application of the new method to two coaly sandstones of the Pokur Formation results in a good correspondence between modelled carbon isotope ratios of δ 13 C values of methane in the reservoirs. The mass of methane thermogenically generated within the Pokur Formation under the gas field structures, however, is not sufficient to explain the mass of accumulated methane. (orig./SR) [de

  3. Geostatistical and stratigraphic analysis of deltaic reservoirs from the Reconcavo Basin, Brazil; Analise estratigrafica e geoestatistica de reservatorios deltaicos da Bacia do Reconcavo (BA)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Carlos Moreira

    1997-07-01

    This study presents the characterization of the external geometry of deltaic oil reservoirs, including the description of their areal distribution using geo statistic tools, such as variography and kriging. A high-resolution stratigraphic study was developed over a 25 km{sup 2} area, by using data from 276 closely-spaced wells of an oil-producer field from the Reconcavo Basin, northeastern Brazil. The studied succession records the progressive lacustrine transgression of a deltaic environment. Core data and stratigraphic cross sections suggest that the oil reservoirs are mostly amalgamated, delta-front lobes, and subordinately, crevasse deposits. Some important geometrical elements were recognized by the detailed variographic analysis developed for each stratigraphic unit (zone). The average width for the groups of deltaic lobes of one zone was measured from the variographic feature informally named as hole effect. This procedure was not possible for the other zones due to the intense lateral amalgamation of sandstones, indicated by many variographic nested structures. Net sand krigged maps for the main zones suggest a NNW-SSE orientation for the deltaic lobes, as also their common amalgamation and compensation arrangements. High-resolution stratigraphic analyses should include a more regional characterization of the depositional system that comprises the studied succession. On the other hand, geostatistical studies should be developed only after the recognition of the depositional processes acting in the study area and the geological meaning of the variable to be treated, including its spatial variability scales as a function of sand body thickness, orientation and amalgamation. (author)

  4. Balancing ecosystem services with energy and food security - assessing trade-offs for reservoir operation and irrigation investment in Kenya's Tana basin

    Science.gov (United States)

    Hurford, A. P.; Harou, J. J.

    2014-01-01

    Competition for water between key economic sectors and the environment means agreeing on allocation is challenging. Managing releases from the three major dams in Kenya's Tana River basin with its 4.4 million inhabitants, 567 MW of installed hydropower capacity, 33 000 ha of irrigation and ecologically important wetlands and forests is a pertinent example. This research seeks to identify and help decision-makers visualise reservoir management strategies which result in the best possible (Pareto-optimal) allocation of benefits between sectors. Secondly we seek to show how trade-offs between achievable benefits shift with the implementation of new proposed rice, cotton and biofuel irrigation projects. To identify the Pareto-optimal trade-offs we link a water resources management model to a multi-criteria search algorithm. The decisions or "levers" of the management problem are volume dependent release rules for the three major dams and extent of investment in new irrigation schemes. These decisions are optimised for objectives covering provision of water supply and irrigation, energy generation and maintenance of ecosystem services which underpin tourism and local livelihoods. Visual analytic plots allow decision makers to assess multi-reservoir rule-sets by understanding their impacts on different beneficiaries. Results quantify how economic gains from proposed irrigation schemes trade-off against disturbance of the flow regime which supports ecosystem services. Full implementation of the proposed schemes is shown to be Pareto-optimal, but at high environmental and social cost. The clarity and comprehensiveness of "best-case" trade-off analysis is a useful vantage point from which to tackle the interdependence and complexity of water-energy-food "nexus" challenges.

  5. Balancing ecosystem services with energy and food security - Assessing trade-offs from reservoir operation and irrigation investments in Kenya's Tana Basin

    Science.gov (United States)

    Hurford, A. P.; Harou, J. J.

    2014-08-01

    Competition for water between key economic sectors and the environment means agreeing allocations is challenging. Managing releases from the three major dams in Kenya's Tana River basin with its 4.4 million inhabitants, 567 MW of installed hydropower capacity, 33 000 ha of irrigation and ecologically important wetlands and forests is a pertinent example. This research seeks firstly to identify and help decision-makers visualise reservoir management strategies which result in the best possible (Pareto-optimal) allocation of benefits between sectors. Secondly, it seeks to show how trade-offs between achievable benefits shift with the implementation of proposed new rice, cotton and biofuel irrigation projects. To approximate the Pareto-optimal trade-offs we link a water resources management simulation model to a multi-criteria search algorithm. The decisions or "levers" of the management problem are volume-dependent release rules for the three major dams and extent of investment in new irrigation schemes. These decisions are optimised for eight objectives covering the provision of water supply and irrigation, energy generation and maintenance of ecosystem services. Trade-off plots allow decision-makers to assess multi-reservoir rule-sets and irrigation investment options by visualising their impacts on different beneficiaries. Results quantify how economic gains from proposed irrigation schemes trade-off against the disturbance of ecosystems and local livelihoods that depend on them. Full implementation of the proposed schemes is shown to come at a high environmental and social cost. The clarity and comprehensiveness of "best-case" trade-off analysis is a useful vantage point from which to tackle the interdependence and complexity of "water-energy-food nexus" resource security issues.

  6. Prediction of shale prospectivity from seismically-derived reservoir and completion qualities: Application to a shale-gas field, Horn River Basin, Canada

    Science.gov (United States)

    Mo, Cheol Hoon; Lee, Gwang H.; Jeoung, Taek Ju; Ko, Kyung Nam; Kim, Ki Soo; Park, Kyung-sick; Shin, Chang Hoon

    2018-04-01

    Prospective shale plays require a combination of good reservoir and completion qualities. Total organic carbon (TOC) is an important reservoir quality and brittleness is the most critical condition for completion quality. We analyzed seismically-derived brittleness and TOC to investigate the prospectivity of the Horn River Group shale (the Muskwa, Otter Park, Evie shales) of a shale-gas field in the western Horn River Basin, British Columbia, Canada. We used the λρ-μρ brittleness template, constructed from the mineralogy-based brittleness index (MBI) and elastic logs from two wells, to convert the λρ and μρ volumes from prestack seismic inversion to the volume for the brittleness petrotypes (most brittle, intermediate, and least brittle). The probability maps of the most brittle petrotype for the three shales were generated from Bayesian classification, based on the λρ-μρ template. The relationship between TOC and P-wave and S-wave velocity ratio (VP/VS) at the wells allowed the conversion of the VP/VS volume from prestack inversion to the TOC volume, which in turn was used to construct the TOC maps for the three shales. Increased TOC is correlated with high brittleness, contrasting with the commonly-held understanding. Therefore, the prospectivity of the shales in the study area can be represented by high brittleness and increased TOC. We propose a shale prospectivity index (SPI), computed by the arithmetic average of the normalized probability of the most brittle petrotype and the normalized TOC. The higher SPI corresponds to higher production rates in the Muskwa and Evie shales. The areas of the highest SPI have not been fully tested. The future drilling should be focused on these areas to increase the economic viability of the field.

  7. Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management, Class III

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, Roy; Clarke, Don; Walker, Scott; Phillips, Chris; Nguyen, John; Moos, Dan; Tagbor, Kwasi

    2001-08-07

    This project was intended to increase recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs, transferring technology so that it can be applied in other sections of the Wilmington field and by operators in other slope and basin reservoirs is a primary component of the project.

  8. Structure and Dynamics of Floods in the upper Delaware River Basin: An Integrated Seasonal Forecasting System for New York City Reservoirs

    Science.gov (United States)

    Najibi, N.; Devineni, N.

    2016-12-01

    The National Weather Service River Forecasting System (NWS-RFS) issues 3-month lead probabilistic forecasts of streamflow for many river basins in the contiguous United States from 12 river forecasting centers. The Ensemble Streamflow Prediction system from NWS-RFS uses conceptual hydrologic models to issue streamflow forecasts based on the current soil moisture, river, and reservoir conditions by assuming that past meteorological events will recur in the future with historical probabilities. Recent investigations focusing on the teleconnection between anomalous sea surface temperature conditions and regional/continental hydroclimatology show that interannual and interdecadal variability in exogenous climatic indices modulates the regional streamflow patterns. In this work, we present a comprehensive framework to quantify the structure and dynamics of floods for the upper Delaware River Basin based on the interaction between the exogenous climate and weather patterns and antecedent flow regimes. We focus on estimating the conditional distribution of flood volume, duration, peak and timing based on large-scale climatic teleconnections (seasonal sea level pressure and pre-season sea surface temperature) and macroscale hydrological factors (start of the season's flow, seasonal rainfall duration and intensity, pre-season snow depth and cover in watershed, and concurrent rain over snow (ROS) events). Statistical techniques such as the semi-parametric k-nearest neighbor resampling, multivariate Kalman filters, and hierarchical Bayesian methods are explored as a strategy to address both model and parameter uncertainties. Ultimately proactive decision models embedded into the operating rules based on the forecasted future conditions -instead of reactive decisions based on current observed conditions- can result in risk mitigation.

  9. Characterization of the pore system in an over-mature marine shale reservoir: A case study of a successful shale gas well in Southern Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2015-09-01

    Full Text Available During the past two years the shale gas exploration in Southern Sichuan basin received some exciting achievements. Data of a new appraisal well showed that the gas producrtions of vertical well and horizontal well are ∼1.5 × 104 m3/day/well (with maximum ∼3.5 × 104 m3/day/well and ∼12.5 × 104 m3/day/well (with maximum ∼40 × 104 m3/day/well, respectively, indicating a good gas potential in this area. Eight core samples from the reservoir were investigated by using a carbon sulfur analyzer, microphotometry, x-ray diffractometry, field-emission scanning electron microscopy (FE-SEM, mercury injection porosimetry (MIP, and low-pressure nitrogen adsorption to obtain a better understanding of the reservoir characteristics of the Upper Ordovician–Lower Silurian organic-rich shale. Results show that the total organic carbon (TOC content ranges from 0.5% to 5.9%, whereas the equivalent vitrinite reflectance (VRr is between 2.8% and 3.0%. Pores in the studied samples were observed in three modes of occurrence, namely, interparticle pores, intraparticle pores, and intraparticle organic pores. The total porosity (P ranges from 1.6% to 5.3%, and MIP data sets suggest that pores with throats larger than 20 nm contribute little to the pore volume. Low-pressure N2 adsorption isotherms indicate that the total specific surface area (SBET ranges from 9.6 m2/g to 18.9 m2/g, and the pore volume (V ranges from 0.011 cm3/g to 0.020 cm3/g. The plot of dV/dW versus W shows that the fine mesopores (pore size(BJH 2% are more than 3.0 m3/ton. The observation can be a good reference for the future exploration and evaluation of reservoir in this area.

  10. Clastic Pipes: Proxies of High Water Tables and Strong Ground Motion, Jurassic Carmel Formation, Southern Utah

    Science.gov (United States)

    Wheatley, David; Chan, Marjorie

    2015-04-01

    Multiple soft sediment deformation features from bed-scale to basin-scale are well preserved within the Jurassic Carmel Formation of Southern Utah. Field mapping reveals thousands of small-scale clastic injectite pipes (10 cm to 10 m diameter, up to 20 m tall) in extremely high densities (up to 500+ pipes per 0.075 square kilometers). The pipes weather out in positive relief from the surrounding host strata of massive sandstone (sabkha) and crossbedded sands with minor conglomerate and shale (fluvial) deposits. The host rock shows both brittle and ductile deformation. Reverse, normal, and antithetical faulting is common with increased frequency, including ring faults, surrounding the pipes. The pipes formed from liquefaction and subsequent fluidization induced by strong ground motion. Down-dropped, graben blocks and ring faults surrounding pipes indicate initial sediment volume increase during pipe emplacement followed by sediment volume decrease during dewatering. Complex crosscutting relationships indicate several injection events where some pipe events reached the surface as sand blows. Multiple ash layers provide excellent stratigraphic and temporal constraints for the pipe system with the host strata deposited between 166 and 164 Ma. Common volcanic fragments and rounded volcanic cobbles occur within sandstone and conglomerate beds, and pipes. Isolated volcanic clasts in massive sandstone indicate explosive volcanic events that could have been the exogenic trigger for earthquakes. The distribution of pipes are roughly parallel to the Middle Jurassic paleoshoreline located in marginal environments between the shallow epicontinental Sundance Sea and continental dryland. At the vertical stratigraphic facies change from dominantly fluvial sediments to dominantly massive sabkha sediments, there is a 1-2 m-thick floodplain mudstone that was a likely seal for underlying, overpressurized sediments. The combination of loose porous sediment at a critical depth of water

  11. Sedimentation in Rio La Venta Canyon in Netzahualcoyotl Reservoir, Chiapas, Mexico

    Science.gov (United States)

    de La Fuente, J. A.; Lisle, T.; Velasquez, J.; Allison, B. L.; Miller, A.

    2002-12-01

    Sedimentation of Rio La Venta as it enters the Netzahualcoyotl Reservoir in Chiapas, Mexico, threatens a unique part of the aquatic ecosystem. Rio La Venta enters the reservoir via a narrow canyon about 16 km long with spectacular, near-vertical limestone bluffs up to 320 m high and inhabited by the flora and fauna of a pristine tropical forest. Karst terrain underlies most of the Rio La Venta basin in the vicinity of the reservoir, while deeply weathered granitic terrain underlies the Rio Negro basin, and the headwaters of the Rio La Venta to the south. The Rio Negro joins Rio La Venta 3 km downstream of the upper limit of the reservoir and delivers the bulk of the total clastic sediment (mostly sand and finer material). The canyon and much of the contributing basin lie within the Reserva de la Biosfera, Selva El Ocote, administered by the Comision Nacional de Areas Naturales Protegidas, part of the Secretaria de Medioambiente y Recursos Naturales. The Klamath National Forest Forest has cooperated with its Mexican counterparts since 1993 in natural resource management, neo-tropical bird inventories, wildfire management, and more recently in watershed analyses. Rates of sedimentation are estimated from bathymetric surveys conducted in March, 2002. A longitudinal profile down the inundated canyon during a high reservoir level shows an inflection from a slope of 0.0017 to one of 0.0075 at 7.2 km downstream of the mouth of Rio Negro. The bed elevation at this point corresponds to the lowest reservoir level, suggesting that the gentler sloping bed upstream is formed by fluvial processes during drawdown and that downstream by pluvial processes. Using accounts that boats could access Rio Negro during low water levels in 1984, we estimate an annual sedimentation rate of roughly 3 million cubic meters per year. This suggests that boats might no longer be able to access the most spectacular section of canyon upstream of Rio Negro within a decade, depending on how the

  12. Concentrations of metals and trace elements in different tissues of nine fish species from the Međuvršje reservoir (West Morava River Basin, Serbia

    Directory of Open Access Journals (Sweden)

    Đikanović Vesna

    2016-01-01

    Full Text Available Element concentrations in selected fish species from different trophic levels were analyzed. The following fish species were analyzed: common nase (Chondrostoma nasus, roach (Rutilus rutilus, freshwater bream (Abramis brama, barbel (Barbus barbus, Prussian carp (Carassius gibelio,chub (Squalius cephalus, European perch (Perca fluviatilis, wels catfish (Silurus glanisand northern pike (Esox lucius. Fish were collected from the Međuvršje Reservoir (West Morava River Basin, western Serbia during 2012, and samples of liver, muscle and gills were analyzed for As, B, Ba, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, Pb, Sr, and Zn using inductively coupled plasma optical emission spectrometry (ICP-OES. The liver and gills had the highest measured element concentrations, with Cu, Zn, Fe and Sr being the most prominent. The bioaccumulation of metals was species-specific, with the accumulation exhibiting the following trends: Prussian carp > northern pike > freshwater bream > European perch > chub > common nase > barbell > roach > wels catfish; Li>Pb>Zn>Cu>Fe>Ba>Mn>Sr>Cr>As>Mo>Ni>B, in all examined species; for Co, Cd and Hg, the bioaccumulation factor (BAF was 0. Results of this study point to the tissue-specific differences in element concentrations, and to distinct differences between fish species regarding the accumulation patterns: common nase, with the highest accumulation observed in the liver, and Prussian carp, with the highest accumulation observed in the gills. [Projekat Ministarstva nauke Republike Srbije, br. 173045 i br. 37009

  13. Diet shifts related to body size of the pirambeba Serrasalmus brandtii Lütken, 1875 (Osteichthyes, Serrasalminae in the Cajuru Reservoir, São Francisco River Basin, Brazil

    Directory of Open Access Journals (Sweden)

    A. K. Oliveira

    Full Text Available This study aimed to identify shifts in the Serrasalmus brandtii Lütken, 1875 diet related to body size. Specimens were collected from April 1992 to January 1993 at the Cajuru Reservoir, in the Pará River, São Francisco River Basin, by seining the shore with nets of nylon, 1 mm opening, and with gill nets. Stomach contents of 152 individuals measuring 15-192 mm SL were examined. Food items were identified and weighed separately. For qualitative analysis, the frequency of occurrence method was used. The relative importance of each food component was determined based on the alimentary index (IAi. The frequencies of occurrence data were subjected to cluster analysis using the Canberra coefficient of dissimilarity and UPGMA as the cluster method. Distinctive gradual changes in food habits, associated with body size, were identified in this species. The smaller individuals fed predominantly on microcrustaceans and insect larvae. The intermediate size classes ingested insects, fish fins, fish scales, and chunks of fish flesh, in this order of importance. For the larger pirambebas, fish was the most abundant food category identified, followed by insects.

  14. Characterization of low contrast shale-sand reservoir using Poisson impedance inversion: Case study of Gumai formation, Jambas field Jambi Sub-basin

    Science.gov (United States)

    Haris, A.; Nenggala, Y.; Suparno, S.; Raguwanti, R.; Riyanto, A.

    2017-07-01

    Low impedance contrast between the shale-sand layer, which can be found in the situation where shale layer wrapped in the sand reservoir, is a challenging case for explorationist in characterizing sand distribution from shale layer. In this paper, we present the implementation of Poisson impedance in mapping sand distribution in Gumai formation, Jambas Field, Jambi Sub-basin. Gumai formation has become a prospective zone, which contains sandstone with strong laterally change. The characteristic of facies at Gumai formation, which is laterally changing, has been properly mapped based on the Acoustic impedance (AI) and Shear impedance (SI). These two impedances, which is yielded by performing seismic simultaneous inversion, is then combined to generate Poisson impedance. The Poisson impedance is conceptually formulated as a contrast between AI and a scaled SI with the scale is estimated from the gradient of the relationship between AI and SI. Our experiment shows that the Poisson impedance map is able to separate the sand distribution from the shale layer. Therefore the sand facies has been clearly delineated from the contrast of Poisson impedance.

  15. Long-term agroecosystem research in the central Mississippi river basin: hyperspectral remote sensing of reservoir water quality.

    Science.gov (United States)

    Sudduth, Kenneth A; Jang, Gab-Sue; Lerch, Robert N; Sadler, E John

    2015-01-01

    In situ methods for estimating water quality parameters would facilitate efforts in spatial and temporal monitoring, and optical reflectance sensing has shown potential in this regard, particularly for chlorophyll, suspended sediment, and turbidity. The objective of this research was to develop and evaluate relationships between hyperspectral remote sensing and lake water quality parameters-chlorophyll, turbidity, and N and P species. Proximal hyperspectral water reflectance data were obtained on seven sampling dates for multiple arms of Mark Twain Lake, a large man-made reservoir in northeastern Missouri. Aerial hyperspectral data were also obtained on two dates. Water samples were collected and analyzed in the laboratory for chlorophyll, nutrients, and turbidity. Previously reported reflectance indices and full-spectrum (i.e., partial least squares regression) methods were used to develop relationships between spectral and water quality data. With the exception of dissolved NH, all measured water quality parameters were strongly related ( ≥ 0.7) to proximal reflectance across all measurement dates. Aerial hyperspectral sensing was somewhat less accurate than proximal sensing for the two measurement dates where both were obtained. Although full-spectrum calibrations were more accurate for chlorophyll and turbidity than results from previously reported models, those previous models performed better for an independent test set. Because extrapolation of estimation models to dates other than those used to calibrate the model greatly increased estimation error for some parameters, collection of calibration samples at each sensing date would be required for the most accurate remote sensing estimates of water quality. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. The Aquatic Environment as a Reservoir of Vibrio cholerae O1 in Hydrographic Basins of the State of Pernambuco, Brazil

    Science.gov (United States)

    Mendes-Marques, Carina Lucena; Silveira Filho, Vladimir da Mota; da Costa, Ana Paula Rocha; Nunes, Mariana de Lira; da Silva Filho, Sandoval Vieira; Figueirôa, Ângela Cristina Torres de Araújo; Hofer, Ernesto; de Almeida, Alzira Maria Paiva; Leal, Nilma Cintra

    2013-01-01

    After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1) positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR); 2 of these were also ctxA (cholera toxin) positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR), and pulsed field gel electrophoresis (PFGE). The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012) and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region. PMID:23533357

  17. The aquatic environment as a reservoir of Vibrio cholerae O1 in hydrographic basins of the state of Pernambuco, Brazil.

    Science.gov (United States)

    Mendes-Marques, Carina Lucena; Silveira Filho, Vladimir da Mota; da Costa, Ana Paula Rocha; Nunes, Mariana de Lira; da Silva Filho, Sandoval Vieira; Figueirôa, Ângela Cristina Torres de Araújo; Hofer, Ernesto; de Almeida, Alzira Maria Paiva; Leal, Nilma Cintra

    2013-01-01

    After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1) positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR); 2 of these were also ctxA (cholera toxin) positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR), and pulsed field gel electrophoresis (PFGE). The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012) and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

  18. The Aquatic Environment as a Reservoir of Vibrio cholerae O1 in Hydrographic Basins of the State of Pernambuco, Brazil

    Directory of Open Access Journals (Sweden)

    Carina Lucena Mendes-Marques

    2013-01-01

    Full Text Available After the worldwide cholera epidemic in 1993, permanent environmental monitoring of hydrographic basins was established in Pernambuco, Brazil, where cholera is endemic. After a quiescent period, 4 rfbN (serogroup O1 positive water samples that were culture negative were detected by multiplex single-tube nested PCR (MSTNPCR; 2 of these were also ctxA (cholera toxin positive. From May to June 2012, 30 V. cholerae O1 isolates were obtained by culturing samples. These isolates were analyzed for the presence of virulence genes by PCR, intergenic spacer region 16S-23S PCR (ISR-PCR, and pulsed field gel electrophoresis (PFGE. The isolates were positive for the rfbN gene and negative for the assessed pathogenic genes and were classified into 2 groups by ISR and the same profile by PFGE. Close genetic similarity was observed between them (2012 and environmental strains from 2004 to 2005, indicating the permanence of endemic V. cholerae O1 in the region.

  19. Controlling effect of fractures on gas accumulation and production within the tight sandstone: A case study on the Jurassic Dibei gas reservoir in the eastern part of the Kuqa foreland basin, China

    Directory of Open Access Journals (Sweden)

    Hui Lu

    2016-02-01

    Full Text Available Using Dibei tight sandstone gas reservoir in the eastern part of the Kuqa foreland basin as an example, this paper discusses tight sandstone reservoir fractures characterization, its effect on storage space and gas flow capacity, and its contribution to gas accumulation, enrichment and production in tight sandstone reservoir by using laser scanning confocal microscope (LSCM observation, mercury intrusion capillary pressure (MICP testing, and gas-water two-phase relative permeability testing. The statistics of laser scanning confocal microscopy observation showed that the microstructural fractures width in the Dibei gas reservoir was mainly 8–25 μm, and the associated micro-fractures width was mainly 4–10 μm. Additionally, the throat radius was mainly 1–4 μm. The fractures width was significantly wider than the throat radius that served as the main channel of in gas flow. In addition, it illustrated that the samples with developed fractures became easier for gas to flow under equal porosity condition, because of lower expulsion pressure, higher mercury injection saturation, and increased gas relative permeability based on the physical simulation experiment of gas charging into core samples with saturated water, mercury injection and gas-water two-phase permeability experiments. Furthermore, it had been concluded that the fractures control tight gas in the following aspects: (1 Fractures play a significant role in reservoir property improvement. The isolated pores were linked by the fractures to form connective reservoir spaces, and dissolution is prone to occur along the fractures forming new pores. The fractures with bigger width are reservoir space as well. (2 Fractures increased fluid flow capacity because it decreased the starting pressure gradient, and it increased gas effective permeability. Thus, fractures improved the gas injection efficiency as well as gas production. (3 Fractures that developed in different time and spatial

  20. CO2 Saline Storage Demonstration in Colorado Sedimentary Basins. Applied Studies in Reservoir Assessment and Dynamic Processes Affecting Industrial Operations

    Energy Technology Data Exchange (ETDEWEB)

    Nummedal, Dag [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Doran, Kevin [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Sitchler, Alexis [Trustees Of The Colorado School Of Mines, Golden, CO (United States); McCray, John [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Mouzakis, Katherine [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Glossner, Andy [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Mandernack, Kevin [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Gutierrez, Marte [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Pranter, Matthew [Trustees Of The Colorado School Of Mines, Golden, CO (United States); Rybowiak, Chris [Trustees Of The Colorado School Of Mines, Golden, CO (United States)

    2012-09-30

    This multitask research project was conducted in anticipation of a possible future increase in industrial efforts at CO2 storage in Colorado sedimentary basins. Colorado is already the home to the oldest Rocky Mountain CO2 storage site, the Rangely Oil Field, where CO2-EOR has been underway since the 1980s. The Colorado Geological Survey has evaluated storage options statewide, and as part of the SW Carbon Sequestration Partnership the Survey, is deeply engaged in and committed to suitable underground CO2 storage. As a more sustainable energy industry is becoming a global priority, it is imperative to explore the range of technical options available to reduce emissions from fossil fuels. One such option is to store at least some emitted CO2 underground. In this NETL-sponsored CO2 sequestration project, the Colorado School of Mines and our partners at the University of Colorado have focused on a set of the major fundamental science and engineering issues surrounding geomechanics, mineralogy, geochemistry and reservoir architecture of possible CO2 storage sites (not limited to Colorado). Those are the central themes of this final report and reported below in Tasks 2, 3, 4, and 6. Closely related to these reservoir geoscience issues are also legal, environmental and public acceptance concerns about pore space accessibility—as a precondition for CO2 storage. These are addressed in Tasks 1, 5 and 7. Some debates about the future course of the energy industry can become acrimonius. It is true that the physics of combustion of hydrocarbons makes it impossible for fossil energy to attain a carbon footprint anywhere nearly as low as that of renewables. However, there are many offsetting benefits, not the least that fossil energy is still plentiful, it has a global and highly advanced distribution system in place, and the footprint that the fossil energy infrastructure occupies is

  1. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-08-08

    The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California, through the testing and application of advanced reservoir characterization and thermal production technologies. The hope is that successful application of these technologies will result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block II-A (Tar II-A) has been relatively inefficient because of several producibility problems which are common in SBC reservoirs: inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery and reduce operating costs, including: (1) Development of three-dimensional (3-D) deterministic and stochastic reservoir simulation models--thermal or otherwise--to aid in reservoir management of the steamflood and post-steamflood phases and subsequent development work. (2) Development of computerized 3-D visualizations of the geologic and reservoir simulation models to aid reservoir surveillance and operations. (3) Perform detailed studies of the geochemical interactions between the steam and the formation rock and fluids. (4) Testing and proposed application of a

  2. Risk Analysis of Reservoir Operations Considering Short-Term Flood Control and Long-Term Water Supply: A Case Study for the Da-Han Creek Basin in Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Ming Cheng

    2017-06-01

    Full Text Available This study applies an integrated methodology to assess short-term over-levee risk and long-term water shortage risk in the Da-Han Creek basin, which is the most important flood control and water storage system in northern Taiwan. An optimization model for reservoir flood control and water supply is adopted, to determine reservoir releases based on synthetic inflow hydrographs during typhoons, which are generated by Monte Carlo simulations. The release is then used to calculate the water level at a downstream control point using a novel developed back-propagation neural network-based model, to reduce computational complexity and achieve automatic-efficient risk evaluation. The calculated downstream water levels and final reservoir water levels after a typhoon event are used to evaluate the mapped over-levee risk and water shortage risk, respectively. The results showed that the different upper limit settings for the reservoir have a significant influence on the variation of 1.19 × 10−5% to 75.6% of the water shortage risk. This occurs because of the insufficient inflow and narrow storage capacity of the Shih-Men Reservoir during drought periods. However, the upper limit settings have a minor influence (with a variation of only 0.149% to 0.157% on the over-levee risk in typhoon periods, because of the high protection standards for the downstream embankment.

  3. TSR versus non-TSR processes and their impact on gas geochemistry and carbon stable isotopes in Carboniferous, Permian and Lower Triassic marine carbonate gas reservoirs in the Eastern Sichuan Basin, China

    Science.gov (United States)

    Liu, Q. Y.; Worden, R. H.; Jin, Z. J.; Liu, W. H.; Li, J.; Gao, B.; Zhang, D. W.; Hu, A. P.; Yang, C.

    2013-01-01

    The Palaeozoic and lowermost Mesozoic marine carbonate reservoirs of the Sichuan Basin in China contain variably sour and very dry gas. The source of the gas in the Carboniferous, Permian and Lower Triassic reservoirs is not known for certain and it has proved difficult to discriminate and differentiate the effects of thermal cracking- and TSR-related processes for these gases. Sixty-three gas samples were collected and analysed for their composition and carbon stable isotope values. The gases are all typically very dry (alkane gases being >97.5% methane), with low (kerogen-derived oil and primary gas and is highly mature. Carboniferous (and non-sour Triassic and Permian) gas has unusual carbon isotopes with methane and propane being isotopically heavier than ethane (a reversal of typical low- to moderate-maturity patterns). The gas in the non-sour Triassic and Permian reservoirs has the same geochemical and isotopic characteristics (and therefore the same source) as the Carboniferous gas. TSR in the deepest Triassic reservoirs altered the gas composition reaching 100% dryness in the deepest, most sour reservoirs showing that ethane and propane react faster than methane during TSR. Ethane evolves to heavier carbon isotope values than methane during TSR leading to removal of the reversed alkane gas isotope trend found in the Carboniferous and non-sour Triassic and Permian reservoirs. However, methane was directly involved in TSR as shown by the progressive increase in its carbon isotope ratio as gas souring proceeded. CO2 increased in concentration as gas souring proceeded, but typical CO2 carbon isotope ratios in sour gases remained about -4‰ V-PDB showing that it was not solely derived from the oxidation of alkanes. Instead CO2 may partly result from reaction of sour gas with carbonate reservoir minerals, such as Fe-rich dolomite or calcite, resulting in pyrite growth as well as CO2-generation.

  4. Imagerie sismique d'un réservoir carbonaté : le dogger du Bassin parisien Seismic Imaging a Carbonate Reservoir: the Paris Basin Dogger

    Directory of Open Access Journals (Sweden)

    Mougenot D.

    2006-11-01

    ût important des acquisitions de surface en trois composantes, nous ne considérons pas cette méthode comme pertinente pour décrire le réservoir du Dogger. En définitive, la combinaison d'un échantillonnage spatial continu, comme celui obtenu en SD et d'une émission vibrosismique adaptée au filtrage terrain, comme celle utilisée en 2D-HR mais limitée à 100 Hz, apportera des informations nouvelles sur le réservoir mince et discontinu du Dogger que la simple corrélation des données de puits ne peut pas fournir. Ainsi, la géométrie du réservoir a pu être décrite avec précision (5 m de même que certaines hétérogénéités correspondant à des failles ou à des variations latérales d'impédance. D'autres paramètres importants pour la production, comme la répartition des drains R1 et R2 qui modifie peu les impédances acoustiques dans le réservoir, restent cependant inaccessibles à la sismique. Néanmoins, pour le prix d'un ou de quelques forages, une sismique 3D avec une émission et un traitement des données adaptés au Bassin parisien fournira une description suffisamment pertinente du réservoir pour pouvoir optimiser l'implantation de forages de délinéation ou de production, réduisant par là les coûts d'exploitation. (1 Dhyca: Direction des Hydrocarbures (Ministère de l'Industrie (2 CGG, EAP, Esso-REP, IFP, Total, Triton France. Within the context of measures taken by the Dhyca(1 to revitalize exploration in France, six industrial partners(2 joined forces (on the Dogger Project to develop an appropriate seismic acquisition, processing and interpretation methodology in order to improve the description of the main oil reservoir (Dogger in the Paris Basin by applying techniques already used on an industrial scale : vibroseis with a high frequency content (10-130 Hz, three-dimension or three-component reflection seismip, P and S emissions, sophisticated signal and static processing, amplitude preservation, careful well tying, stratigraphic

  5. The post-Laramide clastic deposits of the Sierra de Guanajuato: Compositional implications on the tectono-sedimentary and paleographic evolution

    Directory of Open Access Journals (Sweden)

    R. Miranda-Avilés

    2016-11-01

    Full Text Available This article presents the results of the study on sedimentation, sedimentary environments, tectono-sedimentary and paleogeographic evolution of post-Laramide clastic deposits and pre-volcanism of the Sierra Madre Occidental in the Sierra de Guanajuato, central Mexico. The Eocene Duarte Conglomerate and Guanajuato Conglomerate were deposited in the middle and distal parts of alluvial fans. The studied rocks are composed of limestone clasts, granite, andesite, metasediments, diorite, and pyroxenite, indicating the erosion of uplifted blocks of the basal complex of the Sierra de Guanajuato (Arperos basin. The petrographic and compositional analysis of limestone shows a textural variation from basin limestones and shallow platform limestones. The shallow platform limestone contain bivalves, brachiopods, gastropods, echinoderms and benthic foraminifera from the Berriasian-Valanginian. The shallow-water limestone corresponds to the boundary of the Arperos basin whose original outcrops currently not outcrop in the Sierra de Guanajuato.

  6. Model for energy planning of degraded river basins based on hydrological evaluation of hydroelectric reservoirs in operation; Modelo de planejamento energetico de bacias hidrograficas degradadas baseado na avaliacao hidrica de reservatorios hidreletricos em operacao

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Afonso Henriques Moreira [Universidade Federal de Itajuba (UNIFEI), MG (Brazil); Ferreira, Aloisio Caetano; Ottoni, Arthur Benedicto; Nogueira Neto, Claudio; Silva, Denis de Souza

    2008-07-01

    The human occupation of the hydrographic basin, made in the past without plans, generated alteration of the hydrology characteristics, presenting as direct consequence modifications of its hydric availabilities. Or either, the floods in the rainy periods and the droughts in the ones of dryness currently tend to be more frequent and with bigger intensity. These conditions have affected the operation as well as the planning of the hydroelectric reservoirs, that have generated energy in conditions of different hydric availabilities (worse) of those foreseeing at the time of the project. These situations result in uncertainties and energy losses for the investor as well as in the system. Under such premises, the present article analyzes the energy-economic influences of the deterioration of the hydric regimen of some on exploitations in operation to the system, located in basins degrades in the South, Southeastern and Northeast regions; enhancing the importance of the studies of hydric economy of these units of management (degraded basins) as subsidy of taking of decision for gradual recovery of its hydric availabilities; taking in account the energy optimization of the hydroelectric reservoirs in located operation as well as the minimization of inherent the financial losses to the uncertainties of its hydric resources. (author)

  7. Feasibility of high-helium natural gas exploration in the Presinian strata, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    2015-01-01

    Full Text Available Helium in China highly depends on import at present, so the most practical way to change the situation is searching for medium-to-large natural gas fields with high helium content. Therefore, the hydrocarbon accumulation mechanism and the helium origin of the Weiyuan high-helium natural gas reservoir have been analyzed to find out the feasibility of finding natural gas field with high helium content in the Presinian strata of the Sichuan Basin. Based on twelve outcrop sections and drilling data of four wells encountering the Presinian strata, the petrological features, sedimentary facies and source rocks of Presinian strata were systematically analyzed, which shows that the sedimentary formation developed in the Presinian is the Nanhua system, and the stratigraphic sequence revealed by outcrop section in the eastern margin includes the Nantuo, Datangpo, Gucheng and Liantuo Fms, and it is inferred that the same stratigraphic sequence may occur inside the basin. The Nantuo, Gucheng and Liantuo Fms are mainly glacial deposits of glutenite interbedded with mudstone; the Datangpo Fm is interglacial deposits of sandstone and shale, the lower part shale, rich in organic matter, is fairly good source rock. Further study showed that the Nantuo coarse-grained clastic reservoir, Datangpo source rock and the intruded granite “helium source rock” make up a good high-helium gas system. Controlled by the early rift, the thick Presinian sedimentary rocks occur primarily inside the rift. The distribution of sedimentary rocks and granite in the basin was predicted by use of the seismic data, which shows that the feasibility of finding high-helium gas reservoirs in Ziyang area of the Sichuan Basin is great.

  8. Summary of Research through Phase II/Year 2 of Initially Approved 3 Phase/3 Year Project - Establishing the Relationship between Fracture-Related Dolomite and Primary Rock Fabric on the Distribution of Reservoirs in the Michigan Basin

    Energy Technology Data Exchange (ETDEWEB)

    G. Grammer

    2007-09-30

    This final scientific/technical report covers the first 2 years (Phases I and II of an originally planned 3 Year/3 Phase program). The project was focused on evaluating the relationship between fracture-related dolomite and dolomite constrained by primary rock fabric in the 3 most prolific reservoir intervals in the Michigan Basin. The characterization of select dolomite reservoirs was the major focus of our efforts in Phases I and II of the project. Structural mapping and log analysis in the Dundee (Devonian) and Trenton/Black River (Ordovician) suggest a close spatial relationship among gross dolomite distribution and regional-scale, wrench fault-related NW-SE and NE-SW structural trends. A high temperature origin for much of the dolomite in these 2 studied intervals (based upon fluid inclusion homogenization temperatures and stable isotopic analyses,) coupled with persistent association of this dolomite in reservoirs coincident with wrench fault-related features, is strong evidence for these reservoirs being influenced by hydrothermal dolomitization. In the Niagaran (Silurian), there is a general trend of increasing dolomitization shelfward, with limestone predominant in more basinward positions. A major finding is that facies types, when analyzed at a detailed level, are directly related to reservoir porosity and permeability in these dolomites which increases the predictability of reservoir quality in these units. This pattern is consistent with our original hypothesis of primary facies control on dolomitization and resulting reservoir quality at some level. The identification of distinct and predictable vertical stacking patterns within a hierarchical sequence and cycle framework provides a high degree of confidence at this point that the results should be exportable throughout the basin. Much of the data synthesis and modeling for the project was scheduled to be part of Year 3/Phase III, but the discontinuation of funding after Year 2 precluded those efforts

  9. Recovery enhancement at the later stage of supercritical condensate gas reservoir development via CO2 injection: A case study on Lian 4 fault block in the Fushan sag, Beibuwan Basin

    Directory of Open Access Journals (Sweden)

    Wenyan Feng

    2016-11-01

    Full Text Available Lian 4 fault block is located in the northwest of Fushan sag, Beibuwan Basin. It is a high-saturated condensate gas reservoir with rich condensate oil held by three faults. In order to seek an enhanced condensate oil recovery technology that is suitable for this condensate gas reservoir at its later development stage, it is necessary to analyze its reserve producing degree and remaining development potential after depletion production, depending on the supercritical fluid phase behavior and depletion production performance characteristics. The supercritical fluid theories and multiple reservoir engineering dynamic analysis methods were adopted comprehensively, such as dynamic reserves, production decline, liquid-carrying capacity of a production well, and remaining development potential analysis. It is shown that, at its early development stage, the condensate in Lian 4 fault block presented the features of supercritical fluid, and the reservoir pressure was lower than the dew point pressure, so retrograde condensate loss was significant. Owing to the retrograde condensate effect and the fast release of elastic energy, the reserve producing degree of depletion production is low in Lian 4 fault block, and 80% of condensate oil still remains in the reservoir. So, the remaining development potential is great. The supercritical condensate in Lian 4 fault block is of high density. Based on the optimization design by numerical simulation of compositional model, it is proposed to inject CO2 at the top and build up pressure by alternating production and injection, so that the secondary gas cap is formed while the gravity-stable miscible displacement is realized. In this way, the recovery factor of condensate reservoirs can be improved by means of the secondary development technology.

  10. Madbi Amran/Qishn total petroleum system of the Ma'Rib-Al Jawf/Shabwah, and Masila-Jeza basins, Yemen

    Science.gov (United States)

    Ahlbrandt, Thomas S.

    2002-01-01

    Since the first discovery of petroleum in Yemen in 1984, several recent advances have been made in the understanding of that countrys geologic history and petroleum systems. The total petroleum resource endowment for the combined petroleum provinces within Yemen, as estimated in the recent U.S. Geological Survey world assessment, ranks 51st in the world, exclusive of the United States, at 9.8 BBOE, which includes cumulative production and remaining reserves, as well as a mean estimate of undiscovered resources. Such undiscovered petroleum resources are about 2.7 billion barrels of oil, 17 trillion cubic feet (2.8 billion barrels of oil equivalent) of natural gas and 1 billion barrels of natural gas liquids. A single total petroleum system, the Jurassic Madbi Amran/Qishn, dominates petroleum generation and production; it was formed in response to a Late Jurassic rifting event related to the separation of the Arabian Peninsula from the Gondwana supercontinent. This rifting resulted in the development of two petroleum-bearing sedimentary basins: (1) the western MaRibAl Jawf / Shabwah basin, and (2) the eastern Masila-Jeza basin. In both basins, petroleum source rocks of the Jurassic (Kimmeridgian) Madbi Formation generated hydrocarbons during Late Cretaceous time that migrated, mostly vertically, into Jurassic and Cretaceous reservoirs. In the western MaRibAl Jawf / Shabwah basin, the petroleum system is largely confined to syn-rift deposits, with reservoirs ranging from deep-water turbidites to continental clastics buried beneath a thick Upper Jurassic (Tithonian) salt. The salt initially deformed in Early Cretaceous time, and continued halokinesis resulted in salt diapirism and associated salt withdrawal during extension. The eastern Masila-Jeza basin contained similar early syn-rift deposits but received less clastic sediment during the Jurassic; however, no salt formed because the basin remained open to ocean circulation in the Late Jurassic. Thus, Madbi Formation

  11. A method for examining the geospatial distribution of CO2 storage resources applied to the Pre-Punta Gorda Composite and Dollar Bay reservoirs of the South Florida Basin, U.S.A

    Science.gov (United States)

    Roberts-Ashby, Tina; Brandon N. Ashby,

    2016-01-01

    This paper demonstrates geospatial modification of the USGS methodology for assessing geologic CO2 storage resources, and was applied to the Pre-Punta Gorda Composite and Dollar Bay reservoirs of the South Florida Basin. The study provides detailed evaluation of porous intervals within these reservoirs and utilizes GIS to evaluate the potential spatial distribution of reservoir parameters and volume of CO2 that can be stored. This study also shows that incorporating spatial variation of parameters using detailed and robust datasets may improve estimates of storage resources when compared to applying uniform values across the study area derived from small datasets, like many assessment methodologies. Geospatially derived estimates of storage resources presented here (Pre-Punta Gorda Composite = 105,570 MtCO2; Dollar Bay = 24,760 MtCO2) were greater than previous assessments, which was largely attributed to the fact that detailed evaluation of these reservoirs resulted in higher estimates of porosity and net-porous thickness, and areas of high porosity and thick net-porous intervals were incorporated into the model, likely increasing the calculated volume of storage space available for CO2 sequestration. The geospatial method for evaluating CO2 storage resources also provides the ability to identify areas that potentially contain higher volumes of storage resources, as well as areas that might be less favorable.

  12. EVALUATION OF THE LOSS OF SOILS IN THE BASIN OF RIBEIRÃO SERRA AZUL AND THE DEPOSITION OF SEDIMENTS IN THE RESERVOIR OF THE COMPANY OF SANITATION OF MINAS GERAIS-COPASA

    Directory of Open Access Journals (Sweden)

    Ricardo Figueira de Carvalho

    2005-05-01

    Full Text Available The choice of a supplying spring should consider, not only you factor as distance of the consuming center, readiness of flows, but also the use form and occupation of the soil of a hydrographic basin.The area object of this work, the basin of Ribeirão Serra Azul, when of the planning adopted to that time for choice of the spring, final of the decade of 70, it counted not only with I aid him of countless organs in different spheres of decisions, but in the innovation in preserving the atmosphere as a result of the first external pressures of the agents backers.On this first moment the Company of Sanitation of Minas General- COPASA, gave an important step in the environmental subject in the State of Minas Gerais, promoting the mitigation of the current impacts of the stage of construction of the reservoir and investing inthe preservation of his/her patrimony and spring.

  13. Sequence stratigraphy, depositional facies and reservoir continuity of a storm-wave - and tide-dominated Delta: An example from the Lower Cretaceous Ben Nevis and Avalon Formations, Jeanne D'Arc Basin, Grand Banks, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Sabry, H. (Mobil Oil Canada, Calgary, Alberta (Canada))

    1990-05-01

    The Avalon Formation is recognized as a regressive/transgressive sequence of Barremian to late Aptian age, overlain unconformably (sequence boundary) by the Aptian to Albian Ben Nevis transgressive sequence. Sedimentation took place in a Mesozoic failed-rift basin setting dominated by an inferred delta complex that occupied the southern end of the Jeanne D'Arc basin. Geostrophic events, namely storm waves and tidal currents, dispersed and fractionated sediments northward into mainly thin-bedded clean sands with interbedded argillaceous, silty beds. The Avalon and Ben Nevis formations contain collectively four reservoir zones separated by two shale markers representing marine-flooding surfaces. Based on detailed sedimentologic investigation of over 6,000 ft of Avalon and Ben Nevis cores, the following geologic history of events and depositional model are proposed. Prior to the Avalon sequence, a lowstand prograding wedge of the eastern Shoals Formation terminated with lagoonal red mudstones and was locally emergent and rooted. During deposition of the basal Avalon (late Barremian), a slow transgression, marked by brackish water sediments, started, resulting in the formation of transgressive barrier bars and migrating tidal inlets in the Hibernia area. These transgressive shoreline sands display good reservoir continuity across the basin with large oil recoveries, e.g., Hibernia 0-35 field. A subsequent slow drop in relative sea level in the central part of the basin resulted in deposition and development of a prograding delta-front platform. Close to the end of Avalon deposition (middle Aptian), an ensuing rapid drop in relative sea level initiated very rapid seaward progradation of the coastal zone and incision of fluvial/estuarine channels into the older now-exposed delta-front platform.

  14. National Program for Inspection of Non-Federal Dams. Stony Brook Reservoir Dam MA 00293, Charles River Basin, Weston, Massachusetts. Phase I Inspection Report.

    Science.gov (United States)

    1979-06-01

    the dam along the west side of the reservoir. Water supply intakes and a low flow outlet are controlled from the gatehouse near the right end of the dam...face of the dam, the establishment of vegetation on bare areas, the repointing of joints at the spillway and gatehouse , the repair of an inoperative...Stony Brook Reservoir. The routing indicated that there is virtually no reduction of the peak inflow rate of 8,400 cfs into Stony Brook Reservoir and as a

  15. Identify re-development concepts to enhance Abu Roash “C” oil reservoir productivity Sitra Area, Abu Gharadig Basin, Western Desert, Egypt

    Directory of Open Access Journals (Sweden)

    H. Salama

    2017-06-01

    The resultant stratigraphic units consist of: genetically related depositional cycles (3 cycles and their components of facies sequences (5 facies types, each cycle has its own distribution, facies classification and reservoir characteristics.

  16. National Dam Safety Program. Cobbs Hill Reservoir Dam (Inventory Number NY 1448), Lake Ontario Basin, Monroe County, New York. Phase I Inspection Report,

    Science.gov (United States)

    1981-06-30

    Reservoir are hori- zontally lying dolostones of the Lockport Group of Upper Silurian age. Depth to bedrock is unknown. The reservoir is sited on Cobbs Hill...t7 oil L PE w !J " ° ~A 92o IuIsI I FIGURE lb Q , ,. IL I .i. *,’X. ’ -,_ OIL (I) ," ’. o S ,.’lt / I .. ’ " I,"_ __4- . . l ’’I -. .* . I- I ’i’.I

  17. Physical simulation of gas reservoir formation in the Liwan 3-1 deep-water gas field in the Baiyun sag, Pearl River Mouth Basin

    Directory of Open Access Journals (Sweden)

    Gang Gao

    2015-01-01

    Full Text Available To figure out the process and controlling factors of gas reservoir formation in deep-waters, based on an analysis of geological features, source of natural gas and process of reservoir formation in the Liwan 3-1 gas field, physical simulation experiment of the gas reservoir formation process has been performed, consequently, pattern and features of gas reservoir formation in the Baiyun sag has been found out. The results of the experiment show that: ① the formation of the Liwan 3-1 faulted anticline gas field is closely related to the longstanding active large faults, where natural gas is composed of a high proportion of hydrocarbons, a small amount of non-hydrocarbons, and the wet gas generated during highly mature stage shows obvious vertical migration signs; ② liquid hydrocarbons associated with natural gas there are derived from source rock of the Enping & Zhuhai Formation, whereas natural gas comes mainly from source rock of the Enping Formation, and source rock of the Wenchang Formation made a little contribution during the early Eocene period as well; ③ although there was gas migration and accumulation, yet most of the natural gas mainly scattered and dispersed due to the stronger activity of faults in the early period; later as fault activity gradually weakened, gas started to accumulate into reservoirs in the Baiyun sag; ④ there is stronger vertical migration of oil and gas than lateral migration, and the places where fault links effective source rocks with reservoirs are most likely for gas accumulation; ⑤ effective temporal-spatial coupling of source-fault-reservoir in late stage is the key to gas reservoir formation in the Baiyun sag; ⑥ the nearer the distance from a trap to a large-scale fault and hydrocarbon source kitchen, the more likely gas may accumulate in the trap in late stage, therefore gas accumulation efficiency is much lower for the traps which are far away from large-scale faults and hydrocarbon source

  18. CONTRIBUTIONS TO THE STUDY OF THE AVIFAUNA FROM THE SITE NATURE 2000 ROSPA0062 – “THE RESERVOIRS ON THE ARGEŞ RIVER” - THE WINTERING QUARTERS FROM THE MIDDLE BASIN OF THE ARGEŞ RIVER. THE HIEMAL SEASON.

    Directory of Open Access Journals (Sweden)

    Maria Denisa Conete

    2014-11-01

    Full Text Available In the present paper we present the results of our ecological research on the avifauna of some reservoirs (a site of the Nature 2000 Network from the middle basin of the Argeş River, during the hiemal season in the period 2003 – 2010. The hibernal/hiemal season is the poorest in species of the six seasons (118 species belonging to 14 orders, 32 families and 68 genera, of which 49 species are dependent on wetlands, but the richest in the number of individuals (448,064. We also perform an analysis of the avifauna according to ecological indices (IR, constancy, dominancy, the Dzuba index of ecological significance, etc.. The Anseriformes were overdominant. It is the only season in which the order Passeriformes is complementary. Great agglomerations of Anseriformes are constantly present during the hiemal season; the specific composition and the number of individuals of the different species vary continuously on each of the reservoirs in relation to the weather conditions, the accessibility of food, etc. The highest number of Anseriformes species was observed on the Budeasa Reservoir (19 species and the lowest on the Bascov Reservoir (12 species. The correlation between temperature and the total number of individuals of the bird species is negative. As the temperature increases, the number of individuals decreases and vice versa. The most important wintering quarter is, during our research, the Goleşti Reservoir, with impressive concentrations of waterbirds. Mention should be made of five characteristic species (eudominant and dominant present in the area of the reservoirs in the hiemal season: Anas platyrhynchos, Aythya ferina, Fulica atra, Aythya fuligula and Larus ridibundus. The high number of subrecedent species (102 emphasizes the great fluctuation of bird species in the area as a result of the fact that these reservoirs are on the course of some European migration routes and ensure favourable conditions (halting, sheltering and feeding

  19. Provenance of the Lower Triassic Bunter Sandstone Formation: implications for distribution and architecture of aeolian vs. fluvial reservoirs in the North German Basin

    DEFF Research Database (Denmark)

    Olivarius, Mette; Weibel, Rikke; Friis, Henrik

    2017-01-01

    that sediment supply was mainly derived from the Ringkøbing-Fyn High situated north of the basin and from the Variscan belt located south of the basin. Seismic reflection data document that the Ringkøbing-Fyn High was a local barrier for sediment transport during the Early Triassic. Hence, the Fennoscandian...... Shield did not supply much sediment to the basin as opposed to what was previously believed. Sediment from the Variscan belt was transported by wind activity across the North German Basin when it was dried out during deposition of the aeolian part of the Volpriehausen Member (lower Bunter Sandstone......). Fluvial sand was supplied from the Ringkøbing-Fyn High to the basin during precipitation events which occurred most frequently when the Solling Member was deposited (upper Bunter Sandstone). Late Neoproterozoic to Carboniferous zircon ages predominate in the Volpriehausen Member where the dominant age...

  20. Impact of fault damage zones on reservoir performance in the Hibernia oilfield (Jeanne d'Arc Basin, Newfoundland) : an analysis of structural, petrophysical and dynamic well-test data

    Energy Technology Data Exchange (ETDEWEB)

    Porter, J.R.; McAllister, E.; Fisher, Q.J.; Knipe, R.J.; Condliffe, D.M.; Kay, M.A. [Leeds Univ., Leeds (United Kingdom). Dept. of Earth Sciences, Rock Deformation Research Group; Stylianides, G.; Sinclair, I.K. [Hibernia Management and Development Co. Ltd., St. John' s, NL (Canada)

    2005-07-01

    Petroleum reservoirs are typically characterized by combining conventional core analysis results, wire-line log data and sedimentological description with production data. This study emphasized the benefits of including structural analysis of core material as part of general reservoir characterization. In particular, it examined the influence of fault zones on fluid flow within the Hibernia Formation in the Hibernia Oilfield in the Jeanne d'Arc Basin on the Grand Banks of Newfoundland. The geologic setting and background to the Hibernia Field was presented. Fault seal analysis was used in the study to help manage the compartmentalized Hibernia Field. Cross-fault juxtaposition analysis was also integrated with structural logging and petrophysical measurement of core material. The analysis of core material resulted in an increased confidence in production data interpretation. The study also examined how deformation features present within the Hibernia Formation drill cores have the potential to act as baffles or seals to hydrocarbon flow. Deformation features were described with reference to low, intermediate and high clay content fault rocks. It was shown that fault rocks are capable of severely restricting fluid flow, particularly when close to production or injection wells. The targeting of wheels to avoid the damage-zone envelope associated with seismic-scale faults will result in a large improvement in producer-injector performance despite reducing the potential drainage volume. The results confirm that inclusion of structural analysis in reservoir characterization studies can have a great and positive impact on field management strategies. 31 refs., 2 tabs., 8 figs.

  1. Increased oil production and reserves from improved completion techniques in the Bluebell Field, Uinta Basin, Utah. Annual report, September 30, 1993--September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Allison, M.

    1995-07-01

    The Bluebell field produces from the Tertiary lower Green River and Wasatch Formations of the Uinta Basin, Utah. The productive interval consists of thousands of feet of interbedded fractured clastic and carbonate beds deposited in a fluvial-dominated deltaic lacustrine environment, sandstones deposited in fluvial-dominated deltas; and carbonates and some interbedded sandstones of the lower Wasatch transition deposited in mud flats. Bluebell project personnel are studying ways to improve completion techniques used in the field to increase primary production in both new wells and recompletions. The study includes detailed petrographic examination of the different lithologic reservoir types in both the outcrop and core. Outcrop, core, and geophysical logs are being used to identify and map important depositional cycles. Petrographic detail will be used to improve log calculation methods which are currently highly questionable due to varying water chemistry and clay content in the Green River and Wasatch Formations. Field mapping of fractures and their relationship to basin tectonics helps predict the orientation of open fractures in the subsurface. The project includes acquiring bore-hole imaging logs from new wells in the Bluebell field thereby obtaining detailed subsurface fracture data previously not available. Reservoir simulation models are being constructed to improve the understanding of pressure and fluid flow within the reservoir. A detailed database of well completion histories has been compiled and will be studied to determine which were the most and the least effective methods used in the past.

  2. Class III Mid-Term Project, "Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies"

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2007-03-31

    The overall objective of this project was to increase heavy oil reserves in slope and basin clastic (SBC) reservoirs through the application of advanced reservoir characterization and thermal production technologies. The project involved improving thermal recovery techniques in the Tar Zone of Fault Blocks II-A and V (Tar II-A and Tar V) of the Wilmington Field in Los Angeles County, near Long Beach, California. A primary objective has been to transfer technology that can be applied in other heavy oil formations of the Wilmington Field and other SBC reservoirs, including those under waterflood. The first budget period addressed several producibility problems in the Tar II-A and Tar V thermal recovery operations that are common in SBC reservoirs. A few of the advanced technologies developed include a three-dimensional (3-D) deterministic geologic model, a 3-D deterministic thermal reservoir simulation model to aid in reservoir management and subsequent post-steamflood development work, and a detailed study on the geochemical interactions between the steam and the formation rocks and fluids. State of the art operational work included drilling and performing a pilot steam injection and production project via four new horizontal wells (2 producers and 2 injectors), implementing a hot water alternating steam (WAS) drive pilot in the existing steamflood area to improve thermal efficiency, installing a 2400-foot insulated, subsurface harbor channel crossing to supply steam to an island location, testing a novel alkaline steam completion technique to control well sanding problems, and starting on an advanced reservoir management system through computer-aided access to production and geologic data to integrate reservoir characterization, engineering, monitoring, and evaluation. The second budget period phase (BP2) continued to implement state-of-the-art operational work to optimize thermal recovery processes, improve well drilling and completion practices, and evaluate the

  3. Experimental investigation of creep behavior of clastic rock in Xiangjiaba Hydropower Project

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2015-01-01

    Full Text Available There are many fracture zones crossing the dam foundation of the Xiangjiaba Hydropower Project in southwestern China. Clastic rock is the main media of the fracture zone and has poor physical and mechanical properties. In order to investigate the creep behavior of clastic rock, triaxial creep tests were conducted using a rock servo-controlling rheological testing machine. The results show that the creep behavior of clastic rock is significant at a high level of deviatoric stress, and less time-dependent deformation occurs at high confining pressure. Based on the creep test results, the relationship between axial strain and time under different confining pressures was investigated, and the relationship between axial strain rate and deviatoric stress was also discussed. The strain rate increases rapidly, and the rock sample fails eventually under high deviatoric stress. Moreover, the creep failure mechanism under different confining pressures was analyzed. The main failure mechanism of clastic rock is plastic shear, accompanied by a significant compression and ductile dilatancy. On the other hand, with the determined parameters, the Burgers creep model was used to fit the creep curves. The results indicate that the Burgers model can exactly describe the creep behavior of clastic rock in the Xiangjiaba Hydropower Project.

  4. Prediction in Ungauged Basins (PUB) for estimating water availability during water scarcity conditions: rainfall-runoff modelling of the ungauged diversion inflows to the Ridracoli water supply reservoir

    Science.gov (United States)

    Toth, Elena

    2013-04-01

    The Ridracoli reservoir is the main drinking water supply reservoir serving the whole Romagna region, in Northern Italy. Such water supply system has a crucial role in an area where the different characteristics of the communities to be served, their size, the mass tourism and the presence of food industries highlight strong differences in drinking water needs. Its operation allows high quality drinking water supply to a million resident customers, plus a few millions of tourists during the summer of people and it reduces the need for water pumping from underground sources, and this is particularly important since the coastal area is subject also to subsidence and saline ingression into aquifers. The system experienced water shortage conditions thrice in the last decade, in 2002, in 2007 and in autumn-winter 2011-2012, when the reservoir water storage fell below the attention and the pre-emergency thresholds, thus prompting the implementation of a set of mitigation measures, including limitations to the population's water consumption. The reservoir receives water not only from the headwater catchment, closed at the dam, but also from four diversion watersheds, linked to the reservoir through an underground water channel. Such withdrawals are currently undersized, abstracting only a part of the streamflow exceeding the established minimum flows, due to the design of the water intake structures; it is therefore crucial understanding how the reservoir water availability might be increased through a fuller exploitation of the existing diversion catchment area. Since one of the four diversion catchment is currently ungauged (at least at the fine temporal scale needed for keeping into account the minimum flow requirements downstream of the intakes), the study first presents the set up and parameterisation of a continuous rainfall-runoff model at hourly time-step for the three gauged diversion watersheds and for the headwater catchment: a regional parameterisation

  5. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neutral reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  6. Turbidites as proxy for past flood events: Testing this approach in a large clastic system (Lake Geneva, France/Switzerland)

    Science.gov (United States)

    Kremer, Katrina; Girardclos, Stéphanie

    2017-04-01

    Turbidites recorded in lake sediments are often used to reconstruct the frequency of past flood and also seismological events. However, for such a reconstruction, the origin and causes of the recorded turbidites need to be clearly identified. In this study, we test if turbidites can be used as paleohydrological archive based on the the sedimentary record of Lake Geneva resulting from inputs by the Rhone and Dranse clastic river systems. Our approach is based on several methods combining high-resolution seismic reflection data with geophysical (magnetic susceptibility, grain size) and high-resolution XRF/XRD data measured on ca. 10-m-long sediment cores (dated by radiocarbon ages and 137Cs activity). This dataset allows distinguishing between the different sources (rivers or hemipelagic sediment) of the turbidites deposited in the deep basin of Lake Geneva. However, no clear distinction between the various trigger processes (mass failures or floods) could be made, thus flood deposits could not be clearly identified. From our results, we also conclude that the lack of turbidite deposits in the deep basin between the 15th and 18th century seems to be linked to a change in turbidite depocentre due to the Rhone River mouth shifting possibly triggered by human activity and not by any direct climate effect. This study demonstrates that a least two conditions are needed to perform an adequate paleohydrological interpretation based on turbidite records: (1) the holistic understanding of the basin sedimentary system and (2) the distinction of flood-induced turbidites from other types of turbidites (mass failures etc.).

  7. Fouling of coarse-clastic sediments with macrophytes depending on the rate of abrasion, Murmansk coast

    Science.gov (United States)

    Malavenda, S. V.; Mitayev, M. V.; Malavenda, S. S.; Gerasimova, M. V.

    2017-05-01

    It is shown for the first time that the hydrodynamics and average daily gradient of air temperature affect the rate of abrasion of the coarse-clastic material on the boulder littoral of the Murmansk coast, as well as the density of its fouling by macroalgae. The proportion and biomass of species-explerents vary depending on the hydrological and meteorological conditions. The annual species-explerents ( Acrosiphonia arcta, Blidingia minima, Spongomorpha aeruginosa, Pylaiella littoralis) are the basis for new phytocenoses. In the fucus phytocenoses of the boulder littoral, these groupings represent the intermediate stage of fouling of the coarse-clastic material.

  8. Nutrient loads in the river mouth of the Río Verde basin in Jalisco, Mexico: how to prevent eutrophication in the future reservoir?

    Science.gov (United States)

    Jayme-Torres, Gonzalo; Hansen, Anne M

    2017-10-04

    Since nutrients are emitted and mobilized in river basins, causing eutrophication of water bodies, it is important to reduce such emissions and subsequent nutrient loads. Due to processes of attenuation, nutrient loads are reduced during their mobilization in river basins. At the mouth of the Río Verde basin in western Mexico, the El Purgatorio dam is being constructed to supply water to the metropolitan area of the second most populated city in the country, Guadalajara. To analyze situations that allow protecting this future dam from eutrophication, nutrient loads in the mouth of the river basin were determined and their reduction scenarios evaluated by using the NEWS2 (Nutrient Export from Watersheds) model. For this, a nutrient emissions inventory was established and used to model nutrient loads, and modeling results were compared to an analysis of water quality data from two different monitoring sites located on the river. The results suggest that 96% of nitrogen and 99% of phosphorus emissions are attenuated in the watershed. Nutrient loads reaching the mouth of the river basin come mainly from wastewater discharges, followed by livestock activities and different land uses, and loads are higher as emissions are located closer to the mouth of the river basin. To achieve and maintain mesotrophic state of water in the future dam, different nutrient emission reduction scenarios were evaluated. According to these results, the reduction of 90% of the phosphorus loads in wastewater emissions or 75% of the phosphorus loads in wastewater emissions and at least 50% in emissions from livestock activities in the river basin are required.

  9. Predicting permeability of low enthalpy geothermal reservoirs: A case study from the Upper Triassic − Lower Jurassic Gassum Formation, Norwegian–Danish Basin

    DEFF Research Database (Denmark)

    Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

    2017-01-01

    This paper aims at improving the predictability of permeability in low enthalpy geothermal reser-voirs by investigating the effect of diagenesis on sandstone permeability. Applying the best fittedporosity–permeability trend lines, obtained from conventional core analysis, to log-interpreted poros...

  10. Deep Geothermal energy potential in Madrid basin; Potencial de la Geotermia profunda en la Cuenca de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Hidalgo, R.; Sanchez, J.; Ungemach, P.

    2009-07-01

    The Madrid Basin geothermal potential was evidenced in 1980 thanks to an oil exploration well drilled by Shell-Campsa which showed temperatures of 88 degree centigrade and 150 degree centigrade at 1,700 mts and 3,400 mts depth respectively. The low enthalpy geothermal reservoir could be further assessed by four exploratory wells the first one, Pradillo (originals Shell-Campsa oil well), two drilled by ADARO and IGME (Geological survey of Spain) in San Sebastian de los Reyes and Tres Cantos respectively. The latest well, Geomadrid 1, was drilled in 1990 by the Madrid Regional government. The afore mentioned wells have identified a dependable geothermal resource, hosted in a tertiary, clastic, consolidated sandstone reservoir consisting of a thick multilayered sequence (200-800m), with temperatures ranging from 70 degree centigrade to 90 degree centigrade and depths of 1,500 to 2,150 m., overlying a Mesozoic sequence, suitable to be exploited for thermal uses in several district heating grids around Madrid in areas displaying adequate heat loads. A medium temperature reservoir was also identified at the contact between Mesozoic Cretaceous limestones and fractured basement granites at 3,400mts depth, with measured temperatures of 156 degree centigrade, that could be developed and exploited in view of a combined power and heat production (CPH) within the Madrid suburban areas. (Author) 7 refs.

  11. Influence of Clastic Dikes on Vertical Migration of Contaminants in the Vadose Zone at Hanford

    International Nuclear Information System (INIS)

    Murray, Christopher J.; Ward, Anderson L.; Wilson, John L.

    2003-01-01

    The purpose of this study was to examine the hypothesis that clastic dikes could form a preferential flow path through the vadose zone to the water table at the Hanford Site. Clastic dikes are subvertical structures that form within sedimentary sequences after deposition, and cut across the original sedimentary layers. They are common throughout the Hanford Site, often occurring in organized polygonal networks. In the initial phase of the project, we analyzed the large-scale geometry of the clastic dikes and developed an algorithm for simulating their spatial distribution. This result will be useful in providing maps of the potential distribution of clastic dikes in areas where they are not exposed at the surface (e.g., where covered by windblown sand or by construction of facilities like tank farms at the surface). In addition to the study of the large scale distribution of the dikes, a major focus of the project was on field, laboratory, and modeling studies of the hydrogeologic al properties of the clastic dikes and the effect that they have on transport of water through the vadose zone. These studies were performed at two field locations at the Hanford Site. We performed an extensive series of field and laboratory measurements of a large number of samples from the clastic dikes, linked with infrared (IR) and visual imagery of the clastic dikes and surrounding matrix. We developed a series of correlations from the sample data that allowed us to estimate the unsaturated hydraulic conductivity of the dike and matrix at an extremely high resolution (approximately 1 mm). The resulting grids, each of which measured several meters on a side and included nearly 4 grid nodes, were used to study the distribution of moisture between the clastic dike and surrounding matrix, as well as the relative velocities that moisture would have through the clastic dike and matrix for a number of different recharge scenarios. Results show the development of complex flow networks that

  12. Evolution characteristic of gypsum-salt rocks of the upper member of Oligocene Lower Ganchaigou Fm in the Shizigou area, western Qaidam Basin

    Directory of Open Access Journals (Sweden)

    Dinghong Yi

    2017-09-01

    Full Text Available Over years of oil and gas exploration in the Qaidam Basin, reservoirs have been discovered in many layers. In the Shizigou area, western Qaidam Basin, the upper member of Oligocene Lower Ganchaigou Fm is an important target for oil and gas exploration, and gypsum-salt rocks are the high-quality caprocks for the preservation of oil and gas reservoirs in this area. For predicting oil and gas exploration direction and target in the western Qaidam Basin and providing guidance for its oil and gas exploration deployment, its depositional characteristics and environment of gypsum-salt rocks in this area were investigated based on the core observation, thin section identification, and analysis of grain size, sensitivity parameter ratios (Sr/Cu, Fe/Mn, (Fe + Al/(Ca + Mg, V/(V + Ni and Pr/Ph, pyrite content and inclusions. The following characteristics are identified. First, gypsum-salt rocks are mainly distributed in the depocenter of the lake basin and their thickness decreases towards the margin of the basin. They are laterally transformed into carbonate rocks or terrigenous clastic rocks. They are areally distributed in the shape of irregular ellipse. Second, gypsum-salt rocks are vertically developed mainly in the middle and upper parts of the upper member of Lower Ganchaigou Fm and they are interbedded with carbonate rocks or terrigenous clastic rocks. Their single layer thickness changes greatly, and there are many layers with good continuity. Third, Sand Group III to Group I in the upper member of Lower Ganchaigou Fm (inter-salt are of reductive water environment of semi-deep to deep lake facies due to their sedimentation in an arid and hot climate. It is concluded that gypsum-salt rocks of the upper member of Lower Ganchaigou Fm are distributed widely with great accumulative thickness in this area; and that they are originated from deep lake water by virtue of evaporation, concentration and crystallization in an arid and hot climate instead

  13. Sedimentary cycles in coal and evaporite basins and the reconstruction of Paleozoic climate

    NARCIS (Netherlands)

    van den Belt, F.J.G.

    2012-01-01

    This thesis deals with large-scale processes controlling the formation of sedimentary cycles in coal and evaporite basins and their relation to large-scale fluctuations of Palaeozoic climate. Coal-clastic cycles dominate Pennsylvanian sequences in palaeo-equatorial basins from Euramerica. They

  14. Chemical and isotopic changes in Williston Basin brines during long-term oil production: An example from the Poplar dome, Montana

    Science.gov (United States)

    Peterman, Zell; Thamke, Joanna N.

    2016-01-01

    Brine samples were collected from 30 conventional oil wells producing mostly from the Charles Formation of the Madison Group in the East and Northwest Poplar oil fields on the Fort Peck Indian Reservation, Montana. Dissolved concentrations of major ions, trace metals, Sr isotopes, and stable isotopes (oxygen and hydrogen) were analyzed to compare with a brine contaminant that affected groundwater northeast of the town of Poplar. Two groups of brine compositions, designated group I and group II, are identified on the basis of chemistry and 87Sr/86Sr ratios. The solute chemistry and Sr isotopic composition of group I brines are consistent with long-term residency in Mississippian carbonate rocks, and brines similar to these contaminated the groundwater. Group II brines probably resided in clastic rocks younger than the Mississippian limestones before moving into the Poplar dome to replenish the long-term fluid extraction from the Charles Formation. Collapse of strata at the crest of the Poplar dome resulting from dissolution of Charles salt in the early Paleogene probably developed pathways for the ingress of group II brines from overlying clastic aquifers into the Charles reservoir. Such changes in brine chemistry associated with long-term oil production may be a widespread phenomenon in the Williston Basin.

  15. Modeling a complex system of multipurpose reservoirs under prospective scenarios (hydrology, water uses, water management): the case of the Durance River basin (South Eastern France, 12 800 km2)

    Science.gov (United States)

    Monteil, Céline; Hendrickx, Frédéric; Samie, René; Sauquet, Eric

    2015-04-01

    The Durance River and its main tributary, the Verdon River, are two major rivers located in the Southern part of France. Three large dams (Serre-Ponçon, Castillon and Sainte-Croix) were built on their streams during the second half of the 20th century for multiple purposes. Stored water is used for hydropower, recreational, industry, drinking water and irrigation. Flows are partly diverted to feed areas outside the basin. On average 30 plants located in the Durance and Verdon valleys currently produce a total of 600 million kWh per year, equal to the annual residential consumption of a city with over 2.5 million inhabitants. The Southern part of France has been recently affected by severe droughts (2003, 2007 and 2011) and the rules for water allocation and reservoir management are now questioned particularly in the light of global change. The objective of the research project named "R²D²-2050" was to assess water availability and risks of water shortage in the mid-21st century by taking into account changes in both climate and water management. Therefore, a multi-model multi-scenario approach was considered to simulate regional climate, water resources and water demands under present-day (over the 1980-2009 baseline period) and under future conditions (over the 2036-2065 period). In addition, a model of water management was developed to simulate reservoir operating rules of the three dams. This model was calibrated to simulate water released from reservoir under constraints imposed by current day water allocation rules (e.g. downstream water requirements for irrigation, minimum water levels in the reservoirs during summer time for recreational purposes). Four territorial socio-economic scenarios were also elaborated with the help of stake holders to project water needs in the 2050s for the areas supplied with water from the Durance River basin. Results suggest an increase of the average air temperature with consequences on snow accumulation, snowmelt processes

  16. Spatiotemporal sedimentological and petrophysical characterization of El Gueria reservoir (Ypresian) in sFAX and Gulf of Gabes Basins (SE-Tunisia)

    Science.gov (United States)

    Nadhem, Kassabi; Zahra, Njahi; Ménendez, Béatriz; Salwa, Jeddi; Jamel, Touir

    2017-06-01

    El Gueria carbonate Formation (Ypresian) in Tunisia is a proven hydrocarbon reservoir. In the Gulf of Gabes, El Gueria reservoir consists mainly of a nummulitic limestone which is developed in an inner shelf environment. In order to characterize the depositional facies evolution and the petrophysical parameters, and to understand the origin of heterogeneity of El Gueria reservoir, we firstly conducted a sedimentological and a sequence stratigraphy study of this Formation in more than 10 wells especially in P1, then we established a detailed petrophysical study of El Gueria reservoir in P1, P3c and P7d cores. Based on lithostratigraphic and gamma ray correlations of an important number of wells in the study area, a detailed sedimentological study has been established. This latter shows that: (i): The Ypresien deposits are deposited in an inner shelf (El Gueria Formation) in the south and in an outer shelf (Boudabbous Formation) in the north of the study area with the form of horsts and grabens, (ii): 3 distinct members and 7 principal facies within El Gueria Formation have been distinguished. The coupling of data logging and data of the P1 core shows that the El Gueria deposits include 10 transgressive-regressive depositional sequences, while showing from bottom to top a broad regressive tendancy from a subtidal domain during the early Ypresian to an intertidal domain during the middle Ypresian reaching the supratidal environnement during the late Ypresian-early Lutetian. The petrophysical parameters (porosity and permeability) of El Gueria reservoir vary in time and space (laterally and vertically variation) following the deposit environment variation. Particularly, the porosity variation is controlled by eustatic cycles so that high porosities are linked with transgressive phases and low porosities with regressive phases. In addition, the vertical evolution of porosity through the El Gueria reservoir varies following the (i) deposit environments, (ii) type and

  17. Petroleum geology and total petroleum systems of the Widyan Basin and Interior Platform of Saudi Arabia and Iraq

    Science.gov (United States)

    Fox, James E.; Ahlbrandt, Thomas S.

    2002-01-01

    Two total petroleum systems are associated with the Widyan Basin - Interior Platform Province in northern Saudi Arabia and western Iraq. In the Paleozoic Qusaiba/Akkas/Abba/ Mudawwara Total Petroleum System, which consists of one assessment unit - the Horst/Graben-Related Oil and Gas Assessment Unit - high-gravity, low-sulfur crude oil, as well as natural gas, occurs in horst/graben-related traps that formed prior to, during, and after Hercynian deformation (Carboniferous). The source of oil and gas is from organic-rich marine shale at the base of the Silurian sedimentary sequence (Qusaiba, Akkas, Mudawwara, and Abba Formations) that was deposited under dysoxic to anoxic conditions in an intra-shelf basin located north of the Central Arabian Arch. Onset of oil generation in Iraq began about 250 million years ago (Ma) and in eastern Saudi Arabia about 160 Ma, reaching peak generation, expulsion, migration, and entrapment during the Jurassic Period. In Saudi Arabia, petroleum migrated into fluvial and eolian quartzose sandstones of the Carboniferous-Early Permian Unayzah Formation that overlies the Hercynian unconformity, filling in rifts and half-grabens to thicknesses ranging to more than 400 meters. Combined stratigraphic-structural traps exist where the Unayzah Formation is the reservoir, as is the case in central Saudi Arabia. Oil and gas are sealed in those reservoirs by overlying tight carbonate- evaporite strata, and by subunconformity pinchouts of Pre-Unayzah clastic reservoir units against impermeable facies. In Iraq, reservoirs are sandstones of the Ordovician Upper Khabour and Silurian Akkas Formations. Over most of the Southwestern Desert of Iraq, Lower Silurian shale is a seal for hydrocarbons in the underlying Ordovician Khabour Formation.

  18. Fracture properties from tight reservoir outcrop analogues with application to geothermal exploration

    Science.gov (United States)

    Philipp, Sonja L.; Reyer, Dorothea; Afsar, Filiz; Bauer, Johanna F.; Meier, Silke; Reinecker, John

    2015-04-01

    areas of palaeo¬geothermal fields in the Bristol Channel (1), all mineral veins, most of which are extension fractures, are of calcite. They are clearly associated with the faults and indicate that geothermal water was transported along the then-active faults into the host rocks with evidence of injection as hydrofractures. Layers with contrasting mechanical properties (in particular, stiffnesses), however, acted as stress barriers and lead to fracture arrest. Along some faults, veins propagated through the barriers along faults to shallower levels. In the Northwest German Basin (2) there are pronounced differences between normal-fault zones in carbonate and clastic rocks. Only in carbonate rocks clear damage zones occur, characterized by increased fracture frequencies and high amounts of fractures with large apertures. On the Upper Rhine Graben shoulders (3) damage zones in Triassic Muschelkalk limestones are well developed; fault cores are narrow and comprise breccia, clay smear, host rock lenses and mineralization. A large fault zone in Triassic Bunter sandstone shows a clearly developed fault core with fault gouge, slip zones, deformation bands and host rock lenses, a transition zone with mostly disturbed layering and highest fracture frequency, and a damage zone. The latter damage zone is compared to the damage zone of a large Bunter sandstone fault zone currently explored for geothermal energy production. The numerical models focus on stress field development, fracture propagation and associated permeability changes. These studies contribute to the understanding of the hydromechanical behaviour of fault zones and related fluid transport in fractured reservoirs complementing predictions based on geophysical measurements. Eventually we aim at classifying and quantifying fracture system properties in fault zones to improve exploration and exploitation of geothermal reservoirs. Acknowledgements The authors appreciate the support of 'Niedersächsisches Ministerium f

  19. National Program for Inspection of Non-Federal Dams. Norton Reservoir Dam (MA 00815), Coastal Basin, Norton, Massachusetts. Phase I Inspection Report.

    Science.gov (United States)

    1978-08-01

    is the left abutment 0 . . and gatehouse . The right abutment shows signs of erosion and could well - be the first section to fail. Owing to the...its age of almost 80 years, is in fair condition. It is virtually impossible to , 0 ascertain where the embankment or fill behind the concrete wing...Appurtenant Structures. The only appurtenant structure, the gatehouse , is in fair condition. d. Reservoir Area. The banks are flat and wooded. There

  20. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010

    DEFF Research Database (Denmark)

    Kaas, Rolf Sommer; Ngandjio, Antoinette; Nzouankeu, Ariane

    2016-01-01

    The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic m...

  1. A clastic-evaporitic deposit from the Cretaceous of northeastern Mexico: La Mula-La Virgen transition

    Science.gov (United States)

    Gutierrez-Alejandro, Alejandra G.; Chacon-Baca, Elizabeth; Rosales-Domínguez, Carmen; Ramírez-Peña, César Francisco; Girón, Patricia; Grajales-Nishimura, José Manuel

    2017-12-01

    Units from La Mula and La Virgen formations outcrop in central Coahuila in northeastern Mexico. During the Early Cretaceous this sedimentary succession was deposited between the Coahuila and the Tamaulipas blocks as a transitional ramp succession that later became the Sabinas Basin. For years, the lack of fossils in La Virgen Formation has prevented a precise age resolution. This work provides new biostratigraphic data from Potrero de Menchaca, a representative locality that records a siliciclastic-carbonate transition from the clastic La Mula Formation and the evaporites from La Virgen Formation. The microfacies association indicates the presence of foraminiferan representatives of Choffatella decipiens and Charentia sp. in close association with the rare green alga Thaumotoporella parvovesiculifera, a few mollusk bioclasts and other algal fragments that gradually increase in size as the evaporitic succession become more frequent. In addition to the microfossils reported, a significant contribution of this work includes a preliminary geochemical analysis from the preceding green shales from La Mula Formation, which are reported from the first time for this locality and holds high potential for provenance studies.

  2. Amorphous silica maturation in chemically weathered clastic sediments

    Science.gov (United States)

    Liesegang, Moritz; Milke, Ralf; Berthold, Christoph

    2018-03-01

    A detailed understanding of silica postdepositional transformation mechanisms is fundamental for its use as a palaeobiologic and palaeoenvironmental archive. Amorphous silica (opal-A) is an important biomineral, an alteration product of silicate rocks on the surface of Earth and Mars, and a precursor material for stable silica phases. During diagenesis, amorphous silica gradually and gradationally transforms to opal-CT, opal-C, and eventually quartz. Here we demonstrate the early-stage maturation of several million year old opal-A from deeply weathered Early Cretaceous and Ordovician sedimentary rocks of the Great Artesian Basin (central Australia). X-ray diffraction, scanning electron microscopy, and electron probe microanalyses show that the mineralogical maturation of the nanosphere material is decoupled from its chemical properties and begins significantly earlier than micromorphology suggests. Non-destructive and locally highly resolved X-ray microdiffraction (μ-XRD2) reveals an almost linear positive correlation between the main peak position (3.97 to 4.06 Å) and a new asymmetry parameter, AP. Heating experiments and calculated diffractograms indicate that nucleation and growth of tridymite-rich nanodomains induce systematic peak shifts and symmetry variations in diffraction patterns of morphologically juvenile opal-A. Our results show that the asymmetry parameter traces the early-stage maturation of amorphous silica, and that the mineralogical opal-A/CT stage extends to smaller d-spacings and larger FWHM values than previously suggested.

  3. MULTIDISCIPLINARY IMAGING OF ROCK PROPERTIES IN CARBONATE RESERVOIRS FOR FLOW-UNIT TARGETING

    Energy Technology Data Exchange (ETDEWEB)

    Stephen C. Ruppel

    2005-02-01

    Despite declining production rates, existing reservoirs in the US contain large quantities of remaining oil and gas that constitute a huge target for improved diagnosis and imaging of reservoir properties. The resource target is especially large in carbonate reservoirs, where conventional data and methodologies are normally insufficient to resolve critical scales of reservoir heterogeneity. The objectives of the research described in this report were to develop and test such methodologies for improved imaging, measurement, modeling, and prediction of reservoir properties in carbonate hydrocarbon reservoirs. The focus of the study is the Permian-age Fullerton Clear Fork reservoir of the Permian Basin of West Texas. This reservoir is an especially appropriate choice considering (a) the Permian Basin is the largest oil-bearing basin in the US, and (b) as a play, Clear Fork reservoirs have exhibited the lowest recovery efficiencies of all carbonate reservoirs in the Permian Basin.

  4. Controls on clastic sequence geometries in a shallow-marine, transtensional basin: the Bohemian Cretaceous Basin, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Uličný, David; Laurin, Jiří; Čech, S.

    2009-01-01

    Roč. 56, č. 4 (2009), s. 1077-1114 ISSN 0037-0746 R&D Projects: GA ČR GA205/01/0629; GA AV ČR(CZ) IAA300120609 Institutional research plan: CEZ:AV0Z30120515 Keywords : Coarse-grained delta * Coniacian * sea-level * subsidence * tidal current * Turonian Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.114, year: 2009

  5. Reservoir Sedimentation Based on Uncertainty Analysis

    Directory of Open Access Journals (Sweden)

    Farhad Imanshoar

    2014-01-01

    Full Text Available Reservoir sedimentation can result in loss of much needed reservoir storage capacity, reducing the useful life of dams. Thus, sufficient sediment storage capacity should be provided for the reservoir design stage to ensure that sediment accumulation will not impair the functioning of the reservoir during the useful operational-economic life of the project. However, an important issue to consider when estimating reservoir sedimentation and accumulation is the uncertainty involved in reservoir sedimentation. In this paper, the basic factors influencing the density of sediments deposited in reservoirs are discussed, and uncertainties in reservoir sedimentation have been determined using the Delta method. Further, Kenny Reservoir in the White River Basin in northwestern Colorado was selected to determine the density of deposits in the reservoir and the coefficient of variation. The results of this investigation have indicated that by using the Delta method in the case of Kenny Reservoir, the uncertainty regarding accumulated sediment density, expressed by the coefficient of variation for a period of 50 years of reservoir operation, could be reduced to about 10%. Results of the Delta method suggest an applicable approach for dead storage planning via interfacing with uncertainties associated with reservoir sedimentation.

  6. Using the U-Pb system of calcretes to date the time of sedimentation of clastic sedimentary rocks

    Science.gov (United States)

    Wang, Z. S.; Rasbury, E. T.; Hanson, G. N.; Meyers, W. J.

    1998-08-01

    The time of sedimentation of rapidly deposited clastic sedimentary rocks in fluvial environments may be directly dated with an uncertainty of less than three million years using U-Pb dating of pure micritic calcite from calcretes developed in overbank deposits. This conclusion is based on results obtained for calcretes (soil calcite, caliche) formed in the late Triassic New Haven Arkose, Hartford Basin, Connecticut, USA. The paragenesis of calcrete samples from the New Haven Arkose was determined using plane-polarized light and cathodoluminesence petrography, uranium fission track analysis, as well as trace element and stable isotope geochemistry. These calcretes contain an abundance of paleosol microfabrics and diagenetic calcite. The first-generation micritic calcite and second-generation blocky calcite have characteristics consistent with soil calcite. The third generation blocky calcite is a later diagenetic calcite (post-soil calcite). The U-Pb data for pure micritic calcite (first generation) in a horizontal sheet calcrete in sedimentary rocks of Norian age gives a 238U/ 207Pb- 206Pb/ 207Pb isochron age of 211.9 ± 2.1 Ma (2-sigma, and used hereafter for all ages). This age and the stratigraphic position for this sample are in excellent agreement with the ages proposed by Gradstein et al. (1994) for the Norian/Rhaetian boundary of 209.6 ± 4.1 Ma and the Carnian/Norian boundary of 220.7 ± 4.4 Ma. The U-Pb data for two samples of first generation micrite in rhizoliths with about 15% insoluble residues give "ages" of 7 ± 66 Ma and 20 ± 36 Ma. These results suggest that relatively recent events disturbed the U-Pb system of these detrital rich samples, perhaps due to redistribution of U during weathering or during chemical dissolution for analysis. The U-Pb data for a sample of pure third generation blocky calcite cement in a rhizolith yields a 206Pb/ 238U- 207Pb/ 235U isochron age of 81 ± 11 Ma. This age suggests that this sample of third generation blocky

  7. Global prediction of continuous hydrocarbon accumulations in self-sourced reservoirs

    Science.gov (United States)

    Eoff, Jennifer D.

    2012-01-01

    occurred. In contrast, deposition of this resource type on rifted passive margins was likely the result of reactivation of long-lived cratonic features or salt tectonic regimes that created semi-confined basins. Commonly, loading by thick sections of clastic material, following thermal relaxation after plate collision or rift phases, advances kerogen maturation. With few exceptions, North American self-sourced reservoirs appear to be associated with calcitic seas and predominantly greenhouse or transitional ("warm" to "cool") global climatic conditions. Significant changes to the global carbon budget may also be a contributing factor in the stratigraphic distribution of continuous resource plays, requiring additional evaluation.

  8. The Lake Chad Basin, an Isolated and Persistent Reservoir of Vibrio cholerae O1: A Genomic Insight into the Outbreak in Cameroon, 2010.

    Directory of Open Access Journals (Sweden)

    Rolf S Kaas

    Full Text Available The prevalence of reported cholera was relatively low around the Lake Chad basin until 1991. Since then, cholera outbreaks have been reported every couple of years. The objective of this study was to investigate the 2010/2011 Vibrio cholerae outbreak in Cameroon to gain insight into the genomic make-up of the V. cholerae strains responsible for the outbreak. Twenty-four strains were isolated and whole genome sequenced. Known virulence genes, resistance genes and integrating conjugative element (ICE elements were identified and annotated. A global phylogeny (378 genomes was inferred using a single nucleotide polymorphism (SNP analysis. The Cameroon outbreak was found to be clonal and clustered distant from the other African strains. In addition, a subset of the strains contained a deletion that was found in the ICE element causing less resistance. These results suggest that V. cholerae is endemic in the Lake Chad basin and different from other African strains.

  9. Application of Advanced Exploration Technologies for the Development of Mancos Formation Oil Reservoirs, Jicarilla Apache Indian Nation, San Juan Basin, New Mexico

    International Nuclear Information System (INIS)

    Reeves, Scott; Billingsley, Randy

    2002-01-01

    The objectives of this project are to: (1) develop an exploration rationale for the Mancos shale in the north-eastern San Juan basin; (2) assess the regional prospectivity of the Mancos in the northern Nation lands based on that rationale; (3) identify specific leads in the northern Nation as appropriate; (4) forecast pro-forma production, reserves and economics for any leads identified; and (5) package and disseminate the results to attract investment in Mancos development on the Nation lands

  10. National Program for Inspection of Non-Federal Dams. Shepaug Reservoir Dam (CT 00665), Housatonic River Basin, Litchfield and Warren, Connecticut. Phase I Inspection Report.

    Science.gov (United States)

    1979-05-01

    ENGINEERS D-WALTHAM, MASS. 02154 r-is dct" imrnf has beer .) po d MAY 1979 i ’ un1-i to dL N- -.- . . . -’ 0~i . . . . " . . . ..4...transmits * ~water to a tunnel aqueduct which then flows about 3. 6 miles under- * ground to Morris Reservoir. d 1-3 4~ ~~~ .., 4 4 -. A .(2) There are...observed but there were no observable flows. o It would not have been possible to identify any seeps that may occur in the deepest part of the valley because

  11. National Dam Safety Program. Eaton Brook Reservoir Dam (Inventory Number NY 352), Susquehanna River Basin, Madison County, New York. Phase I Inspection Report,

    Science.gov (United States)

    1980-02-19

    Visul IspecionWest Eaton pydrology, Structural Stability OeS iJiiTiAcr~U roawo p*Va *irow % ff n*,c...y sod Idenfi fr by block numbe.r) C) Tis report...provides inforMation andl analys-s on the physical condition of C-") I the dlam as of the report dnte. Information ’and analysis nre based~ on visual...SUSQUEHANNA RIVER BASIN MADISON COUNTY, NEW YORK TABLE OF CONTENTS PAGE NO. ASSESSMENT - OVERVIEW PHOTOGRAPH 1 PROJECT INFORMATION 1 1.1 GENERAL 1 1.2

  12. Recovery act. Characterizing structural controls of EGS-candidate and conventional geothermal reservoirs in the Great Basin. Developing successful exploration strategies in extended terranes

    Energy Technology Data Exchange (ETDEWEB)

    Faulds, James [Univ. of Nevada, Reno, NV (United States)

    2015-06-25

    We conducted a comprehensive analysis of the structural controls of geothermal systems within the Great Basin and adjacent regions. Our main objectives were to: 1) Produce a catalogue of favorable structural environments and models for geothermal systems. 2) Improve site-specific targeting of geothermal resources through detailed studies of representative sites, which included innovative techniques of slip tendency analysis of faults and 3D modeling. 3) Compare and contrast the structural controls and models in different tectonic settings. 4) Synthesize data and develop methodologies for enhancement of exploration strategies for conventional and EGS systems, reduction in the risk of drilling non-productive wells, and selecting the best EGS sites.

  13. Big River Reservoir Project - Pawcatuck River and Narragansett bay Drainage Basins - Water and related Land Resources Study Volume IV. Attachment I.

    Science.gov (United States)

    1981-07-01

    as uneconomical for aquifer recharge, spray irrigation is considered a future option for aquifer re- charge in the South Branch system. Surface water...Inn) t) telatc ocf 0 hos.- So hones. - toic 500 Jh.. C) VproeadrtIy 610 te.cacjand rejad I. SPY IconS - Iota of apprnolnanaly 4000 Jobs. iano At9 -e...SENE study report (see page 1-7) as an uneconomical method for aquifer recharge within the basin. However, land disposal by spray irrigation on

  14. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain, Final Report and Topical Reports 5-8 on Smackover Petroleum system and Underdevelopment Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Ernest A.; Puckett, T. Markham; Parcell, William C.; Llinas, Juan Carlos; Kopaska-Merkel, David C.; Townsend, Roger N.

    2002-03-05

    The Smackover Formation, a major hydrocarbon-producing horizon in the Mississippi Interior Salt Basin (MISB), conformably overlies the Norphlet Formation and is conformably overlain by the Buckner Anhydrite Member of the Haynesville Formation. The Norphlet-Smackover contact can be either gradational or abrupt. The thickness and lithofacies distribution of the Smackover Formation were controlled by the configuration of incipient paleotopography. The Smackover Formation has been subdivided into three informal members, referred to as the lower, middle and upper members.

  15. Crato formation of the Araripe basin: a reservoir analogous to the Trairi limestone, Ceara basin, Brazil; Formacao Crato da Bacia do Araripe: um reservatorio analogo ao Calcario Trairi (Formacao Paracuru), Bacia do Ceara

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Agnelo Leite da [Pernambuco Univ., Recife, PE (Brazil)]. E-mail: agneloleite@bol.com.br; Neumann, Virginio Henrique [Pernambuco Univ., Recife, PE (Brazil). Centro de Tecnologia e Geociencias. Dept. de Geologia]. E-mail: Neumann@ufpe.br

    2003-07-01

    The Trairi limestone (Paracuru Formation of the Ceara Basin) and the Crato Formation (Araripe Basin) are analogs in the stratigraphy/sedimentology, in the depositional environment, in the chronology and in the deformational structures. The rocks of these units were deposited in Aptian-Albian, in a lacustrine system associate with fluvial-deltaic systems. These rocks are characterized by the deposition of levels of laminated limestones separate by lutaceous and arenaceous siliciclastic rocks. In these units are described structures, as microfaults, microslumps, loop bedding and fractures. The Xareu field, in the Ceara Basin, is already considered a mature field and it presents petroleum production problems. The study of the rocks of the Trairi Member in a direct way is difficult by the fact of they be on a water sheet thickness of about 50 meters. To decrease the investment costs in the study of the Trairi limestone, the study of Crato Formation rocks can be used in analogy, to contribute for a best understanding of the Trairi limestone. (author)

  16. Modeling the combined impacts of climate and socio-economic change on water quality, availability and consumption in a multi-purpose reservoir: an application to the Xarrama basin, southern Portugal.

    Science.gov (United States)

    Jacinto, Rita; Nunes, João Pedro; Santos, Juliana

    2014-05-01

    The water resources sector is one of the most vulnerable to climate change. In southern Europe, an increase of water scarcity is expected, combined with a higher frequency and length of severe droughts. Water management in these regions is already a challenge, and several severe droughts occurred there during the last decades, such as the severe droughts of 2005 and 2012 in Portugal, which have highlighted existing vulnerabilities and led to the disruption of part of water supplies. Furthermore, the evolution of socio-economic conditions and even climate change could cause changes to population and land-uses, with the potential to increase pressures on existing resources. The threat of scarcer water resources highlights the need to understand these vulnerabilities and act to reduce them, adapting to the impacts of future climate and land use changes. In fact, water resources governance has been pointed as a key challenge in the present and in the future, as it builds capacity on how to deal with stress and uncertainties generated by climatic variability and global change. Project ERLAND is focused on assessing the eco-hydrological impacts of climate change in Portugal, and therefore water scarcity and droughts are an important focal point on this research. One of the study areas is the Xarrama river basin in southern Portugal, which feeds the multi-purpose Vale do Gaio reservoir used for irrigation and urban water supplies, coupled with a small hydroelectric generating capacity. Currently it experiences some water quality problems and there is already the need of water transfers from other reservoirs to maintain supplies and quality. This is combined with ongoing land-use changes, where irrigated vineyards and olive groves have started to replace traditional rainfed pastures and cereal cultivation. The exposition and vulnerability of the Xarrama basin and the Vale do Gaio reservoir is being addressed for present and future conditions. Future climate scenarios were

  17. Reservoirs in the United States

    Science.gov (United States)

    Harbeck, G. Earl

    1948-01-01

    Man has engaged in the control of flowing water since history began. Among his early recorded efforts were reservoirs for muncipal water-supplies constructed near ancient Jerusalem to store water which was brought there in masonry conduits. 1/  Irrigation was practiced in Egypt as early as 2000 B. C. There the "basin system" was used from ancient times until the 19th century. The land was divided , into basins of approximately 40,000 acres, separated by earthen dikes. 2/  Flood waters of the Nile generally inundated the basins through canals, many of which were built by the Pharaohs. Even then the economic consequences of a deficient annual flood were recognized. Lake Maeris, which according to Herodotus was an ancient storage reservoir, is said to have had an area of 30,000 acres. In India, the British found at the time of their occupancy of the Presidency of Madras about 50,000 reservoirs for irrigation, many believed to be of ancient construction. 3/ During the period 115-130 A. D. reservoirs were built to improve the water-supply of Athens. Much has been written concerning the elaborate collection and distribution system built to supply Rome, and parts of it remain to this day as monuments to the engineering skill employed by the Romans in solving the problem of large-scale municipal water-supplies.

  18. Flux of nitrogen, phosphorus, and suspended sediment from the Susquehanna River Basin to the Chesapeake Bay during Tropical Storm Lee, September 2011, as an indicator of the effects of reservoir sedimentation on water quality

    Science.gov (United States)

    Hirsch, Robert M.

    2012-01-01

    Concentrations of nitrogen, phosphorus, and suspended sediment are measured at the U.S. Geological Survey streamgage at Conowingo Dam at the downstream end of the Susquehanna River Basin in Maryland, where the river flows into the Chesapeake Bay. During the period September 7-15, 2011, in the aftermath of Tropical Storm Lee, concentrations of these three constituents were among the highest ever measured at this site. These measurements indicate that sediment-storage processes behind the three dams on the lower Susquehanna River are evolving. In particular, they indicate that scouring of sediment (and the nitrogen and phosphorus attached to that sediment) may be increasing with time. Trends in flow-normalized fluxes at the Susquehanna River at Conowingo, Maryland, streamgage during 1996-2011 indicate a 3.2-percent decrease in total nitrogen, but a 55-percent increase in total phosphorus and a 97-percent increase in suspended sediment. These large increases in the flux of phosphorus and sediment from the Susquehanna River to the Chesapeake Bay have occurred despite reductions in the fluxes of these constituents from the Susquehanna River watershed upstream from the reservoirs. Although the Tropical Storm Lee flood event contributed about 1.8 percent of the total streamflow from the Susquehanna River to the Chesapeake Bay over the past decade (water years 2002-11), it contributed about 5 percent of the nitrogen, 22 percent of the phosphorus, and 39 percent of the suspended sediment during the same period. These results highlight the importance of brief high-flow events in releasing nitrogen, phosphorus, and sediment derived from the Susquehanna River watershed and stored in the Conowingo Reservoir to the Chesapeake Bay.

  19. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements

    Energy Technology Data Exchange (ETDEWEB)

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  20. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  1. Metal and trace element sediment assessment from Guarapiranga reservoir, Alto Tiete Basin, Sao Paulo, SP, Brazil; Avaliacao da concentracao de metais e elementos traco em amostras de sedimento do reservatorio Guarapiranga, Sao Paulo, SP, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Guilherme Moura

    2011-07-01

    The Guarapiranga Reservoir, located in Sao Paulo metropolitan region, Brazil, is responsible for supplying about 20% of the entire population's water needs of this region or approximately 3.7 million people. However, this system has shown significant degradation in water quality, due to untreated domestic sewage and industrial effluents. In this study sediment samples were collected at five points along the reservoir and total concentration of some major (Fe, K and Na), trace (As, Ba, Br, Co, Cr, Cs, Hf, Hg, Rb, Sb, Sc, Ta, Tb, Th, U, V and Zn) and rare earth (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) elements were determined by instrumental neutron activation analysis (INAA). By inductively coupled plasma optical emission spectrometry (ICP OES) the concentrations of Al, Ba, Be, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Ti, V e Zn were determined after digestion procedure following US EPA 3051 methodology. The concentrations of metals Cd and Pb were determined by graphite furnace atomic absorption spectrometry (GFAAS) and total Hg by cold vapor atomic absorption spectrometry (CVAAS). Methodology validation according to precision and accuracy was performed by reference materials analyses for the three different analytical techniques used. Multielemental results obtained by INAA were compared to NASC (North American Shale Composite), Upper Continental Crust (UCC) and soil from Guarapiranga park values. The Enrichment Factor (EF) and Geo accumulation Index (Igeo) were also evaluated for these data. Metal concentration results by ICP OES and AAS in the samples were compared to the TEL and PEL oriented values established by the Canadian Council of Ministers of the Environment and also adopted by CETESB (Environmental Protection Agency of the Sao Paulo State). The results were also compared to regional reference values (VRR) of limnic sediments from the Alto Tiete Basin. From these data an assessment of metal and trace element accumulated in the sediments from the

  2. Baltazor KGRA and vicinity, Nevada: geothermal reservoir assessment case study, northern Basin and Range province. Final report, 1 October 1978-31 January 1983

    Energy Technology Data Exchange (ETDEWEB)

    Wright, T.C.

    1983-01-01

    The Baltazor KGRA and McGee/Painted Hills geothermal prospects are located in northern Humboldt County, Nevada along the northwestern margin of the Basin and Range province. Exploration work other than drilling has included groundwater sampling, a microearthquake study, a geologic literature search and photogeologic mapping, compilation of aeromagnetic and gravity mapping, soil mercury surveying, electrical resistivity and self-potential surveys and detailed hydrothermal alteration mapping. Exploration drilling included 27 shallow temperature gradient holes, four intermediate-depth gradient wells and one 3703-foot deep test, Baltazor 45-14. The deep test penetrated Miocene rhyolite, andesite, basalt and andesitic basalt flows before excessive hold deviation forced an end to drilling and completion as a deep temperature observation well. A temperature survey two weeks after completion obtained a 119.7/sup 0/C (247.4/sup 0/F) reading at survey total depth, 1110 m (3640 feet).

  3. Material Exchange and Migration between Pore Fluids and Sandstones during Diagenetic Processes in Rift Basins: A Case Study Based on Analysis of Diagenetic Products in Dongying Sag, Bohai Bay Basin, East China

    Directory of Open Access Journals (Sweden)

    W. Meng

    2018-01-01

    Full Text Available The exchange and migration of basin materials that are carried by pore fluids are the essence of diagenesis, which can alter physical properties of clastic rocks as well as control formation and distribution of favorable reservoirs of petroliferous basins. Diagenetic products and pore fluids, resulting from migration and exchange of basin materials, can be used to deduce those processes. In this study, 300 core samples from 46 wells were collected for preparation of casting thin sections, SEM, BSE, EDS, inclusion analysis, and isotope analysis in Dongying Sag, Bohai Bay Basin, East China. Combined with geochemical characteristics of pore fluids and geological background of the study area, the source and exchange mechanisms of materials in the pore fluids of rift basins were discussed. It was revealed that the material exchange of pore fluids could be divided into five stages. The first stage was the evaporation concentration stage during which mainly Ca2+, Mg2+, and CO32- precipitated as high-Mg calcites. Then came the shale compaction stage, when mainly Ca2+ and CO32- from shale compaction water precipitated as calcites. The third stage was the carboxylic acid dissolution stage featured by predominant dissolution of plagioclases, during which Ca2+ and Na+ entered pore fluids, and Si and Al also entered pore fluids and then migrated as clathrates, ultimately precipitating as kaolinites. The fourth stage was the organic CO2 stage, mainly characterized by the kaolinization of K-feldspar as well as dissolution of metamorphic lithic fragments and carbon cements. During this stage, K+, Fe2+, Mg2+, Ca2+, HCO3-, and CO32- entered pore fluids. The fifth stage was the alkaline fluid stage, during which the cementation of ferro-carbonates and ankerites as well as illitization or chloritization of kaolinites prevailed, leading to the precipitation of K+, Fe2+, Mg2+, Ca2+, and CO32- from pore fluids.

  4. Clastic polygonal networks around Lyot crater, Mars: Possible formation mechanisms from morphometric analysis

    Science.gov (United States)

    Brooker, L. M.; Balme, M. R.; Conway, S. J.; Hagermann, A.; Barrett, A. M.; Collins, G. S.; Soare, R. J.

    2018-03-01

    Polygonal networks of patterned ground are a common feature in cold-climate environments. They can form through the thermal contraction of ice-cemented sediment (i.e. formed from fractures), or the freezing and thawing of ground ice (i.e. formed by patterns of clasts, or ground deformation). The characteristics of these landforms provide information about environmental conditions. Analogous polygonal forms have been observed on Mars leading to inferences about environmental conditions. We have identified clastic polygonal features located around Lyot crater, Mars (50°N, 30°E). These polygons are unusually large (>100 m diameter) compared to terrestrial clastic polygons, and contain very large clasts, some of which are up to 15 metres in diameter. The polygons are distributed in a wide arc around the eastern side of Lyot crater, at a consistent distance from the crater rim. Using high-resolution imaging data, we digitised these features to extract morphological information. These data are compared to existing terrestrial and Martian polygon data to look for similarities and differences and to inform hypotheses concerning possible formation mechanisms. Our results show the clastic polygons do not have any morphometric features that indicate they are similar to terrestrial sorted, clastic polygons formed by freeze-thaw processes. They are too large, do not show the expected variation in form with slope, and have clasts that do not scale in size with polygon diameter. However, the clastic networks are similar in network morphology to thermal contraction cracks, and there is a potential direct Martian analogue in a sub-type of thermal contraction polygons located in Utopia Planitia. Based upon our observations, we reject the hypothesis that polygons located around Lyot formed as freeze-thaw polygons and instead an alternative mechanism is put forward: they result from the infilling of earlier thermal contraction cracks by wind-blown material, which then became

  5. Hydroelectric reservoir inundation (Rio Madeira Basin, Amazon) and changes in traditional lifestyle: impact on growth and neurodevelopment of pre-school children.

    Science.gov (United States)

    Marques, Rejane C; Dórea, José G; McManus, Concepta; Leão, Renata S; Brandão, Katiane G; Marques, Rayson C; Vieira, Igor H Ito; Guimarães, Jean-Remy D; Malm, Olaf

    2011-04-01

    To assess the dependence on fish consumption of families and its impact on nutritional status and neurodevelopment of pre-school children. Cross-sectional study that measured children's hair mercury (HHg) as an indicator of family fish consumption, growth (anthropometric Z-scores, WHO standards) and neurological (Gesell developmental scores (GDS)) development. Traditional living conditions among families residing in the area adjacent to the Samuel Dam (Western Amazon) hydroelectric reservoir. Two hundred and forty-nine pre-school children (1-59 months of age) from families transitioning from the traditional Amazonian lifestyle. Family fish consumption was significantly correlated with children's HHg concentration (Spearman's r=0.246, P85), multiple regression analysis showed that fish consumption (as HHg) had no impact on GDS, but that some variables did interact significantly with specific domains (motor and language development). The study showed that the families' shift in fish consumption had no negative impact on the growth of young children and that ensuing methylmercury exposure has not been a noticeable neurodevelopmental hindrance.

  6. Using the U-Pb system of calcretes to date the time of sedimentation of clastic sedimentary rocks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z.S.; Rasbury, E.T.; Hanson, G.N.; Meyers, W.J. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Geosciences

    1998-08-01

    The time of sedimentation of rapidly deposited clastic sedimentary rocks in fluvial environments may be directly dated with an uncertainty of less than three million years using U-Pb dating of pure micritic calcite from calcretes developed in overbank deposits. This conclusion is based on results obtained for calcretes (soil calcite, caliche) formed in the late Triassic New Haven Arkose, Hartford Basin, Connecticut, USA. The paragenesis of calcrete samples from the New Haven Arkose was determined using plane-polarized light and cathodoluminescence petrography, uranium fission track analysis, as well as trace element and stable isotope geochemistry. These calcretes contain an abundance of paleosol microfabrics and diagenetic calcite. The first-generation micritic calcite and second-generation blocky calcite have characteristics consistent with soil calcite. The third generation blocky calcite is a later diagenetic calcite (post-soil calcite). The U-Pb data for pure micritic calcite (first generation) in a horizontal sheet calcrete in sedimentary rocks of Norian age gives a {sup 238}U/{sup 207}Pb-{sup 206}Pb/{sub 207}Pb isochron age of 211.9 {+-} 2.1 Ma (2-sigma, and used hereafter for all ages). The U-Pb data for two samples of first generation micrite in rhizoliths with about 15% insoluble residues give ages of 7 {+-} 66 Ma and 20 {+-} 36 Ma. These results suggest that relatively recent events disturbed the U-Pb system of these detrital rich samples, perhaps due to redistribution of U during weathering or during chemical dissolution for analysis. The U-Pb data for a sample of pure third generation blocky calcite cement in a rhizolith yields a {sup 206}Pb/{sup 238}U-{sup 207}Pb/{sup 235}U isochron age of 81 {+-} 11 Ma. This age suggests that this sample of third generation blocky calcite precipitated during the late Cretaceous perhaps over an extended period.

  7. Geostatistical Three-Dimensional Modeling of a Tight Gas Reservoir: A Case Study of Block S6 of the Sulige Gas Field, Ordos Basin, China

    Directory of Open Access Journals (Sweden)

    Jinliang Zhang

    2017-09-01

    Full Text Available In this study, three-dimensional (3-D geostatistical models were constructed to quantify distributions of sandstone and mudstone. We propose a new method that employs weight coefficients to balance the sandstone and mudstone data from irregular well patterns during stochastic modeling. This new method begins with classifying well groups according to well distribution patterns; areas with similar well distribution patterns are classified within the same zone. Then, the distributions of sandstone and mudstone for each zone are simulated separately using the sequential indicator simulation (SIS method, and the relevant variogram parameters for each zone are computed. In this paper, we used block S6 of the Sulige Gas Field in Ordos Basin in China as a case study. We evaluated the quality of each set of parameters through the vacuation checking method; certain wells were removed to generate equiprobable realizations using different seed numbers. Subsequently, the variogram parameters for the entire S6 area were obtained by assigning different weight coefficients to the parameters of each zone. Finally, a quality assessment of the sandstone and mudstone models of the S6 area was conducted using the horizontal wells, which were not involved in the stochastic modeling process. The results show that these variogram parameters, which were calculated using weight coefficients, are reliable.

  8. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico-stratigraphic hierarchy and cycle stacking facies distribution, and interwell-scale heterogeneity: Grayburg Formation, New Mexico. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barnaby, R.J.; Ward, W.B.; Jennings, J.W. Jr.

    1997-06-01

    The Grayburg Formation (middle Guadalupian) is a major producing interval in the Permian Basin and has yielded more than 2.5 billion barrels of oil in West Texas. Grayburg reservoirs have produced, on average, less than 30 percent of their original oil in place and are undergoing secondary and tertiary recovery. Efficient design of such enhanced recovery programs dictates improved geological models to better understand and predict reservoir heterogeneity imposed by depositional and diagenetic controls. The Grayburg records mixed carbonate-siliciclastic sedimentation on shallow-water platforms that rimmed the Delaware and Midland Basins. Grayburg outcrops in the Guadalupe and Brokeoff Mountains region on the northwest margin of the Delaware Basin present an opportunity to construct a detailed, three-dimensional image of the stratigraphic and facies architecture. This model can be applied towards improved description and characterization of heterogeneity in analogous Grayburg reservoirs. Four orders of stratigraphic hierarchy are recognized in the Grayburg Formation. The Grayburg represents a long-term composite sequence composed of four high-frequency sequences (HFS 1-4). Each HFS contains several composite cycles comprising two or more cycles that define intermediate-scale transgressive-regressive successions. Cycles are the smallest scale upward-shoaling vertical facies successions that can be recognized and correlated across various facies tracts. Cycles thus form the basis for establishing the detailed chronostratigraphic correlations needed to delineate facies heterogeneity.

  9. Ordovician gas exploration breakthrough in the Gucheng lower uplift of the Tarim Basin and its enlightenment

    Directory of Open Access Journals (Sweden)

    Wang Zhaoming

    2014-10-01

    Full Text Available A steady high yield natural gas flow was tapped in the Ordovician strata of Well Gucheng 6 drilled in the Gucheng lower uplift in the Tarim Basin in 2012, marking the discovery of another carbonate gas exploration field after the other two fields in the middle and northern Tarim Basin (the so called Tazhong and Tabei in the industry. The exploration in the Gucheng lower uplift has experienced three stages: the first stage, marine facies clastic exploration from 1995 to 2003, focusing on the Devonian Donghe sandstone lithologic traps, the Silurian overlapping lithologic traps, and the Upper Ordovician shelf slope turbidites; the second stage focusing on the reef shoal carbonate reservoirs from 2003 to 2006, during which oil and gas were first discovered in Well Gucheng 4; the third stage can be divided into two periods, in the first period, deeper insight into interbed karstification reservoir exploration, intense research on tricky seismic issues, selection of favorable zones, and 3D seismic deployment in advance laid a robust foundation for breakthroughs in oil and gas exploration; and during 2009–2012, through an in-depth investigation, Well Gucheng 6 was drilled, bringing about the major breakthrough in oil and gas exploration in this study area. This success proves that the Lower Paleozoic carbonate rocks in the Gucheng area have good geological conditions and broad prospect for oil and gas exploration, which give us enlightenment in three aspects: a. new insight into geologic understanding is the prerequisite of exploration breakthrough; b. addressing bottleneck technologies, and acquiring 3D seismic data are the guarantees of exploration breakthrough; and c. emancipation of mind and persistent exploration are key to the findings in new domains.

  10. Monitoring the formation of clastic-biogenic varves to improve the quality of paleoclimate reconstructions

    Science.gov (United States)

    Ojala, A.; Kosonen, E.; Weckstrom, J.; Korkonen, S.

    2013-12-01

    Annually laminated (varved) sediments are excellent archives for studies of past climate and environmental changes, as they allow analysis of the undisturbed 'in-situ' sediment composition and structure with a seasonal-scale resolution. Among those, clastic-biogenic varved lake sediments have been found and investigated in Finland and Sweden during the last decades. An important prerequisite for applying varved sediments in palaeoenvironmental studies is understanding the mechanism of rhythmic sedimentation and the composition of different laminae representing annual sedimentation events. This knowledge is essential for verifying the annual nature of varves, for investigating the main factors controlling seasonal sedimentation, and for the interpretations of past environmental changes. Here, we report detailed information on the seasonal sedimentation of different varve components and palaeolimnological indicators (diatoms, chrysophycaean cysts) in Lake Nautajärvi, Finland, using near-bottom sediment trap monitoring. The monitoring results strongly support previous interpretations of the formation of clastic-biogenic varves in Fennoscandian lakes. The results also indicate that seasonal sediment fluxes correspond with regional climate and environmental changes. They clearly reveal differences in the amount of seasonal sediment flux between two climatologically and hydrologically different years. For example, higher snow storage in winter and the discharge intensity during the following spring snow melt clearly increases the suspended sediment load, transportation, and net accumulation of detrital mineral matter during spring and early summer. A prolonged autumn and subsequent freezing and thawing cycles in winter, conversely, results in an incremental but slow accumulation of assorted mineral matter and organic particles during winter, whereas the subsequent spring flooding and detrital sediment yield are diminished and thinner clastic laminae are formed. The

  11. Linking pore-scale and basin-scale effects on diffusive methane transport in hydrate bearing environments through multi-scale reservoir simulations

    Energy Technology Data Exchange (ETDEWEB)

    Nole, Michael; Daigle, Hugh; Cook, Ann; Malinverno, Alberto; Hillman, Jess

    2016-12-16

    We explore the gas hydrate-generating capacity of diffusive methane transport induced by solubility gradients due to pore size contrasts in lithologically heterogeneous marine sediments. Through the use of 1D, 2D, and 3D reactive transport simulations, we investigate scale-dependent processes in diffusion-dominated gas hydrate systems. These simulations all track a sand body, or series of sands, surrounded by clays as they are buried through the gas hydrate stability zone. Methane is sourced by microbial methanogenesis in the clays surrounding the sand layers. In 1D, simulations performed in a Lagrangian reference frame demonstrate that gas hydrate in thin sands (3.6 m thick) can occur in high saturations (upward of 70%) at the edges of sand bodies within the upper 400 meters below the seafloor. Diffusion of methane toward the center of the sand layer depends on the concentration gradient within the sand: broader sand pore size distributions with smaller median pore sizes enhance diffusive action toward the sand’s center. Incorporating downhole log- and laboratory-derived sand pore size distributions, gas hydrate saturations in the center of the sand can reach 20% of the hydrate saturations at the sand’s edges. Furthermore, we show that hydrate-free zones exist immediately above and below the sand and are approximately 5 m thick, depending on the sand-clay solubility contrast. A moving reference frame is also adopted in 2D, and the angle of gravity is rotated relative to the grid system to simulate a dipping sand layer. This is important to minimize diffusive edge effects or numerical diffusion that might be associated with a dipping sand in an Eulerian grid system oriented orthogonal to gravity. Two-dimensional simulations demonstrate the tendency for gas hydrate to accumulate downdip in a sand body because of greater methane transport at depth due to larger sand-clay solubility contrasts. In 3D, basin-scale simulations illuminate how convergent sand layers in

  12. The experimental modeling of gas percolation mechanisms in a coal-measure tight sandstone reservoir: A case study on the coal-measure tight sandstone gas in the Upper Triassic Xujiahe Formation, Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Shizhen Tao

    2016-12-01

    Full Text Available Tight sandstone gas from coal-measure source rock is widespread in China, and it is represented by the Xujiahe Formation of the Sichuan Basin and the Upper Paleozoic of the Ordos Basin. It is affected by planar evaporative hydrocarbon expulsion of coal-measure source rock and the gentle structural background; hydrodynamics and buoyancy play a limited role in the gas migration-accumulation in tight sandstone. Under the conditions of low permeability and speed, non-Darcy flow is quite apparent, it gives rise to gas-water mixed gas zone. In the gas displacing water experiment, the shape of percolation flow curve is mainly influenced by core permeability. The lower the permeability, the higher the starting pressure gradient as well as the more evident the non-Darcy phenomenon will be. In the gas displacing water experiment of tight sandstone, the maximum gas saturation of the core is generally less than 50% (ranging from 30% to 40% and averaging at 38%; it is similar to the actual gas saturation of the gas zone in the subsurface core. The gas saturation and permeability of the core have a logarithm correlation with a correlation coefficient of 0.8915. In the single-phase flow of tight sandstone gas, low-velocity non-Darcy percolation is apparent; the initial flow velocity (Vd exists due to the slippage effect of gas flow. The shape of percolation flow curve of a single-phase gas is primarily controlled by core permeability and confining pressure; the lower the permeability or the higher the confining pressure, the higher the starting pressure (0.02–0.08 MPa/cm, whereas, the higher the quasi-initial flow speed, the longer the nonlinear section and the more obvious the non-Darcy flow will be. The tight sandstone gas seepage mechanism study shows that the lower the reservoir permeability, the higher the starting pressure and the slower the flow velocity will be, this results in the low efficiency of natural gas migration and accumulation as well as

  13. Chapter 5. Assessment of undiscovered conventional oil and gas resources-Lower Cretaceous Travis Peak and Hosston formations, Jurassic Smackover interior salt basins total petroleum system, in the East Texas basin and Louisiana-Mississippi salt basins provinces.

    Science.gov (United States)

    Dyman, T.S.; Condon, S.M.

    2006-01-01

    The Lower Cretaceous Travis Peak Formation of east Texas and southern Arkansas (and the correlative Hosston Formation of Louisiana and Mississippi) is a basinward-thickening wedge of terrigenous clastic sedimentary rocks that underlies the northern Gulf of Mexico Basin from east Texas across northern Louisiana to southern Mississippi. Clastic detritus was derived from two main fluvial-deltaic depocenters, one in northeastern Texas and the other extending from southeastern Mississippi northwestward into northeastern Louisiana. Across the main hydrocarbon-productive trend in east Texas and northern Louisiana, the Travis Peak and Hosston Formations are about 2,000 ft thick.

  14. Manyame River Basin, Zimbabwe

    African Journals Online (AJOL)

    Available on website http://www.wrc.org.za. ISSN 1816-7950 (On-line) = Water SA Vol. 42 No. 1 January 2016. Published under a Creative Commons Attribution Licence. A test of the Lake Habitat Survey method in Cleveland Reservoir and. Lake Chivero (Manyame River Basin, Zimbabwe). Tatenda Dalu1*, Edwin ...

  15. Petroleum geology and resources of the middle Caspian Basin, Former Soviet Union

    Science.gov (United States)

    Ulmishek, Gregory F.

    2001-01-01

    The Middle Caspian basin occupies a large area between the Great Caucasus foldbelt and the southern edge of the Precambrian Russian craton. The basin also includes the central part of the Caspian Sea and the South Mangyshlak subbasin east of the sea. The basin was formed on the Hercynian accreted terrane during Late Permian?Triassic through Quaternary time. Structurally, the basin consists of the fold-and-thrust zone of the northern Caucasus foothills, the foredeep and foreland slope, the Stavropol-Prikumsk uplift and East Manych trough to the north of the slope, and the South Mangyshlak subbasin and slope of the Karabogaz arch east of the Caspian Sea. All these major structures extend offshore. Four total petroleum systems (TPS) have been identified in the basin. The South Mangyshlak TPS contains more than 40 discovered fields. The principal reserves are in Lower?Middle Jurassic sandstone reservoirs in structural traps. Source rocks are poorly known, but geologic data indicate that they are in the Triassic taphrogenic sequence. Migration of oil and gas significantly postdated maturation of source rocks and was related to faulting and fracturing during middle Miocene to present time. A single assessment unit covers the entire TPS. Largest undiscovered resources of this assessment unit are expected in the largely undrilled offshore portion of the TPS, especially on the western plunge of the Mangyshlak meganticline. The Terek-Caspian TPS occupies the fold-and-thrust belt, foredeep, and adjoining foreland slope. About 50 hydrocarbon fields, primarily oil, have been discovered in the TPS. Almost all hydrocarbon reserves are in faulted structural traps related to thrusting of the foldbelt, and most traps are in frontal edges of the thrust sheets. The traps are further complicated by plastic deformation of Upper Jurassic salt and Maykop series (Oligocene? lower Miocene) shale. Principal reservoirs are fractured Upper Cretaceous carbonates and middle Miocene sandstones

  16. Fe-oxide grain coatings support bacterial Fe-reducing metabolisms in 1.7-2.0 km-deep subsurface quartz arenite sandstone reservoirs of the Illinois Basin (USA

    Directory of Open Access Journals (Sweden)

    Yiran eDong

    2014-09-01

    Full Text Available The Cambrian-age Mt. Simon Sandstone, deeply buried within the Illinois Basin of the midcontinent of North America, contains quartz sand grains ubiquitously encrusted with iron-oxide cements and dissolved ferrous iron in pore-water. Although microbial iron reduction has previously been documented in the deep terrestrial subsurface, the potential for diagenetic mineral cementation to drive microbial activity has not been well studied. In this study, two subsurface formation water samples were collected at 1.72 and 2.02 km, respectively, from the Mt. Simon Sandstone in Decatur, Illinois. Low-diversity microbial communities were detected from both horizons and were dominated by Halanaerobiales of Phylum Firmicutes. Iron-reducing enrichment cultures fed with ferric citrate were successfully established using the formation water. Phylogenetic classification identified the enriched species to be related to Vulcanibacillus from the 1.72 km depth sample, while Orenia dominated the communities at 2.02 km of burial depth. Species-specific quantitative analyses of the enriched organisms in the microbial communities suggest that they are indigenous to the Mt. Simon Sandstone. Optimal iron reduction by the 1.72 km enrichment culture occurred at a temperature of 40oC (range 20 to 60oC and a salinity of 25 parts per thousand (range 25-75 ppt. This culture also mediated fermentation and nitrate reduction. In contrast, the 2.02 km enrichment culture exclusively utilized hydrogen and pyruvate as the electron donors for iron reduction, tolerated a wider range of salinities (25-200 ppt, and exhibited only minimal nitrate- and sulfate-reduction. In addition, the 2.02 km depth community actively reduces the more crystalline ferric iron minerals goethite and hematite. The results suggest evolutionary adaptation of the autochthonous microbial communities to the Mt. Simon Sandstone and carries potentially important implications for future utilization of this reservoir

  17. Performance evaluation on water-producing gas wells based on gas & water relative permeability curves: A case study of tight sandstone gas reservoirs in the Sulige gas field, Ordos Basin

    Directory of Open Access Journals (Sweden)

    Yuegang Li

    2016-01-01

    Full Text Available An outstanding issue in the oil and gas industry is how to evaluate quantitatively the influences of water production on production performance of gas wells. Based on gas–water flow theories, therefore, a new method was proposed in this paper to evaluate quantitatively the production performance of water-producing gas wells by using gas & water relative permeability curves after a comparative study was conducted thoroughly. In this way, quantitative evaluation was performed on production capacity, gas production, ultimate cumulative gas production and recovery factor of water-producing gas wells. Then, a case study was carried out of the tight sandstone gas reservoirs with strong heterogeneity in the Sulige gas field, Ordos Basin. This method was verified in terms of practicability and reliability through a large amount of calculation based on the actual production performance data of various gas wells with different volumes of water produced. Finally, empirical formula and charts were established for water-producing gas wells in this field to quantitatively evaluate their production capacity, gas production, ultimate cumulative gas production and recovery factor in the conditions of different water–gas ratios. These formula and charts provide technical support for the field application and dissemination of the method. Study results show that water production is serious in the west of this field with water–gas ratio varying in a large range. If the average water–gas ratio is 1.0 (or 2.0 m3/104 m3, production capacity, cumulative gas production and recovery factor of gas wells will be respectively 24.4% (or 40.2%, 24.4% (or 40.2% and 17.4% (or 33.2%.

  18. Pre-lithification tectonic foliation development in a clastic sedimentary rock sequence from SW Ireland

    Science.gov (United States)

    Meere, Patrick; Mulchrone, Kieran; McCarthy, David

    2017-04-01

    The current orthodoxy regarding the development of regionally developed penetrative tectonic cleavage fabrics in sedimentary rocks is that it postdates lithification of those rocks. It is well established that fabric development under these circumstances is achieved by a combination of grain rigid body rotation, crystal-plastic deformation and pressure solution. The latter is believed to be the primary mechanism responsible for the domainal nature of cleavage development commonly observed in low grade metamorphic rocks. While there have been advocates for the development of tectonic cleavages before host rock lithification these are currently viewed as essentially local aberrations without regional significance. In this study we combine new field observations with strain analysis, element mapping and modelling to characterise Acadian (>50%) crustal shortening in a Devonian clastic sedimentary sequence from the Dingle Peninsula of south west Ireland. Fabrics in these rocks reflect significant levels of tectonic shortening are a product of grain translation, rigid body rotation and repacking of intra- and extra-formational clasts during deformation of an unconsolidated clastic sedimentary sequence. There is an absence of the expected domainal cleavage structure and intra-clast deformation expected with conventional cleavage formation. This study requires geologists to consider the possibility such a mechanism contributing to tectonic strain in a wide range of geological settings and to look again at field evidence that indicates early sediment mobility during deformation.

  19. GPR Imaging of Clastic Dikes at the Hanford Site, Hanford, Washington

    International Nuclear Information System (INIS)

    Clement, William P.; Murray, Christopher J.

    2007-01-01

    We use ground penetrating radar (GPR) data to help determine the spatial distribution and the subsurface geometry of clastic injection dikes at the Hanford site. This information will help to improve the understanding of the hydrological role of these ubiquitous clastic dikes at the Hanford Site. We collected 100 MHz ground penetrating radar (GPR) 3D surface reflection data at two sites, the S-16 Pond and the Army Loop Road sites, and 2D reflection data along a 6.9 km linear transect near the Army Loop Road site. The dikes are distinguished in the GPR data by a strongly attenuated zone, disruptions in the continuity of reflections, and diffractions where reflections are disrupted. In general, the data quality is better at the Army Loop Road and Traverse sites than at the S-16 Pond site, probably due to the presence of cobbles at the S-16 Pond site. A high-moisture, fine-grained unit probably causes the strong reflections at the Army Loop Road site and the Traverse survey site. The signal penetration varies between 5 to 12 m below the land surface

  20. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    basin, so stylolite formation in the chalk is controlled by effective burial stress. The stylolites are zones of calcite dissolution and probably are the source of calcite for porefilling cementation which is typical in water zone chalk and also affect the reservoirs to different extent. The relatively...... 50% calcite, leaving the remaining internal surface to the fine grained silica and clay. The high specific surface of these components causes clay- and silica rich intervals to have high irreducible water saturation. Although chalks typically are found to be water wet, chalk with mixed wettability...... stabilizes chemically by recrystallization. This process requires energy and is promoted by temperature. This recrystallization in principle does not influence porosity, but only specific surface, which decreases during recrystallization, causing permeability to increase. The central North Sea is a warm...

  1. Geologic summary of the Appalachian Basin, with reference to the subsurface disposal of radioactive waste solutions

    Science.gov (United States)

    Colton, G.W.

    1962-01-01

    The Appalachian basin is an elongate depression in the crystalline basement complexSilurian clastic sequence. The latter comprises a relatively thin wedge of coarse-grained clastic rocks. Some of the most prolific oil- and gas-producing sandstones in the Appalachian basin are included. Among these are the 'Clinton' sands of Ohio, the Medina Sandstones of New York and Pennsylvania, and the Keefer or 'Big Six' Sandstone of West Virginia and Kentucky. Conformably overlying the Early Silurian clastic sequence is the Silurian-Devonian carbonate sequence, which consists predominantly of limestone and dolomite. It also contains a salt-bearing unit in the north-central part of the basin and a thick wedge of coarse-grained red beds in the northeastern part. The sequence is absent in much of the southern part of the basin. Large volumes of gas and much oil are obtained from some of its rocks, especially from the Oriskany Sandstone and the Huntersville Chert. The Silurian-Devonian carbonate sequence is abruptly overlain by the Devonian clastic sequence--a thick succession of interbedded shale, mudrock, siltstone, and sandstone. Colors range f

  2. Estimated Loads of Suspended Sediment and Selected Trace Elements Transported through the Milltown Reservoir Project Area Before and After the Breaching of Milltown Dam in the Upper Clark Fork Basin, Montana, Water Year 2008

    Science.gov (United States)

    Lambing, John H.; Sando, Steven K.

    2009-01-01

    This report presents estimated daily and cumulative loads of suspended sediment and selected trace elements transported during water year 2008 at three streamflow-gaging stations that bracket the Milltown Reservoir project area in the upper Clark Fork basin of western Montana. Milltown Reservoir is a National Priorities List Superfund site where sediments enriched in trace elements from historical mining and ore processing have been deposited since the construction of Milltown Dam in 1907. Milltown Dam was breached on March 28, 2008, as part of Superfund remedial activities to remove the dam and contaminated sediment that had accumulated in Milltown Reservoir. The estimated loads transported through the project area during the periods before and after the breaching of Milltown Dam, and for the entire water year 2008, were used to quantify the net gain or loss (mass balance) of suspended sediment and trace elements within the project area during the transition from a reservoir environment to a free-flowing river. This study was done in cooperation with the U.S. Environmental Protection Agency. Streamflow during water year 2008 compared to long-term streamflow, as represented by the record for Clark Fork above Missoula (water years 1930-2008), generally was below normal (long-term median) from about October 2007 through April 2008. Sustained runoff started in mid-April, which increased flows to near normal by mid-May. After mid-May, flows sharply increased to above normal, reaching a maximum daily mean streamflow of 16,800 cubic feet per second (ft3/s) on May 21, which essentially equaled the long-term 10th-exceedance percentile for that date. Flows substantially above normal were sustained through June, then decreased through the summer and reached near-normal by August. Annual mean streamflow during water year 2008 (3,040 ft3/s) was 105 percent of the long-term mean annual streamflow (2,900 ft3/s). The annual peak flow (17,500 ft3/s) occurred on May 21 and was 112

  3. Analysis of ancient-river systems by 3D seismic time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia

    Science.gov (United States)

    Sulaiman, Noorzamzarina; Hamzah, Umar; Samsudin, Abdul Rahim

    2014-09-01

    Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D seismic data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1-5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of seismic facies analysis of the two-dimensional (2D) seismic sections, mainly reflecting changes in fluvial channel style and river architecture. The succession has been divided into four seismic units (Unit S1-S4), bounded by basin-wide strata surfaces. Two types of boundaries have been identified: 1) a boundary that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (S3 and S4); 2) a sequence boundary that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as low-stand alluvial bypass channel systems (S1 and S2). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat Sunda land Platform.

  4. Analysis of ancient-river systems by 3D seismic time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia

    International Nuclear Information System (INIS)

    Sulaiman, Noorzamzarina; Hamzah, Umar; Samsudin, Abdul Rahim

    2014-01-01

    Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D seismic data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1–5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of seismic facies analysis of the two-dimensional (2D) seismic sections, mainly reflecting changes in fluvial channel style and river architecture. The succession has been divided into four seismic units (Unit S1-S4), bounded by basin-wide strata surfaces. Two types of boundaries have been identified: 1) a boundary that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (S3 and S4); 2) a sequence boundary that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as low-stand alluvial bypass channel systems (S1 and S2). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat Sunda land Platform

  5. Organic geochemistry of oil and gas in the Kuqa depression, Tarim Basin, NW China

    Energy Technology Data Exchange (ETDEWEB)

    Digang Liang; Shuichang Zhang; Jianping Chen [China National Petroleum Corporation, Beijing (China). Key Laboratory for Petroleum Geochemistry; Research Institute of Petroleum Exploration and Development, PetroChina, Beijing (China); Feiyu Wang [China National Petroleum Corporation, Beijing (China). Key Laboratory for Petroleum Geochemistry; Peirong Wang [China National Petroleum Corporation, Beijing (China). Key Laboratory for Petroleum Geochemistry; Jianghan Petroleum Institute (China)

    2003-07-01

    The Kuqa depression in the Tarim Basin, NW China contains significant natural gas and condensate resources, with only small amounts of black oil. This study demonstrates that the primary reason for the accumulation of large natural gas reserves in the Kuqa depression is the high maturity level of the Jurassic coal-bearing sequence that is currently at the peak stage of dry gas generation. From the combined stable carbon isotopes and molecular and biomarker data it is possible to identify two separate source rocks for the discovered hydrocarbon fluids: the gases were primarily from the Middle-Lower Jurassic coals and associated clastic rocks, and the oils were from the Upper Triassic lacustrine mudstones. Peak oil generation from the Triassic source rocks occurred during the early Miocene (23-12 Ma b.p.). These oils migrated laterally over relatively long distances ({approx}20-50 km) reaching the outer periphery of the depression. Peak gas generation took place more recently, perhaps during the past 5 Ma. The gases migrated mainly along faults over relatively short lateral distances, resulting in accumulations adjacent to the over-matured source kitchens. Different timings for the trap formation along the north and south margins and a late injection of gas into early oil accumulations provided favorable conditions for the formation of evaporative condensates and the preservation of gas pools in the more down-dip reservoirs and oil pools in the more up-dip locations. (author)

  6. ­­Clastic Pipes on Mars: Evidence for a Near Surface Groundwater System

    Science.gov (United States)

    Wheatley, D. F.; Chan, M. A.; Okubo, C. H.

    2017-12-01

    Clastic pipes, a type of vertical, columnar injectite, occur throughout the terrestrial stratigraphic record and are identified across many Martian terrains. Terrestrial pipe analogs can aid in identifying clastic pipes on Mars to understand their formation processes and their implications for a past near-surface groundwater system. On Earth, clastic pipes form through fluidization of overpressurized sediment. Fluidization occurs when the upward frictional (i.e., drag) forces of escaping fluids overpower the downward acting gravitational force. To create the forces necessary for pipe formation requires overpressurization of a body of water-saturated porous media overlain by a low permeability confining layer. As the pressure builds, the confining layer eventually fractures and the escaping fluids fluidize the porous sediment causing the sediment to behave like a fluid. These specific formation conditions record evidence of a violent release of fluid-suspended sediment including brecciation of the host and sealing material, internal outward grading/sorting that results in a coarser-grained commonly better cemented outer rind, traction structures, and a cylindrical geometry. Pipes form self-organized, dispersed spatial relationships due to the efficient diffusion of overpressured zones in the subsurface and the expulsion of sediment under pressure. Martian pipes occur across the northern lowlands, dichotomy boundary, and southern highlands in various forms of erosional relief ranging from newer eruption structures to eroded cylindrical/conical mounds with raised rims to highly eroded mounds/hills. Similar to terrestrial examples, Martian pipes form in evenly-spaced, self-organized arrangements. The pipes are typically internally massive with a raised outer rim (interpreted as a sorted, coarser-grained, better-cemented rim). This evidence indicates that Martian pipes formed through fluidization, which requires a near-surface groundwater system. Pipes create a window

  7. Petrophysical Charaterization of the Kwale Field Reservoir Sands ...

    African Journals Online (AJOL)

    Similarly, the average permeability values vary between 3.2 and 28.0 mD. This study is a first attempt to make available Petrophysical data for the reservoir sands in the Kwale field of the Niger delta basin. The results of this study will also enhance the proper characterization of the reservoir sands. However, other sources of ...

  8. Petrophysical evaluation of reservoir sand bodies in Kwe Field ...

    African Journals Online (AJOL)

    Reservoir sand bodies in Kwe Field, coastal swamp depobelt, onshore eastern Niger Delta Basin were evaluated from a composite log suite comprising gamma ray, resistivity, density and neutron logs of five (5) wells with core photographs of one (1) reservoir of one well. The aim of the study was to evaluate the ...

  9. Angola: source rock control for Lower Congo Coastal and Kwanza Basin petroleum systems

    Energy Technology Data Exchange (ETDEWEB)

    Burwood, R. [Fina Exploration Ltd, Epsom (United Kingdom)

    1999-07-01

    The purpose of this paper is to provide an overview of petroleum occurrence and provenance for the 1000 km West African Atlantic Margin from Cabinda to mid-Angola. Over this margin the Lower Congo Coastal and Kwanza provinces cumulatively account for reserves of c. 6 gigabarrels oil recoverable (GBOR). These are dominantly reservoired in Pinda carbonate traps of the former basin. However, with production from a range of aggradational wedge, carbonate platform and pre-salt reservoirs, a diversity in oil character presupposes complex hydrocarbon habitats charged by multiple sourcing. Each of these two major Atlantic margin salt basins constitutes a different, source rock driven, hydrocarbon habitat. As classic passive margin pull-apart basins, Early Cretaceous initiated rift events (Pre-rift, Syn-rift I, II, etc.) evolved into the drift phase opening of the southern Atlantic. A striking feature of this progression was widespread evaporite deposition of the Aptian Loeme salt. This separates two distinct sedimentary and tectonic domains of the Pre- and Post-Salt. The core Lower Congo Coastal habitat is dominated by the Pre-Salt Bucomazi Formation sourced 'poly' petroleum system. These lacustrine, often super-rich, sediments reveal considerable organofacies variation between their basin fill (Syn-rift I) and sheet drape (Syn-rift II) development, accounting for the compositional diversity in their progenic petroleums. Of crucial impact is a cognate diversity in their kerogen kinetic behaviour. This controls the conditions and timing of generation and realization of charge potential. With the Lower Congo Coastal habitat extending southwards towards the Ambriz Spur, the Bucomazi facies proper appears restricted to the northern and deeper proto-lake trend. Over the more weakly subsident margins such troughs host inferior sheet drape potential. Elswhere, Upper Cretaceous-Palaeogene marine clastic Iabe Formation sourced petroleum systems are hydrocarbon productive

  10. Reservoirs of the basin of Guadalete river (Zahara. El Gastor, Bornos and Arcos) in Cadiz; waters quality and their influence with the drought; Embalses de la cuencia del rio Guadalete (Zahara-El Gastor, Bornos y Arcos) de la provincia de Cadiz: calidad de las aguas y su influencia con la sequia

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Barroso, M. R.; Vidal Valderas, L.; Sales Marquez, D.; Quiroga Alonso, J. M.

    2001-07-01

    In this work the results of the limnological study of the reservoirs of the basin of Guadalete river is presented: Zahara-El Gastor, Bonos and Arcos. These reservoirs are part of the hydrography net of the county of Cadiz (south of Spain) and it belongs to the Guadalquivir Hydrography Confederation. The study of physical chemical parameters, together with the data of the climate variations have allowed to know the quality of the dammed water, as well as, to predict certain behaviour rules in the adaptation of the water, in the drinking waters treatment plant for their final destination ad water of supply. The results obtained show a similarity of the waters quality of the reservoirs of Bornos and Arcos, and different to the reservoirs of Zahara-El Gastor because are more saline content. It is showed a progressive decrees of the waters quality dammed during the drought period (1992-1995). In 1995 the water levels was alarmingly lowest. (Author) 19 refs.

  11. Sedimentology of clastic rocks from the Fra Mauro region of the moon.

    Science.gov (United States)

    Lindsay, J. F.

    1972-01-01

    A thin-section examination of sixteen clastic rock samples returned by the Apollo 14 mission from the Fra Mauro region of the moon suggests the presence of at least two distinctly different lithologies. Five of the samples (group I) are characterized by an abundant glassy matrix and glass particles and lesser amounts of plagioclase and pyroxene grains, and lithic clasts. The other eleven samples (group II) are relatively fine grained, very poorly sorted, and consist largely of pyroxene, plagioclase, and lithic clasts set in an abundant mineralic matrix. Group I and II lithologies were probably both deposited from impact generated base surges. The differences between them stem not as much from the basic sedimentary processes as from the differences in the magnitude of the events generating the base surges and the resultant difference in available detrital materials.

  12. Use of Cutting-Edge Horizontal and Underbalanced Drilling Technologies and Subsurface Seismic Techniques to Explore, Drill and Produce Reservoired Oil and Gas from the Fractured Monterey Below 10,000 ft in the Santa Maria Basin of California

    Energy Technology Data Exchange (ETDEWEB)

    George Witter; Robert Knoll; William Rehm; Thomas Williams

    2006-06-30

    This project was undertaken to demonstrate that oil and gas can be drilled and produced safely and economically from a fractured Monterey reservoir in the Santa Maria Basin of California by employing horizontal wellbores and underbalanced drilling technologies. Two vertical wells were previously drilled in this area with heavy mud and conventional completions; neither was commercially productive. A new well was drilled by the project team in 2004 with the objective of accessing an extended length of oil-bearing, high-resistivity Monterey shale via a horizontal wellbore, while implementing managed-pressure drilling (MPD) techniques to avoid formation damage. Initial project meetings were conducted in October 2003. The team confirmed that the demonstration well would be completed open-hole to minimize productivity impairment. Following an overview of the geologic setting and local field experience, critical aspects of the application were identified. At the pre-spud meeting in January 2004, the final well design was confirmed and the well programming/service company requirements assigned. Various design elements were reduced in scope due to significant budgetary constraints. Major alterations to the original plan included: (1) a VSP seismic survey was delayed to a later phase; (2) a new (larger) surface hole would be drilled rather than re-enter an existing well; (3) a 7-in. liner would be placed into the top of the Monterey target as quickly as possible to avoid problems with hole stability; (4) evaluation activities were reduced in scope; (5) geosteering observations for fracture access would be deduced from penetration rate, cuttings description and hydrocarbon in-flow; and (6) rather than use nitrogen, a novel air-injection MPD system was to be implemented. Drilling operations, delayed from the original schedule by capital constraints and lack of rig availability, were conducted from September 12 to November 11, 2004. The vertical and upper curved sections were

  13. USE OF CUTTING-EDGE HORIZONTAL AND UNDERBALANCED DRILLING TECHNOLOGIES AND SUBSURFACE SEISMIC TECHNIQUES TO EXPLORE, DRILL AND PRODUCE RESERVOIRED OIL AND GAS FROM THE FRACTURED MONTEREY BELOW 10,000 FT IN THE SANTA MARIA BASIN OF CALIFORNIA

    Energy Technology Data Exchange (ETDEWEB)

    George Witter; Robert Knoll; William Rehm; Thomas Williams

    2005-02-01

    This project was undertaken to demonstrate that oil and gas can be drilled and produced safely and economically from a fractured Monterey reservoir in the Santa Maria Basin of California by employing horizontal wellbores and underbalanced drilling technologies. Two vertical wells were previously drilled in this area by Temblor Petroleum with heavy mud and conventional completions; neither was commercially productive. A new well was drilled by the project team in 2004 with the objective of accessing an extended length of oil-bearing, high-resistivity Monterey shale via a horizontal wellbore, while implementing managed-pressure drilling (MPD) techniques to avoid formation damage. Initial project meetings were conducted in October 2003. The team confirmed that the demonstration well would be completed open-hole to minimize productivity impairment. Following an overview of the geologic setting and local field experience, critical aspects of the application were identified. At the pre-spud meeting in January 2004, the final well design was confirmed and the well programming/service company requirements assigned. Various design elements were reduced in scope due to significant budgetary constraints. Major alterations to the original plan included: (1) a VSP seismic survey was delayed to a later phase; (2) a new (larger) surface hole would be drilled rather than re-enter an existing well; (3) a 7-in. liner would be placed into the top of the Monterey target as quickly as possible to avoid problems with hole stability; (4) evaluation activities were reduced in scope; (5) geosteering observations for fracture access would be deduced from penetration rate, cuttings description and hydrocarbon in-flow; and (6) rather than use nitrogen, a novel air-injection MPD system was to be implemented. Drilling operations, delayed from the original schedule by capital constraints and lack of rig availability, were conducted from September 12 to November 11, 2004. The vertical and upper

  14. Use of Cutting-Edge Horizontal and Underbalanced Drilling Technologies and Subsurface Seismic Techniques to Explore, Drill and Produce Reservoired Oil and Gas from the Fractured Monterey Below 10,000 ft in the Santa Maria Basin of California

    Energy Technology Data Exchange (ETDEWEB)

    George Witter; Robert Knoll; William Rehm; Thomas Williams

    2005-09-29

    This project was undertaken to demonstrate that oil and gas can be drilled and produced safely and economically from a fractured Monterey reservoir in the Santa Maria Basin of California by employing horizontal wellbores and underbalanced drilling technologies. Two vertical wells were previously drilled in this area with heavy mud and conventional completions; neither was commercially productive. A new well was drilled by the project team in 2004 with the objective of accessing an extended length of oil-bearing, high-resistivity Monterey shale via a horizontal wellbore, while implementing managed-pressure drilling (MPD) techniques to avoid formation damage. Initial project meetings were conducted in October 2003. The team confirmed that the demonstration well would be completed open-hole to minimize productivity impairment. Following an overview of the geologic setting and local field experience, critical aspects of the application were identified. At the pre-spud meeting in January 2004, the final well design was confirmed and the well programming/service company requirements assigned. Various design elements were reduced in scope due to significant budgetary constraints. Major alterations to the original plan included: (1) a VSP seismic survey was delayed to a later phase; (2) a new (larger) surface hole would be drilled rather than re-enter an existing well; (3) a 7-in. liner would be placed into the top of the Monterey target as quickly as possible to avoid problems with hole stability; (4) evaluation activities were reduced in scope; (5) geosteering observations for fracture access would be deduced from penetration rate, cuttings description and hydrocarbon in-flow; and (6) rather than use nitrogen, a novel air-injection MPD system was to be implemented. Drilling operations, delayed from the original schedule by capital constraints and lack of rig availability, were conducted from September 12 to November 11, 2004. The vertical and upper curved sections were

  15. Economics of Developing Hot Stratigraphic Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  16. An elastic solution for a new notched residual stess specimen subjected to an anti-clastic loading

    DEFF Research Database (Denmark)

    Jakobsen, Johnny; Lyckegaard, Anders

    A new test specimen has been proposed to explore the mechanical properties of thermoset resin exposed to residual stresses induced by curing and thermal expansion. The test principle is based on anti-clastic bending of a plate with a hole. An elastic solution to the bending problem is derived...

  17. INCREASING WATERFLOOD RESERVES IN THE WILMINGTON OIL FIELD THROUGH IMPROVED RESERVOIR CHARACTERIZATION AND RESERVOIR MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Scott Walker; Chris Phillips; Roy Koerner; Don Clarke; Dan Moos; Kwasi Tagbor

    2002-02-28

    This project increased recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs. Transferring technology so that it can be applied in other sections of the Wilmington Field and by operators in other slope and basin reservoirs is a primary component of the project. This project used advanced reservoir characterization tools, including the pulsed acoustic cased-hole logging tool, geologic three-dimensional (3-D) modeling software, and commercially available reservoir management software to identify sands with remaining high oil saturation following waterflood. Production from the identified high oil saturated sands was stimulated by recompleting existing production and injection wells in these sands using conventional means as well as a short radius redrill candidate. Although these reservoirs have been waterflooded over 40 years, researchers have found areas of remaining oil saturation. Areas such as the top sand in the Upper Terminal Zone Fault Block V, the western fault slivers of Upper Terminal Zone Fault Block V, the bottom sands of the Tar Zone Fault Block V, and the eastern edge of Fault Block IV in both the Upper Terminal and Lower Terminal Zones all show significant remaining oil saturation. Each area of interest was uncovered emphasizing a different type of reservoir characterization technique or practice. This was not the original strategy but was necessitated by the different levels of progress in each of the project activities.

  18. Assessing Reservoir Depositional Environments to Develop and Quantify Improvements in CO2 Storage Efficiency. A Reservoir Simulation Approach

    Energy Technology Data Exchange (ETDEWEB)

    Okwen, Roland [University of Illinois, Champaign, IL (United States); Frailey, Scott [University of Illinois, Champaign, IL (United States); Leetaru, Hannes [University of Illinois, Champaign, IL (United States); Moulton, Sandy [Illinois State Geological Survey, Champaign, IL (United States)

    2014-09-30

    The storage potential and fluid movement within formations are dependent on the unique hydraulic characteristics of their respective depositional environments. Storage efficiency (E) quantifies the potential for storage in a geologic depositional environment and is used to assess basinal or regional CO2 storage resources. Current estimates of storage resources are calculated using common E ranges by lithology and not by depositional environment. The objectives of this project are to quantify E ranges and identify E enhancement strategies for different depositional environments via reservoir simulation studies. The depositional environments considered include deltaic, shelf clastic, shelf carbonate, fluvial deltaic, strandplain, reef, fluvial and alluvial, and turbidite. Strategies considered for enhancing E include CO2 injection via vertical, horizontal, and deviated wells, selective completions, water production, and multi-well injection. Conceptual geologic and geocellular models of the depositional environments were developed based on data from Illinois Basin oil fields and gas storage sites. The geologic and geocellular models were generalized for use in other US sedimentary basins. An important aspect of this work is the development of conceptual geologic and geocellular models that reflect the uniqueness of each depositional environment. Different injection well completions methods were simulated to investigate methods of enhancing E in the presence of geologic heterogeneity specific to a depositional environment. Modeling scenarios included horizontal wells (length, orientation, and inclination), selective and dynamic completions, water production, and multiwell injection. A Geologic Storage Efficiency Calculator (GSECalc) was developed to calculate E from reservoir simulation output. Estimated E values were normalized to diminish their dependency on fluid relative permeability. Classifying depositional environments according to

  19. Will building new reservoirs always help increase the water supply reliability? - insight from a modeling-based global study

    Science.gov (United States)

    Zhuang, Y.; Tian, F.; Yigzaw, W.; Hejazi, M. I.; Li, H. Y.; Turner, S. W. D.; Vernon, C. R.

    2017-12-01

    More and more reservoirs are being build or planned in order to help meet the increasing water demand all over the world. However, is building new reservoirs always helpful to water supply? To address this question, the river routing module of Global Change Assessment Model (GCAM) has been extended with a simple yet physical-based reservoir scheme accounting for irrigation, flood control and hydropower operations at each individual reservoir. The new GCAM river routing model has been applied over the global domain with the runoff inputs from the Variable Infiltration Capacity Model. The simulated streamflow is validated at 150 global river basins where the observed streamflow data are available. The model performance has been significantly improved at 77 basins and worsened at 35 basins. To facilitate the analysis of additional reservoir storage impacts at the basin level, a lumped version of GCAM reservoir model has been developed, representing a single lumped reservoir at each river basin which has the regulation capacity of all reservoir combined. A Sequent Peak Analysis is used to estimate how much additional reservoir storage is required to satisfy the current water demand. For basins with water deficit, the water supply reliability can be improved with additional storage. However, there is a threshold storage value at each basin beyond which the reliability stops increasing, suggesting that building new reservoirs will not help better relieve the water stress. Findings in the research can be helpful to the future planning and management of new reservoirs.

  20. Sustainability of small reservoirs and large scale water availability under current conditions and climate change

    NARCIS (Netherlands)

    Krol, Martinus S.; de Vries, Marjella J.; van Oel, P.R.; Carlos de Araújo, José

    2011-01-01

    Semi-arid river basins often rely on reservoirs for water supply. Small reservoirs may impact on large-scale water availability both by enhancing availability in a distributed sense and by subtracting water for large downstream user communities, e.g. served by large reservoirs. Both of these impacts

  1. Early stages of clastic deposition in the Most Basin (Ohre Rift, Czech Republic, Early Miocene): timing and possible controls

    Czech Academy of Sciences Publication Activity Database

    Matys Grygar, Tomáš; Mach, K.; Hošek, Michal; Schnabl, Petr; Martinez, M.; Koubová, M.

    2017-01-01

    Roč. 92, č. 3 (2017), s. 337-355 ISSN 1214-1119 R&D Projects: GA ČR(CZ) GA16-00800S Institutional support: RVO:61388980 ; RVO:67985831 Keywords : cyclostratigraphy * chemostratigraphy * lake sediments * climate forcing * Burdigalian Subject RIV: DD - Geochemistry; DB - Geology ; Mineralogy (GLU-S) OBOR OECD: Geology Impact factor: 1.175, year: 2016

  2. Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River basins, Wyoming. Final technical report, September 15, 1993--October 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, T.L.

    1996-10-01

    This multidisciplinary study was designed to provide improvements in advanced reservoir characterization techniques. This goal was accomplished through: (1) an examination of the spatial variation and anisotropy of relative permeability in the Tensleep Sandstone reservoirs of Wyoming; (2) the placement of that variation and anisotropy into paleogeographic, and depositional regional frameworks; (3) the development of pore-system imagery techniques for the calculation of relative permeability; and (4) reservoir simulations testing the impact of relative permeability anisotropy and spatial variation on Tensleep Sandstone reservoir enhanced oil recovery. Concurrent efforts were aimed at understanding the spatial and dynamic alteration in sandstone reservoirs that is caused by rock-fluid interaction during CO{sub 2} enhanced oil recovery processes. The work focused on quantifying the interrelationship of fluid-rock interaction with lithologic characterization and with fluid characterization in terms of changes in chemical composition and fluid properties. This work establishes new criteria for the susceptibility of Tensleep Sandstone reservoirs to formation alteration that results in wellbore scale damage. This task was accomplished by flow experiments using core material; examination of regional trends in water chemistry; examination of local water chemistry trends the at field scale; and chemical modeling of both the experimental and reservoir systems.

  3. Seismic attribute analysis to enhance detection of thin gold-bearing reefs: South Deep gold mine, Witwatersrand basin, South Africa

    CSIR Research Space (South Africa)

    Manzi, MSD

    2013-11-01

    Full Text Available The gold-bearing Upper Elsburg Reef clastic wedge (UER) in the South Deep gold mine in the Witwatersrand basin (South Africa) hosts the highly auriferous basal conglomerate known as the Elsburg Conglomerate (EC) reef. The reef is less than 20 m...

  4. Characteristics of source rocks of the Datangpo Fm, Nanhua System, at the southeastern margin of Sichuan Basin and their significance to oil and gas exploration

    Directory of Open Access Journals (Sweden)

    Zengye Xie

    2017-11-01

    Full Text Available In recent years, much attention has been paid to the development environment, biogenetic compositions and hydrocarbon generation characteristics of ancient source rocks in the deep strata of the Sichuan Basin because oil and gas exploration extends continuously to the deep and ultra-deep strata and a giant gas field with the explored reserves of more than 1 × 1012 m3 was discovered in the Middle and Upper Proterozoic–Lower Paleozoic strata in the stable inherited paleo-uplift of the central Sichuan Basin. Based on the previous geological research results, outcrop section of the Datangpo Fm, Nanhua System, at the southeastern margin of the Sichuan Basin was observed and the samples taken from the source rocks were tested and analyzed in terms of their organic geochemistry and organic petrology. It is shown that high-quality black shale source rocks of the Datangpo Fm are developed in the tensional background at the southeastern margin of the Sichuan Basin between two glacial ages, i.e., Gucheng and Nantuo ages in the Nanhua Period. Their thickness is 16–180 m and mineral compositions are mainly clay minerals and clastic quartz. Besides, shale in the Datangpo Fm is of high-quality sapropel type source rock with high abundance at an over-mature stage, and it is characterized by low pristane/phytane ratios (0.32–0.83, low gammacerane abundance, high-abundance tricyclic terpane and higher-content C27 and C29 gonane, indicating that biogenetic compositions are mainly algae and microbes in a strong reducing environment with low salinity. It is concluded that the Datangpo Fm source rocks may be developed in the rift of Nanhua System in central Sichuan Basin. Paleo-uplifts and paleo-slopes before the Caledonian are the favorable locations for the accumulation of dispersed liquid hydrocarbons and paleo-reservoirs derived from the Datangpo Fm source rocks. In addition, scale accumulation zones of dispersed organic matter cracking gas and paleo-reservoirs

  5. Thin-bed reservoir characterization using integrated three-dimensional seismic and well log data: A case study of the central Boonsville Field, Fort Worth basin, north-central Texas

    Science.gov (United States)

    Xie, Deyi

    This dissertation is designed to resolve two problems using seismic attributes to: (1) delineate thin-bed reservoirs, and (2) distinguish thin-bed sandstone reservoirs from thin-bed non-reservoir carbonates where they appear similar at seismic scale. I evaluated some widely used techniques, developed new approaches for better imaging of thin-bed reservoirs, and found optimal attributes for thin-bed reservoir characterization. These techniques were then tested on the Pennsylvanian Caddo sequence of the Boonsville Field, Texas using public domain data. The main results found through this study are: (1) A new pattern recognition model has been developed to recognize the subtle geological and geophysical features of a thin-bed sequence based on cross-correlation of seismic traces with one or more traces believed to represent specific depositional environments. This algorithm has been proven, via the case study, to be robust and promising in defining seismic facies for subtle geological features and predicting thin-bed reservoirs. (2) Examination of the conventional thin-bed tuning model reveals that it works well only if one single thin-bed is developed or multiple thin beds are widely spaced in the sequence of interest. In other words, the model does not work for multiple closely-spaced thin-beds because of significant destructive interference. (3) A statistical inversion method was developed using the generalized regression neural network (GRNN). For a comparison study, two commercial packages were applied to the Boonsville Field data set. This study shows that all three models were able to identify the thicker reservoir sandstones and non-reservoir limestones. However, the resulting details for the thin beds vary. The GRNN method predicted the thin beds at 13 out of 20 wells with less noise and can be very useful in detecting thin-bed reservoirs in existing fields where a number of wells are available.

  6. Coupled Heat and Fluid Flow Modeling of the Earth's Largest Zinc Ore Deposit at Red Dog, Alaska: Implications for Structurally-Focused, Free Convection in Submarine Sedimentary Basins

    Science.gov (United States)

    Garven, G.; Dumoulin, J. A.; Bradley, D. A.; Young, L. E.; Kelley, K. D.; Leach, D. L.

    2002-12-01

    . Hydrologically, the Kuna Basin was a 200-km wide, rifted asymmetric basin layered with calcareous turbidites, mudstones and carbonates overlying a thick conglomerate and sandstone aquifer, which likely was thickest and more faulted near Red Dog (Ikalukrok graben). Buoyancy-driven free convection cells drive fluid migration to km-depths in the submarine basin, at rates of about 5 m/yr within permeable normal faults, which are assumed to be conduits. Mostly lateral flow is predicted to occur in the deep clastic formations. The clastic aquifers appear to be the principal reservoir for metal-bearing brines that ultimately discharged near the seafloor within slightly permeable, highly porous and organic rich muds, where sulfate can be reduced to form massive zinc-lead sulfide ores. Basin-wide paleoheat flows of 150 to 160 mW/m2 and focused fluid discharge along normal faults are required to explain the hot thermal venting recorded within these ore fields. This mineralized hydrothermal system provides a remarkable geophysical model for the role of faults, free convection and extensional basin heat flow in ore genesis.

  7. Middle Ordovician brachiopods from the Stairway Sandstone, Amadeus Basin, central Australia

    DEFF Research Database (Denmark)

    Jakobsen, Kristian Grube; Brock, Glenn A.; Nielsen, Arne Thorshøj

    2014-01-01

    Middle Ordovician brachiopod faunas from the Amadeus Basin, central Australia are poorly known. The Darriwilian Stairway Sandstone was sampled stratigraphically for macrofossils in order to provide new information on marine benthic diversity in this clastic-dominated, shallow-water palaeoenvironm......Middle Ordovician brachiopod faunas from the Amadeus Basin, central Australia are poorly known. The Darriwilian Stairway Sandstone was sampled stratigraphically for macrofossils in order to provide new information on marine benthic diversity in this clastic-dominated, shallow......-water palaeoenvironment along the margin of northeastern Gondwana. The brachiopods from the Stairway Sandstone are of low diversity and represent ca 9% of the entire shelly fauna. Five brachiopod taxa are described from the Stairway Sandstone; all are endemic to the Amadeus Basin at species level. Two new species...

  8. Reservoir Routing on Double-Peak Design Flood

    Directory of Open Access Journals (Sweden)

    Andrea Gioia

    2016-11-01

    Full Text Available This work investigates the routing effect provided by an artificial reservoir to a double-peak flood of a given return period. The present paper introduces a dimensionless form of the reservoir balance equation that describes the hydrologic-hydraulic processes that may occur and allows for the evaluation of the reservoir routing coefficient (RC. Exploiting this equation, an extensive sensitivity analysis based on the use of two simple parametric indices that depend on the storage capacity (SC of the reservoir, the discharge capacity (DC of the spillway (with fixed-crest and the hydrologic behavior of the basin was performed.

  9. Geologic framework of the Mississippian Barnett Shale, Barnett-Paleozoic total petroleum system, Bend arch-Fort Worth Basin, Texas

    Science.gov (United States)

    Pollastro, R.M.; Jarvie, D.M.; Hill, R.J.; Adams, C.W.

    2007-01-01

    This article describes the primary geologic characteristics and criteria of the Barnett Shale and Barnett-Paleozoic total petroleum system (TPS) of the Fort Worth Basin used to define two geographic areas of the Barnett Shale for petroleum resource assessment. From these two areas, referred to as "assessment units," the U.S. Geological Survey estimated a mean volume of about 26 tcf of undiscovered, technically recoverable hydrocarbon gas in the Barnett Shale. The Mississippian Barnett Shale is the primary source rock for oil and gas produced from Paleozoic reservoir rocks in the Bend arch-Fort Worth Basin area and is also one of the most significant gas-producing formations in Texas. Subsurface mapping from well logs and commercial databases and petroleum geochemistry demonstrate that the Barnett Shale is organic rich and thermally mature for hydrocarbon generation over most of the Bend arch-Fort Worth Basin area. In the northeastern and structurally deepest part of the Fort Worth Basin adjacent to the Muenster arch, the formation is more than 1000 ft (305 m) thick and interbedded with thick limestone units; westward, it thins rapidly over the Mississippian Chappel shelf to only a few tens of feet. The Barnett-Paleozoic TPS is identified where thermally mature Barnett Shale has generated large volumes of hydrocarbons and is (1) contained within the Barnett Shale unconventional continuous accumulation and (2) expelled and distributed among numerous conventional clastic- and carbonate-rock reservoirs of Paleozoic age. Vitrinite reflectance (Ro) measurements show little correlation with present-day burial depth. Contours of equal Ro values measured from Barnett Shale and typing of produced hydrocarbons indicate significant uplift and erosion. Furthermore, the thermal history of the formation was enhanced by hydrothermal events along the Ouachita thrust front and Mineral Wells-Newark East fault system. Stratigraphy and thermal maturity define two gas

  10. Transitioning Groundwater from an Extractive Resource to a Managed Water Storage Resource: Geology and Recharge in Sedimentary Basins

    Science.gov (United States)

    Maples, S.; Fogg, G. E.; Maxwell, R. M.; Liu, Y.

    2017-12-01

    Civilizations have typically obtained water from natural and constructed surface-water resources throughout most of human history. Only during the last 50-70 years has a significant quantity of water for humans been obtained through pumping from wells. During this short time, alarming levels of groundwater depletion have been observed worldwide, especially in some semi-arid and arid regions that rely heavily on groundwater pumping from clastic sedimentary basins. In order to reverse the negative effects of over-exploitation of groundwater resources, we must transition from treating groundwater mainly as an extractive resource to one in which recharge and subsurface storage are pursued more aggressively. However, this remains a challenge because unlike surface-water reservoirs which are typically replenished over annual timescales, the complex geologic architecture of clastic sedimentary basins impedes natural groundwater recharge rates resulting in decadal or longer timescales for aquifer replenishment. In parts of California's Central Valley alluvial aquifer system, groundwater pumping has outpaced natural groundwater recharge for decades. Managed aquifer recharge (MAR) has been promoted to offset continued groundwater overdraft, but MAR to the confined aquifer system remains a challenge because multiple laterally-extensive silt and clay aquitards limit recharge rates in most locations. Here, we simulate the dynamics of MAR and identify potential recharge pathways in this system using a novel combination of (1) a high-resolution model of the subsurface geologic heterogeneity and (2) a physically-based model of variably-saturated, three-dimensional water flow. Unlike most groundwater models, which have coarse spatial resolution that obscures the detailed subsurface geologic architecture of these systems, our high-resolution model can pinpoint specific geologic features and locations that have the potential to `short-circuit' aquitards and provide orders

  11. The Upper Cretaceous to Palaeogene Sedimentary History and Tectonic Evolution of the Bala Basin, Central Anatolia, Turkey

    OpenAIRE

    Emre, Mehmet Fahrettin

    1985-01-01

    The study area is situated on the northern extension of the Tuzgolu basin, (Central Anatolia) and contains Upper Cretaceous--Tertiary volcanic, clastic, and carbonate rocks with evaporites deposited on an ophiolitic melange basement, the Ankara Melange. The present structure of the area is the result of tectonism during late Alpine movements. The movements controlled the timing and conditions of sediment accumulation. The Bala basin evolved on the northern continental margin of the Kirsehi...

  12. Hydrogeologic assessment of shallow clastic and carbonate rock aquifers in Hendry and Collier counties, southwestern Florida

    Science.gov (United States)

    Brown, C. Erwin; Krulikas, R.K.; Brendle, D.L.

    1996-01-01

    Direct-current electrical resistivity data were collected from 109 vertical electrical sounding sites in Hendry and Collier Counties, southwestern Florida. Selected direct-current electrical resistivity surveys, together with available borehole geologic and geophysical data, were used to determine the approximate areal extent of the shallow clastic aquifers composed of thick sands and carbonate lithologies. Results indicated that a complex pattern of shallow sands, clays, and carbonate lithologies occur throughout the area. Buried channel sands were found as deep as 50 meters below land surface in some places. The channels contain unconsolidated fine- to medium-grained quartz sand interbedded with sandy limestone, shell fragments, and gray-green sandy clay. Both surface and borehole geophysical techniques with lithologic data were necessary to approximately locate and define layers that might behave as confining layers and to locate and define the extent of any buried sand aquifers. The borehole geophysical data were used to analyze the zones of higher resistivity. Direct-current electrical resistivity data indicated the approximate location of certain layer boundaries. The conjunctive use of natural gamma and short- and long-normal resistivity logs was helpful in determining lithologic effects. Geohydrologic sections were prepared to identify potential locations of buried channels and carbonates containing freshwater. Buried channel sands and carbonate rock sections were identified in the subsurface that potentially may contain freshwater supplies.

  13. Sedimentology of clastic rocks returned from the moon by Apollo 15.

    Science.gov (United States)

    Lindsay, J. F.

    1972-01-01

    A petrographic study of eleven samples of clastic rock returned from the moon by Apollo 15 suggests that two lithologies are present. The distinction between the two lithologies is based on the glass content of the rock matrices and the morphology of the detrital particles. Group I rocks have abundant, glass-rich, porous matrices and glass particles with morphologies comparable to those of glass particles in the lunar soil. The group I rocks were probably formed by welding or sintering of surficial soil deposits by impact-generated base surges of limited extent. Group II rocks have an essentially mineralic matrix and have an abundance of rounded mineral grains. Sample 15455 is the only Apollo 15 sample assigned to this group. In its general textural features, sample 15455 is comparable with the group II rocks from the Fra Mauro Formation at the Apollo 14 site. Textural features such as shock modification and rounding of mineral grains suggest that this sample is the product of a large-scale impact-generated base surge which possibly resulted from the Imbrian event.

  14. THE SURDUC RESERVOIR (ROMANIA

    Directory of Open Access Journals (Sweden)

    Niculae Iulian TEODORESCU

    2008-06-01

    Full Text Available The Surduc reservoir was projected to ensure more water when water is scarce and to thus provide especially the city Timisoara, downstream of it with water.The accumulation is placed on the main affluent of the Bega river, Gladna in the upper part of its watercourse.The dam behind which this accumulation was created is of a frontal type made of enrochements with a masque made of armed concrete on the upstream part and protected/sustained by grass on the downstream. The dam is 130m long on its coping and a constructed height of 34 m. It is also endowed with spillway for high water and two bottom outlets formed of two conduits, at the end of which is the microplant. The second part of my paper deals with the hydrometric analysis of the Accumulation Surduc and its impact upon the flow, especially the maximum run-off. This influence is exemplified through the high flood from the 29th of July 1980, the most significant flood recorded in the basin with an apparition probability of 0.002%.

  15. Increased oil production and reserves from improved completion techniques in the Bluebell field, Uinta Basin, Utah. Annual report, October 1, 1995--September 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, C.D.; Allison, M.L.

    1997-08-01

    The Bluebell field is productive from the Tertiary lower Green River and Wasatch Formations of the Uinta Basin, Utah. The productive interval consists of thousands of feet of interbedded fractured clastic and carbonate beds deposited in a fluvial-dominated lacustrine environment. Wells in the Bluebell field are typically completed by perforating 40 or more beds over 1,000 to 3,000 vertical feet (300-900 m), then stimulating the entire interval. This completion technique is believed to leave many potentially productive beds damaged and/or untreated, while allowing water-bearing and low-pressure (thief) zones to communicate with the wellbore. Geologic and engineering characterization has been used to define improved completion techniques. A two-year characterization study involved detailed examination of outcrop, core, well logs, surface and subsurface fractures, produced oil-field waters, engineering parameters of the two demonstration wells, and analysis of past completion techniques and effectiveness. The characterization study resulted in recommendations for improved completion techniques and a field-demonstration program to test those techniques. The results of the characterization study and the proposed demonstration program are discussed in the second annual technical progress report. The operator of the wells was unable to begin the field demonstration this project year (October 1, 1995 to September 20, 1996). Correlation and thickness mapping of individual beds in the Wasatch Formation was completed and resulted in a. series of maps of each of the individual beds. These data were used in constructing the reservoir models. Non-fractured and fractured geostatistical models and reservoir simulations were generated for a 20-square-mile (51.8-km{sup 2}) portion of the Bluebell field. The modeling provides insights into the effects of fracture porosity and permeability in the Green River and Wasatch reservoirs.

  16. Aptian ‘Shale Gas’ Prospectivity in the Downdip Mississippi Interior Salt Basin, Gulf Coast, USA

    Science.gov (United States)

    Hackley, Paul C.; Valentine, Brett J.; Enomoto, Catherine B.; Lohr, Celeste D.; Scott, Krystina R.; Dulong, Frank T.; Bove, Alana M.

    2016-01-01

    This study evaluates regional ‘shale gas’ prospectivity of the Aptian section (primarily Pine Island Shale) in the downdip Mississippi Salt Basin (MSB). Previous work by the U.S. Geological Survey estimated a mean undiscovered gas resource of 8.8 trillion cubic feet (TCF) in the chronostratigraphic-equivalent Pearsall Formation in the Maverick Basin of south Texas, where industry has established a moderately successful horizontal gas and liquids play. Wells penetrating the downdip MSB Aptian section at depths of 12,000-15,000 ft were used to correlate formation tops in a 15-well cross-section extending about 200 miles (mi) east-southeastward from Adams Co. to Jackson Co. Legacy cuttings from these wells were analyzed for thermal maturity and source rock quality. Bitumen reflectance (n=53) increases with increasing present-day burial depth in the east-central study area from 1.0% to 1.7%. As the Aptian section shallows in Adams Co. to the west, bitumen Ro values are higher (1.7-2.0%), either from relatively greater heat flux or greater mid-Cenomanian uplift and erosion in this area. Total organic carbon (TOC) content ranges 0.01-1.21 and averages 0.5 wt.% (n=51); pyrolysis output (S2; n=51) averages 0.40 mg HC/g rock, indicating little present-day hydrocarbon-generative potential. Bitumen reflectance is preferred as a thermal maturity parameter as Tmax values are unreliable. Normalized X-ray diffraction (XRD) mineral analyses (n=26) indicate high average clay abundance (53 wt.%) relative to quartz (29%) and carbonate (18%). Mineral content shows a spatial relationship to an Appalachian orogen clastic sediment source, with proximal high clay and quartz and distal high carbonate content. Clastic influx from the Appalachian orogen is confirmed by detrital zircon U-Pb ages with dominant Grenville and Paleozoic components [105 ages from a Rodessa sandstone and 112 ages from a Paluxy (Albian) sandstone]. Preliminary information from fluid inclusion microthermometry

  17. Geometry of the proximal part of the modern turbidite depositional system of the Carapebus Formation, Campos Basin: a model for reservoir heterogeneities; Geometria da porcao proximal do sistema deposicional turbiditico moderno da Formacao Carapebus, Bacia de Campos; modelo para heterogeneidades de reservatorio

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Luis Claudio Ribeiro; Kowsmann, Renato Oscar; Almeida Junior, Waldemar de; Murakami, Celso Yoshihito; Schreiner, Simone; Miller, Dennis James; Piauilino, Pedro Orlando Vasconcelos [PETROBRAS, Rio de Janeiro, RJ (Brazil). Exploracao e Producao. Unidade de Servico Submarino]. E-mail: machadolc@petrobras.com.br

    2004-11-01

    The deep-water marine sedimentary environment of the Cenozoic of the Campos Basin is examined at the modern sea floor, where it can be better understood. This environment is responsible for the genesis of the turbidite systems of the Carapebus Formation, the reservoirs that hold more than 90% of Brazil's petroleum reserves. The study was developed with the records of regional side-scan sonar, swath bathymetry, sub-bottom profiler data, standard multichannel 3D seismic surveys and piston cores covering almost the entire basin. After leaving the Almirante Camara Canyon, the turbiditic flows erode the muddy debris apron surrounding the continental slope and begin to deposit thick layers of clean sand into a big trough in water depths of 1800 m to 3000 m. The trough is 3.5 km wide, 150 m deep, 150 km long, and is formed by a chain of salt withdrawal mini-basins. In some places the sea floor is flat enough to develop today a depositional lobe, in all aspects analogous to the best, geologically ancient petroleum reservoirs in the basin. Aspects of the system: 1) the arcosean sands are brought by the river, cross the shelf, the incised valley, the canyon, and deposit as turbidites - they do not originate from a collapse of the continental slope; 2) a wide muddy debris apron surrounds the continental slope (slope apron), and represents a huge volume of sediment in the Campos Basin ; 3) the turbidites do not develop a submarine fan, but are deposited in an elongated trough formed by salt tectonics; 4) the turbidite beds, both in the lobe or in the trough, are not deposited during a single episode, but in multiple events over significant geologic time in which small channels which brought the turbidites avulse and meander along the entire depositional area, building a single amalgamated bed; 5) classic channel-levees are not present because this system comprises a sandy braid plain and the levees are as sandy as the channel; 6) a hierarchical depositional model for bulb

  18. Geology, sequence stratigraphy, and oil and gas assessment of the Lewis Shale Total Petroleum System, San Juan Basin, New Mexico and Colorado: Chapter 5 in Total petroleum systems and geologic assessment of undiscovered oil and gas resources in the San Juan Basin Province, exclusive of Paleozoic rocks, New Mexico and Colorado

    Science.gov (United States)

    Dubiel, R.F.

    2013-01-01

    The Lewis Shale Total Petroleum System (TPS) in the San Juan Basin Province contains a continuous gas accumulation in three distinct stratigraphic units deposited in genetically related depositional environments: offshore-marine shales, mudstones, siltstones, and sandstones of the Lewis Shale, and marginal-marine shoreface sandstones and siltstones of both the La Ventana Tongue and the Chacra Tongue of the Cliff House Sandstone. The Lewis Shale was not a completion target in the San Juan Basin (SJB) in early drilling from about the 1950s through 1990. During that time, only 16 wells were completed in the Lewis from natural fracture systems encountered while drilling for deeper reservoir objectives. In 1991, existing wells that penetrated the Lewis Shale were re-entered by petroleum industry operators in order to fracture-stimulate the Lewis and to add Lewis gas production onto preexisting, and presumably often declining, Mesaverde Group production stratigraphically lower in the section. By 1997, approximately 101 Lewis completions had been made, both as re-entries into existing wells and as add-ons to Mesaverde production in new wells. Based on recent industry drilling and completion practices leading to successful gas production from the Lewis and because new geologic models indicate that the Lewis Shale contains both source rocks and reservoir rocks, the Lewis Shale TPS was defined and evaluated as part of this U.S. Geological Survey oil and gas assessment of the San Juan Basin. Gas in the Lewis Shale Total Petroleum System is produced from shoreface sandstones and siltstones in the La Ventana and Chacra Tongues and from distal facies of these prograding clastic units that extend into marine rocks of the Lewis Shale in the central part of the San Juan Basin. Reservoirs are in shoreface sandstone parasequences of the La Ventana and Chacra and their correlative distal parasequences in the Lewis Shale where both natural and artificially enhanced fractures produce

  19. Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Robert Loucks; Stephen C. Ruppel; Dembla Dhiraj; Julia Gale; Jon Holder; Jeff Kane; Jon Olson; John A. Jackson; Katherine G. Jackson

    2006-09-30

    Despite declining production rates, existing reservoirs in the United States contain vast volumes of remaining oil that is not being effectively recovered. This oil resource constitutes a huge target for the development and application of modern, cost-effective technologies for producing oil. Chief among the barriers to the recovery of this oil are the high costs of designing and implementing conventional advanced recovery technologies in these mature, in many cases pressure-depleted, reservoirs. An additional, increasingly significant barrier is the lack of vital technical expertise necessary for the application of these technologies. This lack of expertise is especially notable among the small operators and independents that operate many of these mature, yet oil-rich, reservoirs. We addressed these barriers to more effective oil recovery by developing, testing, applying, and documenting an innovative technology that can be used by even the smallest operator to significantly increase the flow of oil from mature U.S. reservoirs. The Bureau of Economic Geology and Goldrus Producing Company assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The Permian Basin, the largest oil-bearing basin in North America, contains more than 70 billion barrels of remaining oil in place and is an ideal venue to validate this technology. We have demonstrated the potential of HPAI for oil-recovery improvement in preliminary laboratory tests and a reservoir pilot project. To more completely test the technology, this project emphasized detailed characterization of reservoir properties, which were integrated to access the effectiveness and economics of HPAI. The characterization phase of the project utilized geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum

  20. Quantification of Libby Reservoir Levels Needed to Maintain or Enhance Reservoir Fisheries, 1983-1987 Methods and Data Summary.

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, Ian

    1989-12-01

    Libby Reservoir was created under an International Columbia River Treaty between the United States and Canada for cooperative water development of the Columbia River Basin. The authorized purpose of the dam is to provide power, flood control, and navigation and other benefits. Research began in May 1983 to determine how operations of Libby dam impact the reservoir fishery and to suggest ways to lessen these impacts. This study is unique in that it was designed to accomplish its goal through detailed information gathering on every trophic level in the reservoir system and integration of this information into a quantitative computer model. The specific study objectives are to: quantify available reservoir habitat, determine abundance, growth and distribution of fish within the reservoir and potential recruitment of salmonids from Libby Reservoir tributaries within the United States, determine abundance and availability of food organisms for fish in the reservoir, quantify fish use of available food items, develop relationships between reservoir drawdown and reservoir habitat for fish and fish food organisms, and estimate impacts of reservoir operation on the reservoir fishery. 115 refs., 22 figs., 51 tabs.

  1. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  2. Parametrization of environment by geochemistry of the varved clastic and bio- chemogenic lake sediments

    Science.gov (United States)

    Kalugin, Ivan; Darin, Andrey; Babich, Valery; Markovich, Tatiana; Meydan, Feray

    2017-04-01

    . Mineral matter responses to runoff. Mineral clastic part is correlated with x-ray density. It includes "clastic" rock-forming - Si, Al , Ti, Fe, Mg, Ca, K and trace elements such as Sr, Rb, Y, Zr, REE etc. Organic component of sediment more reflects temperature by means of productivity in the catchment and waterbody. Organophillic elements are Br, I, U and others soluble elements correlated with organic Carbon or LOIcarbonates precipitated in dependence of temperature, aridity and water salinity. Separate geochemical indicators are directly used for paleo- environmental evaluation. For example, elements with changing valency may be a proxy of outer conditions. Fe is strictly connected with sulfur in sulphide under anoxic conditions. And also Fe forms siderite in carbonate ion saturated, but calcium poor, water in the sedimentation system. Mn-enriched layers, crusts and nodules mark usually a long - term pauses of sedimentation in oxic systems. Mo/Mn ratio is good correlated with anoxic atmosphere. And so on. The work is supported by grants RFBR 16-05-00641, 16-05-00657, 15-55-46001.

  3. Reactivation of an idle lease to increase heavy oil recovery through application of conventional steam drive technology in a low dip slope and basin reservoir in the Midway-Sunset field, San Jaoquin Basin, California. Annual report, June 13, 1995--June 13, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Deo, M.; Jenkins, C.; Sprinkel, D.; Swain, R.; Wydrinski, R.; Schamel, S.

    1998-09-01

    This project reactivates ARCO`s idle Pru Fee lease in the Midway-Sunset field, California and conducts a continuous steamflood enhanced oil recovery demonstration aided by an integration of modern reservoir characterization and simulation methods. Cyclic steaming is being used to reestablish baseline production within the reservoir characterization phase of the project. During the demonstration phase scheduled to begin in January 1997, a continuous steamflood enhanced oil recovery will be initiated to test the incremental value of this method as an alternative to cyclic steaming. Other economically marginal Class III reservoirs having similar producibility problems will benefit from insight gained in this project. The objectives of the project are: (1) to return the shut-in portion of the reservoir to optimal commercial production; (2) to accurately describe the reservoir and recovery process; and (3) to convey the details of this activity to the domestic petroleum industry, especially to other producers in California, through an aggressive technology transfer program.

  4. Sedimentary facies, correlation, and architecture of Rotliegend reservoirs at the Southern Permian basin margin: The P01-FA case study and the challenged myth of layer-cake stratigraphy

    NARCIS (Netherlands)

    Moscariello, A.

    2011-01-01

    Sedimentology, log analysis, and high-resolution seismic data of the P01-FA structure, located in the western part of the Netherlands sector of the North Sea, were used to assess the correlatability and connectivity of the sand bodies, to unravel the complex internal reservoir architecture, and to

  5. Radioecological impact of effluents from a nuclear facility being decommissioned in the Antas river hydro graphic basin in the state of Minas Gerais, Brazil. Radioecological impact of effluents in the Antas reservoir

    International Nuclear Information System (INIS)

    Ronque, Leilane Barbosa; Azevedo, Heliana de; Lopes do Nascimento, Marcos Roberto; Roque, Claudio Vitor; Silva, Nivaldo Carlos da; Rodgher, Suzelei; Regali-Seleghim, Mirna Helena

    2008-01-01

    The Antas reservoir receives the treated effluents which come from acid drainage of uranium ore from the UTM-INB (Ore Treatment Unit - Brazilian Nuclear Industries), located in Caldas, Minas Gerais. This study was conducted in order to determine the possible environmental impact caused by discharge of the treated liquid effluent from the UTM into the Antas reservoir. Biological (ciliated protozoa and Peridinium sp. phytoflagellate) and physicochemical variables (manganese, zinc, sulfate, uranium, dissolved oxygen and temperature), trophic state and saprobity indexes were evaluated. Sampling in reservoir (Cab, P41, P14S, and P14F points) took place during the dry winter season (July 2006). Each day, samples were collected four times (6:00 am, 12:00 pm, 6:00 pm, and 12:00 am). Biological variables analyzed at the Antas reservoir classified it as an oligo trophic and beta-mesosaprobic environment. Chemical parameters indicate failures in the nuclear facility effluent treatment plant, showing that effluents outside of standard limits established by Brazilian current legislation for Class II water are being discharged at point P41. These results agree with biological analyses, since point P41 has the lowest diversity and biomass values for ciliated protozoa organisms, indicating possible environmental impacts on the ecosystem due to effluent discharge by this mining company.(author)

  6. CALCAREOUS NANNOFOSSIL: THE KEY TO REVEAL THE RELATIONS BETWEEN THE MACIGNO AND MONTE MODINO SANDSTONE, TWO WIDESPREAD CLASTIC WEDGES OF THE NORTHERN APENNINES

    Directory of Open Access Journals (Sweden)

    RITA CATANZARITI

    2009-07-01

    Full Text Available Since the '60s geologists discussed if the Tuscan Nappe includes the Macigno, the Mt. Modino Sandstone and the olistostromes interposed between these two clastic wedges or instead the foredeep deposits of the Tuscan Nappe is the Macigno and, therefore, the Mt. Modino Sandstone sedimented in a distinct basin and belongs to a different tectonic unit. One of the main difficulties to unravel the Macigno-Mt. Modino Sandstone relationships is the absence of continuous biostratigraphic records, helpful to date these formations and the underlying units. To fill this gap, a quantitative biostratigraphical analysis of calcareous nannofossils was performed on a large number of smear slides. The results confirm the stratigraphic continuity between the Tuscan Shale and the Macigno, and prove the stratigraphic continuity between the Fiumalbo Shale, the Marmoreto Marl and the Mt. Modino Sandstone (Mt. Modino Unit auctt., supporting the tectonic superposition of the Mt. Modino Unit onto the Tuscan Nappe. In fact, the upper portion of the Tuscan Nappe ranges from the Late Eocene (MNP19/20 to the lower Miocene (MNN1c and the Tuscan Shale-Macigno boundary lies within the upper Rupelian-Chattian (MNP24-MNP25a, whilst the sampled part of the Mt. Modino Unit spans in age the middle Eocene-lower Miocene (MNP15-MNN1c, and the Fiumalbo Shale-Marmoreto Marl and Marmoreto Marl-Mt. Modino Sandstone boundaries lie within the Rupelian (MNP23 and the uppermost Chattian (MNP25b-MNN1a. 

  7. Pareja limno-reservoir (Guadalajara, Spain): environmental and hydrologic aspects

    International Nuclear Information System (INIS)

    Molina Navarro, E.; Martinez Perez, S.; Sastre Merlin, A.

    2010-01-01

    The construction of small reservoir on the edge of large ones is an innovative idea designed to counteract some of the negative impacts caused by the construction and use of reservoirs. The denomination Limno-reservoirs is proposed here, as these water bodies are created to maintain a natural lake dynamics. Pareja's limno-reservoir is among the first limno-reservoirs in Spain, and its construction raises some questions about hydrological viability and siltation risk. The proposition of the methodologies to solve them and the evaluation of the first results is the aim of this study. A detailed water balance makes possible to affirm that, in a firs approach, the limno-reservoir is viable from the hydrological point of view, because the Ompolveda basin -Tajo's tributary at Entrepenas reservoir- has enough water resources to guarantee the permanence of the water body, even during dry years. To assess the siltation risk, a soil loss observation network will be monitoring the Ompolveda basin for the next three years to evaluate the net erosion in the watershed and the sediment delivery to the reservoir. (Author)

  8. Stream, Lake, and Reservoir Management.

    Science.gov (United States)

    Dai, Jingjing; Mei, Ying; Chang, Chein-Chi

    2017-10-01

    This review on stream, lake, and reservoir management covers selected 2016 publications on the focus of the following sections: Stream, lake, and reservoir management • Water quality of stream, lake, and reservoirReservoir operations • Models of stream, lake, and reservoir • Remediation and restoration of stream, lake, and reservoir • Biota of stream, lake, and reservoir • Climate effect of stream, lake, and reservoir.

  9. Status of Wheeler Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  10. Influence of limnological zones on the spatial distribution of fish assemblages in three Brazilian reservoirs

    Directory of Open Access Journals (Sweden)

    Bárbara Becker

    2015-09-01

    Full Text Available Reservoirs can have both positive and negative effects on differing fish species depending on the species concerned and reservoir morphology, flow regime, and basin location.  We assessed the influence of limnological zones on the ichthyofauna of three large Neotropical reservoirs in two different river basins. We sampled fish through use of gill nets set at 40 systematically selected sites on each reservoir. We used satellite images, algae, and suspended solids concentrations to classify those sites as lacustrine or riverine. We observed significant differences in assemblage composition between riverine and lacustrine zones of each reservoir. We either tested if the same region (lacustrine or riverine showed the same patterns in different reservoirs. In São Simão, the riverine zone produced greater abundances of native species, long-distance migratory species, diversity, and richness, whereas the lacustrine zone supported greater total and non-native species abundances. Conversely, in Três Marias, the riverine zone supported greater total and non-native species abundances, whereas the others traits evaluated did not differ significantly between zones. Only lacustrine sites occurred in Volta Grande Reservoir. The same zones in the three reservoirs usually had significantly different patterns in the traits evaluated. The differences in spatial patterns observed between reservoirs could be explained partly by the differing morphologies (complex versus linear, the differential influence of tributaries of each reservoir and basin positions (presence or absence of upstream dams of the reservoirs.

  11. Log curve amplitude slicing: Visualization of well log amplitudes for paleogeographic reconstruction of the Middle Devonian Traverse Group, Michigan Basin

    Science.gov (United States)

    Wylie, Albert Sidney, Jr.

    Well log curve shapes and amplitude trends are routinely used to correlate and map formations and reservoirs across petroleum basins or fields. The methods typically employed for correlation and mapping fail, however, to make full use of the vertical resolution of well log curves. A new technique, log curve amplitude slicing (LCAS) facilitates correlation by generating a series of subhorizontal slices through the log curves using sample-by-sample analysis of log curve amplitudes in all wells between two correlative time-surfaces. The slices represent approximate time lines and are relative chronostratigraphic surfaces that can be gridded and contoured to show trends and patterns in log curve amplitudes in map view. When appropriate logs are used (e.g. gamma ray, photoelectric effect, resistivity), the slices show the inferred distribution of lithofacies at the time of deposition. Animation allows visualization of changes in the distribution of lithofacies between successive slices. The log curves can be sliced through the interval of interest from the top-down, from the bottom-up, or proportionally depending upon the sequence stratigraphic interpretation. Application of the LCAS technique facilitates correlation because it highlights trends in log curve amplitudes that are not apparent using traditional methods to display and compare log curves. Gamma ray log data from 199 wells are used in this dissertation to identify the location, relative timing, and extent of significant fine-grained clastic influx into the carbonate/evaporite-dominated Michigan Basin during deposition of the Middle Devonian Traverse Group. LCAS maps are combined with outcrop stratigraphy to reconstruct the depositional history of the Traverse Group and to develop a relative water depth curve for the Michigan Basin during the Middle Devonian. Comparison of the relative water depth curve to a eustatic sea level curve suggests that although sea level fall may have resulted in formation of

  12. Methane emissions from northern Amazon savanna wetlands and Balbina Reservoir

    Science.gov (United States)

    Kemenes, A.; Belger, L.; Forsberg, B.; Melack, J. M.

    2006-12-01

    To improve estimates of methane emission for the Amazon basin requires information from aquatic environments not represented in the central basin near the Solimoes River, where most of the current data were obtained. We have combined intensive, year-long measurements of methane emission and water levels made in interfluvial wetlands located in the upper Negro basin with calculations of inundation based on a time series of Radarsat synthetic aperature radar images. These grass-dominated savannas emitted methane at an average rate of 18 mg C per m squared per day, a low rate compared to the habitats with floating grasses the occur in the Solimoes floodplains. Reservoirs constructed in the Amazon typically flood forested landscapes and lead to conditions conducive for methane production. The methane is released to the atmosphere from the reservoir and as the water exits the turbines and from the downstream river. Balbina Reservoir near Manaus covers about 2400 km squared along the Uatuma River. Annual averages of measurements of methane emission from the various habitats in the reservoir range from 23 to 64 mg C per m squared per day. Total annual emission from the reservoir is about 58 Gg C. In addition, about 39 Gg C per year are released below the dam, about 50 percent of which is released as the water passes through the turbines. On an annual areal basis, Balbina Reservoir emits 40 Mg C km squared, in contrast to 30 Mg km squared for the Solimoes mainstem floodplain

  13. Electrical characteristics of rocks in fractured and caved reservoirs

    Science.gov (United States)

    Tang, Tianzhi; Lu, Tao; Zhang, Haining; Jiang, Liming; Liu, Tangyan; Meng, He; Wang, Feifei

    2017-12-01

    The conductive paths formed by fractures and cave in complex reservoirs differ from those formed by pores and throats in clastic rocks. In this paper, a new formation model based on fractured and caved reservoirs is established, and the electrical characteristics of rocks are analyzed with different pore structures using resistance law to understand their effects on rock resistivity. The ratio of fracture width to cave radius (C e value) and fracture dip are employed to depict pore structure in this model. Our research shows that the electrical characteristics of rocks in fractured and caved reservoirs are strongly affected by pore structure and porous fluid distribution. Although the rock electrical properties associated with simple pore structure agree well with Archie formulae, the relationships between F and φ or between I and S w , in more complicated pore structures, are nonlinear in double logarithmic coordinates. The parameters in Archie formulae are not constant and they depend on porosity and fluid saturation. Our calculations suggest that the inclined fracture may lead to resistivity anisotropy in the formation. The bigger dip the inclining fracture has, the more anisotropy the formation resistivity has. All of these studies own practical sense for the evaluation of oil saturation using resistivity logging data.

  14. The Reconcavo Basin reservoirs in transition of the pre-rift and rift phases: new discussion; Os reservatorios da Bacia do Reconcavo na transicao das fases pre-rift e rift: nova discussao

    Energy Technology Data Exchange (ETDEWEB)

    Romao, Felipe [Queiroz Galvao Perfuracoes S.A., Rio de Janeiro, RJ (Brazil); Borghi, Leonardo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2004-07-01

    The facies analysis of the stratigraphic interval represented by Sergi, Itaparica, and Agua Grande formations (Brotas and Santo Amaro groups) of Reconcavo basin was guided by cores description of the well 1-CAL-1-BA (Caldeirao 1), located in the Northwestern part of the Reconcavo Basin. Sedimentary facies (lithofacies) were described and grouped into four facies association interpreted as fluvial (upper Sergi Fm.), fluvial-lacustrine (Itaparica Fm.), and fluvial-eolian (Agua Grande Fm.) depositional systems; also, forced-regression erosive surfaces (unconformities) and transgressive ones were identified. The analysis of these results points that the upper Sergi Fm. would have subsided as consequence of the early rifting of the basin, creating space for the formation of shallow lake (Itaparica Fm.). This ancient lake undergone several forced regressions due to a continuous early tectonism (rifting), responsible by the sand input into the lake, in a coarsening up cycle topped by the expressive fluvio-eolian system of the Agua Grande Fm. Each forced regression smaller cycle is capped by lake flooding shales. Above this major CU cycle, the intensification of tectonic event subsided the basin and created a deep lake (Candeias Fm.) - the Rift Phase. So, the initial rifting would not have started during a 'Candeias time', but by earlier, in a less intense way. It must be stressed that this interpretation was based solely in only one well, but it's important to keep this new idea in mind for revision or new studies on this interval. (author)

  15. Impact of acid mine drainage from mining exploitations on the Margajita River basin and the Hatillo reservoir (Dominican Republic); Impacto del drenaje acido de explotaciones mineras en la cuenca del Rio Margajita y Embalse de Hatillo (Republica Dominicana)

    Energy Technology Data Exchange (ETDEWEB)

    Grandia, F.; Salas, J.; Arcos, D.; Archambault, A.; Cottard, F.

    2009-07-01

    Mining of the Pueblo Viejo high-sulphidation epithermal deposit (Dominican Republic) leads to environmental impact due to the formation of acid mine drainage associated with the oxidative dissolution of sulphides and sulpho salts. In addition to the very low pH, the acid waters are capable of transporting away from the mining areas high concentrations of metals and metalloids in solution. In the present work, a geochemical study of sediments deposited in the Hatillo reservoir is carried out. This reservoir is fed by the Margajita and Yuna streams which transport leachates from the Pueblo Viejo and Falcondo-Bonao (Cr-Ni) mining areas, respectively. The results show that these sediments have very high concentrations of Fe, Al and sulphate, along with significant amounts of As, Zn and Te, which are of especial environmental concern. The main contributor to this metal discharge into the reservoir is the Margajita stream, whereas the Yuna stream does not transport significant amounts of metals in solution due to its neutral pH, although it is likely that metals such as Mn, Cr, Ni and Co can be mobilised as a particulate. (Author) 5 refs.

  16. Advances in carbonate exploration and reservoir analysis

    Science.gov (United States)

    Garland, J.; Neilson, J.; Laubach, S.E.; Whidden, Katherine J.

    2012-01-01

    The development of innovative techniques and concepts, and the emergence of new plays in carbonate rocks are creating a resurgence of oil and gas discoveries worldwide. The maturity of a basin and the application of exploration concepts have a fundamental influence on exploration strategies. Exploration success often occurs in underexplored basins by applying existing established geological concepts. This approach is commonly undertaken when new basins ‘open up’ owing to previous political upheavals. The strategy of using new techniques in a proven mature area is particularly appropriate when dealing with unconventional resources (heavy oil, bitumen, stranded gas), while the application of new play concepts (such as lacustrine carbonates) to new areas (i.e. ultra-deep South Atlantic basins) epitomizes frontier exploration. Many low-matrix-porosity hydrocarbon reservoirs are productive because permeability is controlled by fractures and faults. Understanding basic fracture properties is critical in reducing geological risk and therefore reducing well costs and increasing well recovery. The advent of resource plays in carbonate rocks, and the long-standing recognition of naturally fractured carbonate reservoirs means that new fracture and fault analysis and prediction techniques and concepts are essential.

  17. Exploration and reservoir characterization; Technology Target Areas; TTA2 - Exploration and reservoir characterisation

    Energy Technology Data Exchange (ETDEWEB)

    2008-07-01

    In future, research within exploration and reservoir characterization will play an even more important role for Norway since resources are decreasing and new challenges like deep sea, harsh environment and last but not least environmental issues have to be considered. There are two major fields which have to be addressed within exploration and reservoir characterization: First, replacement of reserves by new discoveries and ultimate field recoveries in mature basins at the Norwegian Continental shelf, e.g. at the Halten Terrace has to be addressed. A wealth of data exists in the more mature areas. Interdisciplinary integration is a key feature of reservoir characterization, where available data and specialist knowledge need to be combined into a consistent reservoir description. A systematic approach for handling both uncertainties in data sources and uncertainties in basic models is needed. Fast simulation techniques are necessary to generate models spanning the event space, covering both underground based and model-based uncertainties. Second, exploration in frontier areas like the Barents Sea region and the deeper Voering Basin has to be addressed. The scarcity of wells in these frontier areas leads to uncertainties in the geological understanding. Basin- and depositional modelling are essential for predicting where source rocks and reservoir rocks are deposited, and if, when and which hydrocarbons are generated and trapped. Predictive models and improved process understanding is therefore crucial to meet these issues. Especially the challenges related to the salt deposits e.g. sub-salt/sub-basalt reservoir definitions in the Nordkapp Basin demands up-front research and technology developments. TTA2 stresses the need to focus on the development of new talents. We also see a strong need to push cooperation as far as possible in the present competitive environment. Projects that may require a substantial financial commitment have been identified. The following

  18. Integrated Hydrographical Basin Management. Study Case - Crasna River Basin

    Science.gov (United States)

    Visescu, Mircea; Beilicci, Erika; Beilicci, Robert

    2017-10-01

    Hydrographical basins are important from hydrological, economic and ecological points of view. They receive and channel the runoff from rainfall and snowmelt which, when adequate managed, can provide fresh water necessary for water supply, irrigation, food industry, animal husbandry, hydrotechnical arrangements and recreation. Hydrographical basin planning and management follows the efficient use of available water resources in order to satisfy environmental, economic and social necessities and constraints. This can be facilitated by a decision support system that links hydrological, meteorological, engineering, water quality, agriculture, environmental, and other information in an integrated framework. In the last few decades different modelling tools for resolving problems regarding water quantity and quality were developed, respectively water resources management. Watershed models have been developed to the understanding of water cycle and pollution dynamics, and used to evaluate the impacts of hydrotechnical arrangements and land use management options on water quantity, quality, mitigation measures and possible global changes. Models have been used for planning monitoring network and to develop plans for intervention in case of hydrological disasters: floods, flash floods, drought and pollution. MIKE HYDRO Basin is a multi-purpose, map-centric decision support tool for integrated hydrographical basin analysis, planning and management. MIKE HYDRO Basin is designed for analyzing water sharing issues at international, national and local hydrographical basin level. MIKE HYDRO Basin uses a simplified mathematical representation of the hydrographical basin including the configuration of river and reservoir systems, catchment hydrology and existing and potential water user schemes with their various demands including a rigorous irrigation scheme module. This paper analyzes the importance and principles of integrated hydrographical basin management and develop a case

  19. Reservoir monitoring and characterization for heavy-oil thermal recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pankaj, P.; Pathak, V. [Indian School of Mines (India)

    2005-11-01

    Cyclic steam stimulation (CSS) techniques can become uneconomical in their later cycles, as the oil to steam ratio can drop significantly. Time-lapse seismic assisted follow-up programs can improve oil to steam ratios and production rates within 1 cycle. This study presented the results of an optimized quantitative cross-calibration and cross-training stream that was developed for time-lapse seismic data analysis using data normalization as a bridge. It was anticipated that the stream would provide more consistent results than independent training for reservoir monitoring. In order to compensate for the redundancy of conventional seismic attributes, seismic attributes calculated from principal component decomposition of the seismic data were developed and used for reservoir monitoring. Time-lapse data sets were analyzed by the merging of 2 data sets. Attributes were calculated separately from individual surveys. A significant improvement was noted on time lapse data analysis. Post-stack inversion was applied to time lapse data sets, as the time lapse data normalization was no longer required because the wavelets were extracted independently from each data set. Vertical conformance revealed that sequence architecture had a significant influence on steam migration. A sequence with a high mud content limited both the vertical and horizontal migration of the steam chamber. It was determined that the functional relation of P- to S- wave velocities played an important role in extracting S-wave information from pre-stack data. The mud-rock line established from in-situ P- and S- wave velocity measurements was optimized for Cold Lake clastic rocks. It was concluded that with an optimized mud-rock line and high frequency seismic data, reservoir heterogeneity can be well defined by fluid factor. When applied to reservoir monitoring, this method defined steam channels and successfully identified lithological barriers within the reservoir. 5 refs., 7 figs.

  20. Orogenesis and Basin Development: U-Pb Detrital Zircon Age Constraints on Evolution of the Late Paleozoic St. Marys Basin, Central Mainland Nova Scotia.

    Science.gov (United States)

    Murphy; Hamilton

    2000-01-01

    The St. Marys Basin, along the southern flank of the composite Late Paleozoic Magdalen Basin in the Canadian Appalachians and along the Avalon-Meguma terrane boundary, contains Late Devonian-Early Carboniferous continental clastic rocks of the Horton Group that were deposited in fluvial and lacustrine environments after the peak of the Acadian orogeny. SHRIMP II (Geological Survey of Canada) data on approximately 100 detrital zircons from three samples of Horton Group rocks from the St. Marys Basin show that most of the zircons have been involved in a multistage history, recycled from clastic rocks in the adjacent Meguma and Avalonian terranes. Although there is a minor contribution from Early Silurian (411 Ma) and Late Devonian suites (ca. 380-370 Ma), Neoproterozoic (ca. 700-550 Ma) and Paleoproterozoic (ca. 2.0-2.2 Ga) zircon populations predominate, with a minor contribution from ca. 1.0-, 1.2-, and 1.8-Ga zircons. Published U-Pb single-zircon analyses on clastic sedimentary rocks indicate that the Meguma and Avalon terranes have different populations of detrital zircons, sourced from discrete portions (Amazonian and West African cratons) of the ancient Gondwanan margin. Both terranes contain Neoproterozoic and Late Archean populations. The SHRIMP data, in conjunction with published sedimentological and geochemical data, indicate that the Horton Group basin-fill sediments are largely the result of rapid uplift and erosion of Meguma terrane metasedimentary and granitoid rocks immediately to the south of the St. Marys Basin during the waning stages of the Acadian orogeny. Regional syntheses indicate that this uplift occurred before and during deposition and was a consequence of dextral ramping of the Meguma terrane over the Avalon terrane along the southern flank of the Magdalen Basin.

  1. Gravity-driven structures and rift basin evolution: Rio Muni Basin, offshore equatorial West Africa

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.P. [Univ. of Birmingham (United Kingdom)

    1995-08-01

    Offshore Equatorial Guinea, west Africa, gravity-driven nappes, more than 1 km thick and 15 km from head to toe, provide key evidence in reconstructing the late synrift: evolution of this part of the South Atlantic margin basin system. Furthermore, Aptian-Cenomanian carbonate and clastic rocks in the nappes` allochthonous hanging walls are attracting interest as a new exploration play in west Africa. The nappes exhibit a range of geometries that suggest they share many of the same deformation processes as thin-skin thrust and linked extensional fault systems. Not only are these structures significant in their own right, representing a rare example of gravity tectonics in the virtual absence of major halokinesis, but their presence may record an other-wise undetectable process active during the transition from a rift basin to a passive continental margin. A review of Equatorial Guinea in its pre-Atlantic configuration, alongside neighboring basins in Brazil (the Sergipe-Alagoas basin) and Gabon, suggests that gravity gliding was sustained by a relatively steep, westward paleoslope promoted by east-ward offset of the locus of thermal uplift from the rift basin (i.e., a simple shear model of basin formation). In contrast to gravity-driven structures in most postrift settings, the Equatorial Guinea nappes developed at the close of the Aptian-Albian synrift episode in response to a growing bathymetric deep caused by rapid subsidence outpacing restricted sedimentation.

  2. Eustatic and tectonic control of deposition of the lower and middle Pennsylvanian strata of the Central Appalachian Basin

    S