Sample records for previously studied reservoirs

  1. Chickamauga reservoir embayment study - 1990

    Meinert, D.L.; Butkus, S.R.; McDonough, T.A.


    The objectives of this report are three-fold: (1) assess physical, chemical, and biological conditions in the major embayments of Chickamauga Reservoir; (2) compare water quality and biological conditions of embayments with main river locations; and (3) identify any water quality concerns in the study embayments that may warrant further investigation and/or management actions. Embayments are important areas of reservoirs to be considered when assessments are made to support water quality management plans. In general, embayments, because of their smaller size (water surface areas usually less than 1000 acres), shallower morphometry (average depth usually less than 10 feet), and longer detention times (frequently a month or more), exhibit more extreme responses to pollutant loadings and changes in land use than the main river region of the reservoir. Consequently, embayments are often at greater risk of water quality impairments (e.g. nutrient enrichment, filling and siltation, excessive growths of aquatic plants, algal blooms, low dissolved oxygen concentrations, bacteriological contamination, etc.). Much of the secondary beneficial use of reservoirs occurs in embayments (viz. marinas, recreation areas, parks and beaches, residential development, etc.). Typically embayments comprise less than 20 percent of the surface area of a reservoir, but they often receive 50 percent or more of the water-oriented recreational use of the reservoir. This intensive recreational use creates a potential for adverse use impacts if poor water quality and aquatic conditions exist in an embayment.

  2. An integrated study of a Campeche Bay fractured carbonate reservoir

    Hampton, D.W.; Hernandez, J.G.; Vasques, G.A.V.; Aquino, E.V.; Barton, C.; Laude, L.; Lockhart, A.M.E.; Peebles, R.G.


    This paper provides a case study in the reservoir description of a fractured carbonate by a multi-disciplinary team. It illustrates how the synergistic interaction of team members during data analysis and model building resulted in: (1) the identification of previously unrecognized links between several reservoir characteristics; (2) produced a superior reservoir model; and (3) increased the likelihood of successful development. In summary, identification, characterization, and delineation of fractured intervals within the deepwater carbonate succession resulted in a preliminary 3-D model of both the static and dynamic properties for the Cretaceous reservoir of the Yum Field which, through reservoir simulation, will provide a predictive tool for development planning.

  3. Reservoir

    M. Mokhtar


    Full Text Available Scarab field is an analog for the deep marine slope channels in Nile Delta of Egypt. It is one of the Pliocene reservoirs in West delta deep marine concession. Channel-1 and channel-2 are considered as main channels of Scarab field. FMI log is used for facies classification and description of the channel subsequences. Core data analysis is integrated with FMI to confirm the lithologic response and used as well for describing the reservoir with high resolution. A detailed description of four wells penetrated through both channels lead to define channel sequences. Some of these sequences are widely extended within the field under study exhibiting a good correlation between the wells. Other sequences were of local distribution. Lithologic sequences are characterized mainly by fining upward in Vshale logs. The repetition of these sequences reflects the stacking pattern and high heterogeneity of the sandstone reservoir. It also refers to the sea level fluctuation which has a direct influence to the facies change. In terms of integration of the previously described sequences with a high resolution seismic data a depositional model has been established. The model defines different stages of the channel using Scarab-2 well as an ideal analog.

  4. Geothermal reservoir insurance study. Final report


    The principal goal of this study was to provide analysis of and recommendations on the need for and feasibility of a geothermal reservoir insurance program. Five major tasks are reported: perception of risk by major market sectors, status of private sector insurance programs, analysis of reservoir risks, alternative government roles, and recommendations.

  5. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    Nurhandoko, Bagus Endar B.; Susilowati


    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir's layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir's character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia.

  6. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    Nurhandoko, Bagus Endar B., E-mail:, E-mail: [Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4" t" hfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia); Susilowati, E-mail:, E-mail: [Rock Fluid Imaging Lab., Bandung (Indonesia)


    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia.

  7. Experimental Design of a Polymeric Solution to Improve the Mobility Ratio in a Reservoir previous implementation of a pilot project of EOR

    Vanessa Cuenca


    Full Text Available This paper describes experimental formulations of polymeric solutions through lab evaluations with the objective of finding optimum solution concentration to fluid mobility in reservoirs as previous step before implementing a pilot project of enhanced oil recovery. The polymers, firstly, were selected based on the properties from fluids from reservoir. Two types of polymers were used TCC-330 and EOR909 and the experimental tests were: thermal stability, compatibility, adsorption, salinity, and displacement. The design with the best results was with polymer TCC-330 at 1,500 ppm concentration.

  8. Reservoir-induced seismicity associated with the Itoiz Reservoir, Spain: a case study

    Durá-Gómez, Inmaculada; Talwani, Pradeep


    Reservoir-induced seismicity was observed in 2004 after the impoundment of the Itoiz Reservoir in the central-western Pyrenees, Spain. Subsequent annual filling cycles were accompanied by large epicentral growth in the northern part of the Jaca-Pamplona basin. Based on the evaluation of the available geohydrologic data, we suggest that the seismicity is associated with the diffusion of increased pore pressures along the carbonate megabreccia systems of the Early to Middle Eocene age Hecho Group. Assuming 1-D pore-pressure diffusion from the Itoiz Reservoir, we estimate that excess pore pressures of ~100-500 kPa are adequate to induce M >= 3.0 earthquakes in this geological terrane. The results of this study have potential applicability in regions where reservoirs are built over karst terranes.

  9. Development of a framework for optimization of reservoir simulation studies

    Zhang, Jiang; Delshad, Mojdeh; Sepehrnoori, Kamy [The University of Texas at Austin, Austin, TX (United States)


    We have developed a framework that distributes multiple reservoir simulations on a cluster of CPUs for fast and efficient process optimization studies. This platform utilizes several commercial reservoir simulators for flow simulations, an experimental design and a Monte Carlo algorithm with a global optimization search engine to identify the optimum combination of reservoir decision factors under uncertainty. This approach is applied to a well placement design for a field-scale development exercise. The uncertainties considered are in the fault structure, porosity and permeability, PVT, and relative permeabilities. The results indicate that the approach is practical and efficient for performing reservoir optimization studies. (author)

  10. Numerical study of reservoir cooling by means of peltier effect

    Farias, Rodrigo Martins; Santos, Elizaldo Domingues dos; Isoldi, Liércio André; Rocha, Luiz Alberto Oliveira


    The present work studies numerically and experimentally the water cooling process by means of natural convection inside a closed reservoir. The cooling process is performed by Peltier or Thermoelectric effect. The purpose here is to obtain the thermal gradient inside the reservoir and to search for the best point where the coldest water can be extracted from the reservoir, which can be considered a geometric optimization of the device thermal design. The analyzed flow is incompressible, lamin...

  11. The glaciogenic reservoir analogue studies project (GRASP)

    Moscariello, A.; Moreau, Julien; Vegt, P. van der

    Tunnel galleys are common features in Palaeozoic glacigenic succession in North Afrcica and Middle East and they are amongst the most challenging target for hydrocarbon exploration and developing drilling in these regions. Similarly, these buried valleys form important groundwater reservoirs...

  12. Previous studies underestimate BMAA concentrations in cycad flour.

    Cheng, Ran; Banack, Sandra Anne


    The traditional diet of the Chamorro people of Guam has high concentrations of the neurotoxin BMAA, beta-methyl-amino-L-alanine, in cycad tortillas and from animals that feed on cycad seeds. We measured BMAA concentration in washed cycad flour and compared different extraction methods used by previous researchers in order to determine how much BMAA may have been unaccounted for in prior research. Samples were analyzed with AQC precolumn derivatization using HPLC-FD detection and verified with UPLC-UV, UPLC-MS, and triple quadrupole LC/MS/MS. Although previous workers had studied only the free amino acid component of BMAA in washed cycad flour, we detected significant levels of protein-associated BMAA in washed cycad flour. These data support a link between ALS/PDC and exposure to BMAA.

  13. Feasibility study of sedimentary enhanced geothermal systems using reservoir simulation

    Cho, Jae Kyoung

    The objective of this research is to evaluate the preliminary feasibility of commercial geothermal projects, from a sedimentary reservoir with low permeability that requires productivity enhancement, using numerical reservoir simulation. The performance of a sedimentary geothermal reservoir is investigated in terms of reservoir hydraulics and thermal evolution. To build a reliable benchmark for simulation study, validation of the numerical reservoir model with respect to an analytical model is presented, and the process to achieve an acceptable match between the numerical and analytical solutions is described. The analytical model used in this study is based on the work of Gringarten (1978), which consists of a conceptual geothermal reservoir, considering an injection and production well doublet in a homogeneous porous media. A commercial thermal reservoir simulator (STARS from Computer Modeling Group, CMG) is used in this work for numerical modeling. In order to reproduce the analytical model results, the numerical simulation model is modified to include the same assumptions of the analytical model. Simulation model parameters that make the numerical results deviate from the analytical solution, such as the grid block size, time step and no-flow boundary are identified and investigated. An analytical tracer test model proposed by Shook (2000) is numerically modeled. This model allows us to predict the time when the temperature of the produced water decreases by capturing a tracer component at production well. Reservoir simulation models with different porosity and permeability distribution are tested to see the effects of reservoir inhomogeneity and anisotropy. In particular, premature thermal breakthrough due to the presence of high permeability streak in a reservoir model is simulated. In an effort to apply the knowledge we obtained from the analytical solutions, the effects of reservoir rock and water properties, as a function of pressure and temperature, are

  14. Studies of Reservoir Hosts for Marburg virus

    Swanepoel, Robert; Smit, Sheilagh B; Rollin, Pierre E


    To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2...

  15. Study of Dieldrin in Coralville Reservoir

    Jeremy Smith


    Using existing experimental data taken over a period of roughly 12 years that documents the concentrations of dieldrin levels in the environment and fatty tissue of the fish, we construct a model of the total dieldrin concentration decline. Comparisons between the experimental data and speculative data can be made using calculus and elements of statistics in order to better understand the movement of dieldrin in the reservoir. Because of the potentially harmful exposure effects of dieldrin to...

  16. Hailstone Reservoir Feasibility Study : Hailstone National Wildlife Refuge

    US Fish and Wildlife Service, Department of the Interior — This study covers the water quality in the Hailstone Reservoir that has been severely impacted by up-gradient saline seeps that contain trace elements. Due to the...

  17. Studies of reservoir hosts for Marburg virus.

    Swanepoel, Robert; Smit, Sheilagh B; Rollin, Pierre E; Formenty, Pierre; Leman, Patricia A; Kemp, Alan; Burt, Felicity J; Grobbelaar, Antoinette A; Croft, Janice; Bausch, Daniel G; Zeller, Hervé; Leirs, Herwig; Braack, L E O; Libande, Modeste L; Zaki, Sherif; Nichol, Stuart T; Ksiazek, Thomas G; Paweska, Janusz T


    To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2 species of insectivorous bat and 1 species of fruit bat. We found antibody to the virus in the serum of 9.7% of 1 of the insectivorous species and in 20.5% of the fruit bat species, but attempts to isolate virus were unsuccessful.

  18. Studies of Reservoir Hosts for Marburg virus

    Swanepoel, Robert; Smit, Sheilagh B; Rollin, Pierre E


    To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2...... species of insectivorous bat and 1 species of fruit bat. We found antibody to the virus in the serum of 9.7% of 1 of the insectivorous species and in 20.5% of the fruit bat species, but attempts to isolate virus were unsuccessful. ...

  19. Study of Dieldrin in Coralville Reservoir

    Jeremy Smith


    Full Text Available Using existing experimental data taken over a period of roughly 12 years that documents the concentrations of dieldrin levels in the environment and fatty tissue of the fish, we construct a model of the total dieldrin concentration decline. Comparisons between the experimental data and speculative data can be made using calculus and elements of statistics in order to better understand the movement of dieldrin in the reservoir. Because of the potentially harmful exposure effects of dieldrin to humans as well as the environment, it is important to be able to predict when stability has been restored to the ecosystem.

  20. Reservoir engineering studies of the Cerro Prieto geothermal field

    Goyal, K. P.; Lippmann, M. J.; Tsang, C. F.


    Reservoir engineering studies of the Cerro Prieto geothermal field began in 1978 under a five-year cooperative agreement between the US Department of Energy and the Comision Federal de Electricidad de Mexico, with the ultimate objective of simulating the reservoir to forecast its production capacity, energy longevity, and recharge capability under various production and injection scenarios. During the fiscal year 1981, attempts were made to collect information on the evolution history of the field since exploitation began; the information is to be used later to validate the reservoir model. To this end, wellhead production data were analyzed for heat and mass flow and also for changes in reservoir pressures, temperatures, and saturations for the period from March 1973 to November 1980.

  1. Study of cystic artery by arteriography. Importance of previous cholecystography

    Machado, G.O.

    An oral cholecystography previously to celiac and mesenteric arteriography is performed, in order to identify the cystic artery, in 42 patients with pancreatitis, according Seldinger technique. The cystic artery was identified in all the cases, the pattern being the outlet of the cystic artery from the right hepatic artery. Infusion pump and seriography were not used.

  2. New study reveals twice as many asteroids as previously believed


    The ISO satellite Credits: ESA ISO An artist's impression of the ISO spacecraft. The ISO Deep Asteroid Search indicates that there are between 1.1 million and 1.9 million 'space rocks' larger than 1 kilometre in diameter in the so-called 'main asteroid belt', about twice as many as previously believed. However, astronomers think it is premature to revise current assessments of the risk of the Earth being hit by an asteroid. Despite being in our own Solar System, asteroids can be more difficult to study than very distant galaxies. With sizes of up to one thousand kilometres in diameter, the brightness of these rocky objects may vary considerably in just a few minutes. They move very quickly with respect to the stars - they have been dubbed 'vermin of the sky' because they often appear as trails on long exposure images. This elusiveness explains why their actual number and size distribution remains uncertain. Most of the almost 40,000 asteroids catalogued so far (1) orbit the Sun forming the 'main asteroid belt', between Mars and Jupiter, too far to pose any threat to Earth. However, space-watchers do keep a closer eye on another category of asteroids, the 'Near Earth Asteroids' or 'NEAs', which are those whose orbits cross, or are likely to cross, that of our planet. The ISO Deep Asteroid Search (IDAS), the first systematic search for these objects performed in infrared light, focused on main belt asteroids. Because it is impossible to simply point the telescope at the whole main belt and count, astronomers choose selected regions of the belt and then use a theoretical model to extrapolate the data to the whole belt. Edward Tedesco (TerraSystems, Inc., New Hampshire, United States) and François-Xavier Desert (Observatoire de Grenoble, France) observed their main belt selected areas in 1996 and 1997 with ESA's ISO. They found that in the middle region of the belt the density of asteroids was 160 asteroids larger than 1 kilometre per square degree - an area of the

  3. PCB studies on fish from Watts Bar, Fort Loudoun, Tellico, and Melton Hill Reservoirs, 1988

    Dycus, D.L.


    The Tennessee Valley Authority (TVA) reservoirs that are the subject of this report have been under investigation for several years due to contamination with polychlorinated biphenyls (PCBs). The study has two primary objectives: (1) define the geographical boundaries where contamination in fish ceases to be a problem and (2) determine the trend in PCB loading in fish from reservoirs where the contamination has been well defined. The purpose of this document is to briefly describe results of PCB analysis of fish collected from these reservoirs in autumn 1988 and compare them to results for previous years. These results were shared with all members on the study team as soon as they were received from the analytical laboratory rather than waiting for this formal report. Therefore, decisions on updating existing advisories and selection of study design for autumn 1989 were made months before this document was prepared. 6 refs., 21 tabs.

  4. Geothermal reservoir categorization and stimulation study

    Overton, H.L.; Hanold, R.J.


    Analyses of the fraction of geothermal wells that are dry (dry-hole fraction) indicate that geothermal reservoirs can be fitted into four basic categories: (i) Quaternary to late Tertiary sediments (almost no dry holes); (ii) Quaternary to late Tertiary extrusives (approximately 20 percent dry holes); (iii) Mesozoic or older metamorphic rocks (approximately 25-30 percent dry holes); and (iv) Precambrian or younger rocks (data limited to Roosevelt Springs where 33 percent of the wells were dry). Failure of geothermal wells to flow economically is due mainly to low-permeability formations in unfractured regions. Generally the permeability correlates inversely with the temperature-age product and directly with the original rock porosity and pore size. However, this correlation fails whenever high-stress fields provide vertical fracturing or faulting, and it is the high-stress/low-permeability category that is most amenable to artificial stimulation by hydraulic fracturing, propellant fracturing, or chemical explosive fracturing. Category (i) geothermal fields (e.g., Cerro Prieto, Mexico; Niland, CA; East Mesa, CA) are not recommended for artificial stimulation because these younger sediments almost always produce warm or hot water. Most geothermal fields fit into category (ii) (e.g., Wairakei, New Zealand; Matsukawa, Japan; Ahuachapan, El Salvador) and in the case of Mt. Home, ID, and Chandler, AZ, possess some potential for stimulation. The Geysers is a category (iii) field, and its highly stressed brittle rocks should make this site amenable to stimulation by explosive fracturing techniques. Roosevelt Springs, UT, well 9-1 is in category (iv) and is a flow failure. It represents a prime candidate for stimulation by hydraulic fracturing because it has a measured temperature of 227/sup 0/C, is cased and available for experimentation, and is within 900 m of an excellent geothermal producing well.

  5. Using reservoir engineering data to solve geological ambiguities : a case study of one of the Iranian carbonate reservoirs

    Kord, S. [National Iranian South Oil Co. (Iran, Islamic Republic of)


    A fractured carbonate reservoir in southwest Iran was studied with reference to reserve estimation, risk analysis, material balance and recovery factor. The 40 km long and 4 km wide reservoir consists of 2 parts with crest depths of 3780 and 3749 mss respectively. The eastern part is smaller and more productive than the western part which has high water saturation and absolutely no production. Economic production from the reservoir began in 1977. By 2004, the cumulative production had reached 12.064 MMSTB. Of the 6 wells drilled, only 2 wells in the eastern part are productive. This study addressed the main uncertainty of whether the 2 parts of the reservoir are sealed or not. The reservoir is under-saturated but the current pressure is near saturation pressure. The reservoir is divided into the following 4 zones: zones 1 and 2 are productive and consist mainly of carbonate rocks; zone 3 has thin beds of sand and shale; and, zone 4 consists of layers of carbonate, shale, marn, and dolomite. Although there are no faults, mud loss suggests that the reservoir has hairline fractures. Oil in place and reserves were estimated for both parts based on calculated reservoir engineering parameters. Material balance calculations were then performed to analyze and simulate the reservoir. The communication between the 2 parts of the reservoir were examined according to core analysis, rock type, fluid characterization, pressure analysis, water-oil contacts, production history and petrophysical evaluations. The porosity was found to be the same in both parts, but the water saturation and net to gross ratios were different between the eastern and western parts. The petrophysical evaluation revealed that there is no communication between the two parts of the reservoir. 4 refs., 2 figs., 2 appendices.

  6. Estimation of Bank Erosion Due To Reservoir Operation in Cascade (Case Study: Citarum Cascade Reservoir

    Sri Legowo


    Full Text Available Sedimentation is such a crucial issue to be noted once the accumulated sediment begins to fill the reservoir dead storage, this will then influence the long-term reservoir operation. The sediment accumulated requires a serious attention for it may influence the storage capacity and other reservoir management of activities. The continuous inflow of sediment to the reservoir will decrease the capacity of reservoir storage, the reservoir value in use, and the useful age of reservoir. Because of that, the rate of the sediment needs to be delayed as possible. In this research, the delay of the sediment rate is considered based on the rate of flow of landslide of the reservoir slope. The rate of flow of the sliding slope can be minimized by way of each reservoir autonomous efforts. This effort can be performed through; the regulation of fluctuating rate of reservoir surface current that does not cause suddenly drawdown and upraising as well. The research model is compiled using the searching technique of Non Linear Programming (NLP.The rate of bank erosion for the reservoir variates from 0.0009 to 0.0048 MCM/year, which is no sigrificant value to threaten the life time of reservoir.Mean while the rate of watershed sediment has a significant value, i.e: 3,02 MCM/year for Saguling that causes to fullfill the storage capacity in 40 next years (from years 2008.

  7. A chemical EOR benchmark study of different reservoir simulators

    Goudarzi, Ali; Delshad, Mojdeh; Sepehrnoori, Kamy


    Interest in chemical EOR processes has intensified in recent years due to the advancements in chemical formulations and injection techniques. Injecting Polymer (P), surfactant/polymer (SP), and alkaline/surfactant/polymer (ASP) are techniques for improving sweep and displacement efficiencies with the aim of improving oil production in both secondary and tertiary floods. There has been great interest in chemical flooding recently for different challenging situations. These include high temperature reservoirs, formations with extreme salinity and hardness, naturally fractured carbonates, and sandstone reservoirs with heavy and viscous crude oils. More oil reservoirs are reaching maturity where secondary polymer floods and tertiary surfactant methods have become increasingly important. This significance has added to the industry's interest in using reservoir simulators as tools for reservoir evaluation and management to minimize costs and increase the process efficiency. Reservoir simulators with special features are needed to represent coupled chemical and physical processes present in chemical EOR processes. The simulators need to be first validated against well controlled lab and pilot scale experiments to reliably predict the full field implementations. The available data from laboratory scale include 1) phase behavior and rheological data; and 2) results of secondary and tertiary coreflood experiments for P, SP, and ASP floods under reservoir conditions, i.e. chemical retentions, pressure drop, and oil recovery. Data collected from corefloods are used as benchmark tests comparing numerical reservoir simulators with chemical EOR modeling capabilities such as STARS of CMG, ECLIPSE-100 of Schlumberger, REVEAL of Petroleum Experts. The research UTCHEM simulator from The University of Texas at Austin is also included since it has been the benchmark for chemical flooding simulation for over 25 years. The results of this benchmark comparison will be utilized to improve

  8. Study on attribute characterization for reservoir dynamic monitoring by seismic


    Study on characterizing reservoir parameters dynamic variations by time-lapse seismic attributes is the theoretical basis for effectively distinguishing reservoir parameters variations and conducting time-lapse seismic interpretation,and it is also a key step for time-lapse seismic application in real oil fields. Based on the rock physical model of unconsolidated sandstone,the different effects of oil saturation and effective pressure variations on seismic P-wave and S-wave velocities are calculated and analyzed. Using numerical simulation on decoupled wave equations,the responses of seismic amplitude with different offsets to reservoir oil saturation variations are analyzed,pre-stack time-lapse seismic attributes differences for oil saturation and effective pressure variations of P-P wave and P-S converted wave are calculated,and time-lapse seismic AVO (Amplitude Versus Offset) response rules of P-P wave and P-S converted wave to effective pressure and oil saturation variations are compared. The theoretical modeling study shows that it is feasible to distinguish different reservoir parameters dynamic variations by pre-stack time-lapse seismic information,including pre-stack time-lapse seismic attributes and AVO information,which has great potential in improving time-lapse seismic interpreta-tion precision. It also shows that the time-lapse seismic response mechanism study on objective oil fields is especially important in establishing effective time-lapse seismic data process and interpreta-tion scheme.

  9. Logging Geology Study of the Caverned Paleokarst Reservoir Distribution

    WuXinsong; YangLei; PanWenqing; GuQiaoyuan


    In recent years, many carbonate rock oilfields such as Lunnan and Tahe have been found in the Tarim Basin, and the main reservoir space of the stable high yield wells in these oilfields consists mainly of the caverns formed by the paleo-karstification and the dissolution pores and fractures connected with them. Nevertheless, it is difficult to predict effectively the distribution of the cavern reservoir because of its extremely serious heterogeneity. In this paper, a case study of the Lunxi Oilfield in the north uplift of the Tarim Basin is conducted to introduce the logging geology method for predicting the distribution of the caverned paleokarst, reservoir. By means of building up the logging recognition style of different caverns and differentiating and correlating the karst zones with logging curves, and through an analysis of the paleokarst topography background, the favorable karst zones and distribution areas of the high quality cavern reservoir have been located, which lays a new basis for further exploration in this area.

  10. Geodetic Study of Ground Instability at Active Geothermal Reservoirs

    Aly, M. H.; Bawner, E.; Nanis, H.; Alotaibi, M.; Suwihli, S.


    Active geothermal systems may cause substantial crustal deformation that can damage the precious infrastructure and increase the frequency and magnitude of earthquakes in the surrounding region. Geothermal production practices commonly contribute to surface motions triggered by natural tectonic and volcanic forces at active geothermal fields and may intensify their significance over years. Hence, routine monitoring of active geothermal sites is required to evaluate the impact of production activities and assess associated ground instabilities. Knowledge of the reservoir geometry, compaction, and response to production behaviors will aid in identifying ideal locations for new production and recharge wells to advance the performance of such a reservoir. This study investigates active geothermal processes and recent seismic events and their impacts on crustal deformation at the Raft River Geothermal Power Plant (RGP) in southeastern Idaho and at the Coso Geothermal (CG) field in eastern California. Contemporary geodetic observations from Synthetic Aperture Radar Interferometry (InSAR) and Global Positioning System (GPS) imply a rapid rate of ground subsidence ( 7 cm/yr) across the Raft River Valley with a local anomaly of ample uplift (3 cm/yr) near RGP. The measured rate of deflation at CG is 3.1 cm/yr throughout a large area ( 55 sq km) that is directly correlating with the extent of active geothermal production. These rapid rates of ground deformation indicate considerable depressurization of the two reservoirs. Volumetric analysis and modeling are currently underway to characterize the two reservoirs and to infer their deformation source parameters. Understanding the hydrothermal-geomechanical response of the reservoirs to fluid production and injection is crucial for their management and development.

  11. Reservoir engineering technology used for geothermal reservoir assessment studies in Germany

    Alkan, H. [ISTec, Inst. fuer Sicherheitstechnologie, Koeln (Germany); Pusch, G. [Inst. fuer Erdoel- und Erdgastechnik, TU Clausthal (Germany)


    The development of the geothermal reservoirs needs and uses the know-how and technology of petroleum reservoir engineering. The interaction of both disciplines is due to the similarities of underground geothermal systems to the oil and gas reservoirs. Because of the its earlier development, petroleum engineering concepts and technologies play an important role in geothermal field developments worldwide since many years. In Germany good examples of this interaction is also seen in the last years especially in exploration and development stages. The assessment of the defined heat reserves needs also to profit from the reservoir assessment and management techniques and technologies of petroleum engineering. Especially modelling of all production stages, from the near wellbore in the reservoir, to the surface could be examined based on the know-how and developed tools of the petroleum industry.

  12. Geological study of Guafita field reservoirs, Apure basin, southwestern Venezuela

    Moya, E.; Abud, J.; Hernandez, J.


    The medium-grade oil reservoirs of the Guafita field, Apure basin, southwestern Venezuela, represent the northeastern extension of the La Yuca-Cano Limon fields of Colombia. A detailed integrated reservoir study is being carried out in Guafita in order to define the geological model and to improve its development plan. The stratigraphic sequence of interest in the southern block of the Guafita field contains approximately 600 ft of sediments of Cretaceous and Oligocene-Miocene ages (Quevedo Member of the Navay and Guafita Formations, respectively). Fifteen prospective intervals, with approximately 150 ft of net oil sand, have been defined within this sequence by detailed correlation in the Colombian fields and four have been defined in the Quevedo Member. Lower delta-plain and delta-front depositional environments have been recognized from core studies in the Tertiary sediments. A combination of both structural and stratigraphic traps controls the hydrocarbon accumulations in the Guafita field, and at least two sealing shale regional markers have been defined. As a preliminary result of the approach of defining reservoir geometry and mapping each major sand body separately, the proven reserves of the Guafita field will decrease by approximately 12%. The possibility of fluid communication with the Colombian fields through the small-displacement riddle faults was established by means of juxtaposition of sand bodies.

  13. PDVSA Petrolera Sinovensa reservoir engineering project and optimization study

    Campos, O. [PDVSA Petroleos de Venezuela SA, Caracas (Venezuela, Bolivarian Republic of). Petrolera Sinovensa; Patino, J. [Kizer Energy Inc., Katy, TX (United States); Chalifoux, G.V. [Petrospec Engineering Ltd., Edmonton, AB (Canada)


    This paper presented a development plan for an extra-heavy oil field in Venezuela's Orinoco belt involving cold heavy oil production (CHOP) as well as a thermal follow-up process to increase the ultimate recovery factor. A reservoir simulation model was used to model various reservoir formations in order to assess their oil recovery potential. Several thermal recovery processes were considered, such as steam assisted gravity drainage (SAGD), horizontal alternate steam drive (HASD), cyclic steam stimulation (CSS), horizontal continuous steam drive, and combined drive drainage (CDD). A geological static model and dynamic reservoir model were coupled for the well optimization evaluation. Production data were used to identify trends related to specific geological conditions. The study also examined methods of improving slotted liner designs and evaluated the use of electric heating as a means of improving CHOP performance. Results of the study showed that CDD offered the highest recovery rates as a follow-up to CHOP. The CDD process allowed for the use of existing wells drilled in the field. New horizontal wells will be placed between the existing wells. It was concluded that a CDD pilot should be implemented in order to prepare for a commercial implementation plan. 8 refs., 2 tabs., 14 figs.

  14. Daily reservoir sedimentation model: Case study from the Fena Valley Reservoir, Guam

    Marineau, Mathieu D.; Wright, Scott A.


    A model to compute reservoir sedimentation rates at daily timescales is presented. The model uses streamflow and sediment load data from nearby stream gauges to obtain an initial estimate of sediment yield for the reservoir’s watershed; it is then calibrated to the total deposition calculated from repeat bathymetric surveys. Long-term changes to reservoir trapping efficiency are also taken into account. The model was applied to the Fena Valley Reservoir, a water supply reservoir on the island of Guam. This reservoir became operational in 1951 and was recently surveyed in 2014. The model results show that the highest rate of deposition occurred during two typhoons (Typhoon Alice in 1953 and Typhoon Tingting in 2004); each storm decreased reservoir capacity by approximately 2–3% in only a few days. The presented model can be used to evaluate the impact of an extreme event, or it can be coupled with a watershed runoff model to evaluate potential impacts to storage capacity as a result of climate change or other hydrologic modifications.

  15. The continent ileal reservoir--an experimental study.

    Meijer, D W


    This thesis describes new concepts pertaining to the continent ileostomy. The aim of the study was twofold: to counter valve desinvagination and to simplify pouch construction. In Chapter 1 a survey is given of the history, the present situation of the technique and the complications of the continent ileostomy. It appears that on the one hand the operation improves the quality of the patient's life, but on the other hand the operation gives rise to many complications. The number of complications quoted in the literature varies and has been reported to be as high as 43%. Most of the time this led to repeat surgery, with equally uncertain results. This is the reason why the operation is not very frequently performed. Most of the time the complications concern the valve system and to a lesser degree the reservoir. In order to obtain a better insight into the origin of and possible gain better control over these complications an investigation was carried out on laboratory animals. This investigation involved: the complications of the valve system, the effect of the suturing method on the function of the reservoir and the simplification of the construction of the reservoir. In Chapter 2 the aim of the investigation was formulated in three questions. 1. Is it possible to diminish the chance of complications of the valve system of the continent ileostomy? 2. Does the method of suturing influence the function of the reservoir? 3. Is it possible to simplify the construction of the reservoir, so that the duration of the operation can be shortened? Chapter 3 is the general materials and methods section. Chapter 4 is about the research on the valve system. Up to now, no method of suturing the valve has consistently produced results good enough to make subsequent re-operations unnecessary. In this study two types of valve experiments have been carried out. First the feasibility of circumventing the problems of the nonpermanent form of the valve was investigated combining a

  16. Monitoring Reservoirs Using MERIS And LANDSAT Fused Images : A Case Study Of Polyfitos Reservoir - West Macedonia - Greece

    Stefouli, M.; Charou, E.; Vasileiou, E.; Stathopoulos, N.; Perrakis, A.


    Research and monitoring is essential to assess baseline conditions in reservoirs and their watershed and provide necessary information to guide decision-makers. Erosion and degradation of mountainous areas can lead to gradual aggradation of reservoirs reducing their lifetime. Collected measurements and observations have to be communicated to the managers of the reservoirs so as to achieve a common / comprehensive management of a large watershed and reservoir system. At this point Remote Sensing could help as the remotely sensed data are repeatedly and readily available to the end users. Aliakmon is the longest river in Greece, it's length is about 297 km and the surface of the river basin is 9.210 km2.The flow of the river starts from Northwest of Greece and ends in Thermaikos Gulf. The riverbed is not natural throughout the entire route, because constructed dams restrict water and create artificial lakes, such as lake of Polyfitos, that prevent flooding. This lake is used as reservoir, for covering irrigational water needs and the water is used to produce energy from the hydroelectric plant of Public Power Corporation-PPC. The catchment basin of Polyfitos' reservoir covers an area of 847.76 km2. Soil erosion - degradation in the mountainous watershed of streams of Polyfitos reservoir is taking place. It has been estimated that an annual volume of sediments reaching the reservoir is of the order of 244 m3. Geomatic based techniques are used in processing multiple data of the study area. A data inventory was formulated after the acquisition of topographic maps, compilation of geological and hydro-geological maps, compilation of digital elevation model for the area of interest based on satellite data and available maps. It also includes the acquisition of various hydro-meteorological data when available. On the basis of available maps and satellite data, digital elevation models are used in order to delineate the basic sub-catchments of the Polyfytos basin as well as

  17. Prediction of water temperature in stratified reservoir and effects on downstream irrigation area: A case study of Xiahushan reservoir

    Yang, Mengfei; Li, Lan; Li, Juan

    With increasing concern in environmental and ecological protection, more studies have focused on solving the problems caused by dam. Large reservoirs often release low-temperature water in spring and summer, which have adverse effects on downstream ecosystem. The 3-D Environmental Fluid Dynamics Code (EFDC) and 1-D longitudinal stream temperature model were used in this paper, to predict the water temperature in reservoir and canal and analyze the effects on irrigation area. The results indicate that the affected area is within a 55 km distance mainly in the period between April and June. Some management and engineering measures should be adopted to reduce the impact.

  18. Limnological study with reference to fish culture of Bothali (Mendha) reservoir, district - Gadchiroli (India).

    Tijare, Rajendra V


    Limnological study with reference to fish culture was carried out at Bothali (Mendha) reservoir, district Gadchiroli, India. Water samples from different sampling locations were collected and processed for physico-chemical analysis. The physico-chemical analysis revealed that the reservoir is favourable for fish culture as the phosphate content in water is moderate in amount. This reservoir can produce a good yield of fishes. Though the reservoir is presently exploited and is under pisciculture, a better treatment of the reservoir such as prevention of entry of organic matter, reduction of phosphate ion concentration to certain extent is necessary to obtain a maximum fish yield.

  19. Case Study of Volcanic Rock Reservoir--Beibao Area of Nanbao Sag

    Guo Qijun; Wan Zhimin; Jiao Shouquan; Liu Laixiang


    @@ Preface Crude has been produced from volcanic rock reservoirs inAmerica, Libya, Indonesia and Japan, according to the available data. Oil and gas Production from volcanic rock reservoirs in Japan accounts for 30% of the total, with the recoverable reserves estimated at 48% of the total. Oil and gas traps of volcanic rock reservoir with better reservoir properties and flow potential have been discovered in Liaohe, Erlian, Jizhong, Huanghua, Jiyang, Linqing,Jiangsu and Xinjiang of China since the 1970's. However,the systematic study of volcanic rock reservoir is just in the beginning.

  20. Reservoir Engineering Studies of Geopressured Geothermal Energy Resource

    Lee, Kun Sang [Kyonggi University, Suwon (Korea)


    Transient pressure analysis techniques were used to evaluate the performance of the Gladys McCall geopressured-geothermal reservoir which has been monitored and tested under U.S. Department of Energy geopressured -geothermal research program. Analysis of transient pressure data furnished a reservoir description such as the formation parameters, pore volume and shape of the reservoir, and average reservoir pressure. Results of pressure tests suggest that the Gladys McCall reservoir probably has a long narrow shape with the well located off-center. During both production and shut-in periods, pressure buildup tests indicated some degree of external pressure support. Aquifer recharging was believed to be the main source. An aquifer influx model was derived from a conceptual model of water leakage through a partially sealing fault into the reservoir under steady-state conditions. Moreover, a match of the pressure history required that the conductivity of the fault be a function of the pressure difference between the supporting aquifer and the reservoir. Results of analyses provided a quantitative evaluation of the reservoir and a better understanding of the reservoir energy drive mechanism. (author). 14 refs., 1 tab., 4 figs.

  1. Geochemical modeling of diagenetic reactions in Snorre Field reservoir sandstones: a comparative study of computer codes

    Marcos Antonio Klunk

    Full Text Available ABSTRACTDiagenetic reactions, characterized by the dissolution and precipitation of minerals at low temperatures, control the quality of sedimentary rocks as hydrocarbon reservoirs. Geochemical modeling, a tool used to understand diagenetic processes, is performed through computer codes based on thermodynamic and kinetic parameters. In a comparative study, we reproduced the diagenetic reactions observed in Snorre Field reservoir sandstones, Norwegian North Sea. These reactions had been previously modeled in the literature using DISSOL-THERMAL code. In this study, we modeled the diagenetic reactions in the reservoirs using Geochemist's Workbench (GWB and TOUGHREACT software, based on a convective-diffusive-reactive model and on the thermodynamic and kinetic parameters compiled for each reaction. TOUGHREACT and DISSOL-THERMAL modeling showed dissolution of quartz, K-feldspar and plagioclase in a similar temperature range from 25 to 80°C. In contrast, GWB modeling showed dissolution of albite, plagioclase and illite, as well as precipitation of quartz, K-feldspar and kaolinite in the same temperature range. The modeling generated by the different software for temperatures of 100, 120 and 140°C showed similarly the dissolution of quartz, K-feldspar, plagioclase and kaolinite, but differed in the precipitation of albite and illite. At temperatures of 150 and 160°C, GWB and TOUGHREACT produced different results from the DISSOL-THERMAL, except for the dissolution of quartz, plagioclase and kaolinite. The comparative study allows choosing the numerical modeling software whose results are closer to the diagenetic reactions observed in the petrographic analysis of the modeled reservoirs.

  2. Crosswell electromagnetic imaging for geothermal reservoir characterization - a feasibility study

    Samrock, Friedemann; Saar, Martin O.


    Most regions in the world do not have ready access to natural convective hydrothermal resources. To use deep geothermal heat as a viable energy resource in low-permeability formations, permeable fracture networks have to be created artificially to enable deep fluid circulation for advective heat transport to a production well. Such generation of enhanced geothermal systems (EGS) is studied in the "Deep Underground Geothermal (DUG)" laboratory at the Grimsel pass, Switzerland. Here, an underground experiment is conducted by hydraulically stimulating a pre-existing shear zone within crystalline rock. The objectives of this project are to better describe and understand the processes acting during reservoir generation. We perform a feasibility study to evaluate the capability of low-frequency crosswell electromagnetic (EM) tomography for mapping of stimulation-induced changes in electrical conductivity. First numerical results show that crosswell EM data are generally sensitive to the inter-well conductivity distribution, which is affected by properties such as interconnected porosity, permeability and the presence of fluids. It thereby provides important information for characterization of potential EGS reservoirs. We present a 3-D forward modeling and inversion study using synthetic data and under realistic conditions, these include the true borehole spacing and the observed electromagnetic noise level in the DUG laboratory. Based on these results we discuss the system requirements and the capability of crosswell EM to recover the inter-well structure and stimulation-induced changes. Besides the numerical study we report on the current status of instrumentation and realization of crosswell EM measurements at the DUG laboratory.

  3. Operational resilience of reservoirs to climate change, agricultural demand, and tourism: A case study from Sardinia.

    Mereu, Simone; Sušnik, Janez; Trabucco, Antonio; Daccache, Andre; Vamvakeridou-Lyroudia, Lydia; Renoldi, Stefano; Virdis, Andrea; Savić, Dragan; Assimacopoulos, Dionysis


    Many (semi-) arid locations globally, and particularly islands, rely heavily on reservoirs for water supply. Some reservoirs are particularly vulnerable to climate and development changes (e.g. population change, tourist growth, hydropower demands). Irregularities and uncertainties in the fluvial regime associated with climate change and the continuous increase in water demand by different sectors will add new challenges to the management and to the resilience of these reservoirs. The resilience of vulnerable reservoirs must be studied in detail to prepare for and mitigate potential impacts of these changes. In this paper, a reservoir balance model is developed and presented for the Pedra e' Othoni reservoir in Sardinia, Italy, to assess resilience to climate and development changes. The model was first calibrated and validated, then forced with extensive ensemble climate data for representative concentration pathways (RCPs) 4.5 and 8.5, agricultural data, and with four socio-economic development scenarios. Future projections show a reduction in annual reservoir inflow and an increase in demand, mainly in the agricultural sector. Under no scenario is reservoir resilience significantly affected, the reservoir always achieves refill. However, this occurs at the partial expenses of hydropower production with implications for the production of renewable energy. There is also the possibility of conflict between the agricultural sector and hydropower sector for diminishing water supply. Pedra e' Othoni reservoir shows good resilience to future change mostly because of the disproportionately large basin feeding it. However this is not the case of other Sardinian reservoirs and hence a detailed resilience assessment of all reservoirs is needed, where development plans should carefully account for the trade-offs and potential conflicts among sectors. For Sardinia, the option of physical connection between reservoirs is available, as are alternative water supply measures

  4. Modeling Study of High Pressure and High Temperature Reservoir Fluids

    Varzandeh, Farhad

    to 250 °C and 2400 bar, in the deep petroleum reservoirs. Furthermore, many of these deep reservoirs are found offshore, including the North Sea and the Gulf of Mexico, making the development even more risky. On the other hand, development of these high pressure high temperature (HPHT) fields can...

  5. Twenty years of water-quality studies in the Cheney Reservoir Watershed, Kansas, 1996-2016

    Graham, Jennifer L.; Foster, Guy M.; Kramer, Ariele R.


    Since 1996, the U.S. Geological Survey (USGS), in cooperation with the City of Wichita, has done studies in the Cheney Reservoir watershed to understand environmental effects on water-quality conditions. Early studies (1996–2001) determined subwatershed sources of contaminants, nutrient and sediment loading to Cheney Reservoir, changes in reservoir sediment quality over time, and watershed sources of phosphorus. Later studies (2001–present) focused on nutrient and sediment concentrations and mass transport from the watershed; the presence of cyanobacteria, cyanotoxins, and taste-and-odor compounds in the reservoir; and development of regression models for real-time computations of water-quality constituents of interest that may affect drinking-water treatment. This fact sheet summarizes key results from studies done by the USGS during 1996–2016 in the Cheney Reservoir watershed and Cheney Reservoir.

  6. Statistical study of seismicity associated with geothermal reservoirs in California

    Hadley, D.M.; Cavit, D.S.


    Statistical methods are outlined to separate spatially, temporally, and magnitude-dependent portions of both the random and non-random components of the seismicity. The methodology employed compares the seismicity distributions with a generalized Poisson distribution. Temporally related events are identified by the distribution of the interoccurrence times. The regions studied to date include the Imperial Valley, Coso, The Geysers, Lassen, and the San Jacinto fault. The spatial characteristics of the random and clustered components of the seismicity are diffuse and appear unsuitable for defining the areal extent of the reservoir. However, from the temporal characteristics of the seismicity associated with these regions a general discriminant was constructed that combines several physical parameters for identifying the presence of a geothermal system.

  7. Reservoir simulation and geochemical study of Cerro Prieto I wells

    Lippmann, M.J. (Lawrence Berkeley Lab., CA (USA)); Truesdell, A.H. (Geological Survey, Menlo Park, CA (USA))


    Combined reservoir simulation and geochemical data analysis are used to investigate the effects of recharge and other reservoir processes occurring in the western part of the Cerro Prieto, Mexico, geothermal field (i.e., Cerro Prieto I area). Enthalpy-based temperatures and bottomhole temperatures are calculated based on simplified models of the system, considering different reservoir boundary conditions and zones of contrasting initial temperatures and reservoir properties. By matching the computed trends with geothermometer-based temperature and enthalpy histories of producing wells, the main processes active in the western area of Cerro Prieto are identified. This part of the geothermal system is strongly influenced by nearby groundwater aquifers; cooler waters readily recharge the reservoirs. In response to exploitation, the natural influx of cold water into the shallower alpha reservoir is mainly from the west and down Fault L, while the recharge to the deeper beta reservoir in this part of the field, seems to be only lateral, from the west and possibly south. 11 refs., 12 figs.

  8. study of ichtyofauna of daberam reservoir, katsina state 172


    increasing human population in developing countries .... practices in village ponds and reservoirs also affected ... Length-weight relationship and diet ... Pauly D, and Gayanilo Jr. FC (1997). A Bee: An alternative approach to estimating the.

  9. Study on the Relationship between Chlorophyll-a and Environmental Impact Factors in Deep Reservoir in Karst Areas——Taking Aha Reservoir for Example


    [Objective] The aim was to study the relationship between chlorophyll-a and environmental impact factors in deep reservoir in Karst Areas.[Method] Taking Aha Reservoir for example,the changes of chlorophyll-a content and its relationship with environmental impact factors were researched,and the water quality of Aha Reservoir was assessed by means of modified Carlson trophic state index.[Result] Chlorophyll-a content in Aha Reservoir was higher in March,April,May and September and lower from June to August,a...

  10. Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

    Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.


    This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release with unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway

  11. Integrated seismic studies at the Rye Patch Geothermal Reservoir, Nevada

    Gritto, Roland; Daley, Thomas M.; Majer, Ernest L.


    A 3-D surface seismic reflection survey, covering an area of over 3 square miles, was conducted at the Rye Patch geothermal reservoir (Nevada) to explore the structural features that may control geothermal production in the area. In addition to the surface sources and receivers, a high-temperature three-component seismometer was deployed in a borehole at a depth of 3900 ft within the basement below the reservoir, which recorded the waves generated by all surface sources. A total of 1959 first-arrival travel times were determined out of 2134 possible traces. Two-dimensional ray tracing was performed to simulate wave propagation from the surface sources to the receiver at depth. Travel time differences between observed and calculated times were mapped to topographic changes in the elevation of the interface between the carbonate basement and the sedimentary and volcanic unit above. Results indicate the presence of two dominant geologic features. The first confirms the regional trend of the geologic units in the Basin and Range province with a north-south strike and dip to the west, as expected for normal faulting encountered in an extensional regime. The second is a local disturbance of this regional pattern in form of an elevation of the interface between the carbonate basement and the overlying sedimentary sequence, striking east-west. The geometry of the structure is corroborated by results from a seismic-reflection survey, and by results of tomographic studies conducted as part of the seismic survey. Seismic waves, generated from far-offset shots during the 3-D surface survey, exhibit a sudden decrease in amplitudes while propagating across the boundaries of the elevation high. This apparent boundary correlates spatially with the location of the Rye Patch fault as interpreted from the 3-D seismic reflection data. Finite-difference modeling of elastic wave propagation is performed to estimate the structural parameters of the fault. Questions to be answered are

  12. Geological and Geochemical Studies of Heavy Oil Reservoirs in China

    胡见义; 徐树宝; 等


    Thickened heavy oils in China are genetically characteristic of continenta .As to their physico-chemical properties,these oils are very high in viscosity and low in sulphur and trace element con-tents.In the group constituents,the concentrations of non-hydrocarbons and asphaltene are very high but those of saturated hydrocarbons and aromatics are very low.The gas chromatograms of alkanes show that these heavy oils have high abundances of iso-alkanes and cyclic hydrocarbons.In all the steroids and terpenoids ,bicyclic sesquiterpenoids,tricyclic diterpenoids,re-arranged steranes and gammacerane are strongly bildegradation-resistent.The formation of heavy oil reservoirs is controlled mainly by late basin ascendance,biodegradation,flushing by meteoric water and oxidation in the oil-bearing formations.Ac-cording to their formation mechanisms,heavy oil reservoirs can be classified as four categories:weathering and denudation,marginal oxidation,secondary migration and thickening of bottom water .Spacially,heavy thick oil reservoirs are distributed regularly:they usually show some paragenetic relationships with normal oil reservoirs.Heavy oil reservoirs often occur in structural highs or in overlying younger strata.Their burial depth is about 200m.Horizontally,most of them are distributed on the margins of basins or depressions.

  13. Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

    Shams, Bilal; Yao, Jun; Zhang, Kai; Zhang, Lei


    Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulation-condensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources. In gas injection, the flooding pattern, injection timing and injection duration are key parameters to study an efficient EOR scenario in order to recover lost condensate. This work contains sensitivity analysis on different parameters to generate an accurate investigation about the effects on performance of different injection scenarios in homogeneous gas condensate system. In this paper, starting time of gas cycling and injection period are the parameters used to influence condensate recovery of a five-spot well pattern which has an injection pressure constraint of 3000 psi and production wells are constraint at 500 psi min. BHP. Starting injection times of 1 month, 4 months and 9 months after natural depletion areapplied in the first study. The second study is conducted by varying injection duration. Three durations are selected: 100 days, 400 days and 900 days. In miscible gas injection, miscibility and vaporization of condensate by injected gas is more efficient mechanism for condensate recovery. From this study, it is proven that the application of gas cycling on five-spot well pattern greatly enhances condensate recovery

  14. Study of Deep Carbonate Reservoirs in the Desert Areas by Transient Electromagnetic Method

    HeZhanxiang; LiuZebin; SongQunhui; gangXianghao; LuJiangnan


    In 1997, the TZ- 162 well in Tazhong area of the Tarim basin hit the lower Paleozoic dolomite reservoir at a depth of 5,900 m. The distribution of the dolomite reservoir, however,was very difficult to delineate due to the complex surface conditions and poor seismic properties. High-precision transient electromagnetic sounding (TEM) was conducted and good results obtained in this area. This paper discussed the principle,data processing and interpretation of this method. The resultsof studying the dolomite reservoirs demonstrated the effectiveness of the method in studying the low-resistance dolomite reservoirs in the high-resistance carbonates. This method should be an effective one to study reservoirs in areas with similar physical properties as well.

  15. Integrating sequence stratigraphy and seismic attributes for quantitative reservoir characterization: A case study of a Pliocene reservoir, Campeche Sound, Mexico

    Mendez-Hernandez, Efrain

    An integrated workflow including analysis of seismic, core, well log and biostratigraphic data was developed and conducted to both construct a reliable geologic model and characterize a Pliocene gas reservoir which overlies the Cantarell field in the Campeche Sound, southern Gulf of Mexico. In 2003, the offshore exploratory Utan #1 well was drilled to investigate the gas potential of the Pliocene sequence. The well provided successful results from facies characterized by thin mixed siliciclastic-carbonate beds contained within a faulted rollover anticline. Campeche Sound is the most prolific Mexican oil producing province where the best fields are Mesozoic-Paleocene carbonates in structural traps. Therefore, little exploration has been focused on the overlying late Tertiary and more siliciclastic section, representing a gap in the knowledge of this part of the basin where new expectations arise for non-associated gas entrapments in a traditionally oil-producing province. Based upon development of a sequence stratigraphic framework, a new play analysis is developed where the reservoirs are identified as retrogradational shoreface parasequences sitting atop third-order sequence boundaries. Basic and advanced seismic attributes contribute to the stratigraphic interpretation and gas detection. Seismic inversion for reflectivity allowed better identification of key stratigraphic surfaces. Modeled Type-I AVO and a dimmed spectral decomposition response following structural contours provide reliability to gas discrimination and reservoir delineation. The seismic attributes will require additional support to be valuable as reservoir quality predictors. Because biogenic methane and thin sheet reservoirs define the rock-fluid system, development may be uneconomic. However, the trapped gas could be reinjected at deeper depths to improve recovery efficiency of oil in the Cantarell field. The knowledge gained from this research is an important contribution to the petroleum

  16. Full Waveform Inversion for Reservoir Characterization - A Synthetic Study

    Zabihi Naeini, E.


    Most current reservoir-characterization workflows are based on classic amplitude-variation-with-offset (AVO) inversion techniques. Although these methods have generally served us well over the years, here we examine full-waveform inversion (FWI) as an alternative tool for higher-resolution reservoir characterization. An important step in developing reservoir-oriented FWI is the implementation of facies-based rock physics constraints adapted from the classic methods. We show that such constraints can be incorporated into FWI by adding appropriately designed regularization terms to the objective function. The advantages of the proposed algorithm are demonstrated on both isotropic and VTI (transversely isotropic with a vertical symmetry axis) models with pronounced lateral and vertical heterogeneity. The inversion results are explained using the theoretical radiation patterns produced by perturbations in the medium parameters.


    XUE Yang; XU Wei-lin; LUO Shu-jing; CHEN Hua-yong; LI Nai-wen; XU Ling-jun


    Dam break can cause a significant disaster in the downstream,especially,in a valley with cascade reservoirs,which would aggravate the disaster extent.The experimental studies of the dam-break flow of cascade reservoirs are few and far between at the present.Most of related studies concern the failure of a single dam..This article presents an experimental study of the characteristics of an instantly filled dam-break flow of cascade reservoirs in a rectangular glass flume with a steep bottom slope.A new method was used to simulate the sudden collapse of the dam.A series of sensors for automatic water-levels were deployed to record the rapid water depth fluctuation.The experimental results show that,the ratio of the initial water depth of the downstream reservoir to that of the upstream reservoir would greatly affect the flood peak water depth in the downstream reservoir area and in the stream channel behind the downstream dam,while the influence of the dam spacing is insignificant.In addition,the comparison between the single reservoir and the cascade reservoirs shows some difference in the dam-break flow pattern and the stage hydrograph at the corresponding gauging points.

  18. Studies Regarding the Safety in Operation of Ezer Reservoir

    Balan Isabela


    Full Text Available The dam of the non-permanent reservoir Ezer, located on Jijia river is an earth dam with a maximum height of 6.18 m, which provides a global retention to the canopy of 10.330 million cubic meters. The dam founded on weak, muddy soils suffered in the years 1989 and 1992 downstream slope failures of the fillings. It was found that hydrostatic levels were high in the piezometric wells and that consolidation of the foundation soil was reduced. This paper presents a brief history of the dam and aspects regarding the behaviour monitoring of Ezer non-permanent reservoir during the years 2000-2012.

  19. Water residence time affecting phytoplankton blooms: study case in Ibitinga Reservoir (São Paulo, Brazil) using Landsat/TM images.

    Londe, L R; Novo, E M L M; Barbosa, C; Araujo, C A S


    Satellite images are an effective tool for the detection of phytoplankton blooms, since they cause striking changes in water color. Bloom intensity can be expressed in terms of chlorophyll-a concentration. Previous studies suggest the use of Landsat TM4/TM3 reflectance ratio to retrieve surface chlorophyll-a concentration from aquatic systems. In this study we assumed that a remote sensing trophic state index can be applied to investigate how changes in HRT along the hydrologic year affect the spatial distribution of the phytoplankton blooms at Ibitinga's reservoir surface. For that, we formulated two objectives: (1) apply a semi-empirical model which uses this reflectance ratio to map chlorophyll-a concentration at Ibitinga reservoir along the 2005 hydrologic year and (2) assess how changes in hydraulic residence time (HRT) affect the spatial distribution of phytoplankton blooms at Ibitinga Reservoir. The study site was chosen because previous studies reported seasonal changes in the reservoir limnology which might be related to the reservoir seasonality and hydrodynamics. Six Landsat/TM images were acquired over Ibitinga reservoir during 2005 and water flow measurements provided by the Brazilian Electric System National Operator - ONS were used to compute the reservoir´s residence time, which varied from 5.37 to 52.39 days during 2005. The HRT in the date of image acquisition was then compared to the distribution of chlorophyll-a in the reservoir. The results showed that the HRT increasing implies the increasing of the reservoir surface occupied by phytoplankton blooms.


    Mirosław Wiatkowski


    Full Text Available The paper presents an analysis of water quality of the small Michalice reservoir. A preliminary assessment of the reservoir water quality and its usability was made. The quality of water in the reservoir is particularly important as the main functions of the reservoir are agricultural irrigation, recreation and flood protection . The following physico-chemical parameters of the Widawa River were analyzed: NO3 -, NO2 -, NH4 +, PO4 3-, COD, water temperature, pH and electrolytic conductivity. Main descriptive statistical data were presented for the analyzed water quality indicators. The research results indicate that the reservoir contributed to the reduced concentrations of the following water quality indicators: nitrates, nitrites, phosphates, electrolytic conductivity and COD (in the outflowing water – St.3 in comparison to the water flowing into the reservoir – St.1. In the water flowing out of the Psurów reservoir higher values of the remaining indicators were observed if compared with the inflowing water. It was stated, as well, that analised waters are not vulnerable to nitrogen compounds pollution coming from the agricultural sources and are eutrophic. For purpose obtaining of the précised information about condition of Michalice reservoir water purity as well as river Widawa it becomes to continue the hydrological monitoring and water quality studies.

  1. Interdisciplinary study of reservoir compartments and heterogeneity. Final report, October 1, 1993--December 31, 1996

    Van Kirk, C.


    A case study approach using Terry Sandstone production from the Hambert-Aristocrat Field, Weld County, Colorado was used to document the process of integration. One specific project goal is to demonstrate how a multidisciplinary approach can be used to detect reservoir compartmentalization and improve reserve estimates. The final project goal is to derive a general strategy for integration for independent operators. Teamwork is the norm for the petroleum industry where teams of geologists, geophysicists, and petroleum engineers work together to improve profits through a better understanding of reservoir size, compartmentalization, and orientation as well as reservoir flow characteristics. In this manner, integration of data narrows the uncertainty in reserve estimates and enhances reservoir management decisions. The process of integration has proven to be iterative. Integration has helped identify reservoir compartmentalization and reduce the uncertainty in the reserve estimates. This research report documents specific examples of integration and the economic benefits of integration.

  2. The impact of previous traumatic brain injury on health and functioning: a TRACK-TBI study.

    Dams-O'Connor, Kristen; Spielman, Lisa; Singh, Ayushi; Gordon, Wayne A; Lingsma, Hester F; Maas, Andrew I R; Manley, Geoffrey T; Mukherjee, Pratik; Okonkwo, David O; Puccio, Ava M; Schnyer, David M; Valadka, Alex B; Yue, John K; Yuh, Esther L


    The idea that multiple traumatic brain injury (TBI) can have a cumulative detrimental effect on functioning is widely accepted. Most research supporting this idea comes from athlete samples, and it is not known whether remote history of previous TBI affects functioning after subsequent TBI in community-based samples. This study investigates whether a previous history of TBI with loss of consciousness (LOC) is associated with worse health and functioning in a sample of individuals who require emergency department care for current TBI. Twenty-three percent of the 586 individuals with current TBI in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study reported having sustained a previous TBI with LOC. Individuals with previous TBI were more likely to be unemployed (χ(2)=17.86; p=0.000), report a variety of chronic medical and psychiatric conditions (4.75≤χ(2)≥24.16; pTBI history. Those with a previous TBI had less-severe acute injuries, but experienced worse outcomes at 6-month follow-up. Results of a series of regression analyses controlling for demographics and acute injury severity indicated that individuals with previous TBI reported more mood symptoms, more postconcussive symptoms, lower life satisfaction, and had slower processing speed and poorer verbal learning, compared to those with no previous TBI history. These findings suggest that history of TBI with LOC may have important implications for health and psychological functioning after TBI in community-based samples.

  3. Matched cohort study of external cephalic version in women with previous cesarean delivery.

    Keepanasseril, Anish; Anand, Keerthana; Soundara Raghavan, Subrahmanian


    To evaluate the efficacy and safety of external cephalic version (ECV) among women with previous cesarean delivery. A retrospective study was conducted using data for women with previous cesarean delivery and breech presentation who underwent ECV at or after 36 weeks of pregnancy during 2011-2016. For every case, two multiparous women without previous cesarean delivery who underwent ECV and were matched for age and pregnancy duration were included. Characteristics and outcomes were compared between groups. ECV was successful for 32 (84.2%) of 38 women with previous cesarean delivery and 62 (81.6%) in the control group (P=0.728). Multivariate regression analysis confirmed that previous cesarean was not associated with ECV success (odds ratio 1.89, 95% confidence interval 0.19-18.47; P=0.244). Successful vaginal delivery after successful ECV was reported for 19 (59.4%) women in the previous cesarean delivery group and 52 (83.9%) in the control group (Pcesarean delivery. To avoid a repeat cesarean delivery, ECV can be offered to women with breech presentation and previous cesarean delivery who are otherwise eligible for a trial of labor. © 2017 International Federation of Gynecology and Obstetrics.


    Maria Denisa Conete


    Full Text Available The author conducted an ornithological study in the Bascov Reservoir area (a square of 2x2 km and observed 102 breeding species; 83 (81% of them are certain breeding species and 19 (19% are probable breeding species. The results of the research were cumulated with those found in the Atlas of the breeding species of Romania. By relating them with the Atlas data, we noted that 83 of the 100 breeding species cited in the Atlas were again recorded during our study. Nineteen new breeding species were identified. Among the species dependent on wetlands, mention should be made of Ixobrychus minutus, Anas platyrhynchos, Fulica atra, Gallinula chloropus, Aythya ferina, etc., with relatively large numbers of individuals. The analysis showed a relatively larger number (66 of euconstant and constant species, which confirmed the wealth of food resources in the area during the nesting period. The specific richness on the Bascov Lake is represented by 119 species, a number that is consistent with the availability of the food resources and nesting places, as well as the somewhat fluctuating presence of predators (stray dogs, and the anthropocentric disturbance (sound and chemical pollution, etc.. The yearly increase in the number of reed clusters, the expansion of the surface of the islets, the emergence of bushes and trees, the ageing of the existing trees have led to a certain yearly increase in the number of breeding individuals in 45 species. But the anthropogenic influence in the area has eventually contributed to a decrease in the number of birds, both as a number of species and as a number of individuals. The study has also shown that in the farmland bird species the number of individuals is in decline. Most of the breeding species - 75 (representing 74% in the area under research are migratory. Eighteen breeding species (17.64% are listed in Annex I of the Birds Directive. The presence of the key breeding species in the area under research must be

  5. Using ensemble streamflow prediction in the reservoir operation during drought by implicit and explicit stochastic optimization: case study in Shihmen Reservoir

    Chou, Kuan-wen; Jiing-Yun You, Gene; Jang, Jiun-Huei


    One of the important goals of water resource management is the establishment of realistic reservoir operating policies for water allocation, especially during periods of drought. In the context of short-term (a few months) water management such as drought, we need to predict the future inflow and allocate current and future water resource to avoid severe economic loss. Because the future flow condition in uncertain, applying the stochastic optimization technique is common in guide reservoir operation. This study is trying to use the ensemble streamflow prediction (ESP) in reservoir operation during drought. We develop reservoir operation model based on two stochastic optimization frameworks, the explicit stochastic optimization (ESO) or implicit stochastic optimization (ISO). Because the forecast is updated time by time, the rolling process is adapted, the decision process is ''rolled over'' every periods and extended into the future. This study use Shihmen Reservoir as a case study. The ensemble streamflow prediction is produced and provided by National Science and Technology Center for Disaster Reduction (NCDR). Not only expect to provide an appropriate framework in integrating streamflow forecast a reservoir operation during drought, we also aim to compare the ISO and ESO to identify their advantages and disadvantages. As a result, the streamflow forecast can directly contribute, rather than just be kept in mind, in the reservoir operation during drought period.


    Ren Dong-mei; Zhang Lie-hui; Zhu Shui-qiao


    Coalbed methane is an unconventional gas resource and its special storage and migration laws need a series of evaluations and predictions. By analyzing the flowing characteristics of coalbed methane reservoir and using the known results for the dynamic prediction of natural gas reservoir, a three-dimensional mathematical model for the two-phase flow in coalbed methane reservoir was established. In this model the Langmuir isothermal adsorption law, the first Fick law and the second Fick law were applied to consider the absorption and diffusion of coalbed methane. The governing equations were discretized in a finite-difference form, and a full-implicit simulator (CBM-GW3D) for three-dimensional two-phase flow was developed. The field data of coalbed methane wells located at Liupanshui, Guizhou was used to verify the reliability of this model. This paper also presented the result of the sensitivity analysis for some factors. And this result proved the reliability and validity of this model.

  7. [Preliminary study on the changes of bacterial community structure in Qingcaosha Reservoir during water storage period].

    Peng, Qing; Xie, Bing; Yuan, Qi; Huang, Zhi-Ting; Cui, Lu-Lu; Wang, Wen-Ting


    In order to investigate the changes in water quality and the bacterial community structure in Qingcaosha Reservoir during water storage and supply period, the microorganisms in water body were studied by microbial culture counting and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DEEG) technique. Results showed that the water quality had been improved significantly and the nitrogen and phosphorus concentrations significantly reduced after the Yangtze River water flowed into the reservoir. The number of culturable microorganisms in the influent and the reservoir changed with the seasons, and there were more microorganisms in the influent than these in the reservoir during spring and summer, and fewer in autumn and winter, and the precipitation of suspended microorganisms in the water caused the increase of organic matter content in the sediment. PCR-DGGE results showed that bacterial community structure in the reservoir changed with the seasons, and the microbial community diversity was the highest in summer and the lowest in autumn. The cluster analysis showed that the similarity of microbial community structure of water and sediment samples was 62% , which might be due to the contribution of the precipitation of the suspended microorganisms. The dominant microbial species in water had high similarity with alpha, beta-Proteobacteria, Flavobacterium, Rheinheimera, Prochlorococcus, Synechococcus and Marine metagenome, indicating that Qingcaosha Reservoir faced the risk of algae bloom and seawater intrusion. The results provide the fundamental understanding on reservoir operation and can be used as reference for future studies.

  8. Environmental and Water Quality Operational Studies. Physical Modeling of Reservoir Hydrodynamics.


    reservoir flume (re- ferred to as the General Reservoir Hydrodynamic ( GRH ) Facility) located in the Hydraulics Laboratory of WES. In this case, the GRH was...their study. 49. GRH simulation. Data from the WES Generalized Reservoir Hydrodynamic ( GRH ) Facility was used as the prototype to make the second model...prototype comparison. The GRH is 80.0 ft long and 2.85 ft wide with a maximum depth of 3.0 ft. Details of the GRH are provided in Figure 6. 44 2.85 FT

  9. Trophic State Evolution and Nutrient Trapping Capacity in a Transboundary Subtropical Reservoir: A 25-Year Study

    Cunha, Davi Gasparini Fernandes; Benassi, Simone Frederigi; de Falco, Patrícia Bortoletto; do Carmo Calijuri, Maria


    Artificial reservoirs have been used for drinking water supply, other human activities, flood control and pollution abatement worldwide, providing overall benefits to downstream water quality. Most reservoirs in Brazil were built during the 1970s, but their long-term patterns of trophic status, water chemistry, and nutrient removal are still not very well characterized. We aimed to evaluate water quality time series (1985-2010) data from the riverine and lacustrine zones of the transboundary Itaipu Reservoir (Brazil/Paraguay). We examined total phosphorus and nitrogen, chlorophyll a concentrations, water transparency, and phytoplankton density to look for spatial and temporal trends and correlations with trophic state evolution and nutrient retention. There was significant temporal and spatial water quality variation ( P chlorophyll a concentrations tended to be lower in the lacustrine zone and decreased over the 25-year timeframe. Reservoir operational features seemed to be limiting primary production and phytoplankton development, which exhibited a maximum density of 6050 org/mL. The relatively small nutrient concentrations in the riverine zone were probably related to the effect of the cascade reservoirs upstream of Itaipu and led to relatively low removal percentages. Our study suggested that water quality problems may be more pronounced immediately after the filling phase of the artificial reservoirs, associated with the initial decomposition of drowned vegetation at the very beginning of reservoir operation.

  10. Vortices in dam reservoir: A case study of Karun III dam

    Maryam Azarpira; Hamed Sarkardeh; Sasan Tavakkol; Reza Roshan; Hossein Bakhshi


    The present study focuses on the effect of vortex formation on plane velocities in a reservoir. Velocity measurements are performed in the hydraulic model of Karun III dam and hydropower plant. Different vortices were produced at the horizontal intake by changing the submerged depth. Tangential velocities were measured on a rectangular mesh in the reservoir. The results were then processed to plot the contour lines of the plane velocities and study the effect of vortex formation on the flow condition in the reservoir. Contour lines in different submerged depths show that circulation zones are formed in different potential locations over the intakes causing vortex formation. These results were correlated with the location of the appearing vortices observed in the experiments. Experimental data of this study could be useful for numerical modelling of vortex in the reservoirs.

  11. Developing Reading Comprehension through Metacognitive Strategies: A Review of Previous Studies

    Channa, Mansoor Ahmed; Nordin, Zaimuariffudin Shukri; Siming, Insaf Ali; Chandio, Ali Asgher; Koondher, Mansoor Ali


    This paper has reviewed the previous studies on metacognitive strategies based on planning, monitoring, and evaluating in order to develop reading comprehension. The main purpose of this review in metacognition, and reading domain is to help readers to enhance their capabilities and power reading through these strategies. The researchers reviewed…

  12. A study of stress change and fault slip in producing gas reservoirs overlain by elastic and viscoelastic caprocks

    Orlic, B.; Wassing, B.B.T.


    Geomechanical simulations were conducted to study the effects of reservoir depletion on the stability of internal and boundary faults in gas reservoirs overlain by elastic and viscoelastic salt caprocks. The numerical models were of a disk-shaped gas reservoir with idealized geometry; they mimic the

  13. Study of Controll over Karstification of Buried Carbonate Hill Reservoir in Renqiu Oilfield

    于俊吉; 韩宝平; 罗承建


    Based on boreholes and dynamic development data, the control over karstification of buried carbonate hill reservoir in Renqiu oil field was studied. The result shows that 1) Karstific caves, fissures, and pores in dolomite of Wumishan Formation are the most important reservoir voids, 2) the barrier of argillaceous dolomite can result in the existence of residual oil areas under oil-water interface, and 3) the mosores located on the surface of buried hill are also potential areas of residual oil.

  14. Evaluation of climate change impact on Blue Nile Basin Cascade Reservoir operation – case study of proposed reservoirs in the Main Blue Nile River Basin, Ethiopia


    This study mainly deals with evaluation of climate change impact on operation of the Blue Nile Basin Cascade Reservoir. To evaluate the impact of climate change, climate change scenarios of evapotranspiration and precipitation were developed for three periods. Output of ECHAM5 with RCM for the A1B emissions scenario were used to develop the future climate change scenarios. A hydrological model, HEC-HMS, was used to simulate current and future inflow volume to the reservoirs. The projected fut...

  15. Study on the enhancement of hydrocarbon recovery by characterization of the reservoir

    Jeong, Tae-Jin; Kwak, Young-Hoon; Huh, Dae-Gee [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)


    The reservoir geochemistry is to understand the origin of these heterogeneities and distributions of the bitumens within the reservoir and to use them not only for exploration but for the development of the petroleums. Methods and principles of the reservoir geochemistry, which are applicable to the petroleum exploration and development, are reviewed in the study. In addition, a case study was carried out on the gas, condensate, water and bitumen samples in the reservoir, taken from the Haenam, Pohang areas and the Ulleung Basin offshore Korea. Mineral geothermometers were studied to estimate the thermal history in sedimentary basins and successfully applied to the Korean onshore and offshore basins. The opal silica-to-quartz transformation was investigated in the Pohang basin as a geothermometer. In Korean basins, the smectite-to-illite changes indicate that smectite and illite can act as the geothermometer to estimate the thermal history of the basins. The albitization reaction was also considered as a temperature indicator. Naturally fractured reservoir is an important source of oil and gas throughout the world. The properties of matrix and fracture are the key parameters in predicting the performances of naturally fractured reservoirs. A new laboratory equipment has been designed and constructed by pressure pulse method to determine the properties, which are (1) the porosity of matrix, (2) the permeability of matrix, (3) the effective width of the fractures, and the permeability of the fractures. (author). 97 refs.

  16. Study on the enhancement of hydrocarbon recovery by characterization of the reservoir

    Jeong, Tae-Jin; Kwak, Young-Hoon; Huh, Dae-Gee [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)


    The reservoir geochemistry is to understand the origin of these heterogeneities and distributions of the bitumens within the reservoir and to use them not only for exploration but for the development of the petroleums. Methods and principles of the reservoir geochemistry, which are applicable to the petroleum exploration and development, are reviewed in the study. In addition, a case study was carried out on the gas, condensate, water and bitumen samples in the reservoir, taken from the Haenam, Pohang areas and the Ulleung Basin offshore Korea. Mineral geothermometers were studied to estimate the thermal history in sedimentary basins and successfully applied to the Korean onshore and offshore basins. The opal silica-to-quartz transformation was investigated in the Pohang basin as a geothermometer. In Korean basins, the smectite-to-illite changes indicate that smectite and illite can act as the geothermometer to estimate the thermal history of the basins. The albitization reaction was also considered as a temperature indicator. Naturally fractured reservoir is an important source of oil and gas throughout the world. The properties of matrix and fracture are the key parameters in predicting the performances of naturally fractured reservoirs. A new laboratory equipment has been designed and constructed by pressure pulse method to determine the properties, which are (1) the porosity of matrix, (2) the permeability of matrix, (3) the effective width of the fractures, and the permeability of the fractures. (author). 97 refs.


    Alexandra M. Kuznetsova


    Full Text Available The paper describes the study of wind-wave regime at the Gorky reservoir. A series of field experiments (carried out from May to October in 2012–2015 showed that the values of the drag coefficient CD for a middle-sized reservoir in the range of moderate and strong winds are approximately 50 % lower than its values typical of the ocean conditions. The obtained parameterization of CD was implemented in the wave model WAVEWATCH III to receive the correct wave forecasts for a middle-sized reservoir. Statistical distribution of the wind speeds and directions called for consideration of wind field heterogeneity over the Gorky reservoir. It was incorporated using the wind forcing from atmospheric model WRF to WAVEWATCH III. Homogeneous wind forcing from the experimental data was compared with heterogeneous wind forcing from WRF. The need for further improvement of the quality of wind and wave prediction is discussed.

  18. Rapid differentiation in a sill-like magma reservoir: a case study from the campi flegrei caldera.

    Pappalardo, Lucia; Mastrolorenzo, Giuseppe


    In recent decades, geophysical investigations have detected wide magma reservoirs beneath quiescent calderas. However, the discovery of partially melted horizons inside the crust is not sufficient to put constraints on capability of reservoirs to supply cataclysmic eruptions, which strictly depends on the chemical-physical properties of magmas (composition, viscosity, gas content etc.), and thus on their differentiation histories. In this study, by using geochemical, isotopic and textural records of rocks erupted from the high-risk Campi Flegrei caldera, we show that the alkaline magmas have evolved toward a critical state of explosive behaviour over a time span shorter than the repose time of most volcanic systems and that these magmas have risen rapidly toward the surface. Moreover, similar results on the depth and timescale of magma storage were previously obtained for the neighbouring Somma-Vesuvius volcano. This consistency suggests that there might be a unique long-lived magma pool beneath the whole Neapolitan area.

  19. How to revitalize a mature reservoir: New development stategy-an integrated study in petroleum engineering

    Rondon, L.; Coll, C.; Cordova, P.; Gamero, H. [Maraven, Caracas (Venezuela)] [and others


    The results from a 3-D, 3-Phase numerical simulation model of Lower Lagunillas reservoir in Block IV Lake Maracaibo indicate the possibility of additional recovery from this mature field by drilling infill horizontal wells. The simulation model was the final outcome of an integrated work effort by a team of specialists. The field has produced approximately 920 MMSTB or 43% of OOIP to date and the remaining reserves are estimated to be 270 MMSTB. The reservoir pressure has declined from 4200 psi to 1400 psi, well below the bubble point pressure of 4000 psi. The objectives of an integrated reservoir study were to understand the reservoir heterogeneity and dynamics, evaluate the efficiency of the gas injection started in 1966 and the strength of the active aquifer as pressure support mechanisms. The new model shows the presence of layers with bypassed oil and higher pressures between layers that show greater pressure depletion and high GOR. This situation demonstrates the need to formulate a new development strategy for efficiently recovering the remaining reserves. The study indicates that the drilling of horizontal wells or infill deviated wells in some of these layers offers the best solution for maximizing recovery from this reservoir taking full advantage of the reservoir heterogeneity, aquifer support and secondary gas cap to optimize well locations.

  20. Sourcing quality-of-life weights obtained from previous studies: theory and reality in Korea.

    Bae, SeungJin; Bae, Eun Young; Lim, Sang Hee


    The quality-of-life weights obtained in previous studies are frequently used in cost-utility analyses. The purpose of this study is to describe how the values obtained in previous studies are incorporated into the industry submissions requesting listing at the Korean National Health Insurance (NHI), focusing on the issues discussed in theoretical studies and national guidelines. The industry submissions requesting listing at the Korean NHI from January 2007 until December 2009 were evaluated by two independent researchers at the Health Insurance Review and Assessment Service (HIRA). Specifically, we observed the methods that were used to pool, predict joint health state utilities, and retain consistency within submissions in terms of the issues discussed in methodological research papers and recommendations from national guidelines. More than half of the submissions used QALY as an outcome measure, and most of these submissions were sourced from prior studies. Heterogeneous methodologies were frequently used within a submission, with the inconsistent use of upper and lower anchors being prevalent. Assumptions behind measuring joint health state utilities or pooling multiple values for single health states were omitted in all submissions. Most national guidelines were rather vague regarding how to predict joint health states, how to select the best available value, how to maintain consistency within a submission, and how to generalize values obtained from prior studies. Previously-generated values were commonly sourced, but this practice was frequently related to inconsistencies within and among submissions. Attention should be paid to the consistency and transparency of the value, especially if the value is sourced from prior studies.

  1. Experimental study on the mechanism of hydraulic fracture growth in a glutenite reservoir

    Ma, Xinfang; Zou, Yushi; Li, Ning; Chen, Ming; Zhang, Yinuo; Liu, Zizhong


    Glutenite reservoirs are frequently significantly heterogeneous because of their unique depositional environment. The presence of gravel in this type of formation complicates the growth path of hydraulic fracture (HF). In this study, laboratory fracturing experiments were conducted on six large natural glutenite specimens (300 mm × 300 mm × 300 mm) using a true triaxial hydraulic fracturing system to investigate the growth law of HF in glutenite reservoirs. Before the experiments were performed, the rock properties of the gravel particles and matrix in the glutenite specimens were determined using various apparatuses. The effects of gravel size, horizontal differential stress, fracturing fluid type (or viscosity), and flow rate on the HF growth pattern, fracture width, and injection pressure were examined in detail. Similar to previous studies, four types of HF intersections with gravel particles, namely, termination, penetration, deflection, and attraction, were observed. The HF growth path in the glutenite specimens with large gravel (40 mm-100 mm) is likely branched and tortuous even under high horizontal differential stress. The HF growth path in the glutenite specimens with small gravel (less than 20 mm) is simple, but a process zone with multiple thin fractures may be created. Breakdown pressure may increase significantly when HF initiates from high-strength gravel particles, which are mainly composed of quartz. HF propagation is likely limited within high-strength gravel particles, thereby resulting in narrow fractures and even termination. The use of low-viscosity fluids, such as slickwater, and the low injection rate can further limit HF growth, particularly its width. As a response, high extension pressure builds up during fracturing.

  2. Mechanistic study of wettability alteration using surfactants with applications in naturally fractured reservoirs.

    Salehi, Mehdi; Johnson, Stephen J; Liang, Jenn-Tai


    In naturally fractured reservoirs, oil recovery from waterflooding relies on the spontaneous imbibition of water to expel oil from the matrix into the fracture system. The spontaneous imbibition process is most efficient in strongly water-wet rock where the capillary driving force is strong. In oil- or mixed-wet fractured carbonate reservoirs, however, the capillary driving force for the spontaneous imbibition process is weak, and therefore the waterflooding oil recoveries are low. The recovery efficiency can be improved by dissolving low concentrations of surfactants in the injected water to alter the wettability of the reservoir rock to a more water-wet state. This wettability alteration accelerates the spontaneous imbibition of water into matrix blocks, thereby increasing the oil recovery during waterflooding. Several mechanisms have been proposed to explain the wettability alteration by surfactants, but none have been verified experimentally. Understanding of the mechanisms behind wettability alteration could help to improve the performance of the process and aid in identification of alternative surfactants for use in field applications. Results from this study revealed that ion-pair formation and adsorption of surfactant molecules through interactions with the adsorbed crude oil components on the rock surface are the two main mechanisms responsible for the wettability alteration. Previous researchers observed that, for a given rock type, the effectiveness of wettability alteration is highly dependent upon the ionic nature of the surfactant involved. Our experimental results demonstrated that ion-pair formation between the charged head groups of surfactant molecules and the adsorbed crude oil components on rock surface was more effective in changing the rock wettability toward a more water-wet state than the adsorption of surfactant molecules as a monolayer on the rock surface through hydrophobic interaction with the adsorbed crude oil components. By comparing

  3. Effect of flow forecasting quality on benefits of reservoir operation ? a case study for the Geheyan reservoir (China)

    Dong, X.; Dohmen-Janssen, C. M.; de Booij, M.; Hulscher, S.


    International audience; This paper presents a methodology to determine the effect of flow forecasting quality on the benefits of reservoir operation. The benefits are calculated in terms of the electricity generated, and the quality of the flow forecasting is defined in terms of lead time and accuracy of the forecasts. In order to determine such an effect, an optimization model for reservoir operation was developed which consists of two sub-models: a long-term (monthly) and a short-term (dail...

  4. Reservoir zonation based on statistical analyses: A case study of the Nubian sandstone, Gulf of Suez, Egypt

    El Sharawy, Mohamed S.; Gaafar, Gamal R.


    Both reservoir engineers and petrophysicists have been concerned about dividing a reservoir into zones for engineering and petrophysics purposes. Through decades, several techniques and approaches were introduced. Out of them, statistical reservoir zonation, stratigraphic modified Lorenz (SML) plot and the principal component and clustering analyses techniques were chosen to apply on the Nubian sandstone reservoir of Palaeozoic - Lower Cretaceous age, Gulf of Suez, Egypt, by using five adjacent wells. The studied reservoir consists mainly of sandstone with some intercalation of shale layers with varying thickness from one well to another. The permeability ranged from less than 1 md to more than 1000 md. The statistical reservoir zonation technique, depending on core permeability, indicated that the cored interval of the studied reservoir can be divided into two zones. Using reservoir properties such as porosity, bulk density, acoustic impedance and interval transit time indicated also two zones with an obvious variation in separation depth and zones continuity. The stratigraphic modified Lorenz (SML) plot indicated the presence of more than 9 flow units in the cored interval as well as a high degree of microscopic heterogeneity. On the other hand, principal component and cluster analyses, depending on well logging data (gamma ray, sonic, density and neutron), indicated that the whole reservoir can be divided at least into four electrofacies having a noticeable variation in reservoir quality, as correlated with the measured permeability. Furthermore, continuity or discontinuity of the reservoir zones can be determined using this analysis.

  5. Vibrations of twisted cantilevered plates - Summary of previous and current studies

    Leissa, A. W.; Macbain, J. C.; Kielb, R. E.


    This work summarizes a comprehensive study made of the free vibrations of twisted, cantilevered plates of rectangular planform. Numerous theoretical and experimental investigations previously made by others have resulted in frequency results which disagree considerably. To clarify the problem a joint industry/government/university research effort was initiated to obtain comprehensive theoretical and experimental results for models having useful ranges of aspect ratios, thickness ratios and twist angles. Theoretical data came from 19 independent computer analyses, including finite element, shell theory and beam theory idealizations. Two independent sets of experimental data were also obtained. The theoretical and experimental results are summarized and compared.

  6. A numerical study of EGS heat extraction process based on a thermal non-equilibrium model for heat transfer in subsurface porous heat reservoir

    Chen, Jiliang; Jiang, Fangming


    With a previously developed numerical model, we perform a detailed study of the heat extraction process in enhanced or engineered geothermal system (EGS). This model takes the EGS subsurface heat reservoir as an equivalent porous medium while it considers local thermal non-equilibrium between the rock matrix and the fluid flowing in the fractured rock mass. The application of local thermal non-equilibrium model highlights the temperature-difference heat exchange process occurring in EGS reservoirs, enabling a better understanding of the involved heat extraction process. The simulation results unravel the mechanism of preferential flow or short-circuit flow forming in homogeneously fractured reservoirs of different permeability values. EGS performance, e.g. production temperature and lifetime, is found to be tightly related to the flow pattern in the reservoir. Thermal compensation from rocks surrounding the reservoir contributes little heat to the heat transmission fluid if the operation time of an EGS is shorter than 15 years. We find as well the local thermal equilibrium model generally overestimates EGS performance and for an EGS with better heat exchange conditions in the heat reservoir, the heat extraction process acts more like the local thermal equilibrium process.

  7. Study on the enhancement of hydrocarbon recovery by characterization of the reservoir

    Kwak, Young Hoon; Son, Jin Dam; Oh, Jae Ho [Korea Institute of Geology Mining and Materials, Taejon (Korea)] [and others


    Three year project is being carried out on the enhancement of hydrocarbon recovery by the reservoir characterization. This report describes the results of the second year's work. This project deals with characterization of fluids, bitumen ad rock matrix in the reservoir. New equipment and analytical solutions for naturally fractured reservoir were also included in this study. Main purpose of the reservoir geochemistry is to understand the origin of fluids (gas, petroleum and water) and distribution of the bitumens within the reservoir and to use them not only for exploration but development of the petroleum. For the theme of reservoir geochemistry, methods and principles of the reservoir gas and bitumen characterization, which is applicable to the petroleum development, are studied. and case study was carried out on the gas, water and bitumen samples in the reservoir taken form Haenam area and Ulleung Basin offshore Korea. Gases taken form the two different wells indicate the different origin. Formation water analyses show the absence of barrier within the tested interval. With the sidewall core samples from a well offshore Korea, the analysis using polarizing microscope, scanning electron microscope with EDX and cathodoluminoscope was performed for the study on sandstone diagenesis. The I/S changes were examined on the cuttings samples from a well, offshore Korea to estimate burial temperature. Oxygen stable isotope is used to study geothermal history in sedimentary basin. Study in the field is rare in Korea and basic data are urgently needed especially in continental basins to determine the value of formation water. In the test analyses, three samples from marine basins indicate final temperature from 55 deg.C to 83 deg.C and one marine sample indicate the initial temperature of 36 deg.C. One sample from continental basin represented the final temperature from 53 and 80 deg.C. These temperatures will be corrected because these values were based on assumed


    F. Jerry Lucia


    This is the final report of the project ''Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonardian-Age) Reservoirs, West Texas and New Mexico'', Department of Energy contract no. DE-AC26-98BC15105 and is the third in a series of similar projects funded jointly by the U.S. Department of Energy and The University of Texas at Austin, Bureau of Economic Geology, Reservoir Characterization Research Laboratory for Carbonates. All three projects focus on the integration of outcrop and subsurface data for the purpose of developing improved methods for modeling petrophysical properties in the interwell environment. The first project, funded by contract no. DE-AC22-89BC14470, was a study of San Andres outcrops in the Algerita Escarpment, Guadalupe Mountains, Texas and New Mexico, and the Seminole San Andres reservoir, Permian Basin. This study established the basic concepts for constructing a reservoir model using sequence-stratigraphic principles and rock-fabric, petrophysical relationships. The second project, funded by contract no. DE-AC22-93BC14895, was a study of Grayburg outcrops in the Brokeoff Mountains, New Mexico, and the South Cowden Grayburg reservoir, Permian Basin. This study developed a sequence-stratigraphic succession for the Grayburg and improved methods for locating remaining hydrocarbons in carbonate ramp reservoirs. The current study is of the Clear Fork Group in Apache Canyon, Sierra Diablo Mountains, West Texas, and the South Wasson Clear Fork reservoir, Permian Basin. The focus was on scales of heterogeneity, imaging high- and low-permeability layers, and the impact of fractures on reservoir performance. In this study (1) the Clear Fork cycle stratigraphy is defined, (2) important scales of petrophysical variability are confirmed, (3) a unique rock-fabric, petrophysical relationship is defined, (4) a porosity method for correlating high-frequency cycles and defining rock

  9. A Study of Permeability Changes Due to Cold Fluid Circulation in Fractured Geothermal Reservoirs.

    Gholizadeh Doonechaly, Nima; Abdel Azim, Reda R; Rahman, Sheik S


    Reservoir behavior due to injection and circulation of cold fluid is studied with a shear displacement model based on the distributed dislocation technique, in a poro-thermoelastic environment. The approach is applied to a selected volume of Soultz geothermal reservoir at a depth range of 3600 to 3700 m. Permeability enhancement and geothermal potential of Soultz geothermal reservoir are assessed over a stimulation period of 3 months and a fluid circulation period of 14 years. This study-by shedding light onto another source of uncertainty-points toward a special role for the fracture surface asperities in predicting the shear dilation of fractures. It was also observed that thermal stress has a significant impact on changing the reservoir stress field. The effect of thermal stresses on reservoir behavior is more evident over longer circulation term as the rock matrix temperature is significantly lowered. Change in the fracture permeability due to the thermal stresses can also lead to the short circuiting between the injection and production wells which in turn decreases the produced fluid temperature significantly. The effect of thermal stress persists during the whole circulation period as it has significant impact on the continuous increase in the flow rate due to improved permeability over the circulation period. In the current study, taking into account the thermal stress resulted in a decrease of about 7 °C in predicted produced fluid temperature after 14 years of cold fluid circulation; a difference which notably influences the potential prediction of an enhanced geothermal system.

  10. Study on fine geological modelling of the fluvial sandstone reservoir in Daqing oilfield

    Zhoa Han-Qing [Daqing Research Institute, Helongjiang (China)


    These paper aims at developing a method for fine reservoir description in maturing oilfields by using close spaced well logging data. The main productive reservoirs in Daqing oilfield is a set of large fluvial-deltaic deposits in the Songliao Lake Basin, characterized by multi-layers and serious heterogeneities. Various fluvial channel sandstone reservoirs cover a fairly important proportion of reserves. After a long period of water flooding, most of them have turned into high water cut layers, but there are considerable residual reserves within them, which are difficult to find and tap. Making fine reservoir description and developing sound a geological model is essential for tapping residual oil and enhancing oil recovery. The principal reason for relative lower precision of predicting model developed by using geostatistics is incomplete recognition of complex distribution of fluvial reservoirs and their internal architecture`s. Tasking advantage of limited outcrop data from other regions (suppose no outcrop data available in oilfield) can only provide the knowledge of subtle changing of reservoir parameters and internal architecture. For the specific geometry distribution and internal architecture of subsurface reservoirs (such as in produced regions) can be gained only from continuous infilling logging well data available from studied areas. For developing a geological model, we think the first important thing is to characterize sandbodies geometries and their general architecture`s, which are the framework of models, and then the slight changing of interwell parameters and internal architecture`s, which are the contents and cells of the model. An excellent model should possess both of them, but the geometry is the key to model, because it controls the contents and cells distribution within a model.


    Gurpreet Kaur


    Full Text Available Previous caesarean section sparks an area of controversy in Obstetrics. The management of women with previous caesarean section regarding the mode of delivery whether to opt for repeat caesarean section or vaginal delivery, is an area of debate. Very often the decision on management is not made on Principle of sound reasoning and many who choose the elective repeat caesarean section do so to circumvent the anxious moment that arise during conduct ion of labour. AIMS AND OBJECTIVE: To determine the maternal and fetal outcome in relation to type of delivery . MATERIALS AND METHOD S: A 18 month prospective observational study was conducted where in 150 patients who had a term pregnancy with a history of prior LSCS were included after obtaining their consent for participation. The obstetric and fetal outcomes of these patients in the present pregnancy were analyzed by Z test. RESULTS: Out of the 150 subjects 78 ( 52% were in age group of 26 - 30 years, 106 ( 70.67% patients belonged to the urban population, 116 ( 77.33% were booked patie nts, 107 ( 71.33% were housewives, 122 ( 81.33% belonged to middle class and 22 ( 14.67% were from high socio economic status. 67 ( 44.67% were second gravid, 112 ( 74.67% were para 1. Out of total 134 patients 29 ( 21.64% had elective caesarean section and 5 ( 3 .73% patients came as emergency admission and underwent caesarean section. Out of 134 patients, with one previous caesarean section. 32 had spontaneous onset of labour. Out of which 20 ( 68.97% had vaginal delivery and 9 ( 31.03% had repeat caesarean section. 13 patients had augmentation, 11 ( 84.62% had vaginal delivery and 2 ( 15.38% had caesarean section. In 58 patients labour was induced 29 ( 50% had section. 14 patients out of 50 who had previous 2 caesarean section only 1 ( 7.69% patient had spontane ous onset of labour and had caesarean section. 3 ( 92.86% patients had elective caesarean section. There were only 2 patients with previous 3 caesarean

  12. Simulation Study of CO2-EOR in Tight Oil Reservoirs with Complex Fracture Geometries.

    Zuloaga-Molero, Pavel; Yu, Wei; Xu, Yifei; Sepehrnoori, Kamy; Li, Baozhen


    The recent development of tight oil reservoirs has led to an increase in oil production in the past several years due to the progress in horizontal drilling and hydraulic fracturing. However, the expected oil recovery factor from these reservoirs is still very low. CO2-based enhanced oil recovery is a suitable solution to improve the recovery. One challenge of the estimation of the recovery is to properly model complex hydraulic fracture geometries which are often assumed to be planar due to the limitation of local grid refinement approach. More flexible methods like the use of unstructured grids can significantly increase the computational demand. In this study, we introduce an efficient methodology of the embedded discrete fracture model to explicitly model complex fracture geometries. We build a compositional reservoir model to investigate the effects of complex fracture geometries on performance of CO2 Huff-n-Puff and CO2 continuous injection. The results confirm that the appropriate modelling of the fracture geometry plays a critical role in the estimation of the incremental oil recovery. This study also provides new insights into the understanding of the impacts of CO2 molecular diffusion, reservoir permeability, and natural fractures on the performance of CO2-EOR processes in tight oil reservoirs.

  13. Simulation Study of CO2-EOR in Tight Oil Reservoirs with Complex Fracture Geometries

    Zuloaga-Molero, Pavel; Yu, Wei; Xu, Yifei; Sepehrnoori, Kamy; Li, Baozhen


    The recent development of tight oil reservoirs has led to an increase in oil production in the past several years due to the progress in horizontal drilling and hydraulic fracturing. However, the expected oil recovery factor from these reservoirs is still very low. CO2-based enhanced oil recovery is a suitable solution to improve the recovery. One challenge of the estimation of the recovery is to properly model complex hydraulic fracture geometries which are often assumed to be planar due to the limitation of local grid refinement approach. More flexible methods like the use of unstructured grids can significantly increase the computational demand. In this study, we introduce an efficient methodology of the embedded discrete fracture model to explicitly model complex fracture geometries. We build a compositional reservoir model to investigate the effects of complex fracture geometries on performance of CO2 Huff-n-Puff and CO2 continuous injection. The results confirm that the appropriate modelling of the fracture geometry plays a critical role in the estimation of the incremental oil recovery. This study also provides new insights into the understanding of the impacts of CO2 molecular diffusion, reservoir permeability, and natural fractures on the performance of CO2-EOR processes in tight oil reservoirs.

  14. CO2 Sequestration in Coalbed Methane Reservoirs: Experimental Studies and Computer Simulations

    Muhammad Sahimi; Theodore T. Tsotsis


    One of the approaches suggested for sequestering CO{sub 2} is by injecting it in coalbed methane (CBM) reservoirs. Despite its potential importance for CO{sub 2} sequestration, to our knowledge, CO{sub 2} injection in CBM reservoirs for the purpose of sequestration has not been widely studied. Furthermore, a key element missing in most of the existing studies is the comprehensive characterization of the CBM reservoir structure. CBM reservoirs are complex porous media, since in addition to their primary pore structure, generated during coal formation, they also contain a variety of fractures, which may potentially play a key role in CO{sub 2} sequestration, as they generally provide high permeability flow paths for both CO{sub 2} and CH{sub 4}. In this report we present an overview of our ongoing experimental and modeling efforts, which aim to investigate the injection, adsorption and sequestration of CO{sub 2} in CBM reservoirs, the enhanced CH{sub 4} production that results, as well as the main factors that affect the overall operation. We describe the various experimental techniques that we utilize, and discuss their range of application and the value of the data generated. We conclude with a brief overview of our modeling efforts aiming to close the knowledge gap and fill the need in this area.

  15. Case-control study for colorectal cancer genetic susceptibility in EPICOLON: previously identified variants and mucins

    Moreno Victor


    Full Text Available Abstract Background Colorectal cancer (CRC is the second leading cause of cancer death in developed countries. Familial aggregation in CRC is also important outside syndromic forms and, in this case, a polygenic model with several common low-penetrance alleles contributing to CRC genetic predisposition could be hypothesized. Mucins and GALNTs (N-acetylgalactosaminyltransferase are interesting candidates for CRC genetic susceptibility and have not been previously evaluated. We present results for ten genetic variants linked to CRC risk in previous studies (previously identified category and 18 selected variants from the mucin gene family in a case-control association study from the Spanish EPICOLON consortium. Methods CRC cases and matched controls were from EPICOLON, a prospective, multicenter, nationwide Spanish initiative, comprised of two independent stages. Stage 1 corresponded to 515 CRC cases and 515 controls, whereas stage 2 consisted of 901 CRC cases and 909 controls. Also, an independent cohort of 549 CRC cases and 599 controls outside EPICOLON was available for additional replication. Genotyping was performed for ten previously identified SNPs in ADH1C, APC, CCDN1, IL6, IL8, IRS1, MTHFR, PPARG, VDR and ARL11, and 18 selected variants in the mucin gene family. Results None of the 28 SNPs analyzed in our study was found to be associated with CRC risk. Although four SNPs were significant with a P-value ADH1C (OR = 1.63, 95% CI = 1.06-2.50, P-value = 0.02, recessive, rs1800795 in IL6 (OR = 1.62, 95% CI = 1.10-2.37, P-value = 0.01, recessive, rs3803185 in ARL11 (OR = 1.58, 95% CI = 1.17-2.15, P-value = 0.007, codominant, and rs2102302 in GALNTL2 (OR = 1.20, 95% CI = 1.00-1.44, P-value = 0.04, log-additive 0, 1, 2 alleles], only rs3803185 achieved statistical significance in EPICOLON stage 2 (OR = 1.34, 95% CI = 1.06-1.69, P-value = 0.01, recessive. In the joint analysis for both stages, results were only significant for rs3803185 (OR = 1

  16. A longitudinal study of plasma insulin and glucagon in women with previous gestational diabetes

    Damm, P; Kühl, C; Hornnes, P


    OBJECTIVE: To investigate whether plasma insulin or glucagon predicts later development of diabetes in women with gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: The subjects studied were 91 women with diet-treated GDM and 33 healthy women. Plasma insulin and glucagon during a 50......-g oral glucose tolerance test (OGTT) were measured during pregnancy, postpartum, and at follow-up 5-11 years later. At follow-up, the women were also examined with a 75-g OGTT or an intravenous glucagon test. RESULTS: Twenty-seven (30%) of the women with previous GDM had abnormal glucose tolerance...... response) at all time points investigated; this was also found when only nonobese glucose-tolerant women were examined. Low insulin secretion during pregnancy together with a high fasting plasma glucose level at the diagnostic OGTT in pregnancy and hyperglycemia during the postpartum OGTT were predictive...

  17. An agricultural drought index to incorporate the irrigation process and reservoir operations: A case study in the Tarim River Basin

    Li, Zehua; Hao, Zhenchun; Shi, Xiaogang; Déry, Stephen J.; Li, Jieyou; Chen, Sichun; Li, Yongkun


    To help the decision making process and reduce climate change impacts, hydrologically-based drought indices have been used to determine drought severity in the Tarim River Basin (TRB) over the past decades. As the major components of the surface water balance, however, the irrigation process and reservoir operations have not been incorporated into drought indices in previous studies. Therefore, efforts are needed to develop a new agricultural drought index, which is based on the Variable Infiltration Capacity (VIC) model coupled with an irrigation scheme and a reservoir module. The new drought index was derived from the simulated soil moisture data from a retrospective VIC simulation from 1961 to 2007 over the irrigated area in the TRB. The physical processes in the coupled VIC model allow the new agricultural drought index to take into account a wide range of hydrologic processes including the irrigation process and reservoir operations. Notably, the irrigation process was found to dominate the surface water balance and drought evolution in the TRB. Furthermore, the drought conditions identified by the new agricultural drought index presented a good agreement with the historical drought events that occurred in 1993-94, 2004, and 2006-07, respectively. Moreover, the spatial distribution of coupled VIC model outputs using the new drought index provided detailed information about where and to what extent droughts occurred.

  18. Numerical Studies of Radioactive Sediment Deposition on Reservoirs in Fukushima Coastal Area

    Yamada, Susumu; Itakura, Mitsuhiro; Okumura, Masahiko; Machida, Masahiko; Kitamura, Akihiro


    The transportation of radioactive Cs is mainly brought about by movement of silt- and clay-sized particles in rivers. Therefore, predicting such a fine sediment flow and deposition in rivers has been one of central issues toward environmental recovery after the Fukushima Dai-ichi nuclear power plant (FDNPP) accident. For the purpose of the Cs transport prediction, we concentrate on a few reservoirs in Fukushima costal area, since they are temporal destinations for contaminated silt and clay transported by rivers. We numerically study how the river water together with floating silt and clays penetrate into the reservoirs and where the sediments settle on the bottom surface of the reservoirs by using 2D river simulation framework named iRIC developed by Shimizu et al. In this presentation, we reveal the typical deposition pattern in the target reservoirs and compare the results with direct sampling data for the sediments on the reservoir bottom surfaces. We believe that the obtained information is useful in planning the water supply and treatment for highly-contaminated districts in Fukushima costal area.

  19. A comparative study on the extracurricularreading environment of urban and rural children in Chongqing Reservoir Area

    Xiaozhao; DENG; Haiyan; YAO; Shubei; ZHU


    Purpose: So far, there have been few studies that discussed children’s reading environment in China’s poverty-stricken areas, this study aims to explore differences existed in extracurricular reading environment between urban and rural children in Chongqing Reservoir Area with empirical evidence.Design/methodology/approach: Using a questionnaire survey, empirical data was collected from 105 participants. Then proposed hypotheses and the reliability of the observation variables were respectively examined with ANOVA and factor analysis. The statistical analysis software SPSS19.0 was used to analyze the data.Findings: Our results showed that 1) differences did exist in school and social reading environment between urban and rural children in Chongqing Reservoir Area; 2) differences in family reading environment between urban and rural children in Chongqing Reservoir Area were not obviously observed.Research limitations: The empirical data were collected from only one county of Chongqing Reservoir Area, which may have partially affected the generalization of our conclusions. In addition, the response rate of questionnaires was comparatively low due to a relatively limited research period. Practical implications: This study would provide some reference for governments, libraries, schools and families to consider how to jointly narrow the gap in the extracurricular reading circumstance between urban and rural children in Chongqing Reservoir Area.Originality value: This is one of the first studies to explore similarities and differences in extracurricular reading environment between urban and rural children in Chinese povertystricken areas, which will help research communities to gain a deeper understanding of children’s reading environment in Chinese Reservoir Area.

  20. A study about the interest and previous contact of high school students with Astronomy

    Carvalho, C. L.; Zanitti, M. H. R.; Felicidade, B. L.; Gomes, A. D. T.; Dias, E. W.; Coelho, F. O.


    The currently problems in Astronomy teaching in Brazilian Basic Education contrast with the space, and the popularity that astronomical themes have in various media in the country. In this work, we present the results of a study about the interest, and previous contact of high school students from a public school in the city of "São João del-Rei"/MG with topics related to Astronomy. The study and the pedagogical intervention were carried out by students of the PIBID/CAPES/UFSJ. The intervention was performed through an oral exposition with the students' participation, followed by the use of the Stellarium program. The results suggest the majority of students surveyed are interested in Astronomy, and have had some contact with the area. However, some inconsistencies in their responses were identified and examined. The implications for research and for Astronomy Education are discussed. We also make some considerations about relationship between the lack of specific knowledge and the misinformation as one possible reason for the little interest of students in various areas of Science.

  1. Simulation studies to evaluate the effect of fracture closure on the performance of fractured reservoirs; Final report

    Howrie, I.; Dauben, D.


    A three-year research program to evaluate the effect of fracture closure on the recovery of oil and gas from naturally fractured reservoirs has been completed. The overall objectives of the study were to: (1) evaluate the reservoir conditions for which fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. The evaluations of reservoir performance were made by a modern dual porosity simulator, TETRAD. This simulator treats both porosity and permeability as functions of pore pressure. The Austin Chalk in the Pearsall Field in of South Texas was selected as the prototype fractured reservoir for this work. During the first year, simulations of vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure change. Sensitivity runs indicated that the simulator was predicting the effects of critical reservoir parameters in a logical and consistent manner. The results confirmed that horizontal wells could increase both rate of oil recovery and total oil recovery from naturally fractured reservoirs. In the second year, the performance of the same vertical and horizontal wells was reevaluated with fracture permeability treated as a function of reservoir pressure. To investigate sensitivity to in situ stress, differing loading conditions were assumed. Simulated natural depletions confirm that pressure sensitive fractures degrade well performance. The severity of degradation worsens when the initial reservoir pressure approaches the average stress condition of the reservoir, such as occurs in over pressured reservoirs. Simulations with water injection indicate that degradation of permeability can be counteracted when reservoir pressure is maintained and oil recovery can be increased when reservoir properties are favorable.

  2. Effect of flow forecasting quality on benefits of reservoir operation - a case study for the Geheyan reservoir (China)

    Dong, Xiaohua; Dohmen-Janssen, Catarine M.; Booij, Martijn J.; Hulscher, Suzanne J.M.H.


    This paper presents a methodology to determine the effect of flow forecasting quality on the benefits of reservoir operation. The benefits are calculated in terms of the electricity generated, and the quality of the flow forecasting is defined in terms of lead time and accuracy of the forecasts. In

  3. A multidisciplinary study on the crustal nature of volcanic conduits and magma reservoirs

    Flinders, Ashton F.

    Volcanic settings vary widely not only in their eruptive style and products, but in the manner magma travels from deep sources to individual eruptive centers. Imaging these pathways, and their associated crustal reservoirs, provides unique and unprecedented views into these environments. Imaging techniques are varied with the strength of the technique often based on data availability. As such, we focus on two methods---gravity and seismic---in two different settings, each with its own unique volcanic environments, crustal structures, and associated data resources. The first, the Hawaiian Islands, are the most geologically studied hot-spot islands in the world, yet the only large-scale compilation of marine and land gravity data is more than 45 years old. We present a new chain-wide gravity compilation allowing us to locate current and former volcanic centers, major rift zones, a previously suggested volcano, and show that volcanoes along the chain are composed of a small proportion of intrusive material (sourced melt to the surface. We image two zones of reduced velocity, one of which correlates with a proposed extensive zone of mid-crustal partial melt which likely supplies evolved magmas to the surrounding volcanoes and vents, including Mounts St. Helens and Adams.

  4. Probe imaging studies of magnetic susceptibility and permeability for sensitive characterisation of carbonate reservoir rocks

    Ivakhnenko, Aleksandr; Bigaliyeva, Akmaral; Dubinin, Vladislav


    In this study were disclosed the main principals of identifying petrophysical properties of carbonate reservoirs such as porosity, permeability and magnetic susceptibility. While exploring and developing reservoir there are significant diversity of tasks that can be solved by appropriate knowledge of properties which are listed above. Behavior of fluid flow, distribution of hydrocarbons and other various industrial applications can be solved by measuring areal distribution of these petrophysical parameters. The results demonstrate how magnetic probe and hysteresis measurements correlate with petrophysical parameters in carbonate reservoirs. We made experimental measurements and theoretical calculations of how much magnetic susceptibility depends on the porosity of the rocks and analyzed data with graphics. In theoretical model of the carbonate rocks we considered calcite, dolomite, quartz and combinations of calcite and dolomite, calcite and Fe-dolomite, calcite and quartz, calcite and aragonite with increasing concentrations of the dolomite, Fe-dolomite, quartz and aragonite up to 50% with step of 5%. Here we defined dependence of magnetic susceptibility from the porosity: the higher porosity measurements, the less slope of magnetic susceptibility, consequently mass magnetization is higher for diamagnetic and lower for paramagnetic carbonate rocks, but in the both cases magnetic susceptibility tries to reach zero with increasing of the total porosity. Rock measurements demonstrate that reservoir zones of the low diamagnetic magnetic susceptibility are generally correlated with higher permeability and also porosity distribution. However for different carbonate reservoirs we establish different relationships depending on the complexity of their mineralogy and texture. Application of integral understanding in distribution of permeability, porosity and mineral content in heterogeneous carbonates represented by this approach can be useful tool for carbonate reservoir

  5. Religious Identity in Iranian Society: A Systematic Review of Previous Studies (2001-2013


    literature on identity, evidence suggests that the role of religion in shaping individuals' and group's identity is widely ignored. However, a growing number of studies have begun to take into consideration the key role of religion (Arweck & Nesbitt 2010, King and Boyatzis 2004, Peek 2005. This article has attempted to review systematically previous research and conceptualizations on the religious identity based on national studies and surveys and academic dissertations.     Materials and Methods   As mentioned, the purpose of this study was to review the results of some influential researches in the field of religious identity. To get this purpose, one of the best known methods for reviewing previous studies, a systematic review, was applied. Systematic review deals with establishing and synthesizing of researches and evidences with focus on a specific question. This occurs through the organized, transparent, formal, clear and flexible procedures and processes. A systematic review of research is not limited to review the history and this overview and review can be used in different levels, fields and goals. During the first phase of the study, terms of "religious identity", "Islamic identity", "Iranian identity" and "religious identity" was searched at libraries and research centers and in databases such as Center for Scientific Information Database (SID, a database of Iranian journals and magazines (Magiran, Noor specialized journals database, and Science and Information Technology Institute (IrnaDoc. After reviewing the gathered documents and specifying its relationship with the object and purpose of the study, a total of 47 documents were selected. Documents based on the five major parameter were summarized and reviewed: 1-general information, 2-goals and research questions, 3-research methodology, 4-variables, 5-findings     Discussion of Results and Conclusion   Findings show that in the highest percentage (38.2% of researches, religious identity has been

  6. Study on detailed geological modelling for fluvial sandstone reservoir in Daqing oil field

    Zhao Hanqing; Fu Zhiguo; Lu Xiaoguang [Institute of Petroleum Exploration and Development, Daqing (China)


    Guided by the sedimentation theory and knowledge of modern and ancient fluvial deposition and utilizing the abundant information of sedimentary series, microfacies type and petrophysical parameters from well logging curves of close spaced thousands of wells located in a large area. A new method for establishing detailed sedimentation and permeability distribution models for fluvial reservoirs have been developed successfully. This study aimed at the geometry and internal architecture of sandbodies, in accordance to their hierarchical levels of heterogeneity and building up sedimentation and permeability distribution models of fluvial reservoirs, describing the reservoir heterogeneity on the light of the river sedimentary rules. The results and methods obtained in outcrop and modem sedimentation studies have successfully supported the study. Taking advantage of this method, the major producing layers (PI{sub 1-2}), which have been considered as heterogeneous and thick fluvial reservoirs extending widely in lateral are researched in detail. These layers are subdivided into single sedimentary units vertically and the microfacies are identified horizontally. Furthermore, a complex system is recognized according to their hierarchical levels from large to small, meander belt, single channel sandbody, meander scroll, point bar, and lateral accretion bodies of point bar. The achieved results improved the description of areal distribution of point bar sandbodies, provide an accurate and detailed framework model for establishing high resolution predicting model. By using geostatistic technique, it also plays an important role in searching for enriched zone of residual oil distribution.

  7. Phase II study of pegylated liposomal doxorubicin plus vinorelbine in breast cancer with previous anthracycline exposure.

    Martin, Miguel; García-Donas, Jesus; Casado, Antonio; de la Gándara, Isabel; Pérez-Segura, Pedro; García-Saenz, Jose-Angel; Ibáñez, Gabriel; Loboff, Belen; García-Ledo, Gemma; Moreno, Fernando; Grande, Enrique; Diaz-Rubio, Eduardo


    Thirty-five patients with metastatic breast cancer (MBC) entered a phase II study of pegylated liposomal doxorubicin 35 mg/m2 intravenously (i.v.) on day 1 plus vinorelbine 30 mg/m2 i.v. on day 1 every 4 weeks. Patients were required to have measurable disease, previous chemotherapy with an anthracycline-containing regimen, and a normal left ventricular ejection fraction (LVEF). Thirty-four patients were assessable for response and toxicity. The overall response rate (on an intent-to-treat basis) was 35% (12 of 34; 95% CI, 20%-54%). One complete response and 11 partial responses were noted. In addition, 14 patients (41%) had stable disease of > 4 months duration, and 7 patients (20.5%) had disease progression. The response rates to the combination when it was used as first- and second-line chemotherapy were 31% (4 of 13) and 38% (8 of 21), respectively. Median time to disease progression was 7 months (range, 1-35 months) and median overall survival was 13 months (range, 2 to > 62 months). Neutropenia was the most frequent toxicity (grade 4 in 44% of patients and 19% of cycles), but neutropenic fever was seen in only 3 cases. No septic deaths occurred. Nonhematologic grade 3 side effects included skin toxicity (palmar-plantar erythrodysesthesia syndrome, 6%) and mucositis (15%). Late alopecia was seen in 53% of patients (grade 1 in 41%, and grade 2 in 12%). The median LVEFs were 64% (range, 50%-81%) at baseline and 62% (range, 37%-70%) after treatment. Three patients presented an LVEF decrease to < 50%; however, no clinical heart failure was noted, and 2 of these patients recovered normal values after cessation of therapy. The combination of pegylated liposomal doxorubicin and vinorelbine can be safely administered to patients with anthracycline-pretreated MBC and is active in this population.

  8. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.


    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  9. Mapping 3D thin shale and permeability pathway within a reservoir system: Case study from the Sleipner Field

    Ponfa Bitrus, Roy; Iacopini, David; Bond, Clare


    Reservoir architecture plays an integral part of seismic reservoir characterization. The characteristics of a reservoir which includes its external and internal geometry are important as they influence the production and development strategy employed in the oil and gas sector. Reservoir architecture is defined by the interpretation of seismic data, thus identifying the basic structural and stratigraphic geometrical framework of a trapping and flow system for hydrocarbon and fluids. One major issue though is the interpretation of thin shales and identification of permeability pathways within the reservoir system. This paper employs a method using attributes to map thin shales and identify permeability pathways or transmissitives that exist within a reservoir taking into consideration the seismic resolution and available data. Case study is the Utsira Formation in the Sleipner field, Norwegian North sea. The Utsira formation presents a classic case of thin beds within a sandstone formation and transmissitives that exist as chimneys within the formation. A total of 10 intra reservoir horizon units of shales where interpreted using complex trace seismic attributes. These interpreted horizons where further analysed through spectral decomposition to reveal possible facies distribution and unit thickness within the horizon. Reservoir transmissitives identified as vertical curvilinear structures were also analysed using unique seismic attributes in other to delineate their extent and characterise their occurrence These interpreted shales and pathway transmissitives illuminate the geometry of the formation, the reservoir heterogeneities on a finer-scale and, in the long term, constrain the migration prediction of reservoir fluids, hydrocarbons and injected CO2 when matched across a 4D seismic data survey. As such, useful insights into the key elements operating within the reservoir can be provided, giving a good indication of the long and short term reservoir performance.

  10. The biomechanics of running in athletes with previous hamstring injury: A case-control study.

    Daly, C; Persson, U McCarthy; Twycross-Lewis, R; Woledge, R C; Morrissey, D


    Hamstring injury is prevalent with persistently high reinjury rates. We aim to inform hamstring rehabilitation by exploring the electromyographic and kinematic characteristics of running in athletes with previous hamstring injury. Nine elite male Gaelic games athletes who had returned to sport after hamstring injury and eight closely matched controls sprinted while lower limb kinematics and muscle activity of the previously injured biceps femoris, bilateral gluteus maximus, lumbar erector spinae, rectus femoris, and external oblique were recorded. Intergroup comparisons of muscle activation ratios and kinematics were performed. Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus (maximum difference -12.5%, P = 0.03), ipsilateral erector spinae (maximum difference -12.5%, P = 0.01), ipsilateral external oblique (maximum difference -23%, P = 0.01), and contralateral rectus femoris (maximum difference -22%, P = 0.02) in the late swing phase. We also detected sagittal asymmetry in hip flexion (maximum 8°, P = 0.01), pelvic tilt (maximum 4°, P = 0.02), and medial rotation of the knee (maximum 6°, P = 0.03) effectively putting the hamstrings in a lengthened position just before heel strike. Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious kinematics. These deficits should be considered and addressed during rehabilitation.

  11. A study of relations between physicochemical properties of crude oils and microbiological characteristics of reservoir microflora

    Yashchenko, I. G.; Polishchuk, Yu. M.; Peremitina, T. O.


    The dependence of the population and activity of reservoir microflora upon the chemical composition and viscosity of crude oils has been investigated, since it allows the problem of improvement in the technologies and enhancement of oil recovery as applied to production of difficult types of oils with anomalous properties (viscous, heavy, waxy, high resin) to be solved. The effect of the chemical composition of the oil on the number, distribution, and activity of reservoir microflora has been studied using data on the microbiological properties of reservoir water of 16 different fields in oil and gas basins of Russia, Mongolia, China, and Vietnam. Information on the physicochemical properties of crude oils of these fields has been obtained from the database created at the Institute of Petroleum Chemistry, Siberian Branch on the physicochemical properties of oils throughout the world. It has been found that formation water in viscous oil reservoirs is char acterized by a large population of heterotrophic and sulfate reducing bacteria and the water of oil fields with a high paraffin content, by population of denitrifying bacteria.

  12. Geomechanical reservoir models. A case study from the Sirte Basin / Libya

    Henk, Andreas [Freiburg Univ. (Germany). Inst. fuer Geowissenschaften; Frischbutter, Andreas [Wintershall Holding AG, Kassel (Germany); Tawengi, Khaeri Segayer [National Oil Company, Tripoli (Libya)


    Geomechanical reservoir models on the basis of numerical simulation techniques provide a tool for the prediction of tectonic stresses and fractures. The workflow to set up and calibrate a geomechanical reservoir model includes import of the subsurface geometry as well as assignment of mechanical properties and boundary conditions. If well data are available, calculated stresses and fractures can be calibrated against observed data. Modeling results are relevant for a variety of tasks ranging from borehole stability and fault slip analysis to planning of hydraulic fracs. Application to a data set from a reservoir in the Eastern Sirte basin of Libya illustrates the practical potential of the modelling approach. The case study shows that stress orientations including local perturbations can be predicted with considerable accuracy even if the reservoir and fault geometries are primarily derived from seismic data, i.e. if well data is sparse. By nature, fracture prediction is less robust as it has to build on several poorly constrained input parameters like magnitude and orientation of paleo-stresses, paleo-pore pressures and former rock mechanical properties. Consequently, sufficient well data with fracture orientations observed on borehole image logs are required to calibrate the geomechanical model and provide a reliable base for fracture prognoses in the inter-well space. (orig.)

  13. HPHT reservoir evolution: a case study from Jade and Judy fields, Central Graben, UK North Sea

    di Primio, Rolando; Neumann, Volkmar


    3D basin modelling of a study area in Quadrant 30, UK North Sea was performed in order to elucidate the burial, thermal, pressure and hydrocarbon generation, migration and accumulation history in the Jurassic and Triassic high pressure high temperature sequences. Calibration data, including reservoir temperatures, pressures, petroleum compositional data, vitrinite reflectance profiles and published fluid inclusion data were used to constrain model predictions. The comparison of different pressure generating processes indicated that only when gas generation is taken into account as a pressure generating mechanism, both the predicted present day as well as palaeo-pressure evolution matches the available calibration data. Compositional modelling of hydrocarbon generation, migration and accumulation also reproduced present and palaeo bulk fluid properties such as the reservoir fluid gas to oil ratios. The reconstruction of the filling histories of both reservoirs indicates that both were first charged around 100 Ma ago and contained initially a two-phase system in which gas dominated volumetrically. Upon burial reservoir fluid composition evolved to higher GORs and became undersaturated as a function of increasing pore pressure up to the present day situation. Our results indicate that gas compositions must be taken into account when calculating the volumetric effect of gas generation on overpressure.

  14. Reservoir operation using El Niño forecasts-case study of Daule Peripa and Baba, Ecuador

    Gelati, Emiliano; Madsen, Henrik; Rosbjerg, Dan


    Reservoir operation is studied for the Daule Peripa and Baba system in Ecuador, where El Niño events cause anomalously heavy precipitation. Reservoir inflow is modelled by a Markov-switching model using El Niño-Southern Oscillation (ENSO) indices as input. Inflow is forecast using 9-month lead time...

  15. Geothermal reservoir assessment case study: Northern Dixie Valley, Nevada

    Denton, J.M.; Bell, E.J.; Jodry, R.L.


    Two 1500 foot temperature gradient holes and two deep exploratory wells were drilled and tested. Hydrologic-hydrochemical, shallow temperature survey, structural-tectonic, petrologic alteration, and solid-sample geochemistry studies were completed. Eighteen miles of high resolution reflection seismic data were gathered over the area. The study indicates that a geothermal regime with temperatures greater than 400/sup 0/F may exist at a depth of approximately 7500' to 10,000' over an area more than ten miles in length.

  16. Rancidity inhibition study in frozen whole mackerel (scomber scombrus by a previous plant extract treatment.

    Aubourg, Santiago P.


    Full Text Available The effect of flaxseeds (Linum usitatissimum on rancidity development in frozen whole mackerel (Scomber scombrus was studied. For it, fresh mackerel were dipped in flaxseeds aqueous extract during 60 min, frozen at –80 ºC during 24 hours and kept frozen (–20 ºC up to 12 months. Sampling was carried out on the initial material and at months 1, 3, 5, 7, 9 and 12 of frozen storage at –20 ºC. A parallel experiment with non treated fish was carried out in the same conditions. Rancidity development was measured by several biochemical indices (free fatty acids, peroxides, conjugated dienes and trienes, secondary oxidation products and lipoxygenase activity and complemented by the sensory analysis (skin, flesh odour, consistency and flesh appearance. As a result of the previous antioxidant treatment, peroxides showed to breakdown faster (pSe ha estudiado el efecto del lino (Linum usitatissimum en el desarrollo de rancidez en caballa entera congelada (Scomber scombrus. Para ello, caballas frescas fueron sumergidas en extractos acuosos de semillas de lino durante 60 min, congeladas a -80 ºC durante 24 h y mantenidas congeladas ( -20 ºC durante 12 meses. Se tomaron muestras del material inicial y tras 1, 3, 5, 7, 9 y 12 meses de congelación a -20 ºC . Un experimento paralelo con pescado no tratado fue llevado acabo en las mismas condiciones. El desarrollo de la rancidez fue medido por varios índices bioquímicos (ácidos grasos libres, peróxidos, dienos y trienos conjugados, productos secundarios de oxidación y actividad lipoxigenasa y completado con análisis sensorial (piel, olor de la carne, consistencia y apariencia de la carne. Como resultado del tratamiento antioxidante, los peróxidos se degradaron más rápidos (p < 0.05 después del mes 7, y por tanto, contenidos mayores (p < 0.05 de dienos y trienos conjugados pudieron ser detectados en el pescado tratado. El tratamiento antioxidante también condujo a un

  17. Chemical stimulation of gas condensate reservoirs: An experimental and simulation study

    Kumar, Viren

    Well productivity in gas condensate reservoirs is reduced by condensate banking when the bottom hole flowing pressure drops below the dewpoint pressure. Several methods have been proposed to restore gas production rates after a decline due to condensate blocking. Gas injection, hydraulic fracturing, horizontal wells and methanol injection have been tried with limited success. These methods of well stimulation either offer only temporary productivity restoration or are applicable only in some situations. Wettability alteration of the rock in the near well bore region is an economic and efficient method for the enhancement of gas-well deliverability. Altering the wettability of porous media from strongly water-wet or oil-wet to intermediate-wet decreases the residual liquid saturations and results in an increase in the relative permeability to gas. Such treatments also increase the mobility and recovery of condensate from the reservoir. This study validates the above hypothesis and provides a simple and cost-efficient solution to the condensate blocking problem. Screening studies were carried out to identify the chemicals based on structure, solubility and reactivity at reservoir temperature and pressure. Experiments were performed to evaluate these chemicals to improve gas and condensate relative permeabilities. The improvement in relative permeability after chemical treatment was quantified by performing high pressure and high temperature coreflood experiments in Berea sandstone, Texas Cream limestone and reservoir cores using synthetic gas mixtures at reservoir conditions. Experiments were done at high flow rates and for long time periods to evaluate the durability of the treatment. Single well simulation studies were conducted to demonstrate the performance of the chemical treatment in the field. The experimental relative permeability data was modeled using a trapping number dependent relative permeability model and incorporated in the simulations. Effect of

  18. Effect of Previous Irradiation on Vascular Thrombosis of Microsurgical Anastomosis: A Preclinical Study in Rats.

    Barrera-Ochoa, Sergi; Gallardo-Calero, Irene; López-Fernández, Alba; Romagosa, Cleofe; Vergés, Ramona; Aguirre-Canyadell, Marius; Soldado, Francisco; Velez, Roberto


    The objective of the present investigation was to compare the effect of neoadjuvant irradiation on the microvascular anastomosis in cervical bundle using an experimental model in rats. One hundred forty male Sprague-Dawley rats were allocated into 4 groups: group I, control, arterial microanastomosis; group II, control, venous microanastomosis; group III, arterial microanastomosis with previous irradiation (20 Gy); and group IV, venous microanastomosis with previous irradiation (20 Gy). Clinical parameters, technical values of anastomosis, patency, and histopathological parameters were evaluated. Irradiated groups (III and IV) and vein anastomosis groups (II and IV) showed significantly increased technical difficulties. Group IV showed significantly reduced patency rates (7/35) when compared with the control group (0/35). Radiotherapy significantly decreased the patency rates of the vein (7/35) when compared with the artery (1/35). Groups III and IV showed significantly reduced number of endothelial cells and also showed the presence of intimal thickening and adventitial fibrosis as compared with the control group. Neoadjuvant radiotherapy reduces the viability of the venous anastomosis in a preclinical rat model with a significant increase in the incidence of vein thrombosis.

  19. Periodic variation of stress field in the Koyna-Warna reservoir triggered seismic zone inferred from focal mechanism studies

    Rao, N. Purnachandra; Shashidhar, D.


    The Koyna-Warna region in western India is globally recognized as the premier site of reservoir triggered seismicity (RTS) associated with the Koyna and Warna reservoirs. The region is characterized by continuous seismic activity observed since several decades, including the world's largest triggered earthquake of M6.3 which occurred in Koyna in 1967. While the role of reservoirs in triggering earthquakes has been widely discussed, the actual tectonic mechanism controlling earthquake genesis in this region is hardly understood. The Koyna-Warna region is exclusively governed by earthquakes of strike-slip and normal fault mechanism distinct from the thrust faulting seen in other active zones in the Indian region. In the present study, a comprehensive catalog of 50 focal mechanism solutions of earthquakes that occurred during the last 45 years in the Koyna-Warna region is developed, both from previous literature and from moment tensor inversion studies by the authors using broadband data from a local seismic network operating since 2005. The seismicity and fault plane data have enabled precise delineation of trends of the major causative faults, which are further accentuated using the double-difference technique. Stress inversion of the focal mechanism data has provided the best fitting principal compressive and tensile stress field of the region, which in conjunction with the deciphered fault zones provides a feasible model of seismogenesis in this region. Based on the observed temporal variation of faulting mechanism a model of alternating cycles of predominantly strike-slip and normal faulting is proposed, which is attributed to a periodic peaking and relaxation respectively of the horizontal compressive stress field in this region due to the Indian plate collision with Eurasia.

  20. Evaluation of sediment management strategies on reservoir storage depletion rate: a case study

    Ali, M.; Sterk, G.


    Sedimentation aspects have a major role during the design of new reservoir projects because life of the reservoir mainly depends upon sediment handling during reservoir operation. Therefore, proper sediment management strategies should be adopted to enhance the life span of reservoirs. Basha Reservo

  1. Revitalisation of Orlík reservoir – case study of a regional restoration project

    Ivana Očásková


    Full Text Available This case study describes the bottom-up formation of a regional project for restoring a reservoir. Land use changes in the upper Vltava river basin caused the eutrophication of Orlík reservoir, which resulted in water blooms, which in association with socio-economic changes caused a decline in tourism in this region and serious difficulties for local people. The study examines how public awareness helped in the establishment of a restoration project, its framework and strategy. Regional governance of the project management took into consideration both knowledge-based solutions and the interests of local people and municipalities. The project has the potential for resolving both environmental and socio-economic problems and providing a sustainable win-win strategy for the region, residents, tourists and stakeholders.

  2. Reef Reservoir Identification by Wavelet Decomposition and Reconstruction: A Case Study from Yuanba Gas Field in China

    Cheng Bingjie


    Full Text Available The organic reef is a special type of carbonate reservoir which always dominates the spatial distribution, reserves and accumulations of natural gas. However, it is difficult to determine the organic reef’s internal structure and gas reservoirs due to numerous adverse factors such as the low resolution of seismic data, depth of burial, strong anisotropy, irregular spatial distribution and complex internal structure. A case study of wavelet decomposition and reconstruction technology applied to elucidate the features of organic reef reservoirs in the Changxing formation from Yuanba gas field shows that the seismic record reconstructed by high frequency signal can adequately describe the internal properties of organic reef reservoirs. Furthermore, the root mean square amplitude ratio of both low and high frequency data obtained from the reconstructed seismic data clearly show spatial distribution of gas and water in reef reservoirs.

  3. Stability and design criteria studies for compressed air energy storage reservoirs. Progress report, FY 1977.

    Smith, G.C.; Stottlemyre, J.A.; Wiles, L.E.; Loscutoff, W.V.; Pincus, H.J.


    Progress made during FY-1977 in establishing design criteria to ensure the successful operation and long-term stability of Compressed Air Energy Storage (CAES) reservoirs in underground porous media, such as aquifers is summarized. The formulation of pertinent criteria is important since the long-term stability of air storage reservoirs is probably the item of greatest risk to the successful demonstration and commercialization of the CAES concept. The study has been divided into four phases: (1) state-of-the-art survey, (2) analytical modeling studies, (3) laboratory studies, and (4) field testing. The first of these phases, the state-of-the-art survey for air storage in porous reservoirs, has been completed on schedule and is reported in Section 2. Sections 3 and 4 are progress reports on Phases 2 and 3. No work has been done on Phase 4. It is planned that the field testing phase of this study will be carried out in conjunction with the Department of Energy/Electric Power Research Institute (DOE/EPRI) CAES Demonstration Program. This phase is not scheduled to begin until FY-1979.

  4. Environmental and Water Quality Operational Studies: An Assessment of Reservoir Mixing Processes


    constituents in the hypo- limnion . Bottom withdrawal can also decrease the thermal stability of the reservoir by depleting the colder layer i, m/sec Equation 44 was used to incorporate variable mixing into the hypo- limnion of a lake. Since wind-generated TKE can indirectly enter...mental Study of Diffusion Characteristics in the Thermocline and Hypo- limnion Regions of Lake Ontario," Proceedings of the Sixteenth Con- ference on

  5. A Study of Thin Sandstone Reservoirs by High-resolution Seismic Inversion

    Ning Songhua


    In this paper seismic inversion was used as a key technique and the seismic wavelet most suitable to the actual underground situation was extracted with the higher-order statistics algorithm. The wavelets extracted in this way and the wavelets extracted with the seismic statistics techniques were used separately for inverting the seismic data of the southern part of Tahe oilfield, Tarim basin. The results showed that the resolution of the wavelet inversion with the higher-order statistics method was greatly improved, and the wavelet-inverted section could better distinguish the thin sandstone reservoirs of the upper and lower Carboniferous and their lateral distribution, providing a reliable basis of analysis for the study of thin sandstone reservoirs.

  6. Sediment Deposition Pattern and Flow Conditions in the Three Gorges Reservoir: A Physical Model Study

    王兴奎; 邵学军; 李丹勋


    Sedimentation in the Three Gorges Reservoir will greatly affect future project functions, such as power generation and navigation, after 50 years of operation. This paper presents results of a physical model study, which indicate that the capacity of both the discharge tunnel and the power plant outlet could be impaired by sediment deposition in front of the dam after 50 years, affecting both the hydropower head and navigation. A flow training scheme based on the third-stage cofferdam for the dam construction is proposed to regulate the flow pattern and control deposition in the near-dam region of the reservoir. This flow training scenario can effectively reduce deposition in the physical model.

  7. Game theory and fuzzy programming approaches for bi-objective optimization of reservoir watershed management: a case study in Namazgah reservoir.

    Üçler, N; Engin, G Onkal; Köçken, H G; Öncel, M S


    In this study, game theory and fuzzy programming approaches were used to balance economic and environmental impacts in the Namazgah reservoir, Turkey. The main goals identified were to maximize economic benefits of land use and to protect water quality of reservoir and land resources. Total phosphorous load (kg ha(-1) year(-1)) and economic income (USD ha(-1) year(-1)) from land use were determined as environmental value and economic value, respectively. The surface area of existing land use types, which are grouped under 10 headings according to the investigations on the watershed area, and the constraint values for the watershed were calculated using aerial photos, master plans, and basin slope map. The results of fuzzy programming approach were found to be very close to the results of the game theory model. It was concluded that the amount of fertilizer used in the current situation presents a danger to the reservoir and, therefore, unnecessary fertilizer use should be prevented. Additionally, nuts, fruit, and vegetable cultivation, instead of wheat and corn cultivation, was found to be more suitable due to their high economic income and low total phosphorus (TP) load. Apart from agricultural activities, livestock farming should also be considered in the area as a second source of income. It is believed that the results obtained in this study will help decision makers to identify possible problems of the watershed.

  8. Convergence in the Bilingual Lexicon: A Pre-registered Replication of Previous Studies

    White, Anne; Malt, Barbara C.; Storms, Gert


    Naming patterns of bilinguals have been found to converge and form a new intermediate language system from elements of both the bilinguals’ languages. This converged naming pattern differs from the monolingual naming patterns of both a bilingual’s languages. We conducted a pre-registered replication study of experiments addressing the question whether there is a convergence between a bilingual’s both lexicons. The replication used an enlarged set of stimuli of common household containers, providing generalizability, and more reliable representations of the semantic domain. Both an analysis at the group-level and at the individual level of the correlations between naming patterns reject the two-pattern hypothesis that poses that bilinguals use two monolingual-like naming patterns, one for each of their two languages. However, the results of the original study and the replication comply with the one-pattern hypothesis, which poses that bilinguals converge the naming patterns of their two languages and form a compromise. Since this convergence is only partial the naming pattern in bilinguals corresponds to a moderate version of the one-pattern hypothesis. These findings are further confirmed by a representation of the semantic domain in a multidimensional space and the finding of shorter distances between bilingual category centers than monolingual category centers in this multidimensional space both in the original and in the replication study. PMID:28167921

  9. A comparative chemometric study for water quality expertise of the Athenian water reservoirs.

    Farmaki, Eleni G; Thomaidis, Nikolaos S; Simeonov, Vasil; Efstathiou, Constantinos E


    The aim of the present study is to compare the application of unsupervised and supervised pattern recognition techniques for the quality assessment and classification of the reservoirs used as the source for the domestic and industrial water supply of the city of Athens, Greece. A new optimization strategy for sampling, monitoring, and water management is proposed. During the period of October 2006 to April 2007, 89 samples were collected from the three water reservoirs (Iliki, Mornos, and Marathon), and 13 parameters (metals and metalloids) were analytically determined. Generally, all the elements were found to fluctuate at very low levels, especially for Mornos that comprises the main water reservoir of Athens. Iliki and Marathon showed relatively elevated values, compared to Mornos, but below the legislative limits. Multivariate unsupervised statistical techniques, such as factor analysis/principal components analysis, and cluster analysis and supervised ones, like discriminant analysis and classification trees, were applied to the data set, and their classification abilities were compared. All the chemometric techniques successfully revealed the critical variables and described the similarities and dissimilarities among the sampling points, emphasizing the individual characteristics in every sample and revealing the sources of elements in the region. New data from posterior samplings (November and December 2007) were used for the validation of the supervised techniques. Finally, water management strategies were proposed concerning the sampling points and representative parameters.

  10. Feasibility Study on Steam and Gas Push with Dual Horizontal Wells in a Moderate-Depth Heavy Oil Reservoir

    Jie Fan; Xiangfang Li; Tianjie Qin


    Non-condensable gas (NCG) with steam co-injection makes steam assisted gravity drainage less energy-intensive as well as reduces greenhouse gas emission and water consumption. Numerous studies have shown that the technology called steam and gas push (SAGP) is feasible for heavy oil and bitumen. However, most of these studies have focused on shallow heavy oil reservoirs and only a few works have investigated moderate-depth heavy oil reservoirs. In this study, laboratory experiments...

  11. Randomized phase 2 study of obinutuzumab monotherapy in symptomatic, previously untreated chronic lymphocytic leukemia.

    Byrd, John C; Flynn, Joseph M; Kipps, Thomas J; Boxer, Michael; Kolibaba, Kathryn S; Carlile, David J; Fingerle-Rowson, Guenter; Tyson, Nicola; Hirata, Jamie; Sharman, Jeff P


    Obinutuzumab is a glycoengineered, type 2 anti-CD20 humanized antibody with single-agent activity in relapsed chronic lymphocytic leukemia (CLL). With other CD20 antibodies, a dose-response relationship has been shown. We therefore performed a randomized phase 2 study in symptomatic, untreated CLL patients to evaluate if an obinutuzumab dose response exists. Obinutuzumab was given at a dose of 1000 mg (100 mg IV day 1, 900 mg day 2, 1000 mg day 8 and day 15 of cycle 1; 1000 mg day 1 of cycles 2-8) or 2000 mg (100 mg IV day 1, 900 mg day 2, 1000 mg day 3, 2000 mg day 8 and day 15 of cycle 1; 2000 mg day 1 of cycles 2-8). The primary end point was overall response rate (ORR). Eighty patients were enrolled with similar demographics: median age 67 years, 41% high-risk Rai disease, and 10% del(17p)(13.1). ORR (67% vs 49%, P = .08) and complete response (CR) or CR with incomplete cytopenia response (20% vs 5%) favored 2000 mg obinutuzumab. Overall, therapy was well tolerated, and infusion events were manageable. This study demonstrates significant efficacy of obinutuzumab monotherapy, for 1000 mg as well as for 2000 mg, in untreated CLL patients with acceptable toxicity. Although exploratory, a dose-response relationship may exist, but its relevance to improving progression-free survival is uncertain and will require further follow-up. This trial was registered at as #NCT01414205.




    Full Text Available With the world - wide rising trend of caesarean delivery (CD, modern obstetric practice deals with a new group of mothers carrying reproductive performance upon a scarred uterus with obvious risk in feto - maternal outcome. AIMS: (1 To analyse the maternal & neonatal outcome in post - caesarean pregnancy. (2 To evaluate the factors influencing outcome in such cases. Design : Observational analytical study. MATERIALS & METHODS: The present study was carried out over two years (2010 - 11 taking consecutive 100 p ost - caesarean cases as admitted on my admission days & delivered in BR Singh Hospital. Data collection was done by interview technique along with hospital records. ANALYSIS USED: Percentage analysis was most often done. Categorical variables were compared with chi - square test; P value was calculated with 2012 Graphpad Software. Relative risk (RR & Odd ratio (OR were calculated with 1993 - 2012 Medcalc Software bvba (Version 12.3.0. All statistical tests were evaluated at the 0.05 significance level. RESULT S: Post - caesarean pregnancy rate was 26.02%. Vaginal birth after caesarean (VBAC incidence was 22% whereas VBAC success on trial of labour was 55%. VBAC gave best morbidity outcome (18.18% & 27.27%. But failed VBAC cases result more significant maternal morbidity (RR=3.97, P=0.0037 & NICU admission was also found highest in failed VBAC cases (38.89%. Maternal and neonatal morbidity were significantly high when scar integrity was lost; also significantly co - related with elderly mothers (>35 yrs., un - boo ked cases & non - admitted cases undergone repeat CD. CONCLUSIONS: Post - caesarean cases need meticulous antenatal check - up & mandatory institutional delivery with proper selection of mode of confinement to have a better maternal & neonatal outcome

  13. Reservoir geochemistry. A reservoir engineering perspective

    England, W.A. [BP Exploration, Chertsey Road, Sunbury-on-Thames, Middlesex, TW16 7LN (United Kingdom)


    This paper reviews the applications of reservoir geochemistry from a reservoir engineering point of view. Some of the main tasks of reservoir engineering are discussed with an emphasis on the importance of appraising reservoirs in the pre-development stage. A brief review of the principal methods and applications of reservoir geochemistry are given, in the context of applications to reservoir engineering problems. The importance of compositional differences in fluid samples from different depths or spatial locations is discussed in connection with the identification of internal flow barriers. The importance of understanding the magnitude and origin of vertical compositional gradients is emphasised because of possible confusion with purely lateral changes. The geochemical origin and rate of dissipation of compositional differences over geological time is discussed. Geochemical techniques suitable for bulk petroleum fluid samples include GC fingerprinting, GCMS, isotopic and PVT measurements. Core sample petroleum extracts may also be studied by standard geochemical methods but with the added complication of possible contamination by drilling mud. Aqueous phase residual salt extracts can be studied by strontium isotope analysis from core samples. Petroleum fluid inclusions allow the possibility of establishing the composition of paleo-accumulations. The problems in predicting flow barriers from geochemical measurements are discussed in terms of 'false positives' and 'false negatives'. Suggestions are made for areas that need further development in order to encourage the wider acceptance and application of reservoir geochemistry by the reservoir engineering community. The importance of integrating all available data is emphasised. Reservoir geochemistry may be applied to a range of practical engineering problems including production allocation, reservoir compartmentalisation, and the prediction of gravitational gradients. In this review

  14. Life cycle impact assessment of ammonia production in Algeria: A comparison with previous studies

    Makhlouf, Ali, E-mail:; Serradj, Tayeb; Cheniti, Hamza


    In this paper, a Life Cycle Analysis (LCA) from “cradle to gate” of one anhydrous ton of ammonia with a purity of 99% was achieved. Particularly, the energy and environmental performance of the product (ammonia) were evaluated. The eco-profile of the product and the share of each stage of the Life Cycle on the whole environmental impacts have been evaluated. The flows of material and energy for each phase of the life cycle were counted and the associated environmental problems were identified. Evaluation of the impact was achieved using GEMIS 4.7 software. The primary data collection was executed at the production installations located in Algeria (Annaba locality). The analysis was conducted according to the LCA standards ISO 14040 series. The results show that Cumulative Energy Requirement (CER) is of 51.945 × 10{sup 3} MJ/t of ammonia, which is higher than the global average. Global Warming Potential (GWP) is of 1.44 t CO{sub 2} eq/t of ammonia; this value is lower than the world average. Tropospheric ozone precursor and Acidification are also studied in this article, their values are: 549.3 × 10{sup −6} t NMVOC eq and 259.3 × 10{sup −6} t SO{sub 2} eq respectively.

  15. Experimental bluetongue virus infection of sheep; effect of previous vaccination: clinical and immunologic studies.

    Mahrt, C R; Osburn, B I


    Clinical and immunologic responses of sheep to vaccination and subsequent bluetongue virus (BTV) challenge exposure were studied and compared with those of non-vaccinated sheep. Sheep were vaccinated with inactivated BTV administered with aluminum hydroxide and cimetidine or levamisole. After sheep were vaccinated, precipitating group-specific antibodies to BTV were detected, but serotype-specific neutralizing antibodies were not detected. Cellular immune responses (lymphocyte blastogenesis) to BTV were not detected. After virulent BTV challenge exposure, vaccinated and nonvaccinated sheep developed acute clinical disease of similar severity. Clinical signs included hyperemia and petechiae of oral mucosa and coronary bands of the feet, excess salivation, nasal discharge with crusting, ulceration of the muzzle, and edema of lips and intermandibular space. Marked increases in serum creatine kinase activity were associated with stiff gait, reluctance to move, and vomiting. Fever and leukopenia were detected in most of the challenge-exposed sheep. Viremia and neutralizing antibodies were detected in vaccinated and nonvaccinated sheep after challenge exposure. Bluetongue virus-specific reaginic antibodies were not detected in sera from any of the sheep when the passive cutaneous anaphylaxis test was used.

  16. Phase III Randomized Study of Bendamustine Compared With Chlorambucil in Previously Untreated Patients With Chronic Lymphocytic Leukemia

    Wolfgang U. Knauf; Toshko Lissichkov; Ali Aldaoud; Anna Liberati; Javier Loscertales; Raoul Herbrecht; Gunnar Juliusson; Gerhard Postner; Liana Gercheva; Stefan Goranov; Martin Becker; Hans-Joerg Fricke; Francoise Huguet; Ilaria Del Giudice; Peter Klein; Lothar Tremmel; Karlheinz Merkle; Marco Montillo


    This randomized, open-label, parallel-group, multicenter study was designed to compare the efficacy and safety of bendamustine and chlorambucil in previously untreated patients with advanced (Binet stage B or C...

  17. Mechanism study on a plague outbreak driven by the construction of a large reservoir in southwest china (surveillance from 2000-2015).

    Wang, Xin; Wei, Xiaoyu; Song, Zhizhong; Wang, Mingliu; Xi, Jinxiao; Liang, Junrong; Liang, Yun; Duan, Ran; Tian, Kecheng; Zhao, Yong; Tang, Guangpeng; You, Lv; Yang, Guirong; Liu, Xuebin; Chen, Yuhuang; Zeng, Jun; Wu, Shengrong; Luo, Shoujun; Qin, Gang; Hao, Huijing; Jing, Huaiqi


    Plague, a Yersinia pestis infection, is a fatal disease with tremendous transmission capacity. However, the mechanism of how the pathogen stays in a reservoir, circulates and then re-emerges is an enigma. We studied a plague outbreak caused by the construction of a large reservoir in southwest China followed 16-years' surveillance. The results show the prevalence of plague within the natural plague focus is closely related to the stability of local ecology. Before and during the decade of construction the reservoir on the Nanpan River, no confirmed plague has ever emerged. With the impoundment of reservoir and destruction of drowned farmland and vegetation, the infected rodent population previously dispersed was concentrated together in a flood-free area and turned a rest focus alive. Human plague broke out after the enzootic plague via the flea bite. With the construction completed and ecology gradually of human residential environment, animal population and type of vegetation settling down to a new balance, the natural plague foci returned to a rest period. With the rodent density decreased as some of them died, the flea density increased as the rodents lived near or in local farm houses where had more domestic animals, and human has a more concentrated population. In contrast, in the Himalayan marmot foci of the Qinghai-Tibet Plateau in the Qilian Mountains. There are few human inhabitants and the local ecology is relatively stable; plague is prevalence, showing no rest period. Thus the plague can be significantly affected by ecological shifts.

  18. An integrated study of the Grayburg/San Andres reservoir, Foster and South Cowden Fields, Ector County, Texas

    Reeves, J.J.; Trentham, R.C.; Weinbrandt, R.; Flanders, W.


    An enhanced oil recovery project is being proposed in response to the US Department of Energy`s Near Term Class 2 Oil Program for shallow shelf carbonate reservoirs. Productivity problems associated with a shallow shelf carbonate reservoir will be addressed by integrating high resolution 3-D seismic data, reservoir characterization techniques, and 3-D reservoir simulation. The purpose of the study is to yield results which will preserve access to existing well bores by identifying additional reserves. The general approach will be to shoot a 3-D seismic survey designed specifically for imaging the Grayburg/San Andres interval. The data will then be processed and interpreted using state of the art techniques aimed at identifying porosity, permeability barriers and their zones within the reservoir. A technical team will integrate existing geological data with the geophysical results of the seismic survey for detailed reservoir characterization. These results will be used in a 3-D reservoir simulation model to delineate flow units. A field demonstration of infill drilling and water flood development will follow. The authors expect the results of this study to demonstrate a methodology for reservoir characterization which is feasible for the independent operator. Furthermore, it will provide one of the first public demonstrations of the enhancement of reservoir characterization using high resolution 3-D seismic data. Additionally, it will showcase the improvement of water flood development by using an integrated multi-disciplinary approach, and the addition of otherwise unrecovered reserves by selective infill drilling. This report has four sections: summary of preliminary data; plots and maps; well production data; and well data.

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

    Liang Wang


    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.

  20. Enhanced heavy oil recovery for carbonate reservoirs integrating cross-well seismic–a synthetic Wafra case study

    Katterbauer, Klemens


    Heavy oil recovery has been a major focus in the oil and gas industry to counter the rapid depletion of conventional reservoirs. Various techniques for enhancing the recovery of heavy oil were developed and pilot-tested, with steam drive techniques proven in most circumstances to be successful and economically viable. The Wafra field in Saudi Arabia is at the forefront of utilizing steam recovery for carbonate heavy oil reservoirs in the Middle East. With growing injection volumes, tracking the steam evolution within the reservoir and characterizing the formation, especially in terms of its porosity and permeability heterogeneity, are key objectives for sound economic decisions and enhanced production forecasts. We have developed an integrated reservoir history matching framework using ensemble based techniques incorporating seismic data for enhancing reservoir characterization and improving history matches. Examining the performance on a synthetic field study of the Wafra field, we could demonstrate the improved characterization of the reservoir formation, determining more accurately the position of the steam chambers and obtaining more reliable forecasts of the reservoir’s recovery potential. History matching results are fairly robust even for noise levels up to 30%. The results demonstrate the potential of the integration of full-waveform seismic data for steam drive reservoir characterization and increased recovery efficiency.

  1. Geothermal energy from the Main Karoo Basin (South Africa): An outcrop analogue study of Permian sandstone reservoir formations

    Campbell, Stuart A.; Lenhardt, Nils; Dippenaar, Matthys A.; Götz, Annette E.


    The geothermal potential of the South African Main Karoo Basin has not been addressed in the past, although thick siliciclastic successions in geothermal prone depths are promising target reservoir formations. A first assessment of the geothermal potential of the Karoo Basin is based on petro- and thermophysical data gained from an outcrop analogue study of Permian sandstones in the Eastern Cape Province, and evaluation of groundwater temperature and heat flow values from literature. A volumetric approach of the sandstones' reservoir potential leads to a first estimation of 2240 TWh (8.0 EJ) of power generation within the central and southern part of the basin. Comparison with data from other sedimentary basins where deep geothermal reservoirs are identified shows the high potential of the Karoo for future geothermal resource exploration, development and production. The mainly low permeability lithotypes may be operated as stimulated systems, depending on the fracture porosity in the deeper subsurface. In some areas auto-convective thermal water circulation might be expected and direct heat use becomes reasonable. The data presented here serve to identify exploration areas and are valuable attributes for reservoir modeling, contributing to (1) a reliable reservoir prognosis, (2) the decision of potential reservoir stimulation, and (3) the planning of long-term efficient reservoir utilization.

  2. Hydrodynamic influence on reservoir sustainability in semi-arid climate: A physicochemical and environmental isotopic study.

    Ammar, Rawaa; Kazpard, Véronique; El Samrani, Antoine G; Amacha, Nabil; Saad, Zeinab; Chou, Lei


    Water scarcity and increasing water demand require the development of water management plans such as establishing artificial lakes and dams. Plans to meet water needs are faced by uprising challenges to improve water quality and to ensure the sustainability of hydro-projects. Environmental isotopes coupled to water physicochemical characteristics were investigated over a biennial cycle to assess both geomorphological and environmental impacts on the water quality of a reservoir situated in an intensively used agricultural watershed under a Mediterranean semi-arid climate. The particularity of the semi-arid climate and the diverse topography generate a continental and orographic rain effect on the isotopic composition of precipitation and the water recharged sources. The studied reservoir responds quickly to land-use activities and climatic changes as reflected by temporal and spatial variations of water chemistry and isotopic composition. Increasing changes in precipitation rate and dry periods significantly modified the water isotopic composition in the reservoir. During the first year, hydrogen (δD) and oxygen (δ(18)O) isotopes are depleted by 6 and 2‰ between dry and wet season, respectively. While a shift of -2‰ for δD and -1‰ for δ(18)O was detected during the second annual cycle. Environmental isotopic compositions demonstrate for the first time the occurrence of groundwater inflow to the central (Cz) and dam (Dz) zones of the Qaraaoun reservoir. The Cz and Dz can be considered as open water bodies subjected to dilution by groundwater inflow, which induces vertical mixing and reverse isotopic stratification of the water column. In the contrary, the river mouth zone acts as a closed system without groundwater intrusion, where heavy water accumulates and may act as a sink for contaminants during dry season. Groundwater influx acts as a dilution factor that renews the hypolimnion, and minimizes the perturbations induced by both internal


    Ristiyanto -


    Full Text Available ENGLISHReservoir Reference Study Collection Disease, particularly rats have been conducted in several areas such as the enzootic plague area in the district of Nongkojajar, Pasuruan, East Java and Ciwidey district, Bandung regency, West Java. These were organized in May-October 2007. The method used for the collection and reference reservoir of disease is rodentia survey methods. Result of the reference collection reservoir of disease is the house rat Rattus tanezumi Nongkojajar found either in the of Pasuruan, East Java (3 rats and the District of Ciwidey (4 rats. Polynesian rat R. exulans, three rats were only found in the District Nongkojajar, whereas three rats R. tiomanicus, three rats were found in Ciwidey. In addition another types of mice were also found 1 Insectivora mice Suncus murinus in the District Ciwidey. Type of rats captured in habitat homes in the District Ciwidey Bandung regency, West Java and Pasuruan, East Java is the same type, namely house rat Rattus tanezumi. Types of mice caught in the habitat garden in the District Ciwidey Bandung regency, West Java (tiomanicus R. tree rats were different from mice found in Pasuruan, East Java (Polynesian rat R. exulans. Local environment in plague enzootic area in Pasuruan, East Java is mountainous and forest conservation area Bromo-Tengger, while District Ciwidey, Bandung is the highland tourism areas / mountainous and agricultural areas.INDONESIAKoleksi referensi reservoir penyakit khususnya tikus telah dilakukan di beberapa daerah enzootik pes seperti di Kecamatan Nongkojajar, Kabupaten Pasuruan, Jawa Timur dan Kecamatan Ciwidey, Kabupaten Bandung, Jawa Barat. Kegiatan tersebut dilaksanakan pada bulan Mei-Oktober 2007. Metode yang digunakan untuk koleksi dan referensi reservoir penyakit adalah metode survei rodensia. Hasil koleksi referensi reservoir penyakit adalah tikus rumah Rattus tanezumi ditemukan baik di Kecamatan Nongkojajar, Kabupaten Pasuruan, Jawa Timur (3 ekor maupun

  4. MHD coal-fired flow facility baseline water-quality study. Woods Reservoir, May 1979-April 1980

    Cooper, J.


    The Department of Energy (DOE) Magnetohydrodynamics (MHD) Coal-Fired Flow Facility (CFFF) is located on Woods Reservoir at The University of Tennessee Space Institute (UTSI). Part of the role of UTSI, as participants in the DOE program, is to document environmental aspects of coal-fired MHD. In early 1979, prior to operation of the CFFF, a water quality program was initiated to establish baseline conditions for the reservoir. The study was designed to provide an accurate assessment of water quality which could be used as a basis for comparison to evaluate the impact, if any, of the plant operation on the aquatic environment. Results of a one year baseline study of water quality on Woods Reservoir are presented in this report. The key findings are that this reservoir is a eutrophic lake. Its predominant ions are calcium and bicarbonate and its pH is circumneutral.

  5. Effective Teaching and Learning Environments and Principal Self-Efficacy in Oklahoma: Replication of a Previous Study

    Berry, Kathryn


    The purpose of this study was to replicate a previous study by Smith et al. (2006) that explored principal self-efficacy beliefs for facilitating effective instructional environments at their schools. There has been limited research conducted on principal's self-efficacy, and the studies that have been completed on the topic have not been…

  6. Geophysical and geological investigations of subsurface reservoirs : case studies of Spitsbergen, Norway

    Baelum, Karoline


    The thesis gives a description of the subsurface and outcrop geology at a number of localities on Svalbard through a selection of various geophysical and geological methods. The localities represent a series of geological settings of varying scale, from near surface paleokarst and glacial environments to large scale geological features such as fault zones, grabens and dolerite intrusions. The geophysical and geological methods deployed likewise represent both detailed small scale investigations such as Lidar, radar and geoelectric investigations on and near the surface, and seismic investigations covering larger areas to a depth of several kilometers. The overall aim for all the studies has been to better understand reservoir and cap rock/ice systems in a barren arctic desert characterized by a frozen ground that challenges common geophysical methods. The investigations undertaken in connection with this thesis cover several areas The first part addresses the Billefjorden fault zone (BFZ) with its eastern hanging wall classic rift-basin. This fault zone can be traced for more than 200 km as a lineament that runs almost the entire length of Spitsbergen, from Wijdefjorden in the north to Storfjorden in the south. The seismic data along with surface observations and Lidar scans illustrate the long and complicated history of the BFZ and associated basin, from the initial formation via linkage of reverse faults in the Devonian, through Carboniferous reactivation as a normal fault with adjacent rift-basin in an extensional tectonic regime, to finally Tertiary contraction seen as fault reactivation and basin inversion in connection with the formation of the west-coast fold and thrust-belt. Especially the development of the Carboniferous rift-basin is of interest. An integrated study by seismic and georadar mapping, and Lidar data interpretation combined with outcrop analysis of faults and sedimentary succession, have shed new, detailed information on the good sandstone

  7. Simulation studies to evaluate the effect of fracture closure on the performance of naturally fractured reservoirs. Annual report


    The first of a three-year research program to evaluate the effect of fracture closure on the recovery of oil and gas from naturally fractured reservoirs has been completed. The objectives of the study are to (1) evaluate the reservoir conditions where fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. Simulation studies were conducted with a dual porosity simulator capable of simulating the performance of vertical and horizontal wells. Each simulator was initialized using properties typical of the Austin Chalk reservoir in Pearsall Field, Texas. Simulations of both vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure change. Sensitivity runs indicate that the simulator is predicting the effects of critical reservoir parameters in a logical and consistent manner. The results to-date confirm that horizontal wells can increase both oil recovery rate and total oil recovery from naturally fractured reservoirs. The year one simulation results will provide the baseline for the ongoing study which will evaluate the performance degradation caused by the sensitivity of fracture permeability to pressure change, and investigate fluid injection pressure maintenance as a means to improve oil recovery performance. The study is likely to conclude that fracture closure decreases oil recovery and that pressure support achieved through fluid injection could be beneficial in improving recovery.

  8. Environmental Impact Assessment of reservoir construction: new perspectives for restoration economy, and development: the Belo Monte Power Plant case study

    JG. Tundisi

    Full Text Available Abstract The Environmental Impact Assessment of reservoir construction can be viewed as a new strategic perspective for the economic development of a region. Based on the principles of a watershed approach a interdisciplinary and multidisciplinary systemic view including biogeophysiographical, economic and socio environmental studies the new vision of a EIA provides a basic substratum for the restoration economy and an advanced model for the true development much well ahead of the modernization aspects of the project of a reservoir construction.

  9. Study of Mg-based materials to be used in a functional solid state hydrogen reservoir for vehicular applications

    Maddalena, Amedeo; Petris, Milo; Palade, Petru; Sartori, Sabrina; Principi, Giovanni [Settore Materiali and CNISM, Dipartimento di Ingegneria Meccanica, Universita di Padova, via Marzolo 9, 35131 Padova (Italy); Settimo, Eliseo [Celco-Profil, via dell' Artigianato 4, 30030 Vigonovo (Venezia) (Italy); Molinas, Bernardo [Venezia Tecnologie, via delle Industrie 39, 30175 Marghera (Venezia) (Italy); Lo Russo, Sergio [Dipartimento di Fisica and CNISM, Universita di Padova, via Marzolo 8, 35131 Padova (Italy)


    Powders mixtures of nanosized MgH{sub 2} and suitable additives, obtained by high energy milling, have been studied as materials to be used in a functional solid state hydrogen reservoir. A prototype of a two stages reservoir is under development (patent pending). The hydrogen release from the main stage, with high capacity Mg-based hydrides, is primed by a primer stage containing commercial hydrides able to operate at room temperature. (author)

  10. Optimized reservoir operation model of regional wind and hydro power integration. Case study: Zambezi Basin and South Africa

    Gebretsadik, Yohannes; Fant, Chas; Strzepek, Kenneth


    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 hydro power. A combined water resources model for a system of reservoirs that implements a priority based linear programing algorithm and a single node power grid system model is implemented on an hourly time step. This model was then accompanied by a genetic algorithm solver to determine optimum operation targets...

  11. Environmental Impact Assessment of reservoir construction: new perspectives for restoration economy, and development: the Belo Monte Power Plant case study.

    Tundisi, J G; Matsumura-Tundisi, T; Tundisi, J E M


    The Environmental Impact Assessment of reservoir construction can be viewed as a new strategic perspective for the economic development of a region. Based on the principles of a watershed approach a interdisciplinary and multidisciplinary systemic view including biogeophysiographical, economic and socio environmental studies the new vision of a EIA provides a basic substratum for the restoration economy and an advanced model for the true development much well ahead of the modernization aspects of the project of a reservoir construction.

  12. Experiment and Simulation Study on the Special Phase Behavior of Huachang Near-Critical Condensate Gas Reservoir Fluid

    Dali Hou


    Full Text Available Due to the special phase behavior of near-critical fluid, the development approaches of near-critical condensate gas and near-critical volatile oil reservoirs differ from conventional oil and gas reservoirs. In the near-critical region, slightly reduced pressure may result in considerable change in gas and liquid composition since a large amount of gas or retrograde condensate liquid is generated. It is of significance to gain insight into the composition variation of near-critical reservoir during the depletion development. In our study, we performed a series of PVT experiments on a real near-critical gas condensate reservoir fluid. In addition to the experimental studies, a commercial simulator combined with the PREOS model was utilized to study retrograde condensate characteristics and reevaporation mechanism of condensate oil with CO2 injection based on vapor-liquid phase equilibrium thermodynamic theory. The research shows that when reservoir pressure drops below a certain pressure, the variation of retrograde condensate liquid saturation of the residual reservoir fluid exhibits the phase behavior of volatile oil.

  13. Succession of phytoplankton assemblages in response to large-scale reservoir operation: a case study in a tributary of the Three Gorges Reservoir, China.

    Xiao, Yan; Li, Zhe; Guo, Jinsong; Fang, Fang; Smith, Val H


    The Three Gorges Dam (TGD) has greatly altered ecological and environmental conditions within the reservoir region, but it is not known how these changes affect phytoplankton structure and dynamics. Here, a bimonthly monitoring program was implemented from 2007 to 2009 to study the impact of damming on phytoplankton assemblages in the backwater area of the Pengxi River (PBA). By application of the phytoplankton functional group (C strategists, competitive species; S strategists, stress-tolerant species; R strategists, rapid propagation species), seasonal changes in phytoplankton relative to environmental variations were evaluated using ordination analysis. Seasonal patterns of phytoplankton dynamics were detected during this study, with CS/S strategists causing algal blooms from mid-spring to early summer, CS/CR strategists often observed during flood season, and CS strategists dominant during mid-autumn. CR/R groups dominated during winter and caused algal blooms in February. Our results indicated that phytoplankton assemblages were directly related to reservoir operation effects. Generally, the TGD had a low water level during flood season, resulting in a relatively short hydraulic retention time and intensive variability, which supported the cooccurrence of CS and CR species. During the winter drought season, water storage in the TGD increased the water level and the hydraulic retention time in the PBA, enabling R/CR strategists to overcome the sedimentation effect and to out-compete S/CS species in winter. As expected, these diversity patterns were significantly correlated with the hydraulic retention time and nutrient limitation pattern in the PBA. This study provides strategic insight for evaluating the impacts of reservoir operations on phytoplankton adaptation.

  14. Local Water Management of Small Reservoirs: Lessons from Two Case Studies in Burkina Faso

    Hilmy Sally


    Full Text Available Burkina Faso is actively pursuing the implementation of Integrated Water Resources Management (IWRM in its development plans. Several policy and institutional mechanisms have been put in place, including the adoption of a national IWRM action plan (PAGIRE and the establishment so far of 30 local water management committees (Comités Locaux de l’Eau, or CLE. The stated purpose of the CLE is to take responsibility for managing water at sub-basin level. The two case studies discussed in this paper illustrate gaps between the policy objective of promoting IWRM on the one hand, and the realities associated with its practical on-the-ground implementation on the other. A significant adjustment that occurred in practice is the fact that the two CLE studied have been set up as entities focused on reservoir management, whereas it is envisioned that a CLE would constitute a platform for sub-basin management. This reflects a concern to minimise conflict and optimally manage the country’s primary water resource and illustrates the type of pragmatic actions that have to be taken to make IWRM a reality. It is also observed that the local water management committees have not been able to satisfactorily address questions regarding access to, and allocation of, water, which are crucial for the satisfactory functioning of the reservoirs. Water resources in the reservoirs appear to be controlled by the dominant user. In order to correct this trend, measures to build mutual trust and confidence among water users 'condemned' to work together to manage their common resource are suggested, foremost of which is the need to collect and share reliable data. Awareness of power relationships among water user groups and building on functioning, already existing formal or informal arrangements for water sharing are key determinants for successful implementation of the water reform process underway.

  15. Fractured reservoir analogs: case study of paelocirculation markers on Tamariu's Granite.

    Bertrand, Lionel; Legarzic, Edouard; Geraud, Yves; Diraison, Marc


    In fractured crystalline reservoirs, the grain matrix has in general a very low permeability and the fluid flow is localized in the fracture pattern. The flow in such fracture network is generally complicated to characterize, in on hand because many parameters (length, connectivity, aperture, tortuosity,…) are acting on the fluid flow, in other hand because the fractures at a reservoir scale using seismic data are not easy to characterize. In fact, the only information we have on fracture in buried reservoir are at a local scale with boreholes and at a kilometric scale with seismic. The study of field analogs is one way to establish a better comprehension of the fracture pattern between those two scales. Regional and outcrop studies on Tamariu's granite, which outcrops on the Catalonian Coastal Ranges, has permit the characterization of the faults and fractures at different scales. The faults network defines different sizes of structural blocks bordered by faults. In an unfaulted structural block, the granite exhibits a fracture network filled with hydrothermal carbonates, markers of important paleofluid circulation. These carbonates were analysed at different scales using fracture mapping, calcimetry and microscopy on thin- sections in order to define the location and the volume of the carbonates precipitation and to have an estimation of the paleo-porosity used by the fluids in the fracture network. With precise fracture maps, we analysed the principal flow direction and the nature of the hydrothermal deposits. The same maps, combined with calcimetry measurements, allow us to quantify the 2D volume of porosity used by the paleofluids. We have quantified the carbonates in different areas of percolation: the main veins, breccias cimented by carbonates, fractured granite and poorly fractured granite. The percentage of paleofluids markers reaches to 3% of the granitic rock, and the main part of them are localized in some fractured corridor composed of mains veins

  16. A Physical Study of Converted Wave AVO in a Fractured Reservoir

    Chang, C. H.; Chang, Y. F.; Tsao, H. C.; Chang, J. W.


    Benefiting by the multicomponent seismic acquisition and processing techniques, the applications of converted waves in petroleum exploration is thus highlighted. A converted (C-) wave is initiated by a downward traveling P-wave that is converted on reflection to upcoming S-waves. Ascribing to its origins, C-wave takes the behaviors of P- and S-wave and becomes as one of the popular seismic attributes in the studies of a fractured reservoir. Making use of the scaled physical model, we aim on inspecting the azimuthal Amplitude Variation with Offset (AVO) of C-wave in a reservoir of vertically aligned fractures. In order to facilitate the objective of this study, reflection experiments were carried out on the orthogonal plane of a Horizontal Transversely Isotropic (HTI) model which is created to simulate a fractured reservoir. In laboratory manipulation, acoustic energy is triggered by a P-type transducer and the reflected energy is received an S-type transducer to detect the reflected energy, i.e. C-waves, originating by mode conversion. From fracture strike to facture normal, end-on shooting reflections were acquired from seven different directions. The angular interval in between the successive observation is 15 degrees. While viewing into the reflection profiles, events of P-, C1- and C2-waves can be readily identified. In the acquired profiles, the P-wave AVO is clearly observed and the phenomenon of C-wave splitting is revealed by the separation of traveltime-distance curves of C1- and C2-waves. However, it is aware of that the C-wave amplitudes are not simply varied or attenuated with offset in each observation. The complicated behaviors of C-wave AVO could be caused by the amount of energy, which is incident angle dependent, in reflected S-waves. Hence, our results indicate that the azimuthal C-wave AVO might not be a reliable seismic signature which can be used to delineate the fracture orientation of a fractured reservoir.

  17. The application study on the multi-scales integrated prediction method to fractured reservoir description

    Chen Shuang-Quan; Zeng Lian-Bo; Huang Ping; Sun Shao-Han; Zhang Wan-Lu; Li Xiang-Yang


    In this paper, we implement three scales of fracture integrated prediction study by classifying it to macro- (> 1/4λ), meso- (> 1/100λ and < 1/4λ) and micro- (< 1/100λ) scales. Based on the multi-scales rock physics modelling technique, the seismic azimuthal anisotropy characteristic is analyzed for distinguishing the fractures of meso-scale. Furthermore, by integrating geological core fracture description, image well-logging fracture interpretation, seismic attributes macro-scale fracture prediction and core slice micro-scale fracture characterization, an comprehensive multi-scale fracture prediction methodology and technique workfl ow are proposed by using geology, well-logging and seismic multi-attributes. Firstly, utilizing the geology core slice observation (Fractures description) and image well-logging data interpretation results, the main governing factors of fracture development are obtained, and then the control factors of the development of regional macro-scale fractures are carried out via modelling of the tectonic stress field. For the meso-scale fracture description, the poststack geometric attributes are used to describe the macro-scale fracture as well, the prestack attenuation seismic attribute is used to predict the meso-scale fracture. Finally, by combining lithological statistic inversion with superposed results of faults, the relationship of the meso-scale fractures, lithology and faults can be reasonably interpreted and the cause of meso-scale fractures can be verified. The micro-scale fracture description is mainly implemented by using the electron microscope scanning of cores. Therefore, the development of fractures in reservoirs is assessed by valuating three classes of fracture prediction results. An integrated fracture prediction application to a realfi eld in Sichuan basin, where limestone reservoir fractures developed, is implemented. The application results in the study area indicates that the proposed multi-scales integrated

  18. Maternal and perinatal outcomes of delivery after a previous Cesarean section in Enugu, Southeast Nigeria: a prospective observational study.

    Ugwu, George O; Iyoke, Chukwuemeka A; Onah, Hyacinth E; Egwuatu, Vincent E; Ezugwu, Frank O


    Obstetricians in developing countries appear generally reluctant to conduct vaginal delivery in women with a previous Cesarean because of lack of adequate facilities for optimal fetomaternal monitoring. To describe delivery outcomes among women with one previous Cesarean section at a tertiary hospital in Southeast Nigeria. This was a prospective observational study to determine maternal and perinatal outcomes of attempted vaginal birth after Cesarean sections (VBAC) following one previous Cesarean section. Analysis was done with SPSS statistical software version 17.0 for Windows using descriptive and inferential statistics at 95% level of confidence. Two thousand six hundred and ten women delivered in the center during the study period, of whom 395 had one previous Cesarean section. A total of 370 women with one previous Cesarean section had nonrecurrent indications, of whom 355 consenting pregnant women with one previous Cesarean section were studied. A majority of the women (320/355, 90.1%) preferred to have vaginal delivery despite the one previous Cesarean section. However, only approximately 54% (190/355) were found suitable for trial of VBAC, out of whom 50% (95/190 had successful VBAC. Ninety-five women (50.0%) had failed attempt at VBAC and were delivered by emergency Cesarean section while 35 women (9.8%) had emergency Cesarean section for other obstetric indications (apart from failed VBAC). There was no case of uterine rupture or neonatal and maternal deaths recorded in any group. Apgar scores of less than 7 in the first minute were significantly more frequent amongst women who had vaginal delivery when compared to those who had elective repeat Cesarean section (P=0.03). Most women who had one previous Cesarean delivery chose to undergo trial of VBAC, although only about half were considered suitable for VBAC. The maternal and fetal outcomes of trial of VBAC in selected women with one previous Cesarean delivery for non-recurrent indications were good

  19. Low robustness of increasing reservoir capacity for adaptation to climate change: A case study for an agricultural river basin

    Kim, Daeha; Eum, Hyung-Il


    With growing concerns of the uncertain climate change, investments in water infrastructures are considered as adaptation policies for water managers and stakeholders despite their negative impacts on the environment. Particularly in regions with limited water availability or conflicting demands, building reservoirs and/or augmenting their storage capacity were already adopted for alleviating influences of the climate change. This study provides a probabilistic assessment of climate change impacts on water scarcity in a river system regulated by an agricultural reservoir in South Korea, which already increased its storage capacity for water supply. For the assessment, we developed the climate response functions (CRFs) defined as relationships between bi-decadal system performance indicators (reservoir reliability and vulnerability) and corresponding climatic conditions, using hydrological models with 10,000-year long stochastic generation of daily precipitation and temperatures. The climate change impacts were assessed by plotting 52 downscaled climate projections of general circulation models (GCMs) on the CRFs. Results indicated that augmented reservoir capacity makes the reservoir system more sensitive to changes in long-term averages of precipitation and temperatures despite improved system performances. Increasing reservoir capacity is unlikely to be "no regret" adaptation policy for the river system. On the other hand, converting the planting strategy from transplanting to direct sowing (i.e., a demand control) could be a more robust to bi-decadal climatic changes based on CRFs and thus could be good to be a no-regret policy.

  20. Development of a study design and implementation plan to estimate juvenile salmon survival in Lookout Point Reservoir and other reservoirs of the Willamette Project, western Oregon

    Kock, Tobias J.; Perry, Russell W.; Monzyk, Fred R.; Pope, Adam C.; Plumb, John M.


    Survival estimates for juvenile salmon and steelhead fry in reservoirs impounded by high head dams are coveted data by resource managers.  However, this information is difficult to obtain because these fish are too small for tagging using conventional methods such as passive-integrated transponders or radio or acoustic transmitters.  We developed a study design and implementation plan to conduct a pilot evaluation that would assess the performance of two models for estimating fry survival in a field setting.  The first model is a staggered-release recovery model that was described by Skalski and others (2009) and Skalski (2016).  The second model is a parentage-based tagging N-mixture model that was developed and described in this document.  Both models are conceptually and statistically sound, but neither has been evaluated in the field.  In this document we provide an overview of a proposed study for 2017 in Lookout Point Reservoir, Oregon, that will evaluate survival of Chinook salmon fry using both models.  This approach will allow us to test each model and compare survival estimates, to determine model performance and better understand these study designs using field-collected data.

  1. Estimating the effect of current, previous and never use of drugs in studies based on prescription registries

    Nielsen, Lars Hougaard; Løkkegaard, Ellen; Andreasen, Anne Helms;


    PURPOSE: Many studies which investigate the effect of drugs categorize the exposure variable into never, current, and previous use of the study drug. When prescription registries are used to make this categorization, the exposure variable possibly gets misclassified since the registries do not ca...... with Hazard Ratios ranging from 1.68 to 1.78 for current use compared to never use. CONCLUSIONS: The findings suggest that it is possible to estimate the effect of never, current and previous use of HT on breast cancer using prescription data.......PURPOSE: Many studies which investigate the effect of drugs categorize the exposure variable into never, current, and previous use of the study drug. When prescription registries are used to make this categorization, the exposure variable possibly gets misclassified since the registries do...... not carry any information on the time of discontinuation of treatment.In this study, we investigated the amount of misclassification of exposure (never, current, previous use) to hormone therapy (HT) when the exposure variable was based on prescription data. Furthermore, we evaluated the significance...

  2. a Study of a High Frequency Miniature Reservoir-Less Pulse Tube

    Garaway, I.; Grossman, G.


    A miniature high frequency reservoir-less pulse tube cryocooler has been designed and tested in our laboratory. The cryocooler having a regenerator length of 12.0 mm and an overall volume of 2.3cc (excluding the compressor) reached a low temperature of 146K and provided 100mW of cooling at 160K. This experimental study shows that it is possible to miniaturize a pulse tube cryocooler to very short regenerator lengths by implementing a few basic principles: Most importantly, high operating frequencies at small tidal displacements, a regenerator matrix with small hydraulic diameters, and increased helium fill pressures. This study also shows that as the operating frequency of a miniature cryocooler increases, the reservoir becomes less necessary as a phase shifting device. At higher frequencies and appropriate inertance tube geometries, the impedance and capacitance of the inertance tube itself takes over the phase shifting task. An outline of the design and modeling principles is presented along with some details of the experimental apparatus and testing procedures.

  3. Surveillance of hantaviruses in Poland: a study of animal reservoirs and human hantavirus disease in Subcarpathia.

    Michalski, Aleksander; Niemcewicz, Marcin; Bielawska-Drózd, Agata; Nowakowska, Anna; Gaweł, Jerzy; Pitucha, Grzegorz; Joniec, Justyna; Zielonka, Katarzyna; Marciniak-Niemcewicz, Anna; Kocik, Janusz


    The first cluster of hemorrhagic fever with renal syndrome (HFRS) in Poland was identified in 2007 in the Subcarpathian region. The natural environment of this area is a key habitat for hantavirus vectors. The animal reservoir of existing human HFRS clusters was studied to assess the occurrence of viruses (including Tula virus, Puumala virus, and Dobrava-Belgrade virus) among rodents. We examined 70 suspected human cases with symptoms corresponding to the clinical picture of HFRS. Serological analysis (indirect immunofluorescence assay and immunoblot) confirmed the presence of anti-hantavirus antibodies in 18 patients, which were surveyed with regard to developed symptoms and presumed rodent contact. Seroepidemiological analysis of newly confirmed human cases was performed, putative areas of human exposure were studied, and 194 rodents were subsequently captured from identified areas. Internal organs (lungs, heart, spleen, bladder, and kidneys) were collected from 64 Apodemus flavicollis, 55 Apodemus agrarius, 40 Myodes glareolus, 21 Mus musculus, and 14 Microtus arvalis and tested for the presence of hantavirus RNA by reverse transcription and subsequent real-time PCR. Positive samples were also tested by indirect immunofluorescence. Animal reservoir surveillance enabled the first detection of Puumala virus and Dobrava-Belgrade virus among animals in Poland. Furthermore, some places where rodents were captured correlated with areas of residence of laboratory-confirmed human cases and likely detected virus species. Moreover, three species of hantaviruses coexisting in a relatively small area were identified.

  4. Chemical Processes with Supercritical CO2 in Engineered Geologic Systems: Significance, Previous Study, and Path Forward (Invited)

    Xu, T.; Pruess, K.


    Chemical reactions with dissolved CO2 in the aqueous phase have long been considered in fundamental geosciences and practical applications. Recently, studies on geologic carbon sequestration and enhanced geothermal systems using CO2 as heat transmission fluid have brought new interests in chemical reaction processes directly with supercritical CO2 (scCO2, or gas phase). In the vicinity of a CO2 injection well, the aqueous fluid initially present in a geological formation would be quickly removed by dissolution (evaporation) into the flowing gas stream and by immiscible displacement by the scCO2, creating a gas phase dominant zone. In this zone, the water evaporation could cause formation dry-out and precipitation of salt near the injection well, reducing formation porosity, permeability, and injectivity. The scCO2 may directly attack well construction materials such as cement. Over time, the gas phase will tend to migrate upwards towards the caprock because the density of the scCO2 is lower than that of the aqueous phase. In the upper portions of the reservoir, the scCO2 will directly react with caprock minerals and alter the hydrological properties and mechanical strength. On the other hand, the scCO2 phase will maintain the dissolution into the aqueous phase, lowering pH, inducing mineral dissolution, complexing with dissolved cations, increasing CO2 solubility, increasing the density of the aqueous phase, and promoting “convective mixing”. Chemical processes are quite different in the scCO2 dominant geologic systems. The absence of an aqueous phase poses unique questions, as little is presently known about the chemistry of non-aqueous systems. Additional issues arise from the reactivity of water that is dissolved in the ScCO2 phase. In this presentation, the author will discuss the importance, state of the studies performed, and future research directions.

  5. Integrated reservoir interpretation

    Caamano, Ed; Dickerman, Ken; Thornton, Mick (Conoco Indonesia Inc., Jakarta (Indonesia)); Corbett, Chip; Douglas, David; Schultz, Phil (GeoQuest, Houston, TX (United States)); Gir, Roopa; Nicholson, Barry (GeoQuest, Jakarta (Indonesia)); Martono, Dwi; Padmono, Joko; Novias; Kiagus; Suroso, Sigit (Pertamina Sumbagut, Brandan, North Sumatra (Indonesia)); Mathieu, Gilles (Etudes et Productions Schlumberger, Clamart (France)); Yan, Zhao (China National Petroleum Company, Beijing (China))


    Improved reservoir management often relies on linking a variety of application software that helps geoscientists handle, visualize and interpret massive amounts of diverse data. The goal is to obtain the best possible reservoir model so its behavior can be understood and optimized. But diverse application software creates specialty niches and discourages integrated interpretation. A description is given of a new reservoir management package that covers all required functionalities and encourages the geologist, geophysicist, petrophysicist and reservoir engineer to embrace the integrated approach. Case studies are included in the article. 21 figs., 13 refs.

  6. Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

    Zahid, Adeel; Shapiro, Alexander; Stenby, Erling Halfdan;


    In recent years, many core displacement experiments of oil by seawater performed on chalk rock samples have reported SO42–, Ca2+, and Mg2+ as potential determining ions for improving oil recovery. Most of these studies were carried out with outcrop chalk core plugs. The objective of this study...... is to investigate the potential of the advanced waterflooding process by carrying out experiments with reservoir chalk samples. The study results in a better understanding of the mechanisms involved in increasing the oil recovery with potential determining ions. We carried out waterflooding instead of spontaneous...... with the following injecting fluids: distilled water, brine with and without sulfate, and brine containing only magnesium ions. The total oil recovery, recovery rate, and interaction mechanisms of ions with rock were studied for different injecting fluids at different temperatures and wettability conditions. Studies...

  7. A 3D elasto-plastic FEM program developed for reservoir Geomechanics simulations: Introduction and case studies

    Amin Chamani


    Full Text Available The development of yielded or failure zone due to an engineering construction is a subject of study in different disciplines. In Petroleum engineering, depletion from and injection of gas into a porous rock can cause development of a yield zone around the reservoir. Studying this phenomenon requires elasto-plastic analysis of geomaterial, in this case the porous rocks. In this study, which is a continuation of a previous study investigating the elastic behaviour of geomaterial, the elasto-plastic responses of geomaterial were studied. A 3D finite element code (FEM was developed, which can consider different constitutive models. The code features were explained and some case studies were presented to validate the output results of the code. The numerical model was, then, applied to study the development of the plastic zone around a horizontal porous formation subjected to the injection of gas. The model is described in detail and the results are presented. It was observed that by reducing the cohesion of rocks the extension of the plastic zone increased. Comparing to the elastic model, the ability to estimate the extension of the yield and failure zone is the main advantage of an elasto-plastic model.

  8. Remedial investigation/feasibility study report for Lower Watts Bar Reservoir Operable Unit



    This document is the combined Remedial Investigation and Feasibility Study Report for the lower Watts Bar Reservoir (LWBR) Operable Unit (OU). The LWBR is located in Roane, Rhea, and Meigs counties, Tennessee, and consists of Watts Bar Reservoir downstream of the Clinch river. This area has received hazardous substances released over a period of 50 years from the US Department of Energy`s Oak Ridge Reservation (ORR), a National Priority List site established under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). As required by this law, the ORR and all off-site areas that have received contaminants, including LWBR, must be investigated to determine the risk to human health and the environment resulting from these releases, the need for any remedial action to reduce these risks, and the remedial actions that are most feasible for implementation in this OU. Contaminants from the ORR are primarily transported to the LWBR via the Clinch River. There is little data regarding the quantities of most contaminants potentially released from the ORR to the Clinch River, particularly for the early years of ORR operations. Estimates of the quantities released during this period are available for most radionuclides and some inorganic contaminants, indicating that releases 30 to 50 years ago were much higher than today. Since the early 1970s, the release of potential contaminants has been monitored for compliance with environmental law and reported in the annual environmental monitoring reports for the ORR.

  9. Reevaluation of the Reservoir Gas Sands of Rashidpur Gas Field: A Case Study

    Eahsanul Haque, Akm; Ahmed, Nur


    Rashidpur Gas Field is located in the west of Srimongal in East Central Bangladesh. The accumulation associated with the Miocene Bhuban-Boka Bil Sandstone Reservoirs in a structural trap. The structure is about 35 km long and 7 km wide with amplitude of some 4900 ft. Rashidpur anticline is a sub-meriodinal axis, elongated, asymmetrical doubly plunging anticline which has two pay sands namely Upper Gas Sand (UGS) and Lower Gas Sand (LGS) indicated in all four wells drilled in the structure. After penetrating the shalebsection beneath LGS, drilling plan was rescheduled to a depth of 9200 ft in order to investigate the deeper sands of potential hydrocarbon accumulation. On reaching a depth of 10073 ft a sudden kick occurred, which halted the drilling operation and forced to kill the well. An immediate sidetrack well (4521 ft) was drilled at Well-4 and an existence of a sealing fault was drawn on the final report. But mud logs of Well-3 and Well-4 based on the hydrocarbon component of UGS and LGS clearly indicate the absence of any fault between Well-3 and Well-4. Recent geological investigation in the study area reveals the updated facts on the two wells of Rashidpur Gas Field. The paper analyses mud logs and other geological data and reevaluates the reservoir gas sands of Rashidpur Gas Field.

  10. Disinfection byproduct formation in drinking water sources: A case study of Yuqiao reservoir.

    Zhai, Hongyan; He, Xizhen; Zhang, Yan; Du, Tingting; Adeleye, Adeyemi S; Li, Yao


    This study investigated the potential formation of disinfection byproducts (DBPs) during chlorination and chloramination of 20 water samples collected from different points of Yuqiao reservoir in Tianjin, China. The concentrations of dissolved organic matter and ammonia decreased downstream the reservoir, while the specific UV absorbance (SUVA: the ratio of UV254 to dissolved organic carbon) increased [from 0.67 L/(mg*m) upstream to 3.58 L/(mg*m) downstream]. The raw water quality played an important role in the formation of DBPs. During chlorination, haloacetic acids (HAAs) were the major DBPs formed in most of the water samples, followed by trihalomethanes (THMs). CHCl3 and CHCl2Br were the major THM species, while trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) were the major HAA species. Chloramination, on the other hand, generally resulted in lower concentrations of THMs (CHCl3), HAAs (TCAA and DCAA), and haloacetonitriles (HANs). All the species of DBPs formed had positive correlations with the SUVA values, and HANs had the highest one (R(2) = 0.8). The correlation coefficients between the analogous DBP yields and the SUVA values in chlorinated samples were close to those in chloraminated samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

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


    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 (enhance the oil recovery. Water flooding is recommended as the first step of oil recovery enhancement by

  12. An fMRI study of neuronal activation in schizophrenia patients with and without previous cannabis use

    Else-Marie eLøberg


    Full Text Available Previous studies have mostly shown positive effects of cannabis use on cognition in patients with schizophrenia, which could reflect lower neurocognitive vulnerability. There are however no studies comparing whether such cognitive differences have neuronal correlates. Thus, the aim of the present study was to compare whether patients with previous cannabis use differ in brain activation from patients who has never used cannabis. The patients groups were compared on the ability to up-regulate an effort mode network during a cognitive task and down-regulate activation in the same network during a task-absent condition. Task-present and task-absent brain activation was measured by functional magnetic resonance neuroimaging (fMRI. Twenty-six patients with a DSM-IV and ICD-10 diagnosis of schizophrenia were grouped into a previous cannabis user group and a no-cannabis group. An auditory dichotic listening task with instructions of attention focus on either the right or left ear stimulus was used to tap verbal processing, attention and cognitive control, calculated as an aggregate score. When comparing the two groups, there were remaining activations in the task-present condition for the cannabis group, not seen in the no-cannabis group, while there was remaining activation in the task-absent condition for the no-cannabis group, not seen in the cannabis group. Thus, the patients with previous cannabis use showed increased activation in an effort mode network and decreased activation in the default mode network as compared to the no-cannabis group. It is concluded that the present study show some differences in brain activation to a cognitively challenging task between previous cannabis and no-cannabis schizophrenia patients.

  13. Elastostatic effects around a magma reservoir and pathway due to historic earthquakes: a case study of Mt. Fuji, Japan

    Hosono, Masaki; Mitsui, Yuta; Ishibashi, Hidemi; Kataoka, Jun


    We discuss elastostatic effects on Mt. Fuji, the tallest volcano in Japan, due to historic earthquakes in Japan. The 1707 Hoei eruption, which was the most explosive historic eruption of Mt. Fuji, occurred 49 days after the Hoei earthquake (Mw 8.7) along the Nankai Trough. It was previously suggested that the Hoei earthquake induced compression of a basaltic magma reservoir and unclamping of a dike-intruded region at depth, possibly triggering magma mixing and the subsequent Plinian eruption. Here, we show that the 1707 Hoei earthquake was a special case of induced volumetric strain and normal stress changes around the magma reservoir and pathway of Mt. Fuji. The 2011 Tohoku earthquake (Mw 9), along the Japan Trench, dilated the magma reservoir. It has been proposed that dilation of a magma reservoir drives the ascent of gas bubbles with magma and further depressurization, leading to a volcanic eruption. In fact, seismicity notably increased around Mt. Fuji during the first month after the 2011 Tohoku earthquake, even when we statistically exclude aftershocks, but the small amount of strain change (< 1 μ strain) may have limited the ascent of magma. For many historic earthquakes, the magma reservoir was compressed and the magma pathway was wholly clamped. This type of interaction has little potential to mechanically trigger the deformation of a volcano. Thus, Mt. Fuji may be less susceptible to elastostatic effects because of its location relative to the sources of large tectonic earthquakes. As an exception, a possible local earthquake in the Fujikawa-kako fault zone could induce a large amount of magma reservoir dilation beneath the southern flank of Mt. Fuji.

  14. Simulation studies to evaluate the effect of fracture closure on the performance of naturally fractured reservoirs. Annual report


    The second year of this three-year research program to evaluate the effect of fracture closure on the recovery of oil and gas from naturally fractured reservoirs has been completed. The overall objectives of the study are to: (1) evaluate the reservoir conditions where fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. Simulation studies have been conducted with a dual porosity simulator capable of simulating the performance of vertical and horizontal wells. Each simulation model has been initialized with properties typical of the Austin Chalk reservoir in Pearsall Field, Texas. During year one, simulations of both vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure charge. The results confirmed that horizontal wells could increase both rate of oil recovery and total oil recovery from naturally fractured reservoirs. During the second year the performances of the same vertical and horizontal wells were evaluated with the assumption that fracture permeability was a function of reservoir pressure. This required repetition of most of the natural depletion cases simulated in year one while invoking the pressure-sensitive fracture permeability option. To investigate sensitivity to in situ stress, two stress conditions were simulated for each primary variable. The water injection cases, begun in year one, were extended to include most of the reservoir parameters investigated for natural depletion, including fracture permeability as a function of net stress and the use of horizontal wells. The results thus far confirm that pressure-sensitive fractures degrade well performance and that the degradation is reduced by water injection pressure maintenance. Furthermore, oil recovery can be significantly increased by water injection pressure maintenance.

  15. Limno-reservoirs as a new landscape, environmental and touristic resource: Pareja Limno-reservoir as a case of study (Guadalajara, Spain)

    Díaz-Carrión, I.; Sastre-Merlín, A.; Martínez-Pérez, S.; Molina-Navarro, E.; Bienes-Allas, R.


    A limno-reservoir is a hydrologic infrastructure with the main goal of generating a body of water with a constant level in the riverine zone of a reservoir, building a dam that makes de limno-reservoir independent from the main body of water. This dam can be built in the main river supplying the reservoir or any tributary as well flowing into it. Despite its novel conception and design, around a dozen are already operative in some Spanish reservoirs. This infrastructure allows the new water body to be independent of the main reservoir management, so the water level stability is its main distinctive characteristic. It leads to the development of environmental, sports and cultural initiatives; which may be included in a touristic exploitation in a wide sense. An opinion poll was designed in 2009 to be carried out the Pareja Limno-reservoir (Entrepeñas reservoir area, Tajo River Basin, central Spain). The results showed that for both, Pareja inhabitants and occasional visitors, the limno-reservoir has become an important touristic resource, mainly demanded during summer season. The performance of leisure activities (especially swimming) are being the main brand of this novel hydraulic and environmental infrastructure, playing a role as corrective and/or compensatory action which is needed to apply in order to mitigate the environmental impacts of the large hydraulic constructions.

  16. Recycling of Clay Sediments for Geopolymer Binder Production. A New Perspective for Reservoir Management in the Framework of Italian Legislation: The Occhito Reservoir Case Study

    Bruno Molino; Annamaria De Vincenzo; Claudio Ferone; Francesco Messina; Francesco Colangelo; Raffaele Cioffi


    Reservoir silting is an unavoidable issue. It is estimated that in Italy, the potential rate of silting-up in large reservoirs ranges from 0.1% to 1% in the presence of wooded river basins and intensive agricultural land use, respectively. In medium and small-sized reservoirs, these values vary between 0.3% and 2%. Considering both the types of reservoirs, the annual average loss of storage capacity would be of about 1.59%. In this paper, a management strategy aimed at sediment productive re...

  17. A priori data-driven multi-clustered reservoir generation algorithm for echo state network.

    Xiumin Li

    Full Text Available Echo state networks (ESNs with multi-clustered reservoir topology perform better in reservoir computing and robustness than those with random reservoir topology. However, these ESNs have a complex reservoir topology, which leads to difficulties in reservoir generation. This study focuses on the reservoir generation problem when ESN is used in environments with sufficient priori data available. Accordingly, a priori data-driven multi-cluster reservoir generation algorithm is proposed. The priori data in the proposed algorithm are used to evaluate reservoirs by calculating the precision and standard deviation of ESNs. The reservoirs are produced using the clustering method; only the reservoir with a better evaluation performance takes the place of a previous one. The final reservoir is obtained when its evaluation score reaches the preset requirement. The prediction experiment results obtained using the Mackey-Glass chaotic time series show that the proposed reservoir generation algorithm provides ESNs with extra prediction precision and increases the structure complexity of the network. Further experiments also reveal the appropriate values of the number of clusters and time window size to obtain optimal performance. The information entropy of the reservoir reaches the maximum when ESN gains the greatest precision.

  18. Study of ionically modified water performance in carbonate reservoir system by multivariate data analysis

    Sohal, Muhammad Adeel Nassar; Kucheryavskiy, Sergey V.; Thyne, Geoffrey


    in other cases. Most of the published results attributed EOR to improved water wetness in initially oil-wet carbonates. Nevertheless, in a few studies EOR was observed without apparent wettability alteration. We undertake the analysis of a large set of published recovery experiments to try to identify...... the critical mechanisms at the pore scale. Better pore scale physico-chemical understanding will guide to formulate accurate reservoir-scale models. This paper presents a comprehensive meta-analysis of the proposed mechanisms using multivariate data analysis. Detailed review of the subject, including...... mechanisms with supporting and contradictory evidence has been presented by Sohal et al. (2016). In this study, the significance of each contributing factor to EOR was quantified and subjected to rigorous multivariate statistical analysis. The analysis was limited because there is no uniform methodology...

  19. Study on reservoir operation optimization of Ertan Hydropower Station considering GFS forecasted precipitation


    The medium-term runoff forecasting provided new information for forecast of medium and long term runoff and optimal hydroelectric power generation.According to the actual runoff and hydropower generating characteristics of Ertan Hydropower Station,we studied the decade runoff quantitatively and grade forecast model based on Global Forecasting System(GFS) precipitation forecast information in wet season,then used the posteriori runoff transition probability and measurable probability of runoff forecast to research the uncertain runoff description based on runoff forecast;finally on the basis of the runoff description and the grading forecast accuracy of GFS-based next 10 days’total forecast precipitation,we studied the uncertain optimal operating model of Ertan Hydropower Station considering runoff forecast.The results showed that the runoff forecast considering GFS forecast precipitation and uncertainty has significantly improved the existing runoff description and operating optimization model,and obviously raised the hydropower generation efficiency of Ertan Reservoir.

  20. Factors Associated with Unfavorable Treatment Outcomes in New and Previously Treated TB Patients in Uzbekistan: A Five Year Countrywide Study.

    Jamshid Gadoev

    Full Text Available TB is one of the main health priorities in Uzbekistan and relatively high rates of unfavorable treatment outcomes have recently been reported. This requires closer analysis to explain the reasons and recommend interventions to improve the situation. Thus, by using countrywide data this study sought to determine trends in unfavorable outcomes (lost-to-follow-ups, deaths and treatment failures and describe their associations with socio-demographic and clinical factors.A countrywide retrospective cohort study of all new and previously treated TB patients registered in the National Tuberculosis programme between January 2006 and December 2010.Among 107,380 registered patients, 67% were adults, with smaller proportions of children (10%, adolescents (4% and elderly patients (19%. Sixty per cent were male, 66% lived in rural areas, 1% were HIV-infected and 1% had a history of imprisonment. Pulmonary TB (PTB was present in 77%, of which 43% were smear-positive and 53% were smear-negative. Overall, 83% of patients were successfully treated, 6% died, 6% were lost-to-follow-up, 3% failed treatment and 2% transferred out. Factors associated with death included being above 55 years of age, HIV-positive, sputum smear positive, previously treated, jobless and living in certain provinces. Factors associated with lost-to-follow-up were being male, previously treated, jobless, living in an urban area, and living in certain provinces. Having smear-positive PTB, being an adolescent, being urban population, being HIV-negative, previously treated, jobless and residing in particular provinces were associated with treatment failure.Overall, 83% treatment success rate was achieved. However, our study findings highlight the need to improve TB services for certain vulnerable groups and in specific areas of the country. They also emphasize the need to develop unified monitoring and evaluation tools for drug-susceptible and drug-resistant TB, and call for better TB

  1. A Percolation Study of Wettability Effect on the Electrical Properties of Reservoir Rocks

    Zhou, Dengen; Arbabi, Sepehr; Stenby, Erling Halfdan


    Measurements of the electrical resistivity of oil reservoirs are commonly used to estimate other properties of reservoirs, such as porosity and hydrocarbon reserves. However, the interpretation of the measurements is based on empirical correlations, because the underlying mechanisms that control...... the electrical properties of oil bearing rocks have not been well understood. In this paper, we employ percolation concepts to investigate the effect of wettability on the electrical conductivity of a reservoir formation. A three-dimensional simple cubic network is used to represent an ideal reservoir formation...... behavior of reservoir resistivities of different wettabilities. It demonstrates that the resistivity index depends on saturation history and wettability. For strongly oil-wet systems, significant hysteresis is expected, while there is little hysteresis for strongly water-wet systems, and some hysteresis...

  2. Numerical study on transient flow in the deep naturally fractured reservoir with high pressure


    According to the experimental results and the characteristics of the pressure-sensitive fractured formation, a transient flow model is developed for the deep naturally-fractured reservoirs with different outer boundary conditions. The finite element equations for the model are derived. After generating the unstructured grids in the solution regions, the finite element method is used to calculate the pressure type curves for the pressure-sensitive fractured reservoir with different outer boundaries, such as the infinite boundary, circle boundary and combined linear boundaries, and the characteristics of the type curves are comparatively analyzed. The effects on the pressure curves caused by pressure sensitivity module and the effective radius combined parameter are determined, and the method for calculating the pressure-sensitive reservoir parameters is introduced. By analyzing the real field case in the high temperature and pressure reservoir, the perfect results show that the transient flow model for the pressure-sensitive fractured reservoir in this paper is correct.

  3. Numerical study on transient flow in the deep naturally fractured reservoir with high pressure

    LIU YueWu; CHEN WeiLiang; LIU QingQuan


    According to the experimental results and the characteristics of the pressure-sensitive fractured for-mation, a transient flow model is developed for the deep naturally-fractured reservoirs with different outer boundary conditions. The finite element equations for the model are derived. After generating the unstructured grids in the solution regions, the finite element method is used to calculate the pressure type curves for the pressure-eensitive fractured reservoir with different outer boundaries, such as the infinite boundary, circle boundary and combined linear boundaries, and the characteristics of the type curves are comparatively analyzed. The effects on the pressure curves caused by pressure sensitivity module and the effective radius combined parameter are determined, and the method for calculating the pressure-sensitive reservoir parameters is introduced. By analyzing the real field case in the high temperature end pressure reservoir, the perfect results show that the transient flow model for the pressure-sensitive fractured reservoir in this paper is correct.

  4. Preliminary study of a potential CO2 reservoir area in Hungary

    Sendula, Eszter; Király, Csilla; Szabó, Zsuzsanna; Falus, György; Szabó, Csaba; Kovács, István; Füri, Judit; Kónya, Péter; Páles, Mariann; Forray, Viktória


    Since the first international agreement in 1997 (the Kyoto Protocol) the reduction of greenhouse gas emission has a key role in the European Union's energy and climate change policy. Following the Directive 2009/31/EC we are experiencing a significant change in the Hungarian national activity. Since the harmonization procedure, which was completed in May 2012, the national regulation obligates the competent authority to collect and regularly update all geological complexes that are potential for CO2 geological storage. In Hungary the most abundant potential storage formations are mostly saline aquifers of the Great Hungarian Plain (SE-Hungary), with sandstone reservoir and clayey caprock. The Neogene basin of the Great Hungarian Plain was subsided and then filled by a prograding delta system from NW and NE during the Late Miocene, mostly in the Pannonian time. The most potential storage rock was formed as a fine-grained sandy turbidite interlayered by thin argillaceous beds in the deepest part of the basin. It has relatively high porosity, depth and more than 1000 m thickness. Providing a regional coverage for the sandy turbidite, a 400-500 m thick argillaceous succession was formed in the slope environment. The composition, thickness and low permeability is expected to make it a suitable, leakage-safe caprock of the storage system. This succession is underlain by argillaceous rocks that were formed in the basin, far from sediment input and overlain by interfingering siltstone, sandstone and claystone succession formed in delta and shoreline environments and in the alluvial plain. Core samples have been collected from the potential reservoir rock and its cap rock in the Great Hungarian Plain's succession. The water compositions of the studied depth were known from well-log database. Using the information, acquired from these archive documents, we have constructed input data for geochemical modeling in order to to study the effect of pCO2 injection in the potential

  5. Diagenesis and Restructuring Mechanism of Oil and Gas Reservoir in the Marine Carbonate Formation, Northeastern Sichuan: A Case Study of the Puguang Gas Reservoir

    DU Chunguo; WANG Jianjun; ZOU Huayao; ZHU Yangming; WANG Cunwu


    Based on the technology of balanced cross-section and physical simulation experiments associated with natural gas geochemical characteristic analyses, core and thin section observations, it has been proven that the Puguang gas reservoir has experienced two periods of diagenesis and restructuring since the Late lndo-Chinese epoch. One is the fluid transfer controlled by the tectonic movement and the other is geochemical reconstruction controlled by thermochemical sulfate reduction (TSR). The middle Yanshan epoch was the main period that the Puguang gas reservoir experienced the geochemical reaction of TSR. TSR can recreate the fluid in the gas reservoir, which makes the gas drying index higher and carbon isotope heavier because C_(2+) (ethane and heavy hydrocarbon) and ~(12)C (carbon 12 isotope) is first consumed relative to CH_4 and ~(13)C (carbon 13 isotope). However, the reciprocity between fluid regarding TSR (hydrocarbon, sulfureted hydrogen (H_2S), and water) and reservoir rock results in reservoir rock erosion and anhydrite alteration, which increases porosity in reservoir, thereby improving the petrophysical properties. Superimposed by later tectonic movement, the fluid in Puguang reservoir has twice experienced adjustment, one in the late Yanshan epoch to the early Himalayan epoch and the other time in late Himalayan epoch, after which Puguang gas reservoir is finally developed.

  6. Assessment of empathy in first-episode psychosis and meta-analytic comparison with previous studies in schizophrenia.

    Achim, Amelie M; Ouellet, Rosalie; Roy, Marc-André; Jackson, Philip L


    Empathy is a multidimensional construct that relies on affective and cognitive component processes. A few studies have reported impairments of both cognitive and affective empathy components in patients with schizophrenia. It is, however, not known whether these difficulties are already present at psychosis onset. The affective and cognitive components of empathy were thus assessed in 31 patients with first-episode psychosis (FEP) and 31 matched healthy controls using the Interpersonal Reactivity Index (IRI). Our results were then compared to previous studies of empathy in patients with more chronic schizophrenia via a meta-analysis. In addition, we also assessed the relationship between empathy ratings, Mentalizing performance and clinical symptoms. Contrary to what has been reported in people with more chronic schizophrenia, the IRI ratings did not significantly differ between FEP and controls in our study, though a trend was observed for the Personal distress scale. For the Perspective taking scale, our meta-analysis revealed a significantly lower effect size in this study with FEP patients relative to previous schizophrenia studies. In the FEP group, the IRI ratings were not related to positive, negative or general psychopathology symptoms, but a significant relationship emerged between the Liebowitz Social Anxiety Scale and Perspective taking (negative correlation). In addition, a significant positive correlation was observed between the Empathic concern subscale and our theory of mind task. This study supports the idea that the cognitive component of empathy is less affected in patients with first-episode psychosis relative to patients with more chronic schizophrenia, and the impairments reported in previous reports with more chronic populations should be interpreted in light of a possible deterioration of this cognitive skill. The findings also provide some insight into the relationship between empathy and clinical symptoms such as social anxiety.

  7. Mapping lacustrine syn-rift reservoir distribution using spectral attributes: A case study of the Pematang Brownshale Central Sumatra Basin

    Haris, A.; Yustiawan, R.; Riyanto, A.; Ramadian, R.


    Pematang Brownshale is the lake sediment, which is proven as the main source rock in Malacca Strait Area. So far Brownshale is only considered as source rock, but the well data show intercalated sand layers encountered within the Pematang Brownshale, where several downhole tests proved this series as a potential hydrocarbon reservoir. Pematang formation is a syn-rift sequent deposited in Malacca Strait following the opening of central Sumatra basin during a late cretaceous to early Oligocene, which is proven as potential source rock and reservoir. The aim of the study is to identify the distribution of sandstone reservoir in Pematang Brownshale using spectral attributes. These works were carried out by integrating log data analysis and frequency maps extracted from spectral attributes Continuous Wavelet Transform (CWT). All these data are used to delineate reservoir distribution in Pematang Brownshale. Based on CWT analysis the anomalies are only visible on the frequency of I5 and I0 Hz maps, which are categorized as low frequencies. Low-frequency shadow anomaly is commonly used as an indication of the presence of hydrocarbons. The distribution of these anomalies is covering an area of approximately 3840.66 acres or equal to I554.25 sq. km, where the low-frequency pattern is interpreted as a deltaic lacustrine feature. By considering the Pematang Brown Shale of Malacca Strait area as a potential reservoir, it would open new play to another basin that has similar characteristics.

  8. Psychotic illness in first-time mothers with no previous psychiatric hospitalizations: a population-based study.

    Unnur Valdimarsdóttir


    Full Text Available BACKGROUND: Psychotic illness following childbirth is a relatively rare but severe condition with unexplained etiology. The aim of this study was to investigate the impact of maternal background characteristics and obstetric factors on the risk of postpartum psychosis, specifically among mothers with no previous psychiatric hospitalizations. METHODS AND FINDINGS: We investigated incidence rates and potential maternal and obstetric risk factors of psychoses after childbirth in a national cohort of women who were first-time mothers from 1983 through 2000 (n = 745,596. Proportional hazard regression models were used to estimate relative risks of psychoses during and after the first 90 d postpartum, among mothers without any previous psychiatric hospitalization and among all mothers. Within 90 d after delivery, 892 women (1.2 per 1,000 births; 4.84 per 1,000 person-years were hospitalized due to psychoses and 436 of these (0.6 per 1,000 births; 2.38 per 1,000 person-years had not previously been hospitalized for any psychiatric disorder. During follow-up after the 90 d postpartum period, the corresponding incidence rates per 1,000 person-years were reduced to 0.65 for all women and 0.49 for women not previously hospitalized. During (but not after the first 90 d postpartum the risk of psychoses among women without any previous psychiatric hospitalization was independently affected by: maternal age (35 y or older versus 19 y or younger; hazard ratio 2.4, 95% confidence interval [CI] 1.2 to 4.7; high birth weight (> or = 4,500 g; hazard ratio 0.3, 95% CI 0.1 to 1.0; and diabetes (hazard ratio 0. CONCLUSIONS: The incidence of psychotic illness peaks immediately following a first childbirth, and almost 50% of the cases are women without any previous psychiatric hospitalization. High maternal age increases the risk while diabetes and high birth weight are associated with reduced risk of first-onset psychoses, distinctly during the postpartum period.

  9. Geothermal reservoir engineering research

    Ramey, H. J., Jr.; Kruger, P.; Brigham, W. E.; London, A. L.


    The Stanford University research program on the study of stimulation and reservoir engineering of geothermal resources commenced as an interdisciplinary program in September, 1972. The broad objectives of this program have been: (1) the development of experimental and computational data to evaluate the optimum performance of fracture-stimulated geothermal reservoirs; (2) the development of a geothermal reservoir model to evaluate important thermophysical, hydrodynamic, and chemical parameters based on fluid-energy-volume balances as part of standard reservoir engineering practice; and (3) the construction of a laboratory model of an explosion-produced chimney to obtain experimental data on the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs.

  10. Comparative Study of Basins within Palaeogene Seaway in East China and Cretaceous Seaway in North America and Its Reservoir Significance

    Wu Xiantao


    The well known Cretaceous seaway in North America was recognized in the middle of the last century and the Palaeogene seaway in East China was proposed by the author recently. The two seaways located on the opposite sides of North Pacific Ocean may be not a coincidence,and a comparative study was made in this paper. The results show that the two seaways inundated basins share several similarities particularly in basin origin,filling processes and reservoir facies. It is suggested that reservoir facies of estuarine sandstone and shelf bar sandstone related to sea level fluctuation,which are well developed in the Cretaceous seaway covered basins in North America might have been also developed here in Palaeogene seaway inundated basins in East China. Therefore it is worth paying more attention to finding these new reservoir facies on this side of the Pacific ocean. Evidences of sedimentology and ichnology indicate that good prospects are likely.

  11. Mechanism study on a plague outbreak driven by the construction of a large reservoir in southwest china (surveillance from 2000-2015.

    Xin Wang


    Full Text Available Plague, a Yersinia pestis infection, is a fatal disease with tremendous transmission capacity. However, the mechanism of how the pathogen stays in a reservoir, circulates and then re-emerges is an enigma.We studied a plague outbreak caused by the construction of a large reservoir in southwest China followed 16-years' surveillance.The results show the prevalence of plague within the natural plague focus is closely related to the stability of local ecology. Before and during the decade of construction the reservoir on the Nanpan River, no confirmed plague has ever emerged. With the impoundment of reservoir and destruction of drowned farmland and vegetation, the infected rodent population previously dispersed was concentrated together in a flood-free area and turned a rest focus alive. Human plague broke out after the enzootic plague via the flea bite. With the construction completed and ecology gradually of human residential environment, animal population and type of vegetation settling down to a new balance, the natural plague foci returned to a rest period. With the rodent density decreased as some of them died, the flea density increased as the rodents lived near or in local farm houses where had more domestic animals, and human has a more concentrated population. In contrast, in the Himalayan marmot foci of the Qinghai-Tibet Plateau in the Qilian Mountains. There are few human inhabitants and the local ecology is relatively stable; plague is prevalence, showing no rest period. Thus the plague can be significantly affected by ecological shifts.

  12. Study and Application of Fault Prediction Methods with Improved Reservoir Neural Networks

    Qunxiong Zhu; Yiwen Jia; Di Peng; Yuan Xu


    Time-series prediction is one of the major methodologies used for fault prediction. The methods based on recur-rent neural networks have been widely used in time-series prediction for their remarkable non-liner mapping ability. As a new recurrent neural network, reservoir neural network can effectively process the time-series pre-diction. However, the il-posedness problem of reservoir neural networks has seriously restricted the generaliza-tion performance. In this paper, a fault prediction algorithm based on time-series is proposed using improved reservoir neural networks. The basic idea is taking structure risk into consideration, that is, the cost function in-volves not only the experience risk factor but also the structure risk factor. Thus a regulation coefficient is intro-duced to calculate the output weight of the reservoir neural network. As a result, the amplitude of output weight is effectively controlled and the il-posedness problem is solved. Because the training speed of ordinary reservoir networks is naturally fast, the improved reservoir networks for time-series prediction are good in speed and gen-eralization ability. Experiments on Mackey-Glass and sunspot time series prediction prove the effectiveness of the algorithm. The proposed algorithm is applied to TE process fault prediction. We first forecast some time-series obtained from TE and then predict the fault type adopting the static reservoirs with the predicted data. The final prediction correct rate reaches 81%.

  13. Abundance and diversity of bacteria in oxygen minimum drinking water reservoir sediments studied by quantitative PCR and pyrosequencing.

    Zhang, Hai-han; Huang, Ting-lin; Chen, Sheng-nan; Yang, Xiao; Lv, Kai; Sekar, Raju


    Reservoir sediment is one of the most stressful environments for microorganisms due to periodically oxygen minimum conditions. In this study, the abundance and composition of bacteria associated with sediments from three drinking water reservoirs (Zhoucun, ZCR; Shibianyu, SBYR; and Jinpen, JPR) were investigated by quantitative polymerase chain reaction and 16S rRNA-based 454 pyrosequencing. The results of physico-chemical analysis of sediments showed that the organic matter and total nitrogen were significantly higher in ZCR as compared to JPR (P oxygen minimum and stressful freshwater environments.

  14. Sediment and nutrient budgets are inherently dynamic: evidence from a long-term study of two subtropical reservoirs

    O'Brien, Katherine R.; Weber, Tony R.; Leigh, Catherine; Burford, Michele A.


    Accurate reservoir budgets are important for understanding regional fluxes of sediment and nutrients. Here we present a comprehensive budget of sediment (based on total suspended solids, TSS), total nitrogen (TN) and total phosphorus (TP) for two subtropical reservoirs on rivers with highly intermittent flow regimes. The budget is completed from July 1997 to June 2011 on the Somerset and Wivenhoe reservoirs in southeast Queensland, Australia, using a combination of monitoring data and catchment model predictions. A major flood in January 2011 accounted for more than half of the water entering and leaving both reservoirs in that year, and approximately 30 % of water delivered to and released from Wivenhoe over the 14-year study period. The flood accounted for an even larger proportion of total TSS and nutrient loads: in Wivenhoe more than one-third of TSS inputs and two-thirds of TSS outputs between 1997 and 2011 occurred during January 2011. During non-flood years, mean historical concentrations provided reasonable estimates of TSS and nutrient loads leaving the reservoirs. Calculating loads from historical mean TSS and TP concentrations during January 2011, however, would have substantially underestimated outputs over the entire study period, by up to a factor of 10. The results have important implications for sediment and nutrient budgets in catchments with highly episodic flow. First, quantifying inputs and outputs during major floods is essential for producing reliable long-term budgets. Second, sediment and nutrient budgets are dynamic, not static. Characterizing uncertainty and variability is therefore just as important for meaningful reservoir budgets as accurate quantification of loads.

  15. Ozone reservoir layers in a coastal environment – a case study in southern Taiwan

    Lin, C.-H.; Wu, Y.-L.; Lai, C. -H.


    The air layer between the nocturnal boundary layer and the top of the daily mixing layer in an ozone-polluted area is known to serve as an ozone reservoir since the ozone that is produced in the mixing layer on the preceding day is effectively preserved throughout the night in the air layer. Ozone reservoir layers existing at night can enhance the accumulation of surface ozone on the following day. However, our knowledge of the characteristics of ozone reservoir layers and their effects on th...

  16. A multicenter phase II study of irinotecan in patients with advanced colorectal cancer previously treated with 5-fluorouracil.

    Méndez, Miguel; Salut, Antonieta; García-Girón, Carlos; Navalon, Marta; Diz, Pilar; García López, Maria José; España, Pilar; de la Torre, Ascensión; Martínez del Prado, Purificación; Duarte, Isabel; Pujol, Eduardo; Arizcun, Alberto; Cruz, Juan Jesús


    This multicenter, open-label, phase II study was performed to assess the efficacy and toxicity of irinotecan 350 mg/m2 intravenously every 3 weeks in patients with advanced colorectal cancer (CRC) previously treated with 5-fluorouracil (5-FU). The study enrolled 115 patients and a total of 558 cycles (median, 6 per patient) were administered. The overall objective response rate on an intent-to-treat basis was 18% (with 1 complete response and 20 partial responses), whereas 42 patients (37%) showed stable disease. Median time to progression was 4.8 months and median survival was 13.6 months. Grade 3/4 toxicities included delayed diarrhea (19.1%), nausea/vomiting (10.4%), and neutropenia (8.7%). There were 2 toxic deaths, 1 from delayed diarrhea and 1 from hemorrhage and grade 4 mucositis. In conclusion, the present study confirms the antitumor efficacy of irinotecan monotherapy in patients with CRC pretreated with 5-FU.

  17. Diagenesis and application of LiDAR in reservoir analogue studies: karstification in the Cretaceous Apulia carbonate platform dolomitization in the Triassic Latemar carbonate buildup

    Jacquemyn, Carl


    The ever-increasing demand for energy and hydrocarbons coincides with gradual depletion of currently producing conventional oil and gas reservoirs. Therefore new exploration plays are extended to more complex oil and gas plays, such as karstified limestones and hydrothermal dolomites. Furthermore production from currently producing reservoirs is optimized by revisiting or improving the geological knowledge of these reservoirs. These two perspectives are covered in this study on dolomitization...

  18. Reservoir Maintenance and Development Task Report for the DOE Geothermal Technologies Office GeoVision Study.

    Lowry, Thomas Stephen; Finger, John T.; Carrigan, Charles R.; Foris, Adam; Kennedy, Mack B.; Corbet, Thomas F.,; Doughty, Christine A.; Pye, Steven; Sonnenthal, Eric L.


    This report documents the key findings from the Reservoir Maintenance and Development (RM&D) Task of the U.S. Department of Energy's (DOE), Geothermal Technologies Office (GTO) Geothermal Vision Study (GeoVision Study). The GeoVision Study had the objective of conducting analyses of future geothermal growth based on sets of current and future geothermal technology developments. The RM&D Task is one of seven tasks within the GeoVision Study with the others being, Exploration and Confirmation, Potential to Penetration, Institutional Market Barriers, Environmental and Social Impacts, Thermal Applications, and Hybrid Systems. The full set of findings and the details of the GeoVision Study can be found in the final GeoVision Study report on the DOE-GTO website. As applied here, RM&D refers to the activities associated with developing, exploiting, and maintaining a known geothermal resource. It assumes that the site has already been vetted and that the resource has been evaluated to be of sufficient quality to move towards full-scale development. It also assumes that the resource is to be developed for power generation, as opposed to low-temperature or direct use applications. This document presents the key factors influencing RM&D from both a technological and operational standpoint and provides a baseline of its current state. It also looks forward to describe areas of research and development that must be pursued if the development geothermal energy is to reach its full potential.

  19. Assessment of reservoir system variable forecasts

    Kistenmacher, Martin; Georgakakos, Aris P.


    Forecast ensembles are a convenient means to model water resources uncertainties and to inform planning and management processes. For multipurpose reservoir systems, forecast types include (i) forecasts of upcoming inflows and (ii) forecasts of system variables and outputs such as reservoir levels, releases, flood damage risks, hydropower production, water supply withdrawals, water quality conditions, navigation opportunities, and environmental flows, among others. Forecasts of system variables and outputs are conditional on forecasted inflows as well as on specific management policies and can provide useful information for decision-making processes. Unlike inflow forecasts (in ensemble or other forms), which have been the subject of many previous studies, reservoir system variable and output forecasts are not formally assessed in water resources management theory or practice. This article addresses this gap and develops methods to rectify potential reservoir system forecast inconsistencies and improve the quality of management-relevant information provided to stakeholders and managers. The overarching conclusion is that system variable and output forecast consistency is critical for robust reservoir management and needs to be routinely assessed for any management model used to inform planning and management processes. The above are demonstrated through an application from the Sacramento-American-San Joaquin reservoir system in northern California.

  20. Use of bias correction techniques to improve seasonal forecasts for reservoirs - A case-study in northwestern Mediterranean.

    Marcos, Raül; Llasat, Ma Carmen; Quintana-Seguí, Pere; Turco, Marco


    In this paper, we have compared different bias correction methodologies to assess whether they could be advantageous for improving the performance of a seasonal prediction model for volume anomalies in the Boadella reservoir (northwestern Mediterranean). The bias correction adjustments have been applied on precipitation and temperature from the European Centre for Middle-range Weather Forecasting System 4 (S4). We have used three bias correction strategies: two linear (mean bias correction, BC, and linear regression, LR) and one non-linear (Model Output Statistics analogs, MOS-analog). The results have been compared with climatology and persistence. The volume-anomaly model is a previously computed Multiple Linear Regression that ingests precipitation, temperature and in-flow anomaly data to simulate monthly volume anomalies. The potential utility for end-users has been assessed using economic value curve areas. We have studied the S4 hindcast period 1981-2010 for each month of the year and up to seven months ahead considering an ensemble of 15 members. We have shown that the MOS-analog and LR bias corrections can improve the original S4. The application to volume anomalies points towards the possibility to introduce bias correction methods as a tool to improve water resource seasonal forecasts in an end-user context of climate services. Particularly, the MOS-analog approach gives generally better results than the other approaches in late autumn and early winter. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Outcomes of induction of labour in women with previous caesarean delivery: a retrospective cohort study using a population database.

    Sarah J Stock

    Full Text Available BACKGROUND: There is evidence that induction of labour (IOL around term reduces perinatal mortality and caesarean delivery rates when compared to expectant management of pregnancy (allowing the pregnancy to continue to await spontaneous labour or definitive indication for delivery. However, it is not clear whether IOL in women with a previous caesarean section confers the same benefits. The aim of this study was to describe outcomes of IOL at 39-41 weeks in women with one previous caesarean delivery and to compare outcomes of IOL or planned caesarean delivery to those of expectant management. METHODS AND FINDINGS: We performed a population-based retrospective cohort study of singleton births greater than 39 weeks gestation, in women with one previous caesarean delivery, in Scotland, UK 1981-2007 (n = 46,176. Outcomes included mode of delivery, perinatal mortality, neonatal unit admission, postpartum hemorrhage and uterine rupture. 40.1% (2,969/7,401 of women who underwent IOL 39-41 weeks were ultimately delivered by caesarean. When compared to expectant management IOL was associated with lower odds of caesarean delivery (adjusted odds ratio [AOR] after IOL at 39 weeks of 0.81 [95% CI 0.71-0.91]. There was no significant effect on the odds of perinatal mortality but greater odds of neonatal unit admission (AOR after IOL at 39 weeks of 1.29 [95% CI 1.08-1.55]. In contrast, when compared with expectant management, elective repeat caesarean delivery was associated with lower perinatal mortality (AOR after planned caesarean at 39 weeks of 0.23 [95% CI 0.07-0.75] and, depending on gestation, the same or lower neonatal unit admission (AOR after planned caesarean at 39 weeks of 0.98 [0.90-1.07] at 40 weeks of 1.08 [0.94-1.23] and at 41 weeks of 0.77 [0.60-1.00]. CONCLUSIONS: A more liberal policy of IOL in women with previous caesarean delivery may reduce repeat caesarean delivery, but increases the risks of neonatal complications.

  2. Feasibility Study on Steam and Gas Push with Dual Horizontal Wells in a Moderate-Depth Heavy Oil Reservoir

    Jie Fan


    Full Text Available Non-condensable gas (NCG with steam co-injection makes steam assisted gravity drainage less energy-intensive as well as reduces greenhouse gas emission and water consumption. Numerous studies have shown that the technology called steam and gas push (SAGP is feasible for heavy oil and bitumen. However, most of these studies have focused on shallow heavy oil reservoirs and only a few works have investigated moderate-depth heavy oil reservoirs. In this study, laboratory experiments and numerical simulations were conducted to study shape change, steam chamber expansion, and temperature change after co-injecting NCG with steam into an actual moderate-depth heavy oil reservoir. Results showed that after co-injecting NCG with steam, the transverse expansion rate of the steam chamber accelerated, vertical expansion slowed down, thermal utilization increased, and oil–steam ratio improved. In addition, the injection parameters of SAGP were also optimized via numerical simulation, which indicated that SAGP could effectively improve development effect and recovery for moderate-depth heavy oil reservoirs.

  3. Legal study on water environmental protection of Three Gorges Reservoir Area

    DENG He


    Water environment security of the Three Gorges Reservoir Area has become a more extensive concern since the impoundment of the reservoir. This paper describes the existing water environmental hazards and defects in current legal system for water environmental protection in this area, and also discusses their possible causes and potential problems in the future based on first hand materials and other literature. According to the theories of integrated river basin management and environmental equity principle, legal proposals are put forward, which include building an unitary legal system dedicated to the Reservoir Area, setting up a basin authority of the Yangtze River to preside over the resources protection and development, using interests' compensation system to solve interest conflicts among different reaches, and making concrete regulations to direct public participation in water environmental security protection of the Three Gorges Reservoir Area.

  4. Study of effects of discharges of Carson River below Lahontan Reservoir on Stillwater Marsh

    US Fish and Wildlife Service, Department of the Interior — This report contains tables of recorded flows in the Carson River below Lahontan Reservoir for the water years 1956-57 to 1962-63. The report states that Stillwater...

  5. Birth outcome in women with previously treated breast cancer--a population-based cohort study from Sweden.

    Kristina Dalberg


    Full Text Available BACKGROUND: Data on birth outcome and offspring health after the appearance of breast cancer are limited. The aim of this study was to assess the risk of adverse birth outcomes in women previously treated for invasive breast cancer compared with the general population of mothers. METHODS AND FINDINGS: Of all 2,870,932 singleton births registered in the Swedish Medical Birth Registry during 1973-2002, 331 first births following breast cancer surgery--with a mean time to pregnancy of 37 mo (range 7-163--were identified using linkage with the Swedish Cancer Registry. Logistic regression analysis was used. The estimates were adjusted for maternal age, parity, and year of delivery. Odds ratios (ORs and 95% confidence intervals (CIs were used to estimate infant health and mortality, delivery complications, the risk of preterm birth, and the rates of instrumental delivery and cesarean section. The large majority of births from women previously treated for breast cancer had no adverse events. However, births by women exposed to breast cancer were associated with an increased risk of delivery complications (OR 1.5, 95% CI 1.2-1.9, cesarean section (OR 1.3, 95% CI 1.0-1.7, very preterm birth (<32 wk (OR 3.2, 95% CI 1.7-6.0, and low birth weight (<1500 g (OR 2.9, 95% CI 1.4-5.8. A tendency towards an increased risk of malformations among the infants was seen especially in the later time period (1988-2002 (OR 2.1, 95% CI 1.2-3.7. CONCLUSIONS: It is reassuring that births overall were without adverse events, but our findings indicate that pregnancies in previously treated breast cancer patients should possibly be regarded as higher risk pregnancies, with consequences for their surveillance and management.

  6. Does the previous diagnosis of arterial hypertension affect one´s daily life? Pró-Saúde Study

    Gilberto Senechal de Goffredo Filho


    Full Text Available In addition to damaging several target organs, arterial hypertension may negatively impact patients' activities of daily living. Biological and behavioral mechanisms underlying such limitations have yet to be clarified. The objectives of this study were to investigate whether having been previously told of a hypertension diagnosis is associated with the frequency and duration of temporary limitations in activities of daily living, and whether these relationships differ by gender, age, or socioeconomic position. We analyzed sectional data from 2,666 participants (56% women; 55% with high school or lower schooling at the baseline phase (1999 - 2001 of a longitudinal investigation of university employees in Rio de Janeiro, Brazil (Pró-Saúde Study, asking participants whether they had ever been diagnosed with hypertension by a health professional, if they had been unable to perform any activities of daily living due to a health problem in the previous 2 weeks, and for how many days that had occurred. Multinomial logistic regression models were fitted for the overall study population and for age, gender, educational level, and per capita household income strata. Associations between hypertension diagnosis and temporary limitations were not observed in the overall study population and in gender, education and income strata. However, there were higher odds of temporary limitations among participants aged 55 years old or more with hypertension diagnosis (adjusted OR = 9.5; 95%CI 1.5 - 58.6, regardless of blood pressure levels and use of antihypertensive medication. Elderly people may keep an attitude of higher vigilance regarding conditions or events potentially worsening their health status.

  7. Biotelemetry study of spring and summer habitat selection by striped bass in Cherokee Reservoir, Tennessee, 1978. [Morone saxatilis

    Schaich, B.A.; Coutant, C.C.


    Habitat selection of 31 adult striped bass was monitored by temperature sensing ultrasonic and radio transmitters in Cherokee Reservoir, Tennessee, from March through October 1978. This study sought to corroborate summer data obtained by Waddle (1979) in 1977 and to examine mechanisms of habitat selection by observing establishment of the summer distribution. During the spring and early summer months the striped bass ranged throughout the study area in the downstream half of the reservoir. Fish stayed near the bottom at the preferred temperatures throughout the whole study, and no individuals were observed in open water. Movement rates of up to 2.6 km/day were estimated, and rates of 1 km/day were common in the spring. By late July they were apparently avoiding low dissolved oxygen (D.O.) concentrations (<3 mg/l) near the bottom of the main reservoir and epilimnion temperatures greater than 22/sup 0/C, and they moved into cool, oxygenated spring or creek channels (refuges). Low movement rates of 0 to 25 m/day within these refuges occurred. The rates of the few migrations between refuges could not be estimated. Tagged fish moved out of the refuges 3 to 4 weeks after the fall overturn when reservoir temperatures approximated 22 to 24/sup 0/C.

  8. Predicting DUI recidivism of male drunken driving: a prospective study of the impact of alcohol markers and previous drunken driving.

    Portman, M; Penttilä, A; Haukka, J; Eriksson, P; Alho, H; Kuoppasalmi, K


    The aim of the present study was to determine whether the alcohol biomarkers CDT, GGT, the biomarker gamma-CDT index and previous drunken driving contributed significantly to the prediction of DUI recidivism. The subjects consisted of two different samples of drivers, viz. drivers who were found to have a positive breath alcohol concentration during random breath testing surveys (n=237), and drunken drivers who were apprehended during ordinary police work (n=193). The drunken driving events were monitored using a data-base both retrospectively and prospectively. It was found that the biomarker index, gamma-CDT, emerged as a notable predictor of recidivism in the group of random breath tested drivers. Measurement of gamma-CDT and its impact on DUI recidivism has not to our knowledge been applied to random breath tested drivers before. The apprehended drunken drivers, on the other hand, did not show a significant relationship between gamma-CDT and DUI recidivism. However, in both groups of drivers it was found that a previous conviction for drunken driving strongly predicted DUI recidivism. More attention should be paid by both physicians and the police to the high risk of recidivism among those convicted of drunken driving.

  9. Simulation study of the VAPEX process in fractured heavy oil system at reservoir conditions

    Azin, Reza; Ghotbi, Cyrus [Department of Chemical and Petroleum Engineering, Sharif Univ. Tech., Tehran (Iran); Kharrat, Riyaz; Rostami, Behzad [Petroleum University of Technology Research Center, Tehran (Iran); Vossoughi, Shapour [4132C Learned Hall, Department of Chemical and Petroleum Engineering, Kansas University, Lawrence, KS (United States)


    The Vapor Extraction (VAPEX) process, a newly developed Enhanced Oil Recovery (EOR) process to recover heavy oil and bitumen, has been studied theoretically and experimentally and is found a promising EOR method for certain heavy oil reservoirs. In this work, a simulation study of the VAPEX process was made on a fractured model, which consists of a matrix surrounded by horizontal and vertical fractures. The results show a very interesting difference in the pattern of solvent flow in fractured model compared with the conventional model. Also, in the fractured system, due to differences in matrix and fracture permeabilities, the solvent first spreads through the fractures and then starts diffusing into matrix from all parts of the matrix. Thus, the solvent surrounds the oil bank, and an oil rather than the solvent chamber forms and shrinks as the process proceeds. In addition, the recovery factor is higher at lower solvent injection rates for a constant pore volume of the solvent injected into the model. Also, the diffusion process becomes important and higher recoveries are obtained at low injection rates, provided sufficient time is given to the process. The effect of inter-connectivity of the surrounding fractures was studied by making the side vertical fractures shorter than the side length of the model. It was observed that inter-connectivity of the fractures affects the pattern of solvent distribution. Even for the case of side fractures being far apart from the bottom fracture, the solvent distribution in the matrix was significantly different than that in the model without fractures. Combination of diffusion phenomenon and gravity segregation was observed to be controlling factors in all VAPEX processes simulated in fractured systems. The early breakthrough of the solvent for the case of matrix surrounded by the fracture partially inhibited diffusion of the solvent into the oil and consequently the VAPEX process became the least effective. It is concluded

  10. The suitability of XRF analysis for compositional classification of archaeological ceramic fabric: A comparison with a previous NAA study

    Padilla, R. [Centro de Aplicaciones Tecnologicas y Desarrollo Nuclear (CEADEN), Laboratorio de Analisis Quimico, Calle 30 no. 502, Playa, Ciudad Habana (Cuba)]. E-mail:; Espen, P. van [University of Antwerp (Belgium); Torres, P.P. Godo [Centro de Antropologia, Havana (Cuba)


    The main drawbacks of EDXRF techniques, restricting its more frequent use for the specific purpose of compositional analysis of archaeological ceramic fabric, have been the insufficient sensitivity to determine some important elements (like Cr, REE, among others), a somewhat worse precision and the inability to perform standard-less quantitative procedures in the absence of suitable certified reference materials (CRM) for ceramic fabric. This paper presents the advantages of combining two energy dispersive X-ray fluorescence methods for fast and non-destructive analysis of ceramic fabric with increased sensitivity. Selective polarized excitation using secondary targets (EDPXRF) and radioisotope excitation (R-XRF) using a {sup 241}Am source. The analytical performance of the methods was evaluated by analyzing several CRM of sediment type, and the fitness for the purpose of compositional classification was compared with that obtained by using Instrumental Neutron Activation Analysis in a previous study of Cuban aborigine pottery.

  11. Coupling of a reservoir model and of a poro-mechanical model. Application to the study of the compaction of petroleum reservoirs and of the associated subsidence; Couplage d'un modele de gisement et d'un modele mecanique. Application a l'etude de la compaction des reservoirs petroliers et de la subsidence associee

    Bevillon, D.


    The aim of this study is to provide a better description of the rock contribution to fluid flows in petroleum reservoirs. The production of oil/gas in soft highly compacting reservoirs induces important reduction of the pore volume, which increases oil productivity. This compaction leads to undesirable effects such as surface subsidence or damage of well equipment. Analysis of compaction and subsidence can be performed using either engineering reservoir models or coupled poro-mechanical models. Poro-mechanical model offers a rigorous mechanical framework, but does not permit a complete description of the fluids. The reservoir model gives a good description of the fluid phases, but the description of the mechanic phenomenon is then simplified. To satisfy the set of equations (mechanical equilibrium and diffusivity equations), two simulators can be used together sequentially. Each of the two simulators solves its own system independently, and information passed both directions between simulators. This technique is usually referred to the partially coupled scheme. In this study, reservoir and hydro-mechanical simulations show that reservoir theory is not a rigorous framework to represent the evolution of the high porous rocks strains. Then, we introduce a partially coupled scheme that is shown to be consistent and unconditionally stable, which permits to describe correctly poro-mechanical theory in reservoir models. (author)

  12. Evaluation of questionnaire-based information on previous physical work loads. Stockholm MUSIC 1 Study Group. Musculoskeletal Intervention Center.

    Torgén, M; Winkel, J; Alfredsson, L; Kilbom, A


    The principal aim of the present study was to evaluate questionnaire-based information on past physical work loads (6-year recall). Effects of memory difficulties on reproducibility were evaluated for 82 subjects by comparing previously reported results on current work loads (test-retest procedure) with the same items recalled 6 years later. Validity was assessed by comparing self-reports in 1995, regarding work loads in 1989, with worksite measurements performed in 1989. Six-year reproducibility, calculated as weighted kappa coefficients (k(w)), varied between 0.36 and 0.86, with the highest values for proportion of the workday spent sitting and for perceived general exertion and the lowest values for trunk and neck flexion. The six-year reproducibility results were similar to previously reported test-retest results for these items; this finding indicates that memory difficulties was a minor problem. The validity of the questionnaire responses, expressed as rank correlations (r(s)) between the questionnaire responses and workplace measurements, varied between -0.16 and 0.78. The highest values were obtained for the items sitting and repetitive work, and the lowest and "unacceptable" values were for head rotation and neck flexion. Misclassification of exposure did not appear to be differential with regard to musculoskeletal symptom status, as judged by the calculated risk estimates. The validity of some of these self-administered questionnaire items appears sufficient for a crude assessment of physical work loads in the past in epidemiologic studies of the general population with predominantly low levels of exposure.

  13. Land Use Land Cover Impact on Probable Maximum Flood and Sedimentation for Artificial Reservoirs: A Case Study in Western US

    Yigzaw, W. Y.; Hossain, F.


    Unanticipated peak inflows that can exceed the inflow design flood (IDF) for spillways and result in possible storage loss in reservoirs from increased sedimentation rates lead to a greater risk for downstream floods. Probable maximum precipitation (PMP) and probable maximum flood (PMF) are mostly used to determine IDF. Any possible change of PMP and PMF due to future land use and land cover (LULC) change therefore requires a methodical investigation. However, the consequential sediment yield, due to altered precipitation and flow patterns into the reservoir has not been addressed in literature. Thus, this study answers the following question: "What is the combined impact of a modified PMP on PMF and sediment yield for an artificial reservoir? The Owyhee dam of Owyhee River watershed (ORW) in Oregon is selected as a case study area for understanding the impact of LULC change on PMF and sedimentation rates. Variable Infiltration Capacity (VIC) is used for simulating stream flow (PMF) and the Revised Universal Soil Loss Equation (RUSLE) to estimate sediment yield over ORW as a result of change in precipitation intensity and LULC. Scenarios that represent pre-Owyhee dam (Pre-Dam) and post Owyhee dam (Non-Irrigation, Control, 1992, 2001, 2006) are used to simulate PMF's and consequential sediment yield. Peak PMF result for Pre-Dam scenarios is found to increase by 26m3s-1 (1%) and 81m3s-1 (3%) from Non-Irrigation and Control scenario, respectively. Considering only LULC change, sediment yield decreased over ORW due to the transformation of LULC from grassland to shrubland (from Pre-Dam period to the post-Dam years). However, increase in precipitation intensity caused a significant (0.1% storage loss over 21days storm period) increase in sediment yield resulting in largely reservoir sedimentation. This study underscores the need to consider future impact of LULC change on IDF calculation as well as sedimentation rates for more robust reservoir operations and planning.

  14. LAND USE CHANGE AND ITS SOCIO-ECONOMIC DRIVING FORCES UNDER STRESS OF PROJECT IN OLD RESERVOIR AREA --Case Study of Linshui Reservoir Area of Dahonghe Reservoir in Sichuan Province

    SHAO Jin-gan; HUANG Xue-qin; QU Ming; WEI Chao-fu; XIE De-ti


    The old reservoir areas built in 1950s-1970s left behind many socio-economic problems, because of the administrative backward migration and little migration fund, and all these problems would be tied to land. Based on interviewing with peasant households, combining land use survey and socio-economic statistical index, this paper analyzed land use change and its corresponding driving forces in Linshui reservoir area of Dahonghe Reservoir. Results showed that land use change in the reservoir area was mainly embodied on low-lying land submergence and migration requisition land. The former changed the land use patterns, and the latter mainly reconstructed original land property and made land over-fragmented. Cultivated land per capita was 0.041ha in this area, below the cordon of cultivated land per capita enacted by FAO. Currently, there were still 30.25% of peasant households being short of grain in trimester of one year, and there were 35.27% of people living under the poverty line. The conditions of eco-environment in Linshui Reservoir Area were worse, and healthy and sub-healthy eco-environment accounted for less proportion, composed of green belt around the reservoir area and paddy field ecosystem, and economic forest and orchard ecosystem, respectively. The stress of the reservoir project was macroscopic background to analyze the driving factors of land use change, and real underlying diving factor of the land use change in the area was the change of cultural landscape under the stress of reservoir project. The rapid increase of population was the key factor to induce the change of man-land relationship in the reservoir area, the low level of rural economy was the crucial factor to decide how migrants input for production, and the belief of migrants, influencing the land use patterns in a certain extent, was the inducing factor to keep land use stable. The low-lying submergence and infrastructure construction accompanied the reservoir project were leading

  15. Feasibility study of the in-situ combustion in shallow, thin, and multi-layered heavy oil reservoir

    Zhong, L. [Society of Petroleum Engineers, Kuala Lumpur (Malaysia)]|[Daqing Petroleum Inst., Beijing (China); Yu, D. [Daqing Petroleum Inst., Beijing (China); Gong, Y. [China National Petroleum Corp., Beijing (China). Liaohe Oilfield; Wang, P.; Zhang, L. [China National Petroleum Corp., Beijing (China). Huabei Oilfield; Liu, C. [China National Petroleum Corp., Beijing (China). JiLin Oilfield


    In situ combustion is a process where oxygen is injected into oil reservoirs in order to oxidize the heavier components of crude oil. The oil is driven towards the production wells by the combustion gases and steam generated by the combustion processes. This paper investigated dry and wet forward in situ combustion processes designed for an oil reservoir with thin sand layers. Laboratory and numerical simulations were conducted to demonstrate the feasibility of the processes in a shallow, thin, heterogenous heavy oil reservoir in China. Combustion tube experiments were conducted in order to determine fuel consumption rates. A numerical geological model was constructed to represent the reservoir conditions. Gas, water, oil and solid phases were modelled. Four processes were considered: cracking; pyrolysis of heavy fractions; the combustion of light and heavy fractions; and the combustion of coke. Oil recovery rates were calculated for a period of 10 years. Reactor experiments were conducted to investigate igniting temperatures and air injection rates using an apparatus comprised of an electric heater, oil sand pack tube and a computerized control system. Experiments were performed at different temperature and injection rates. The experiments demonstrated that ignition times and air volumes decreased when air temperature was increased. Results of the study showed that a 20 per cent increase in oil recovery using the in situ combustion processes. It was concluded that adequate air injection rates are needed to ensure effective combustion front movement. 4 refs., 6 tabs., 4 figs.

  16. Alemtuzumab as rescue therapy in a cohort of 16 aggressive multiple sclerosis patients previously treated by Mitoxantrone: an observational study.

    Le Page, Emmanuelle; Deburghgraeve, Véronique; Lester, Marie-Antoinette; Cardiet, Isabelle; Leray, Emmanuelle; Edan, Gilles


    Our study aimed to describe safety and neurological impact of alemtuzumab as last-line rescue therapy in aggressive multiple sclerosis (MS) patients, previously treated by Mitoxantrone (MITOX). Between June 2004 and October 2013, 13 patients received alemtuzumab at 20 mg/day and 3 at 12 mg/day for 5 days. EDSS, relapses, secondary progression were prospectively assessed 12 and 6 months before treatment, at baseline and every 3 months. Mean follow-up was 6.2 years [1-10]. Mean age at alemtuzumab start was 40 years [26-49] for 8 Secondary Progressive (SP) and 30 years [26-35] for 8 Relapsing-Remitting (RR) patients. MS duration was 13.7 (± 3) and 8.3 (± 4) years, respectively. During the 12 months before alemtuzumab, annual relapse rate was 0.75 and 3.14, respectively and the 16 patients accumulated 2-30 new gadolinium enhancing lesions. 4 patients (suboptimal responders) received alemtuzumab during MITOX and 12 patients 1-7.8 years after MITOX. Out of 8 SPMS, 2 were disease free up to last visit (4.7 and 8 years), 5 improved or stabilized but only transiently and 1 worsened. Out of 8 RRMS, 1 remained stable up to last visit (8.7 years) despite 1 relapse and active MRI at 18 months and 7 improved (1-4 point EDSS): 4 remained disease free up to last visit (12, 24, 38 months and 7 years), 2 were successfully retreated at 25 and 33 months and 1 worsened progressively 24 months after alemtuzumab. 2 patients developed Grave's disease and 1 hypothyroidism. Alemtuzumab controls aggressive RRMS despite previous use of MITOX.

  17. Exploring reservoir dynamics: a case study of rabies in the Serengeti ecosystem.

    Lembo, Tiziana; Hampson, Katie; Haydon, Daniel T; Craft, Meggan; Dobson, Andy; Dushoff, Jonathan; Ernest, Eblate; Hoare, Richard; Kaare, Magai; Mlengeya, Titus; Mentzel, Christine; Cleaveland, Sarah


    Knowledge of infection reservoir dynamics is critical for effective disease control, but identifying reservoirs of multi-host pathogens is challenging. Here, we synthesize several lines of evidence to investigate rabies reservoirs in complex carnivore communities of the Serengeti ecological region in northwest Tanzania, where the disease has been confirmed in 12 carnivore species.Long-term monitoring data suggest that rabies persists in high-density domestic dog Canis familiaris populations (> 11 dogs km(-2)) and occurs less frequently in lower-density (transmission was more frequently inferred from high-resolution epidemiological data than between-species transmission. Incidence patterns indicate that spill-over of rabies from domestic dog populations sometimes initiates short-lived chains of transmission in other carnivores.Synthesis and applications. The balance of evidence suggests that the reservoir of rabies in the Serengeti ecosystem is a complex multi-host community where domestic dogs are the only population essential for persistence, although other carnivores contribute to the reservoir as non-maintenance populations. Control programmes that target domestic dog populations should therefore have the greatest impact on reducing the risk of infection in all other species including humans, livestock and endangered wildlife populations, but transmission in other species may increase the level of vaccination coverage in domestic dog populations necessary to eliminate rabies.

  18. A combination of streamtube and geostatical simulation methodologies for the study of large oil reservoirs

    Chakravarty, A.; Emanuel, A.S.; Bernath, J.A. [Chevron Petroleum Technology Company, LaHabra, CA (United States)


    The application of streamtube models for reservoir simulation has an extensive history in the oil industry. Although these models are strictly applicable only to fields under voidage balance, they have proved to be useful in a large number of fields provided that there is no solution gas evolution and production. These models combine the benefit of very fast computational time with the practical ability to model a large reservoir over the course of its history. These models do not, however, directly incorporate the detailed geological information that recent experience has taught is important. This paper presents a technique for mapping the saturation information contained in a history matched streamtube model onto a detailed geostatistically derived finite difference grid. With this technique, the saturation information in a streamtube model, data that is actually statistical in nature, can be identified with actual physical locations in a field and a picture of the remaining oil saturation can be determined. Alternatively, the streamtube model can be used to simulate the early development history of a field and the saturation data then used to initialize detailed late time finite difference models. The proposed method is presented through an example application to the Ninian reservoir. This reservoir, located in the North Sea (UK), is a heterogeneous sandstone characterized by a line drive waterflood, with about 160 wells, and a 16 year history. The reservoir was satisfactorily history matched and mapped for remaining oil saturation. A comparison to 3-D seismic survey and recently drilled wells have provided preliminary verification.

  19. An Integrated Study of the Grayburg/San Andres Reservoir Foster and South Cowden fields,



    GEOPHYSICAL OBJECTIVES: The goals of work done this quarter were to (1) refine the maps of seismic-derived porosity for the upper Grayburg for reapplication to the production model, (2) determine rock fabric and porosity patterns for the lower Grayburg and the upper San Andres, (3) relate any seismic-derived porosity characteristics, particularly seismic waveform attributes, to the historical production of oil allocated to lower Grayburg and San Andres zones, and (4) to test other geologic attributes for possible inter-relationships. GEOLOGIC OBJECTIVES: Continue the integrated geological/geophysical effort to develop a usable seismic velocity/log porosity transform for each Grayburg producing interval. The lower Grayburg and San Andres core were revisited to glean lithology and porosity information for the seismic inversion model. Update recent production and injection for each well in the study area. Add new production and injection wells to spreadsheet. Continue evaluation of effectiveness of recent completions, plug backs and injector conversions by monitoring oil production and produced water composition. ENGINEERING OBJECTIVES: To build the most accurate reservoir picture by continued integration of all data types available and utilize that model to optimize oil production. Monitoring and testing of new and worked-over wells continues to test the early production models. Methods to improve water quality are being evaluated using normal field management procedures.

  20. Experimental Study of the Feasibility of Air Flooding in an Ultra-Low Permeability Reservoir

    Guohui Qu


    Full Text Available The development effect of water flooding in an ultra-low permeability reservoir is poor due to its poor physical properties and high shale content, so an experimental study of air flooding which helps to complement energy production was carried out. Based on the Accelerating Rate Calorimeter experimental results, the crude oil of N block in L oilfield can undergo low-temperature oxidation reactions, which are the basic condition for air flooding. Three groups of experimental natural cylinder cores designed for oil displacement, water flooding and air flooding were used respectively, and the relationship between differential pressure, oil recovery, injection capacity with injection volume was investigated. It is observed that the recovery efficiency increased 2.58%, the injection-production pressure difference dropped 60% and the injection capability increased 60% in the experiment of shifting air flooding after water flooding to 75% moisture content, compared with water flooding alone. It has been shown in the results that the recovery efficiency improved sharply more than water flooding, the effect of depressurization and augmented injection was obvious, and the air displacement was thus validated. We suggest that other science and technology workers should perform further tests and verify this result through numerical simulation.

  1. 蒸汽驱对储层润湿性的影响%Study of steam flooding on reservoir wettability

    阳晓燕; 杨胜来; 李秀峦; 赵春明


    储层润湿性决定着注入流体在储层中渗流的难易程度,对原油的驱油效率、采出程度起着决定性作用.为了明确蒸汽驱过程中储层润湿性的变化,通过室内实验非稳态法水驱油、蒸汽驱油测定油藏相对渗透率曲线的变化,研究了疏松砂岩油藏蒸汽驱对储层润湿性改变的影响.实验结果表明,由水驱到蒸汽驱,油相相对渗透率增加,残余油饱和度下降,残余油饱和度对应的水相相对渗透率增加,等渗点右移;综合相对渗透率曲线特征表明,蒸汽驱使得储层润湿性向亲水方向发展.通过非稳态法研究相对渗透率曲线,由相对渗透率曲线特征点的变化来判断储层润湿性的改变简单易行,蒸汽驱对储层润湿性的改善非常有利.%Wettability of the reservoir determines the degree of difficulty with the fluid flow in the reservoir, which plays a decisive role in oil displacement efficiency. In order to clarify the process of steam flooding reservoir and the change of wettability, we use non-steady-state method in lab by water flooding and steam flooding oil reservoir relative permeability curves measured to study changes in steam flooding caused by changes of wettability. Experimental results show that from water flooding to steam flooding, the oil relative permeability increased, residual oil saturation corresponds to the penetration of the water phase increased, the residual oil saturation decreased, and the permeability equivalent points moved right. The overall relative permeability curves show that the wettability is driven by steam reservoir to hydrophilic direction. Based on the non-steady-state relative permeability curves and relative permeability curves from the point of wettability changing of the reservoir, we can determine the changes simply and easily, and the steam flooding of the reservoir is very beneficial to the amelioration of wettability.

  2. A phase I study of imatinib mesylate in combination with chlorambucil in previously treated chronic lymphocytic leukemia patients.

    Hebb, Jonathan; Assouline, Sarit; Rousseau, Caroline; Desjardins, Pierre; Caplan, Stephen; Egorin, Merrill J; Amrein, Lilian; Aloyz, Raquel; Panasci, Lawrence


    The tyrosine kinase inhibitor, imatinib, has the potential to indirectly inhibit DNA repair. This mechanism of action has been shown to mediate sensitization to chlorambucil in chronic lymphocytic leukemia (CLL). To evaluate this effect in vivo, we performed a phase I study of chlorambucil combined with imatinib in relapsed CLL patients. The three dose levels studied included imatinib at 300, 400, or 600 mg/day. Imatinib was given on days 1-10, and chlorambucil (8 mg/m(2) daily) was given on days 3-7 of a 28-day cycle (up to 6 cycles). Eleven patients participated in this study. Low-grade gastrointestinal toxicities were observed in a dose-dependent manner. Forty-five percent of patients responded (two unconfirmed CRs and three PRs). Two responding patients were fludarabine refractory. The in vitro IC(50) of chlorambucil alone or in the presence of 5 μM imatinib in CLL lymphocytes correlated with the decrease in lymphocyte counts on day 15. Imatinib plasma concentrations achieved in patients were in the range of those effective in in vitro sensitization studies. The combination of chlorambucil and imatinib in patients with previously treated CLL was well tolerated and showed evidence of clinical efficacy. Based on our results, we recommend the 400 mg daily dose of imatinib on days 1-10 with 8 mg/m(3) chlorambucil on days 3-7 every 28 days as the phase II dose. This represents the first clinical trial examining the potential synergy between a tyrosine kinase inhibitor and a conventional alkylating agent for the treatment of CLL.

  3. Experimental studies of low salinity water flooding in carbonate reservoirs: A new promising approach

    Zahid, Adeel; Shapiro, Alexander; Skauge, Arne


    additional oil recovery can be achieved when successively flooding composite carbonate core plugs with various diluted versions of seawater. The experimental data on carbonates is very limited, so more data and better understanding of the mechanisms involved is needed to utilize this method for carbonate...... reservoirs. In this paper, we have experimentally investigated the oil recovery potential of low salinity water flooding for carbonate rocks. We used both reservoir carbonate and outcrop chalk core plugs. The flooding experiments were carried out initially with the seawater, and afterwards additional oil...... of experimental results, discussions are made about possible mechanisms for improving oil recovery in carbonate reservoir as a function of change in brine salinity. Copyright 2012, Society of Petroleum Engineers....

  4. Production of a Porosity Map by Kriging in Sandstone Reservoirs, Case Study from the Sava Depression

    Tomislav Malvić


    Full Text Available Variogram analyses and usages of geostatistical interpolations have been standard analytical tools in Croatian geology in the last five years. Such analyses have especially been applied in the mapping of petroleum geological data. In this paper, spatial modelling of porosity data and, consequently, kriging mapping are described for a relatively large dataset obtained at an oil field located in the Croatian part of Pannonian basin (Sava depression. Analyzed datasets included porosity values measured in a sandstone reservoir of Pannonian age. The original dataset can be considered as a rare extensive porosity set available for Croatian hydrocarbon reservoirs. It made possible very reliable semivariogram modelling and kriging interpolation of porosity. The obtained results point out kriging as the most appropriate interpolation approach for porosity, but also for other geological data in sandstone reservoirs of Miocene age.

  5. Stochastic reservoir optimization using El Niño information: case study of Daule Peripa, Ecuador

    Gelati, Emiliano; Madsen, Henrik; Rosbjerg, Dan


    of reservoir releases with monthly time-steps. To account for inflow uncertainty, we generate multiple synthetic inflow time series and apply a multi-objective genetic algorithm to evaluate the objective functions. The results highlight the advantages of using a climate-driven stochastic model to produce......Reservoir optimization requires the ability to produce inflow scenarios that are consistent with the available climatic information. We approach stochastic inflow modelling with a Markov-switching model where inflow anomalies are described by a mixture of autoregressive models with exogenous input......) indices constitute the climatic input of the inflow model. The Daule Peripa reservoir serves a hydropower plant and a downstream water supply facility. Based on ENSO forecasts, which are available with 9 month lead time, monthly inflow scenarios are generated to perform stochastic optimization...

  6. Study of desorption in a vapor dominated reservoir with fractal geometry

    Tudor, Monica; Horne, Roland N.; Hewett, Thomas A.


    This paper is an attempt to model well decline in a vapor dominated reservoir with fractal geometry. The fractal network of fractures is treated as a continuum with characteristic anomalous diffusion of pressure. A numerical solver is used to obtain the solution of the partial differential equation including adsorption in the fractal storage space. The decline of the reservoir is found to obey the empirical hyperbolic type relation when adsorption is not present. Desorption does not change the signature of the flow rate decline but shifts it on the time/flow rate axis. Only three out of six model parameters can be estimated from field data, due to the linear correlation between parameters. An application to real well data from The Geysers field is presented together with the estimated reservoir, fractal space and adsorption parameters. Desorption dominated flow is still a questionable approximation for flow in fractal objects.


    YIN Hong-jun; FU Chun-quan; HE Ying-fu


    The steady-state flow mathematical model of arbitrary shaped homogeneous reservoirs with impermeable barrier is constructed in this paper. By using Boundary Element Method (BEM), the mathematical model is solved. And a streamline generating technique is presented. The figures of streamlines are plotted and analyzed considering the effect of complex boundary and impermeable barriers. Through analyzing, it indicates that the size, shape and orientation of impermeable barriers have various degree of influence on the streamlines. So, if there are impermeable barriers in reservoir according to the geological materials, the influence of impermeable barriers must be considered when adjusting flood pattern and injection strategy.

  8. Chapter A10. Lakes and reservoirs: Guidelines for study design and sampling

    Green, William R.; Robertson, Dale M.; Wilde, Franceska D.


    The National Field Manual for the Collection of Water-Quality Data (National Field Manual, NFM) is an online report with separately published chapters that provides the protocols and guidelines by which U.S. Geological Survey personnel obtain the data used to assess the quality of the Nation’s surface-water and groundwater resources. Chapter 10 reviews limnological principles, describes the characteristics that distinguish lakes from reservoirs, and provides guidance for developing temporal and spatial sampling strategies and data-collection approaches to be used in lake and reservoir environmental investigations.

  9. LipL32 Is a Subsurface Lipoprotein of Leptospira interrogans: presentation of new data and reevaluation of previous studies.

    Marija Pinne

    Full Text Available The agents of leptospirosis, a zoonosis with worldwide distribution, are pathogenic spirochetes belonging to the genus Leptospira. The leptospiral life cycle involves transmission via fresh water and colonization of the renal tubules of their reservoir hosts. Infection of accidental hosts, including humans, may result in life-threatening sequelae. Bacterial outer membrane proteins (OMPs, particularly those with surface-exposed regions, play crucial roles in pathogen virulence mechanisms and adaptation to environmental conditions, including those found in the mammalian host. Therefore, elucidation and characterization of the surface-exposed OMPs of Leptospira spp. is of great interest in the leptospirosis field. A thorough, multi-pronged approach for assessing surface exposure of leptospiral OMPs is essential. Herein, we present evidence for a sub-surface location for most or all of the major leptospiral lipoprotein, LipL32, based on surface immunofluorescence utilizing three different types of antibodies and four different permeabilization methods, as well as surface proteolysis of intact and lysed leptospires. We reevaluate prior evidence presented in support of LipL32 surface-exposure and present a novel perspective on a protein whose location has been misleading researchers, due in large part to its extraordinary abundance in leptospiral cells.

  10. Cultural Resources Survey, Harry S. Truman Dam and Reservoir Project, Missouri. Volume 5. Lithic and Ceramic Studies.


    History Site Testing Pomme de Terre River Architectural Survey Rock Shelters Grand River Archeological Survey Environmental Studies Deepwater Creek...the lower Pomme de Terre River valley. Volume VII is a study of the re- sults of preliminary testing at several sites in the lower Pomme de Terre ...Mound. Missouri Archaeologist 7(1): 2-8. *1954 Preliminary Salvage in the Pomme de Terre Reservoir Area, Missouri. Missouri Archaeologist 16(3-4): 1-113

  11. Patterns and Determinants of Treatment Seeking among Previously Untreated Psychotic Patients in Aceh Province, Indonesia: A Qualitative Study

    Marthoenis Marthoenis


    Full Text Available Immediate treatment of first-episode psychosis is essential in order to achieve a positive outcome. However, Indonesian psychiatric patients often delay accessing health services, the reason for which is not yet fully understood. The current study aimed to understand patterns of treatment seeking and to reveal determinants of the delay in accessing psychiatric care among first-time user psychotic patients. Qualitative interviews were conducted with sixteen family members who accompanied the patients to a psychiatric hospital. Many families expressed beliefs that mental illness appertains to village sickness and not hospital sickness; therefore, they usually take the patients to traditional or religious healers before taking them to a health professional. They also identified various factors that potentially delay accessing psychiatric treatment: low literacy and beliefs about the cause of the illness, stigmatisation, the role of extended family, financial problems, and long distance to the psychiatric hospital. On the other hand, the family mentioned various factors related to timely help seeking, including being a well-educated family, living closer to health facilities, previous experience of successful psychotic therapy, and having more positive symptoms of psychosis. The findings call for mental health awareness campaigns in the community.

  12. Phase III randomized study of bendamustine compared with chlorambucil in previously untreated patients with chronic lymphocytic leukemia.

    Knauf, Wolfgang U; Lissichkov, Toshko; Aldaoud, Ali; Liberati, Anna; Loscertales, Javier; Herbrecht, Raoul; Juliusson, Gunnar; Postner, Gerhard; Gercheva, Liana; Goranov, Stefan; Becker, Martin; Fricke, Hans-Joerg; Huguet, Francoise; Del Giudice, Ilaria; Klein, Peter; Tremmel, Lothar; Merkle, Karlheinz; Montillo, Marco


    This randomized, open-label, parallel-group, multicenter study was designed to compare the efficacy and safety of bendamustine and chlorambucil in previously untreated patients with advanced (Binet stage B or C) chronic lymphocytic leukemia (CLL). Patients (chlorambucil 0.8 mg/kg (Broca's normal weight) orally on days 1 and 15; treatment cycles were repeated every 4 weeks for a maximum of six cycles. The response to treatment was assessed according to National Cancer Institute Working Group criteria, and the final determination of response was made by a blinded independent review committee. A total of 319 patients were randomly assigned (162 bendamustine, 157 chlorambucil). Complete or partial responses were achieved in 110 (68%) of 162 bendamustine-treated and 48 (31%) of 157 chlorambucil-treated patients (P chlorambucil (31% v 2%). Median progression-free survival was 21.6 months with bendamustine and 8.3 months with chlorambucil (P chlorambucil (median, 21.8 v 8.0 months). Hematologic National Cancer Institute Common Toxicity Criteria grade 3 to 4 adverse events were more common with bendamustine than with chlorambucil (occurring in 40% v 19% of patients). Severe infections (grade 3 to 4) occurred in 8% of bendamustine-treated patients and 3% of chlorambucil-treated patients. Bendamustine offers significantly greater efficacy than chlorambucil, and a manageable toxicity profile, when used as first-line therapy in patients with advanced CLL.

  13. Integrating Sonography Training Into Undergraduate Medical Education: A Study of the Previous Exposure of One Institution's Incoming Residents.

    Day, James; Davis, Joshua; Riesenberg, Lee Ann; Heil, Daniel; Berg, Katherine; Davis, Robyn; Berg, Dale


    Sonography is a crucial and versatile tool within the field of medicine. Recent advancements in technology have led to increased use of point-of-care sonography. We designed a survey to assess prior point-of-care sonography training among incoming interns at an academic teaching hospital. In 2012 and 2013, we surveyed incoming interns (n = 154 and 145, respectively) regarding point-of-care sonography training received during medical school. The survey questions included formal didactic sessions, bedside instruction, and the use of simulation technology. One-fourth (26.3% in 2012 and 23.4% in 2013) of responding interns reported having never done an ultrasound scan at the bedside. In 2012 and 2013, 55.0% and 55.6% of respondents reported never having done an ultrasound scan in a simulation center, respectively. Interns agreed that sonography education should be provided during medical school. On average, interns disagreed with the statement that sonography should be taught in residency only. There was no significant difference in the sex or general previous experience with sonography across both intern classes. Point-of-care sonography is inconsistently taught in medical school. The interns in our study also thought that sonography education should begin in medical school, and sonography should be taught by using simulation and at the bedside. © 2015 by the American Institute of Ultrasound in Medicine.

  14. Pilot Study of an Individualised Early Postpartum Intervention to Increase Physical Activity in Women with Previous Gestational Diabetes

    Harold David McIntyre


    Full Text Available Optimal strategies to prevent progression towards overt diabetes in women with recent gestational diabetes remain ill defined. We report a pilot study of a convenient, home based exercise program with telephone support, suited to the early post-partum period. Twenty eight women with recent gestational diabetes were enrolled at six weeks post-partum into a 12 week randomised controlled trial of Usual Care (n=13 versus Supported Care (individualised exercise program with regular telephone support; n=15. Baseline characteristics (Mean ± SD were: Age  33±4  years; Weight 80 ± 20 kg and Body Mass Index (BMI 30.0±9.7 kg/m2. The primary outcome, planned physical activity {Median (Range}, increased by 60 (0–540 mins/week in the SC group versus 0 (0–580 mins/week in the UC group (P=0.234. Walking was the predominant physical activity. Body weight, BMI, waist circumference, % body fat, fasting glucose and insulin did not change significantly over time in either group. This intervention designed to increase physical activity in post-partum women with previous gestational diabetes proved feasible. However, no measurable improvement in metabolic or biometric parameters was observed over a three month period.

  15. Western Shallow Oil Zone, Elk Hills Field, Kern County, California: General reservoir study, Appendix 4, Fourth Wilhelm sand

    Carey, K.B.


    The general Reservoir Study of the Western Shallow Oil Zone was prepared by Evans, Carey and Crozier as Task Assignment 009 with the United States Department of Energy. This study, Appendix IV, addresses the Fourth Wilhelm Sand and its sub units and pools. Basic pressure, production and assorted technical data were provided by the US Department of Energy staff at Elk Hills. Basic pressure production and assorted technical data were provided by the US Department of Energy staff at Elk Hills. These data were accepted as furnished with no attempt being made by Evans, Carey and Crozier for independent verification. This study has identified the petrophysical properties and the past productive performance of the reservoir. Primary reserves have been determined and general means of enhancing future recovery have been suggested. It is hoped that this volume can now additionally serve as a take off point for exploitation engineers to develop specific programs toward the end. 12 figs., 9 tabs.

  16. Reconstruction of Existing Reservoir Model for Its Calibration to Dynamic Data

    Le Ravalec-Dupin, M.; Hu, L. Y.; Roggero, F.

    The increase in computer power and the recent developments in history-matching can motivate the reexamination of previously built reservoir models. To save the time of engineers and the CPU time, four distinct algorithms, which allow for rebuilding an existing reservoir model without restarting the reservoir study from scratch, were formulated. The algorithms involve techniques such as optimization, relaxation, Wiener filtering, or sequential reconstruction. They are used to identify a stochastic function and a set of random numbers. Given the stochastic function, the random numbers yield a realization that is close to the existing reservoir model. Once the random numbers are known, the existing reservoir model can be submitted to a new history-matching process to improve the data fit or to account for newly collected data. A practical implementation is presented within the context of facies reservoirs. This article focuses on a previously built facies reservoir model. Although the simulation procedure is unknown to the authors, a set of random numbers are identified so that when provided to a multiple-point statistics simulator, a realization very close to the existing reservoir model is obtained. A new history-matching procedure is then run to update the existing reservoir model and to integrate the fractional flow rates measured in two producing wells drilled after the building of the existing reservoir model.

  17. Risk factors and therapeutic coverage at 6 years in patients with previous myocardial infarction: the CASTUO study

    Félix-Redondo, Francisco Javier; Lozano Mera, Luis; Consuegra-Sánchez, Luciano; Giménez Sáez, Fernando; Garcipérez de Vargas, Francisco Javier; Castellano Vázquez, José María; Fernández-Bergés, Daniel


    Objectives To determine the degree of risk factor control, the clinical symptoms and the therapeutic management of patients with a history of previous myocardial infarction. Methods Cross-sectional study at 6 years of a first episode of acute myocardial infarction between 2000 and 2009, admitted at a hospital in the region of Extremadura (Spain). Of 2177 patients with this diagnosis, 1365 remained alive and therefore were included in the study. Results We conducted a person-to-person survey in 666 (48.8%) individuals and telephone survey in 437 (31.9%) individuals. The former are analysed. 130 were female (19.5%). The mean age was 67.4 years and the median time since the event was 5.8 (IQR 3.6–8.2) years. Active smokers made up 13.8%, low-density lipoprotein (LDL) cholesterol was ≥70 mg/dL: 82%, blood pressure ≥140/90 mm Hg (≥140/85 in diabetics): 49.8%, fasting glucose ≥126 mg/dL: 26%, heart rate 50–59 bpm: 60.7%, and obesity: 45.9%. Patients reported presenting angina comprised 22.4% and those with dyspnoea, 29.3%. Drug coverage was: 88.0% antiplatelet drugs, 86.5% statins, 75.6% β-blockers and 65.8% blockers of the renin-angiotensin system. Patients receiving all four types of drugs made up 41.9%, with only 3.0% having jointly controlled cholesterol, blood pressure, heart rate and glycaemia. Conclusions LDL cholesterol, heart rate and blood pressure were risk factors with less control. More than 1/5 of patients had angina and more than 1/4, dyspnoea. Risk factor control and the clinical condition were far from optimal, as was drug coverage, although to a lesser degree. PMID:27127637

  18. Inversion of surface subsidence data to quantify reservoir compartmentalization: A field study

    Fokker, P.A.; Visser, K.; Peters, E.; Kunakbayeva, G.; Muntendam-Bos, A.G.


    The Roswinkel gas field in the northeastern part of the Netherlands has been in production between 1980 and 2005. Located at about 2100 m depth, it is a severely faulted anticlinal structure, constituting up to 30 reservoir compartments. Due to the complicated nature of this field, there are large u


    Thomas ELSNER; Sven HARTMANN


    The Inn river, major tributary of the Danube river in Germany, has its origin in the higher alpine region of Switzerland and Austria. Mainly for flood management reasons and the extensive production of hydropower based electricity it was fixed with massive embankments and subdivided into a chain of reservoirs. Caused by severe amounts of sediments, mostly fine material as suspended load, a significant sedimentation of the reservoirs takes place. Different strategies are known and investigated to extend the life-cycle of the reservoirs and the efficient use of the turbines. During the past decades parts of the reservoirs turned into ecologically valuable habitats which had to be excluded from e.g. flushing operations and are protected areas nowadays. In the meantime ecologists had to realize that the value of those ecosystems is declining as the result of further aggradation of the depositions leading to a new but static condition. Measures are discussed to stimulate dynamic changes of the sand bars avoiding their stabilization by vegetation like bushes and trees. Basic ideas of the concept and the 2d-model to simulate and optimize engineering solutions are described respecting ecological restrictions.

  20. Acoustic study of fish and invertebrate behavior in a tropical reservoir

    Prchalová, M.; Drastík, V.; Kubeka, J.; Sricharoendham, B.; Schiemer, F.; Vijverberg, J.


    The fish and invertebrate behavior of the Ubol Ratana Reservoir, Thailand, were monitored using up- and downlooking split beam sonar located at a fixed location. In the same area and period, ichthyoplankton nets and multimesh gillnets were used. The bulk of targets, recorded by acoustics and direct

  1. A Survey on the Reservoir Emigration in the Recent Thirty Years and the Related Studies%近三十年水库移民及其研究述评



    This article, on the basis of the policy change of the reservoir emigration and the related domestic studies, divides the reservoir immigration affairs into five stages. It briefly introduces the main contents of the four aspects of the studies on the reservoir emigration in the resent thirty years. With an analysis of the characteristics and the insufficiencies of the previous studies, it proposes four suggestions for furthering the reservoir emigration so that this kind of studies can be done better.%文章根据水库移民政策变化和国内相关研究成果,将建国后的水库移民工作分为五个阶段;概括介绍近三十年来水库移民研究四个方面的主要内容,分析以往研究的特点和存在的不足,并对进一步深化水库移民研究提出四项建议。

  2. Metabolomics and the Legacy of Previous Ecosystems: a Case Study from the Brine of Lake Vida (Antarctica)

    Chou, L.; Kenig, F. P. H.; Murray, A. E.; Doran, P. T.; Fritsen, C. H.


    The McMurdo Dry Valleys of Antarctica are regarded as one of the best Earth analogs for astrobiological investigations of icy worlds. In the dry valleys, Lake Vida contains an anoxic and aphotic ice-sealed brine that has been isolated for millennia and yet is hosting a population of active microbes at -13˚ C. The biogeochemical processes used by these slow-growing microbes are still unclear. We attempt to elucidate the microbial processes responsible for the survivability of these organisms using metabolomics. Preliminary investigations of organic compounds of Lake Vida Brine (LVBr) was performed using gas chromatography-mass spectrometry (GC-MS) and solid-phase micro-extraction (SPME) GC-MS. LVBr contains a vast variety of lipids and is dominated by low molecular weight compounds. Many of these compounds are biomarkers of processes that took place in Lake Vida prior to evaporation and its cryo-encapsulation. These compounds include dimethylsulfide that is derived from the photosynthate dimethylsulfoniopropionate, dihydroactinidiolide that is derived from a diatom pigment, and 2-methyl-3-ethyl-maleimide that is derived from chlorophyll. These compounds, which dominate the lipid reservoir, represent a legacy from an ecosystem that is different from the current bacterial ecosystem of the brine. The abundance of the legacy compounds in the brine is most likely a reflection of the very slow metabolism of the bacterial community in the cold brine. It is important, thus, to be able to distinguish the legacy metabolites and their diagenetic products from the metabolites of the current ecosystem. This legacy issue is specific to a slow growing microbial ecosystem that cannot process the legacy carbon completely. It applies not only to Lake Vida brine, but other slow growing ecosystems such as other subglacial Antarctic lakes, the Arctic regions, and the deep biosphere.

  3. Persistence of cardiovascular risk factors in women with previous preeclampsia: a long-term follow-up study.

    Aykas, Fatma; Solak, Yalcin; Erden, Abdulsamet; Bulut, Kadir; Dogan, Selcuk; Sarli, Bahadr; Acmaz, Gokhan; Afsar, Baris; Siriopol, Dimitrie; Covic, Adrian; Sharma, Shailendra; Johnson, Richard J; Kanbay, Mehmet


    Preeclampsia is a cardiovascular (CV) disease risk factor, and lifestyle modifications are recommended. It was suggested that preeclampsia may increase the prevalence of various CV disease risk factors such as metabolic syndrome, hypertension, insulin resistance, microalbuminuria, and endothelial dysfunction, among others. Here, we investigate the role of serum uric acid in preeclampsia in the development of CV complications. This was an observational case-control study that compared women with history of preeclampsia (n = 25) with age-matched controls with uncomplicated pregnancies (n = 20) who were followed for at least 5 years. Measurements included clinical and ambulatory blood pressure monitoring, ultrasound-measured flow-mediated dilatation (FMD), microalbuminuria, carotid intima-media thickness (CIMT) and serum uric acid, as well as clinical and demographic features. Cardiovascular disease risk factors were compared in women with and without previous preeclampsia. At the time of index gestation, preeclamptic women had higher serum uric acid values (4.36 ± 0.61 vs 2.27 ± 0.38 mg/dL, P preeclampsia were more likely to have hypertension and had higher serum uric acid levels, higher microalbuminuria and CIMT levels, and lower FMD values than did the patients who did not have preeclampsia. The 2 groups were similar with regard to various ambulatory blood pressure parameters. Univariate associates of FMD were history of preeclampsia and the current hypertension status. Microalbuminuria correlated with gestational uric acid levels (coefficient of correlation of 0.40, P = 0.01 for FMD and coefficient of correlation of 0.37, P = 0.01 for CIMT, respectively). Preeclampsia might be a risk factor for the development of cardiovascular risk factors at least 5 years after index pregnancy. Serum uric acid and microalbuminuria may be mechanistic mediators of heightened risk, along with impaired endothelial function in preeclampsia.

  4. Sitagliptin added to previously taken antidiabetic agents on insulin resistance and lipid profile: a 2-year study evaluation.

    Derosa, Giuseppe; Ragonesi, Pietro Dario; Fogari, Elena; Cicero, Arrigo Francesco Giuseppe; Bianchi, Lucio; Bonaventura, Aldo; Romano, Davide; Maffioli, Pamela


    The aim of this study was to evaluate whether the positive effects of sitagliptin on glycemic control and insulin resistance were maintained also after 2 years of therapy and whether sitagliptin could be effective also in improving lipid profile. In this randomized, double-blind, placebo-controlled trial, 205 patients with type 2 diabetes in therapy with different antidiabetic drugs were randomized to add sitagliptin 100 mg once a day or placebo to their current therapy. We evaluated at the baseline and after 6, 12, 18, and 24 months the following parameters: body mass index, glycated hemoglobin (HbA1c ), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance index (HOMA-IR), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (Tg). Sitagliptin, added to previously taken antidiabetic agents, proved to be effective in improving glycemic profile, reducing HbA1c by -17.5%, FPG by -12.7%, PPG by -20.5%. Regarding insulin resistance, sitagliptin decreased FPI by -8.3% and HOMA-IR by -20.0%, confirming that what have been already reported in short-term studies can be applied also after 2 years of treatment. Sitagliptin also reduced body weight by -4.3%. Our study also showed the positive effect of sitagliptin on lipid profile; in particular, sitagliptin decreased TC by -13.3%, LDL-C by -20.4%, and Tg by -32.3%, and also increased HDL-C by + 13.6%. Sitagliptin proved to be effective on glycemic profile and insulin resistance even after 2 years of therapy and to be effective in improving body weight and lipid profile. © 2012 The Authors Fundamental and Clinical Pharmacology © 2012 Société Française de Pharmacologie et de Thérapeutique.

  5. Study of Reservoir Heterogencities and Structural Features Affecting Production in the Shallow Oil Zone, Eastern Elk Hills Area, California

    Janice Gillespie


    Late Neogene (Plio-Pleistocene) shallow marine strata of the western Bakersfield Arch and Elk Hills produce hydrocarbons from several different reservoirs. This project focuses on the shallow marine deposits of the Gusher and Calitroleum reservoirs in the Lower Shallow Oil Zone (LSOZ). In the eastern part of the study area on the Bakersfield Arch at North and South Coles Levee field and in two wells in easternmost Elk Hills, the LSOZ reservoirs produce dry (predominantly methane) gas. In structurally higher locations in western Elk Hills, the LSOZ produces oil and associated gas. Gas analyses show that gas from the eastern LSOZ is bacterial and formed in place in the reservoirs, whereas gas associated with oil in the western part of the study area is thermogenic and migrated into the sands from deeper in the basin. Regional mapping shows that the gas-bearing LSOZ sands in the Coles Levee and easternmost Elk Hills area are sourced from the Sierra Nevada to the east whereas the oil-bearing sands in western Elk Hills appear to be sourced from the west. The eastern Elk Hills area occupied the basin depocenter, farthest from either source area. As a result, it collected mainly low-permeability offshore shale deposits. This sand-poor depocenter provides an effective barrier to the updip migration of gases from east to west. The role of small, listric normal faults as migration barriers is more ambiguous. Because our gas analyses show that the gas in the eastern LSOZ reservoirs is bacterial, it likely formed in-place near the reservoirs and did not have to migrate far. Therefore, the gas could have been generated after faulting and accumulated within the fault blocks as localized pools. However, bacterial gas is present in both the eastern AND western parts of Elk Hills in the Dry Gas Zone (DGZ) near the top of the stratigraphic section even though the measured fault displacement is greatest in this zone. Bacterial gas is not present in the west in the deeper LSOZ which

  6. Eos modeling and reservoir simulation study of bakken gas injection improved oil recovery in the elm coulee field, Montana

    Pu, Wanli

    The Bakken Formation in the Williston Basin is one of the most productive liquid-rich unconventional plays. The Bakken Formation is divided into three members, and the Middle Bakken Member is the primary target for horizontal wellbore landing and hydraulic fracturing because of its better rock properties. Even with this new technology, the primary recovery factor is believed to be only around 10%. This study is to evaluate various gas injection EOR methods to try to improve on that low recovery factor of 10%. In this study, the Elm Coulee Oil Field in the Williston Basin was selected as the area of interest. Static reservoir models featuring the rock property heterogeneity of the Middle Bakken Member were built, and fluid property models were built based on Bakken reservoir fluid sample PVT data. By employing both compositional model simulation and Todd-Longstaff solvent model simulation methods, miscible gas injections were simulated and the simulations speculated that oil recovery increased by 10% to 20% of OOIP in 30 years. The compositional simulations yielded lower oil recovery compared to the solvent model simulations. Compared to the homogeneous model, the reservoir model featuring rock property heterogeneity in the vertical direction resulted in slightly better oil recovery, but with earlier CO2 break-through and larger CO2 production, suggesting that rock property heterogeneity is an important property for modeling because it has a big effect on the simulation results. Long hydraulic fractures shortened CO2 break-through time greatly and increased CO 2 production. Water-alternating-gas injection schemes and injection-alternating-shut-in schemes can provide more options for gas injection EOR projects, especially for gas production management. Compared to CO2 injection, separator gas injection yielded slightly better oil recovery, meaning separator gas could be a good candidate for gas injection EOR; lean gas generated the worst results. Reservoir

  7. 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

    Zhongping Li


    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

  8. Large Dam Effects on Flow Regime and Hydraulic Parameters of river (Case study: Karkheh River, Downstream of Reservoir Dam

    Farhang Azarang


    Full Text Available Introduction: The critical role of the rivers in supplying water for various needs of life has led to engineering identification of the hydraulic regime and flow condition of the rivers. Hydraulic structures such dams have inevitable effects on their downstream that should be well investigated. The reservoir dams are the most important hydraulic structures which are the cause of great changes in river flow conditions. Materials and Methods: In this research, an accurate assessment was performed to study the flow regime of Karkheh river at downstream of Karkheh Reservoir Dam as the largest dam in Middle East. Karkheh River is the third waterful river of Iran after Karun and Dez and the third longest river after the Karun and Sefidrud. The Karkheh Dam is a large reservoir dam built in Iran on the Karkheh River in 2000. The Karkheh Reservoir Dam is on the Karkheh River in the Northwestern Khouzestan Province, the closest city being Andimeshk to the east. The part of Karkheh River, which was studied in this research is located at downstream of Karkheh Reservoir Dam. This interval is approximately 94 km, which is located between PayePol and Abdolkhan hydrometric stations. In this research, 138 cross sections were used along Karkheh River. Distance of cross sections from each other was 680m in average. The efficient model of HEC-RAS has been utilized to simulate the Karkheh flow conditions before and after the reservoir dam construction using of hydrometric stations data included annually and monthly mean discharges, instantaneous maximum discharges, water surface profiles and etc. Three defined discharges had been chosen to simulate the Karkheh River flow; maximum defined discharge, mean defined discharge and minimum defined discharge. For each of these discharges values, HEC-RAS model was implemented as a steady flow of the Karkheh River at river reach of study. Water surface profiles of flow, hydraulic parameters and other results of flow regime in

  9. Pteropid bats are confirmed as the reservoir hosts of henipaviruses: a comprehensive experimental study of virus transmission.

    Halpin, Kim; Hyatt, Alex D; Fogarty, Rhys; Middleton, Deborah; Bingham, John; Epstein, Jonathan H; Rahman, Sohayati Abdul; Hughes, Tom; Smith, Craig; Field, Hume E; Daszak, Peter


    Bats of the genus Pteropus have been identified as the reservoir hosts for the henipaviruses Hendra virus (HeV) and Nipah virus (NiV). The aim of these studies was to assess likely mechanisms for henipaviruses transmission from bats. In a series of experiments, Pteropus bats from Malaysia and Australia were inoculated with NiV and HeV, respectively, by natural routes of infection. Despite an intensive sampling strategy, no NiV was recovered from the Malaysian bats and HeV was reisolated from only one Australian bat; no disease was seen. These experiments suggest that opportunities for henipavirus transmission may be limited; therefore, the probability of a spillover event is low. For spillover to occur, a range of conditions and events must coincide. An alternate assessment framework is required if we are to fully understand how this reservoir host maintains and transmits not only these but all viruses with which it has been associated.

  10. An integrated study of the Grayburg/San Andres reservoir, Foster and South Cowden fields, Ector County, Texas, Class II

    Trentham, DGS, Robert C.; Robinson, M.S., William C.; Wider, Kevin; Weinbrandt, Ph.D.,PE, Richard


    A project to recover economic amounts of oil from a very mature oil field is being conducted by Laguna Petroleum Corporation of Midland, Texas, with partial funding from a U. S. Department of Energy (DOE) grant to study shallow carbonate rock reservoirs. The objectives of the project are to use modern engineering methods to optimize oil field management and to use geological and geophysical data to recover untapped potential within the petroleum reservoirs. The integration of data and techniques from these disciplines has yielded results greater than those achievable without their cooperation. The cost of successfully accomplishing these goals is to be low enough for even small independent operators to afford. This article is a report describing accomplishments for the fiscal year 1998-1999.

  11. Real-time parallel processing of grammatical structure in the fronto-striatal system: a recurrent network simulation study using reservoir computing.

    Hinaut, Xavier; Dominey, Peter Ford


    Sentence processing takes place in real-time. Previous words in the sentence can influence the processing of the current word in the timescale of hundreds of milliseconds. Recent neurophysiological studies in humans suggest that the fronto-striatal system (frontal cortex, and striatum--the major input locus of the basal ganglia) plays a crucial role in this process. The current research provides a possible explanation of how certain aspects of this real-time processing can occur, based on the dynamics of recurrent cortical networks, and plasticity in the cortico-striatal system. We simulate prefrontal area BA47 as a recurrent network that receives on-line input about word categories during sentence processing, with plastic connections between cortex and striatum. We exploit the homology between the cortico-striatal system and reservoir computing, where recurrent frontal cortical networks are the reservoir, and plastic cortico-striatal synapses are the readout. The system is trained on sentence-meaning pairs, where meaning is coded as activation in the striatum corresponding to the roles that different nouns and verbs play in the sentences. The model learns an extended set of grammatical constructions, and demonstrates the ability to generalize to novel constructions. It demonstrates how early in the sentence, a parallel set of predictions are made concerning the meaning, which are then confirmed or updated as the processing of the input sentence proceeds. It demonstrates how on-line responses to words are influenced by previous words in the sentence, and by previous sentences in the discourse, providing new insight into the neurophysiology of the P600 ERP scalp response to grammatical complexity. This demonstrates that a recurrent neural network can decode grammatical structure from sentences in real-time in order to generate a predictive representation of the meaning of the sentences. This can provide insight into the underlying mechanisms of human cortico

  12. Central Arctic atmospheric summer conditions during the Arctic Summer Cloud Ocean Study (ASCOS: contrasting to previous expeditions

    M. Tjernström


    Full Text Available Understanding the rapidly changing climate in the Arctic is limited by a lack of understanding of underlying strong feedback mechanisms that are specific to the Arctic. Progress in this field can only be obtained by process-level observations; this is the motivation for intensive ice-breaker-based campaigns such as that described in this paper: the Arctic Summer Cloud-Ocean Study (ASCOS. However, detailed field observations also have to be put in the context of the larger-scale meteorology, and short field campaigns have to be analysed within the context of the underlying climate state and temporal anomalies from this.

    To aid in the analysis of other parameters or processes observed during this campaign, this paper provides an overview of the synoptic-scale meteorology and its climatic anomaly during the ASCOS field deployment. It also provides a statistical analysis of key features during the campaign, such as some key meteorological variables, the vertical structure of the lower troposphere and clouds, and energy fluxes at the surface. In order to assess the representativity of the ASCOS results, we also compare these features to similar observations obtained during three earlier summer experiments in the Arctic Ocean, the AOE-96, SHEBA and AOE-2001 expeditions.

    We find that these expeditions share many key features of the summertime lower troposphere. Taking ASCOS and the previous expeditions together, a common picture emerges with a large amount of low-level cloud in a well-mixed shallow boundary layer, capped by a weak to moderately strong inversion where moisture, and sometimes also cloud top, penetrate into the lower parts of the inversion. Much of the boundary-layer mixing is due to cloud-top cooling and subsequent buoyant overturning of the cloud. The cloud layer may, or may not, be connected with surface processes depending on the depths of the cloud and surface-based boundary layers and on the relative strengths of

  13. Ecological and floristic characteristics of higher aquatic plants in Volgograd reservoir

    Kochetkova Anna Igorevna


    Full Text Available In this paper the long-term gydro-botanical studies of Volgograd reservoir were analyzed. Flora in different parts of the reservoir, located in Volgograd and Saratov regions was compared. In the floristic investigations, several species of flora, rare in Volgograd region and previously not noted were revealed. The regularities in the floristic composition changes depending on the amplification of climate aridity and features of the hydrological regime of the Volgograd reservoir were determined. Unstable hydrological conditions in the reservoir contribute to the emergence of new free habitats, which are so necessary for the spread and establishment of different plants, including new invasive ones and formed hybrids.

  14. Assessing the Habitat Suitability of Dam Reservoirs: A Quantitative Model and Case Study of the Hantan River Dam, South Korea

    Hyeongsik Kang


    Full Text Available The main objective of this study was to investigate ecologically healthy regions near a dam reservoir. This study developed a model for assessing habitat suitability as a proxy for the ecological value of reservoirs. Three main factors comprising nine assessment variables were selected and classified as having a habitat suitability (HS between 0 and 1: (1 geomorphic factors of altitude, slope steepness, and slope aspect; (2 vegetation factors of forest physiognomy, vegetation type, and tree age; and (3 ecological factors of land cover, ecological quality index, and environmental conservation value assessment. The spatial distribution of the nine HS indices was determined using geographic information systems and combined into one HS index value to determine ecologically healthy regions. The assessment model was applied to areas surrounding the Hantan River Dam, South Korea. To verify the model, wildlife location data from the national ecosystem survey of the Ministry of Environment were used. Areas with an HS index between 0.73 and 1 were found to contain 72% of observed wildlife locations. Ecologically healthy areas were identified by adding the indices of each variable. The methods shown here will be useful for establishing ecological restoration plans for dam reservoirs in South Korea.

  15. Reservoir optimisation using El Niño information. Case study of Daule Peripa (Ecuador)

    Gelati, Emiliano; Madsen, Henrik; Rosbjerg, Dan


    The optimisation of water resources systems requires the ability to produce runoff scenarios that are consistent with available climatic information. We approach stochastic runoff modelling with a Markov-modulated autoregressive model with exogenous input, which belongs to the class of Markov-switching models. The model assumes runoff parameterisation to be conditioned on a hidden climatic state following a Markov chain, whose state transition probabilities depend on climatic information. This approach allows stochastic modeling of non-stationary runoff, as runoff anomalies are described by a mixture of autoregressive models with exogenous input, each one corresponding to a climate state. We calibrate the model on the inflows of the Daule Peripa reservoir located in western Ecuador, where the occurrence of El Niño leads to anomalously heavy rainfall caused by positive sea surface temperature anomalies along the coast. El Niño - Southern Oscillation (ENSO) information is used to condition the runoff parameterisation. Inflow predictions are realistic, especially at the occurrence of El Niño events. The Daule Peripa reservoir serves a hydropower plant and a downstream water supply facility. Using historical ENSO records, synthetic monthly inflow scenarios are generated for the period 1950-2007. These scenarios are used as input to perform stochastic optimisation of the reservoir rule curves with a multi-objective Genetic Algorithm (MOGA). The optimised rule curves are assumed to be the reservoir base policy. ENSO standard indices are currently forecasted at monthly time scale with nine-month lead time. These forecasts are used to perform stochastic optimisation of reservoir releases at each monthly time step according to the following procedure: (i) nine-month inflow forecast scenarios are generated using ENSO forecasts; (ii) a MOGA is set up to optimise the upcoming nine monthly releases; (iii) the optimisation is carried out by simulating the releases on the

  16. Volcanic settings and their reservoir potential: An outcrop analog study on the Miocene Tepoztlán Formation, Central Mexico

    Lenhardt, Nils; Götz, Annette E.


    The reservoir potential of volcanic and associated sedimentary rocks is less documented in regard to groundwater resources, and oil and gas storage compared to siliciclastic and carbonate systems. Outcrop analog studies within a volcanic setting enable to identify spatio-temporal architectural elements and geometric features of different rock units and their petrophysical properties such as porosity and permeability, which are important information for reservoir characterization. Despite the wide distribution of volcanic rocks in Mexico, their reservoir potential has been little studied in the past. In the Valley of Mexico, situated 4000 m above the Neogene volcanic rocks, groundwater is a matter of major importance as more than 20 million people and 42% of the industrial capacity of the Mexican nation depend on it for most of their water supply. Here, we present porosity and permeability data of 108 rock samples representing five different lithofacies types of the Miocene Tepoztlán Formation. This 800 m thick formation mainly consists of pyroclastic rocks, mass flow and fluvial deposits and is part of the southern Transmexican Volcanic Belt, cropping out south of the Valley of Mexico and within the two states of Morelos and Mexico State. Porosities range from 1.4% to 56.7%; average porosity is 24.8%. Generally, permeabilities are low to median (0.2-933.3 mD) with an average permeability of 88.5 mD. The lavas are characterized by the highest porosity values followed by tuffs, conglomerates, sandstones and tuffaceous breccias. On the contrary, the highest permeabilities can be found in the conglomerates, followed by tuffs, tuffaceous breccias, sandstones and lavas. The knowledge of these petrophysical rock properties provides important information on the reservoir potential of volcanic settings to be integrated to 3D subsurface models.

  17. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 8: Design approaches: UPH. Appendix A: Upper reservoir


    Overriding considerations including operating range, volume and lining of reservoir, embankment design, intake/outlet arrangements and filling and make up water provisions were studied within the context of minimizing facility costs and optimizing the plant layout. The study led to the selection of a reservoir formed by embankment of compacted rockfill together with an intake/outlet structure located in the embankment. The reservoir floor and upstream slopes of the embankment will have an asphalt lining to prevent leakage. The material and cost estimates presented are based on the requirements for a 2000 MW plant providing 20,000 MWh of storage with a nominal head of 4600 ft.

  18. Classification of Complex Reservoirs in Superimposed Basins of Western China

    PANG Xiongqi; ZHOU Xinyuan; LIN Changsong; HUO Zhipeng; LUO Xiaorong; PANG Hong


    Many of the sedimentary basins in western China were formed through the superposition and compounding of at least two previously developed sedimentary basins and in general they can be termed as complex superimposed basins.The distinct differences between these basins and monotype basins are their discontinuous stratigraphic sedimentation,stratigraphic structure and stratigraphic stress-strain action over geological history.Based on the correlation of chronological age on structural sections,superimposed basins can be divided into five types in this study:(1)continuous sedimentation type superimposed basins,(2)middle and late stratigraphic superimposed basins,(3)early and late stratigraphic superimposed basins,(4)early and middle stratigraphic superimposed basins,and(5)long-term exposed superimposed basins.Multiple source-reservoir-caprock assemblages have developed in such basins.In addition,multi-stage hydrocarbon generation and expulsion,multiple sources,polycyclic hydrocarbon accumulation and multiple-type hydrocarbon reservoirs adjustment,reformation and destruction have occurred in these basins.The complex reservoirs that have been discovered widely in the superimposed basins to date have remarkably different geologic features from primary reservoirs,and the root causes of this are folding,denudation and the fracture effect caused by multiphase tectonic events in the superimposed basins as well as associated seepage,diffusion,spilling,oxidation,degradation and cracking.Based on their genesis characteristics,complex reservoirs are divided into five categories:(1)primary reservoirs,(2)trap adjustment type reservoirs,(3)component variant reservoirs,(4)phase conversion type reservoirs and(5)scale-reformed reservoirs.

  19. Discussion on further studies to measure and evaluate fitness and motor performance for preschool children; summary and previous studies in Japan and future consideratin

    Murase, Tomohiko; Demura, Shinichi


    This article discusses and summarizes previous studies dealing with fitness and motor performance in preschool children from the viewpoint of measurement and evaluation, and determines topics for further studies. The studies reviewed in this article were mainly published in the “Japan Journal of Physical Education, Health and Sport Sciences” (edited by the Japan Society of Physical Education, Health and Sport Sciences), and the “Japanese Journal of Physical Fitness and Sports Medicine” (edite...

  20. An Integrated Study of the Grayberg/San andres Reservoir, Foster and South Cowden Fields, Ector County, Texas



    The characteristics of seismic- derived porosity maps have been further qualified by geologic and production relationships not previously explained nor their significance recognized. Patterns of seismic- derived porosity in the upper Grayburg compare accurately to geologic well data and to historic oil production in section 36. Areas of economic reservoir seem to be separated hydrodynamically, based on the porosity distribution and related differences of gas- to- oil ratio values. Porosity values east of the current limit of the seismic inversion model (where the current seismic data quality is poor) have been estimated for the Grayburg zones, to be used in the next production model run. Production data for that area are being requested from offset operators. When those data become available, they will be included in a revised engineering model will be made to match the production history and to simulate the effect of waterflood efforts. The mapping of porosity of the upper Grayburg zones from the seismic data was completed during the third quarter of 1997, with further qualification of the results done during the fourth quarter. The cross- plots of well log- determined porosity versus seismic velocity have shown a strong linear relationship useful for calibrating the conversion of velocity to porosity. Maps of porosity for the A, B, and C zones are being tested against geological and engineering data. Complexity of reservoir demonstrated in those maps has exposed the need to include significantly more geologic and production data in the area around section 36 in order to create a proper model for the Grayburg reservoir in section 36.

  1. Simulation study to determine the feasibility of injecting hydrogen sulfide, carbon dioxide and nitrogen gas injection to improve gas and oil recovery oil-rim reservoir

    Eid, Mohamed El Gohary

    This study is combining two important and complicated processes; Enhanced Oil Recovery, EOR, from the oil rim and Enhanced Gas Recovery, EGR from the gas cap using nonhydrocarbon injection gases. EOR is proven technology that is continuously evolving to meet increased demand and oil production and desire to augment oil reserves. On the other hand, the rapid growth of the industrial and urban development has generated an unprecedented power demand, particularly during summer months. The required gas supplies to meet this demand are being stretched. To free up gas supply, alternative injectants to hydrocarbon gas are being reviewed to support reservoir pressure and maximize oil and gas recovery in oil rim reservoirs. In this study, a multi layered heterogeneous gas reservoir with an oil rim was selected to identify the most optimized development plan for maximum oil and gas recovery. The integrated reservoir characterization model and the pertinent transformed reservoir simulation history matched model were quality assured and quality checked. The development scheme is identified, in which the pattern and completion of the wells are optimized to best adapt to the heterogeneity of the reservoir. Lateral and maximum block contact holes will be investigated. The non-hydrocarbon gases considered for this study are hydrogen sulphide, carbon dioxide and nitrogen, utilized to investigate miscible and immiscible EOR processes. In November 2010, re-vaporization study, was completed successfully, the first in the UAE, with an ultimate objective is to examine the gas and condensate production in gas reservoir using non hydrocarbon gases. Field development options and proces schemes as well as reservoir management and long term business plans including phases of implementation will be identified and assured. The development option that maximizes the ultimate recovery factor will be evaluated and selected. The study achieved satisfactory results in integrating gas and oil

  2. Comparative analysis of measures of viral reservoirs in HIV-1 eradication studies.

    Susanne Eriksson


    Full Text Available HIV-1 reservoirs preclude virus eradication in patients receiving highly active antiretroviral therapy (HAART. The best characterized reservoir is a small, difficult-to-quantify pool of resting memory CD4(+ T cells carrying latent but replication-competent viral genomes. Because strategies targeting this latent reservoir are now being tested in clinical trials, well-validated high-throughput assays that quantify this reservoir are urgently needed. Here we compare eleven different approaches for quantitating persistent HIV-1 in 30 patients on HAART, using the original viral outgrowth assay for resting CD4(+ T cells carrying inducible, replication-competent viral genomes as a standard for comparison. PCR-based assays for cells containing HIV-1 DNA gave infected cell frequencies at least 2 logs higher than the viral outgrowth assay, even in subjects who started HAART during acute/early infection. This difference may reflect defective viral genomes. The ratio of infected cell frequencies determined by viral outgrowth and PCR-based assays varied dramatically between patients. Although strong correlations with the viral outgrowth assay could not be formally excluded for most assays, correlations achieved statistical significance only for integrated HIV-1 DNA in peripheral blood mononuclear cells and HIV-1 RNA/DNA ratio in rectal CD4(+ T cells. Residual viremia was below the limit of detection in many subjects and did not correlate with the viral outgrowth assays. The dramatic differences in infected cell frequencies and the lack of a precise correlation between culture and PCR-based assays raise the possibility that the successful clearance of latently infected cells may be masked by a larger and variable pool of cells with defective proviruses. These defective proviruses are detected by PCR but may not be affected by reactivation strategies and may not require eradication to accomplish an effective cure. A molecular understanding of the discrepancy

  3. Reservoir Cannulas for Pediatric Oxygen Therapy: A Proof-of-Concept Study

    Grace Wu; Alec Wollen; Robert M. DiBlasi; Stephen Himley; Eugene Saxon; Glenn Austin; Jaclyn Delarosa; Rasa Izadnegahdar; Amy Sarah Ginsburg; Darin Zehrung


    Hypoxemia is a complication of pneumonia—the leading infectious cause of death in children worldwide. Treatment generally requires oxygen-enriched air, but access in low-resource settings is expensive and unreliable. We explored use of reservoir cannulas (RCs), which yield oxygen savings in adults but have not been examined in children. Toddler, small child, and adolescent breathing profiles were simulated with artificial lung and airway models. An oxygen concentrator provided flow rates of 0...

  4. Seismicity study in Pournari reservoir area (W. Greece) 1981-2010

    Pavlou, K.; Drakatos, G.; Kouskouna, V.; Makropoulos, K.; Kranis, H.


    The spatial-temporal evolution of seismicity is examined, during the initial impoundment of Pournari reservoir located on Arachthos River (Western Greece), as well as for the next 30 years. The results show that, despite the relatively moderate-to-high seismicity from west to east, there is no remarkable earthquake in the vicinity before the first reservoir impoundment. Immediately after the impoundment (January 1981), and during the first 4 months, a considerable number of low-magnitude seismic events were recorded in the broader area of the dam. Moreover, two independent major events occurred on March 10, 1981 ( M L = 5.6) and April 10, 1981 ( M L = 4.7) with focal depths 13 and 10 km, respectively. The detailed analysis of the two corresponding aftershock sequences shows that they present different behaviors (e.g., larger b-value and lower magnitude of the main aftershock) than that of other aftershock sequences in Greece. This seismicity is probably due to triggering, via the water loading mechanism and the undrained response due to a flysch appearance on the reservoir basement. The activation of the thrust fault may be attributed to the bulging of evaporites that characterize the disordered structure of W. Greece, via possible water intake. The detailed processing of the recorded seismicity during the period 1982-2010, in comparison with the variations of Pournari Dam water level, shows an increase of shallow seismicity ( h ≤ 5 km) in the vicinity of the reservoir up to a 10-km distance—in contrast to the initial period, characterized by a number of deeper events due to the background response change from undrained to drained status.

  5. Study of synthetic surfactants application under the conditions of the Nagylengyel reservoir

    Wagner, O.; Lakatos, I.; Lakatosne, J.S.; Zoltan, G.


    One of the most fundamental requirements concerning surfactants to be used for oil recovery is that they steadily keep their advantageous features at the temperatures of application. The authors have examined the thermal stability of various surfactants under Nagylengyel reservoir conditions and evaluated structural changes suffered by surfactants under the influence of heat treatment. On the basis of experimental data, it has been established which surfactants of those examined can be taken into account in respect of applicability.

  6. Are coarse particles unexpected common reservoirs for some atmospheric anthropogenic trace elements? A case study

    Catinon, Mickaël; Ayrault, Sophie; Boudouma, Omar; Bordier, Louise; Agnello, Gregory; Reynaud, Stéphane; Tissut, Michel


    Without specific experimental equipment, it is very difficult to sample long-term atmospheric deposits on a pure state. That is why the composition of air-transferred solid material accumulated for 40 years in the 2 m-high walls, pierced with numerous holes of an outdoor public shelter, Grenoble city, France, was studied. An appropriate fractionation procedure allowed to obtain several fractions which were i) a sand fraction (8.3%) (fraction A), ii) a large mass of organic matter corresponding mostly to large fragments (>250 μm) of plant origin (66.7%) (fraction B) or to pollen fraction C (0.4%), iii) a slowly depositing organo-clay fraction (20%) (fractions D1 and D2) and iv) a solution mixed with non-settable particles (4.3%) (fraction E). The composition of each fraction was determined for 20 elements. The sand fraction showed very high concentrations specifically in Cu, Pb and Fe corresponding respectively to 81.5, 48.2 and 35.2% of the samples content in these elements. In contrast, Cd and Zn were mainly accumulated in the fraction B (67.5 and 62.2%, respectively). The scanning electron microscopy coupled to energy dispersive X-ray analysis (SEM-EDX) study of the fraction A showed the presence of large particles bearing Pb and Fe, particles rich in Cu and typical fly ashes originating mostly from iron industry. Most of these particles had a crystalline shape suggesting that they were formed after emission at a high temperature. The Pb-Fe-Cu deposit seen in fraction A likely originates from the neighbouring road surface contaminated by car traffic for several decades. The 206Pb/207Pb ratio (1.146 ± 0.004) showed that in the coarse sandy fraction A, Pb was represented at 65% by non-gasoline lead and 35% by "gasoline" lead emitted before 1999. The fraction A particles can only be transported on a limited distance by high magnitude events. They constitute a large reservoir for Cu and Pb and may play a major role in the long-term contamination of urban soils.

  7. Geomechanical and Numerical Studies of Casing Damages in a Reservoir with Solid Production

    Gholami, Raoof; Rasouli, Vamegh; Aadnoy, Bernt; Mohammadnejad, Mojtaba


    Casings damage is a usually reported incident during production in many fields. This incident is conventionally induced by compressional, tensional, burst or collapse forces applied to the casing string. Excessive anisotropic and non-uniform stresses, causing shear failure in unconsolidated reservoirs, are one of the main reasons reported for the casing failure. In this paper, geomechanical and finite element numerical analysis was applied to model hydraulic and mechanical interactions between casing, cement sheath and formations in a carbonate reservoir located in Southern of Iran. The geomechanical analysis indicated that significant in situ stresses induced as a result of the fault reactivation and pore pressure reduction due to reservoir depletion could be the potential reasons for the casing damage experienced in this field. To assess this, numerical analysis was carried out to simulate the casing in the presence of existing forces during drilling, completion and production phases. It was found that excessive and non-uniform stresses surrounding the wellbore together with pore pressure reduction caused the formation to loss its strength and fail. This shear failure results in solid production, creation of the cavities and deformation of the casing because of the excessive buckling force. In addition, a new empirical equation for prediction of ultimate strength of the casing was developed according to the parameters introduced by sensitivity analysis.

  8. Study on the endogenous phosphorus load of sediments in Miyun reservoir

    XU; Qing; LIU; Xiaoduan; WANG; Huifeng; LIU; Liu; LIU; Jing


    Based on the research into the physical-chemical properties and distribution of sediments and the characteristics of pore water in sediments of Miyun reservoir, the release flux of the total phosphorus (TP) from sediments is estimated by simulating deposit environment of reservoir bottom in laboratory. They are 0.018 mg·cm-2·d-1 and 0.821 mg·cm-2·d-1 at 2℃ and 8℃ respectively. The gross TP released in a year is 11.34t. As a contrast, the pore water diffusion simulation method is used to measure gross TP released and gains 11.56t. The two results are relatively close and prove that experiment simulation has some reliability. On the basis of experiments, some conclusions can be drawn: (1) Endogenous phosphorus from sediments accounts for 27.9 percent of the TP entering the reservoir, and it cannot be ignored; and (2) increasing temperature is helpful to TP releasing from sediments.

  9. Bones and oil reservoirs : bioengineers use oilpatch technology to study fluid flow in bones

    Marsters, S.


    The fact that porosity and the presence of channels are qualities that are common to oil reservoirs and bones, led to the use of reservoir modelling technology in investigating bone disorders and to the discovery of dramatic changes in the structure and blood supply of osteoarthritic bones that lie under degenerating cartilage. CMG (Computer Modelling Group) Ltd., developers of reservoir simulation software claim that their software packages can help with the modelling of cellular responses to strains and deformations that occur as fluid flows through bone after a traumatic event such as a tear in the anterior cruciate ligament, a common sports-related injury. Researchers at the University of Calgary expect that by looking at the changes in blood and fluid flow within the bone, they can attain a better understanding of the chain of events that leads to osteoarthritis. Better understanding of the progression of the disease could eventually lead to more precise administration of drugs to deal with osteoarthritic pain, and even to the prevention of painful arthritic joints.

  10. Connectivity of channelized reservoirs: a modelling approach

    Larue, David K. [ChevronTexaco, Bakersfield, CA (United States); Hovadik, Joseph [ChevronTexaco, San Ramon, CA (United States)


    Connectivity represents one of the fundamental properties of a reservoir that directly affects recovery. If a portion of the reservoir is not connected to a well, it cannot be drained. Geobody or sandbody connectivity is defined as the percentage of the reservoir that is connected, and reservoir connectivity is defined as the percentage of the reservoir that is connected to wells. Previous studies have mostly considered mathematical, physical and engineering aspects of connectivity. In the current study, the stratigraphy of connectivity is characterized using simple, 3D geostatistical models. Based on these modelling studies, stratigraphic connectivity is good, usually greater than 90%, if the net: gross ratio, or sand fraction, is greater than about 30%. At net: gross values less than 30%, there is a rapid diminishment of connectivity as a function of net: gross. This behaviour between net: gross and connectivity defines a characteristic 'S-curve', in which the connectivity is high for net: gross values above 30%, then diminishes rapidly and approaches 0. Well configuration factors that can influence reservoir connectivity are well density, well orientation (vertical or horizontal; horizontal parallel to channels or perpendicular) and length of completion zones. Reservoir connectivity as a function of net: gross can be improved by several factors: presence of overbank sandy facies, deposition of channels in a channel belt, deposition of channels with high width/thickness ratios, and deposition of channels during variable floodplain aggradation rates. Connectivity can be reduced substantially in two-dimensional reservoirs, in map view or in cross-section, by volume support effects and by stratigraphic heterogeneities. It is well known that in two dimensions, the cascade zone for the 'S-curve' of net: gross plotted against connectivity occurs at about 60% net: gross. Generalizing this knowledge, any time that a reservoir can be regarded as &apos

  11. Water reservoir as resource of raw material for ceramic industry

    Irie, M.; Tarhouni, J.


    The industries related to the ceramics such as construction bricks, pottery and tile are the important sectors that cover the large part of the working population in Tunisia. The raw materials, clay or silt are excavated from opencast site of limestone clay stratum. The opencast site give the negative impact on landscape and environment, risks of landslide, soil erosion etc. On the other hand, a most serious problem in water resource management, especially in arid land such as Tunisia, is sedimentation in reservoirs. Sediment accumulation in the reservoirs reduces the water storage capacity. The authors proposed the exploitation of the sediment as raw material for the ceramics industries in the previous studies because the sediment in Tunisia is fine silt. In this study, the potential of the water reservoirs in Tunisia as the resource of the raw material for the ceramics industries is estimated from the sedimentation ratio in the water reservoirs.

  12. Randomized, multicenter, phase 2 study (EVOLUTION) of combinations of bortezomib, dexamethasone, cyclophosphamide, and lenalidomide in previously untreated multiple myeloma.

    Kumar, Shaji; Flinn, Ian; Richardson, Paul G; Hari, Parameswaran; Callander, Natalie; Noga, Stephen J; Stewart, A Keith; Turturro, Francesco; Rifkin, Robert; Wolf, Jeffrey; Estevam, Jose; Mulligan, George; Shi, Hongliang; Webb, Iain J; Rajkumar, S Vincent


    Combinations of bortezomib (V) and dexamethasone (D) with either lenalidomide (R) or cyclophosphamide (C) have shown significant efficacy. This randomized phase 2 trial evaluated VDC, VDR, and VDCR in previously untreated multiple myeloma (MM). Patients received V 1.3 mg/m2 (days 1, 4, 8, 11) and D 40 mg (days 1, 8, 15), with either C 500 mg/m2 (days 1, 8) and R 15 mg (days 1-14; VDCR), R 25 mg (days 1-14; VDR), C 500 mg/m2 (days 1, 8; VDC) or C 500 mg/m2 (days 1, 8, 15; VDC-mod) in 3-week cycles (maximum 8 cycles), followed by maintenance with V 1.3 mg/m2 (days 1, 8, 15, 22) for four 6-week cycles (all arms)≥very good partial response was seen in 58%, 51%, 41%, and 53% (complete response rate of 25%, 24%, 22%, and 47%) of patients (VDCR, VDR, VCD, and VCD-mod, respectively); the corresponding 1-year progression-free survival was 86%, 83%, 93%, and 100%, respectively. Common adverse events included hematologic toxicities, peripheral neuropathy, fatigue, and gastrointestinal disturbances. All regimens were highly active and well tolerated in previously untreated MM, and, based on this trial, VDR and VCD-mod are preferred for clinical practice and further comparative testing. No substantial advantage was noted with VDCR over the 3-drug combinations. This trial is registered at (NCT00507442).

  13. Crossover from ballistic to diffusive thermal transport in quantum Langevin dynamics study of a harmonic chain connected to self-consistent reservoirs

    Roy, Dibyendu


    Through an exact analysis using quantum Langevin dynamics, we demonstrate the crossover from ballistic to diffusive thermal transport in a harmonic chain with each site connected to Ohmic heat reservoirs. The temperatures of the two heat baths at the boundaries are specified from the beginning, whereas the temperatures of the interior heat reservoirs are determined self-consistently by demanding that in the steady state, on average, there is no heat current between any such (self-consistent) reservoir and the harmonic chain. The essence of our study is that the effective mean free path separating the ballistic regime of transport from the diffusive one emerges naturally.

  14. Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir

    Robert Loucks; Stephen C. Ruppel; Dembla Dhiraj; Julia Gale; Jon Holder; Jeff Kane; Jon Olson; John A. Jackson; Katherine G. Jackson


    Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. The successful development of HPAI technology has tremendous potential for increasing the flow of oil from deep carbonate reservoirs in the Permian Basin, a target resource that can be conservatively estimated at more than 1.5 billion barrels. Successful implementation in the field chosen for demonstration, for example, could result in the recovery of more than 34 million barrels of oil that will not otherwise be produced. Geological and petrophysical analysis of available data at Barnhart field reveals the following important observations: (1) the Barnhart Ellenburger reservoir is similar to most other Ellenburger reservoirs in terms of depositional facies, diagenesis, and petrophysical attributes; (2) the reservoir is characterized by low to moderate matrix porosity much like most other Ellenburger reservoirs in the Permian Basin; (3) karst processes (cave formation, infill, and collapse) have substantially altered stratigraphic architecture and reservoir properties; (4) porosity and permeability increase with depth and may be associated with the degree of karst-related diagenesis; (5) tectonic fractures overprint the reservoir, improving overall connectivity; (6) oil-saturation profiles show that the oil-water contact (OWC) is as much as 125 ft lower than previous estimations; (7) production history and trends suggest that this reservoir is very similar to other solution-gas-drive reservoirs in the Permian Basin; and (8) reservoir simulation study showed that the Barnhart reservoir is a good candidate for HPAI and that application of horizontal-well technology can improve ultimate resource recovery from the reservoir.

  15. Reservoir Operation to Minimize Sedimentation

    Dyah Ari Wulandari


    Full Text Available The Wonogiri Reservoir capacity decreases rapidly, caused by serious sedimentation problems. In 2007, JICA was proposed a sediment storage reservoir with a new spillway for the purpose of sediment flushing / sluicing from The Keduang River. Due to the change of reservoir storage and change of reservoir system, it requires a sustainable reservoir operation technique. This technique is aimed to minimize the deviation between the input and output of sediments. The main objective of this study is to explore the optimal Wonogiri reservoir operation by minimizing the sediment trap. The CSUDP incremental dynamic programming procedure is used for the model optimization.  This new operating rules will also simulate a five years operation period, to show the effect of the implemented techniques. The result of the study are the newly developed reservoir operation system has many advantages when compared to the actual operation system and the disadvantage of this developed system is that the use is mainly designed for a wet hydrologic year, since its performance for the water supply is lower than the actual reservoir operations.Doi: 10.12777/ijse.6.1.16-23 [How to cite this article:  Wulandari, D.A., Legono, D., and Darsono, S., 2014. Reservoir Operation to Minimize Sedimentation. International Journal of Science and Engineering, 5(2,61-65. Doi: 10.12777/ijse.6.1.16-23] Normal 0 false false false EN-US X-NONE X-NONE

  16. A study on the seismic AVO signatures of deep fractured geothermal reservoirs in an intrusive basement.

    Aleardi, M.; Mazzotti, A.


    Amplitude-variation-with-offset (AVO) analysis of reflected waves has become an important tool for hydrocarbon prospecting. However, while the AVO responses of reservoirs in clastic lithologies (oil or gas bearing sands) are well known, the AVO behaviour of reservoirs hosted in the interconnected fractures of massive rocks are almost unknown due to the rarity of this type of reservoirs and the consequent lack of seismic and well log data. Thanks to the availability of the data of boreholes that ENEL GreenPower drilled in the deep intrusive basement of the Larderello-Travale geothermal field, we have derived the expected AVO responses of the vapour reservoirs found in some intensely, but very localized, fractured volumes within the massive rocks. Therefore we wish to determine what are the expected AVO responses of geothermal reservoirs inside fractured igneous rocks and we seek to find one or more AVO attributes that may help identifying fracture locations. To this end, we have analysed the velocity (P-wave and S-wave) and the density logs pertaining to three wells which reached five deep fractured zones in the basement. However, comparing well log data with surface seismic data the known issues of the different scales and thus different resolutions arise. Therefore, making use of the Backus theory of the equivalent layer, we have downscaled the well logs, acquired at a decimetric scale, to a decametric scale typical of the wavelengths of seismic waves, producing a blocky model of the original logs. Subsequently, we have followed two different approaches to estimate the expected responses. First, on the basis of the P and S velocities and densities of the fractured level and of the encasing rock, we have computed the analytical AVO response of each fractured zone. To this end we have made use of the linear Shuey equation that well describes the AVO response up to incident angles of 30 degrees. This would be the theoretical, noise free, response that perfectly

  17. Geochemical evaluation of CO2 injection into storage reservoirs based on case-studies in The Netherlands

    Tambach, T.; Koenen, M.; Bergen, F. van


    Over the past few years several geochemical evaluations of CO2 storage in Dutch potential reservoirs are carried out, including predictions of the short- and long-term impact of CO2 on the reservoir using geochemical modelling. The initial mineralogy of the reservoir is frequently obtained from core

  18. Study of the Effect of Clay Particles on Low Salinity Water Injection in Sandstone Reservoirs

    Sina Rezaei Gomari


    Full Text Available The need for optimal recovery of crude oil from sandstone and carbonate reservoirs around the world has never been greater for the petroleum industry. Water-flooding has been applied to the supplement primary depletion process or as a separate secondary recovery method. Low salinity water injection is a relatively new method that involves injecting low salinity brines at high pressure similar to conventional water-flooding techniques, in order to recover crude oil. The effectiveness of low salinity water injection in sandstone reservoirs depends on a number of parameters such as reservoir temperature, pressure, type of clay particle and salinity of injected brine. Clay particles present on reservoir rock surfaces adsorb polar components of oil and modify wettability of sandstone rocks to the oil-wet state, which is accountable for the reduced recovery rates by conventional water-flooding. The extent of wettability alteration caused by three low salinity brines on oil-wet sandstone samples containing varying clay content (15% or 30% and type of clay (kaolinite/montmorillonite were analyzed in the laboratory experiment. Contact angles of mica powder and clay mixture (kaolinite/montmorillonite modified with crude oil were measured before and after injection with three low salinity sodium chloride brines. The effect of temperature was also analyzed for each sample. The results of the experiment indicate that samples with kaolinite clay tend to produce higher contact angles than samples with montmorillonite clay when modified with crude oil. The highest degree or extent of wettability alteration from oil-wet to intermediate-wet state upon injection with low salinity brines was observed for samples injected with brine having salinity concentration of 2000 ppm. The increase in temperature tends to produce contact angles values lying in the higher end of the intermediate-wet range (75°–115° for samples treated at 50 °C, while their corresponding

  19. Patient acceptance and clinical impact of Bravo monitoring in patients with previous failed catheter-based studies.

    Sweis, R; Fox, M; Anggiansah, R; Anggiansah, A; Basavaraju, K; Canavan, R; Wong, T


    Standard pH monitoring is performed over 24 h with a naso-oesophageal catheter (C-pH). Limitations include naso-pharyngeal discomfort, nausea and social embarrassment resulting in reduced reflux-provoking activities. Recently a catheter-free pH-monitoring technique has become available. The tolerability and diagnostic yield of this system in patients who failed standard monitoring remain unknown. To examine the tolerability and diagnostic outcome of catheter-free pH-monitoring technique in patients who failed standard monitoring. Patients referred for C-pH and catheter-free pH monitoring completed a tolerability questionnaire. Acid exposure in the distal oesophagus and symptom index (SI) were reviewed. Over 4 years, 883/1751 (50%) of patients with typical reflux symptoms referred for C-pH were diagnosed with gastro-oesophageal reflux disease (GERD) based on a pathological percentage time acid exposure (%time pH patients failed C-pH and, of these, 129 successfully completed 2-day catheter-free pH monitoring. Ninety-eight (76%) of these patients had a pathological percentage pH patients (P patients who had previously failed C-pH; catheter-free pH monitoring assists the definitive diagnosis of GERD in this group.

  20. Reservoir geochemistry; Geoquimica de reservatorios

    Lopes, Joelma Pimentel; Rangel, Mario Duncan; Morais, Erica Tavares de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)], Emails:,,; Aguiar, Helen G.M. de [Fundacao GORCEIX, Ouro Preto, MG (Brazil)], E-mail:


    Reservoir Geochemistry has many important practical applications during petroleum exploration, appraisal and development of oil fields. The most important uses are related to providing or disproving connectivity between reservoirs of a particular well or horizon. During exploration, reservoir geochemistry can indicate the direction of oil filling, suggesting the most appropriate places for drilling new wells. During production, studies of variations in composition with time and determination of proportions of commingled production from multiple zones, may also be carried out. The chemical constituents of petroleum in natural reservoirs frequently show measurable compositional variations, laterally and vertically. Due to the physical and chemical nature of petroleum changes with increasing maturity (or contribution of a second source during the filling process), lateral and vertical compositional variations exist in petroleum columns as reservoir filling is complete. Compositional variation can also be introduced by biodegradation or water washing. Once the reservoir is filled, density driven mixing and molecular diffusion tend to eliminate inherited compositional variations in an attempt to establish mechanical and chemical equilibrium in the petroleum column (England, 1990). Based on organic geochemical analysis it is possible to define these compositional variations among reservoirs, and use these data for developing of petroleum fields and for reservoir appraisal. Reservoir geochemistry offers rapid and low cost evaluation tools to aid in understanding development and production problems. Moreover, the applied methodology is relatively simple and gives reliable results, and can be performed routinely in any good geochemical laboratory at a relatively low cost. (author)

  1. A Study of the Relationship between Previous Exposure to Education and Practice-Teaching Performance at the University of Ife.

    Olatunji, S. A.


    A study to identify relationships between the amount of exposure students have to education (as a discipline) and their student teaching performances is reported. Students attending the University of Ife from 1973-1976 were studied. A positive relationship was discovered, but other factors need to be researched further. (MLW)

  2. Study on metal accumulation in aquatic plants of Cuciurgan cooling reservoir

    Zubcov Elena


    Full Text Available The biomass of plants from the Cuciurgan cooling reservoir of the Moldovan Thermal Power Plant is dependent on the reservoir thermofication and bore considerable modifications. The contents of many metals in aquatic plants were highly correlated with their contents in water: r=0,87-0,91. The dynamics of trace element accumulation depends on seasonal factors. From the beginning of spring to the end of summer and beginning of autumn, the concentrations of trace elements increased by large increments, while with the decrease in temperature below 10°C, an opposite effect was observed. After plant death, a significant part of accumulated trace elements are released into the water, in the most cases this being associated with organic compounds. More than one half of the amount of trace elements is deposited with the decaying plants in the bottom sediments. Therefore, difficulties may arise, while identifying the role of aquatic plants in biogenic migration of metals in aquatic ecosystems and water purification processes.

  3. Assessment of Reservoir Water Quality Using Multivariate Statistical Techniques: A Case Study of Qiandao Lake, China

    Qing Gu


    Full Text Available Qiandao Lake (Xin’an Jiang reservoir plays a significant role in drinking water supply for eastern China, and it is an attractive tourist destination. Three multivariate statistical methods were comprehensively applied to assess the spatial and temporal variations in water quality as well as potential pollution sources in Qiandao Lake. Data sets of nine parameters from 12 monitoring sites during 2010–2013 were obtained for analysis. Cluster analysis (CA was applied to classify the 12 sampling sites into three groups (Groups A, B and C and the 12 monitoring months into two clusters (April-July, and the remaining months. Discriminant analysis (DA identified Secchi disc depth, dissolved oxygen, permanganate index and total phosphorus as the significant variables for distinguishing variations of different years, with 79.9% correct assignments. Dissolved oxygen, pH and chlorophyll-a were determined to discriminate between the two sampling periods classified by CA, with 87.8% correct assignments. For spatial variation, DA identified Secchi disc depth and ammonia nitrogen as the significant discriminating parameters, with 81.6% correct assignments. Principal component analysis (PCA identified organic pollution, nutrient pollution, domestic sewage, and agricultural and surface runoff as the primary pollution sources, explaining 84.58%, 81.61% and 78.68% of the total variance in Groups A, B and C, respectively. These results demonstrate the effectiveness of integrated use of CA, DA and PCA for reservoir water quality evaluation and could assist managers in improving water resources management.

  4. Fracture characterization by fusion of geophysical and geomechanical data: a case study from the Asmari reservoir, the Central Zagros fold-thrust belt

    Kosari, Ehsan; Ghareh-Cheloo, Sajjad; Kadkhodaie-Ilkhchi, Ali; Bahroudi, Abbas


    Fractured reservoirs contain a large proportion of hydrocarbon reserves in the Middle East. In these types of reservoirs, a variety of fracture types and networks provide the required permeability for hydrocarbon storage and flow. Fractured reservoir characterization has been challenging to petroleum geoscientists and reservoir engineers in terms of developing new approaches in this direction. A variety of techniques have been developed in the literature to study the distribution and the impact of fracture pore types on reservoir characterization. However, such techniques are not suitable for subsurface cases where prediction of fractures become troublesome and each of the developed techniques has its own advantages and limitations. In this study, an integrated approach is proposed for fracture characterization by employing different sources of data including 3D seismic attributes, geomechanical parameters, unconventional logs (image log and nuclear magnetic response (NMR) log), velocity-deviation log (VDL), conventional well logs, and routine core analysis data. Based on the azimuths of horizontal principal stresses and natural fractures, location of the wells over the structure hanging wall is determined. Interpretation of the seismic profiles from the study area indicated a fault-related fold structure style with fault throws controlling the magnitude of curvature. Moreover, fracture distribution of the Asmari reservoir is predicted by using curvature attribute, geomechanical parameters and horizontal slices of VDL. It seems that fractures probably have a much higher distribution at zone 1 and zone 3 of the Asmari formation.

  5. Session: Reservoir Technology

    Renner, Joel L.; Bodvarsson, Gudmundur S.; Wannamaker, Philip E.; Horne, Roland N.; Shook, G. Michael


    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five papers: ''Reservoir Technology'' by Joel L. Renner; ''LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies'' by Gudmundur S. Bodvarsson; ''Geothermal Geophysical Research in Electrical Methods at UURI'' by Philip E. Wannamaker; ''Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data'' by Roland N. Horne; ''TETRAD Reservoir Simulation'' by G. Michael Shook

  6. Marine fouling community in the Eastern harbour of Alexandria, Egypt compared with four decades of previous studies



    Full Text Available The aim of the present study is to compare the fouling communities between the years 1960 and 1999 in the Eastern harbour of Alexandria, Egypt and to study the main factors that may be controlling these communities. This comparison is based on monthly durations of panel immersion. By using roughened white polystyrene test panels (12.5x12.5 cm, monthly samples of marine fouling were collected from the harbour from October 1998 through September 1999. It is clear that a remarkable variation in number and diversity of fouling communities throughout the last four decades is evident. The minimum diversities were recorded during the studies of 1960 and 1970 (19 and 20 species respectively, while the maximum diversity (35 species was achieved during the 1991 study. Moreover, a small shift among the four dominant groups (Polychaeta, Cirripedia, Bryozoa and Amphipoda was noted during the four decades of the studies. The present comparison indicated that many factors may contribute to this variation, of which nutrient enrichment is the most important and the nature of the applied test panel is lees so.

  7. Study on the application of seismic sedimentology in a stratigraphic-lithologic reservoir in central Junggar Basin

    Yu, Yixin; Xia, Zhongmou


    This paper discusses the research idea of description for stratigraphic-lithologic reservoir based on seismic sedimentology methods. The sandstone reservoir of Jurrassic XiShanyao Formation in Junggar Basin is studied according to the theory and approaches of seismic sedimentology. By making full use of borehole data, the technologies of layer correlation based on the stratigraphic sequence framework, the forward seismic modeling, the stratal slicing and lithologic inversion are applied. It describes the range of denudation line, the distribution characteristics of sedimentary facies of the strata, the vertical and horizontal distribution of sand bodies and the favourable oil-gas bearing prospective area. The results shows that study area are dominated braided delta deposition including underwater distributary channel and distributary bay microfacies, the nip-out lines of the formation are northeast to southwest from north to south, the second Middle Jurassic sand body is the most widely distributed one among three sand bodies, the prospective oil-gas bearing area located in the south part and around the YG2 well area. The study result is effective on the practice of exploration in study area.

  8. A cross-sectional study of personality traits in women previously treated or untreated for alcohol use disorders

    Sundh Valter


    Full Text Available Abstract Background A better understanding of the relationship between treatment-seeking for alcohol problems and personality traits could give useful insight in factors promoting or hindering treatment for alcohol use disorders (AUD. The aim of this study was to analyze the associations between treatment-seeking for AUD, personality traits, and psychiatric co-morbidity in women. The study was based on pooled cross-sectional data from three population based samples and one clinical sample (n = 1,339. Comparisons were made between treated and untreated women with AUD, and between those with resolved and unresolved AUD. Results A stepwise logistic regression model showed that treatment-seeking for AUD was not associated with personality traits. Among women with lifetime AUD (n = 217, those who had been treated (n = 42 had significantly higher scores than untreated women (n = 175 on three personality traits of the Karolinska Scales of Personality (KSP; somatic anxiety, muscular tension, and guilt. Women with resolved AUD, who had received treatment (n = 23 had significantly higher scores on scales measuring somatic anxiety, psychic anxiety, muscular tension, irritability, and guilt than untreated women with resolved AUD. The latter group resembled women without AUD on most personality traits. There were no differences in occurrence of lifetime psychiatric disorders between the treated and the untreated women, whereas treated women with current AUD had increased risk of lifetime anxiety (OR: 3.1, 95% CI: 1.1–8.7. Conclusion Treatment-seeking was not associated with personality traits in this study. Still, it can be concluded that women with resolved AUD who had received treatment had high scores on the KSP-scales measuring psychic and somatic anxiety, tension, irritability, and feelings of guilt. This suggests that personality assessment might be a useful tool in tailoring individual treatment programs for women with AUD. Future studies need to

  9. Fracture density determination using a novel hybrid computational scheme: a case study on an Iranian Marun oil field reservoir

    Nouri-Taleghani, Morteza; Mahmoudifar, Mehrzad; Shokrollahi, Amin; Tatar, Afshin; Karimi-Khaledi, Mina


    Most oil production all over the world is from carbonated reservoirs. Carbonate reservoirs are abundant in the Middle East, the Gulf of Mexico and in other major petroleum fields that are regarded as the main oil producers. Due to the nature of such reservoirs that are associated with low matrix permeability, the fracture is the key parameter that governs the fluid flow in porous media and consequently oil production. Conventional methods to determine the fracture density include utilizing core data and the image log family, which are both time consuming and costly processes. In addition, the cores are limited to certain intervals and there is no image log for the well drilled before the introduction of this tool. These limitations motivate petroleum engineers to try to find appropriate alternatives. Recently, intelligent systems on the basis of machine learning have been applied to various branches of science and engineering. The objective of this study is to develop a mathematical model to predict the fracture density using full set log data as inputs based on a combination of three intelligent systems namely, the radial basis function neural network, the multilayer perceptron neural network and the least square supported vector machine. The developed committee machine intelligent system (CMIS) is the weighted average of the individual results of each expert. Proper corresponding weights are determined using a genetic algorithm (GA). The other important feature of the proposed model is its generalization capability. The ability of this model to predict data that have not been introduced during the training stage is very good.

  10. Geo-Chemo-Mechanical Studies for Permanent CO{sub 2} Storage in Geologic Reservoirs

    Kelemen, Peter; Park, Ah-hyung; Matter, Jurg; Gadikota, Greeshma; Lisabeth, Harrison; Zhu, Wenlu


    This two-pronged study investigated the rates and mechanisms of formation of Ca and Mg carbonate minerals via reaction of aqueous fluids with silicate minerals and rocks, and the geomechanical effects of such reactions. The kinetic studies focused on the separation of variables, following from previous studies demonstrating rapid formation of carbonates via reaction of the mineral olivine with aqueous fluids rich in NaHCO{sub 3} (plus KHCO{sub 3} and RbHCO{sub 3}) and NaCl at a high partial pressure of CO{sub 2}. We wished to separate and quantify the effects of NaHCO{sub 3} and NaCl, and to investigate whether bicarbonate-rich, aqueous fluids would also cause rapid formation of carbonates via reaction with other minerals and rocks. Further, we wished to improve upon previous work by adding precise characterization of grain size distributions and surface area, and their changes as a result of reaction. We confirmed previous reports of very rapid olivine carbonation. We found that at a given temperature and CO{sub 2} partial pressure the previously observed rate enhancement in olivine carbonation is due mainly to NaHCO{sub 3}, and not to dissolved NaCl. Further, though reaction of the mineral plagioclase, and two rock compositions, were all faster in the presence of NaHCO{sub 3}-rich fluids, compared with saline and de-ionized water, they were all much slower than reaction of olivine. In the experiments showing the fastest reaction rate, average grain size tended to increase during experiments, presumably due to dissolution of small reactant grains plus growth of product phases on reactant surfaces. Porosity/surface area of grains tended to change with reaction progress, due to the formation of dissolution pits and irregular growth of product phases on reactant grain surfaces. Development of a passivating phase (e.g., a layer of silica) due to incongruent dissolution of solid reactants and/or precipitation of solid products was detected, but was relatively minor and


    human resources. It is also intended to make known to the general public that ... port processes were not properly taken into account. ... Studies carried out on 19 reservoirs in Cen- tral Europe with storage capacity ranging be- tween 1.48 x ...

  12. Study on distribution of reservoir endogenous microbe and oil displacement mechanism.

    Yue, Ming; Zhu, Weiyao; Song, Zhiyong; Long, Yunqian; Song, Hongqing


    In order to research oil displacement mechanism by indigenous microbial communities under reservoir conditions, indigenous microbial flooding experiments using the endogenous mixed bacterium from Shengli Oilfield were carried out. Through microscopic simulation visual model, observation and analysis of distribution and flow of the remaining oil in the process of water flooding and microbial oil displacement were conducted under high temperature and high pressure conditions. Research has shown that compared with atmospheric conditions, the growth of the microorganism metabolism and attenuation is slowly under high pressure conditions, and the existence of the porous medium for microbial provides good adhesion, also makes its growth cycle extension. The microbial activities can effectively launch all kinds of residual oil, and can together with metabolites, enter the blind holes off which water flooding, polymer flooding and gas flooding can't sweep, then swap out remaining oil, increase liquidity of the crude oil and remarkably improve oil displacement effect.

  13. Laboratory study of acid stimulation of drilling-mud-damaged geothermal-reservoir materials. Final report


    Presented here are the results of laboratory testing performed to provide site specific information in support of geothermal reservoir acidizing programs. The testing program included laboratory tests performed to determine the effectiveness of acid treatments in restoring permeability of geologic materials infiltrated with hydrothermally altered sepiolite drilling mud. Additionally, autoclave tests were performed to determine the degree of hydrothermal alteration and effects of acid digestion on drilling muds and drill cuttings from two KGRA's. Four laboratory scale permeability/acidizing tests were conducted on specimens prepared from drill cuttings taken from two geothermal formations. Two tests were performed on material from the East Mesa KGRA Well No. 78-30, from a depth of approximately 5500 feet, and two tests were performed on material from the Roosevelt KGRA Well No. 52-21, from depths of approximately 7000 to 7500 feet. Tests were performed at simulated in situ geothermal conditions of temperature and pressure.

  14. Improved recovery from Gulf of Mexico reservoirs. Quarterly status report, January 1--March 31, 1996

    Kimbrell, W.C.; Bassiouni, Z.A.; Bourgoyne, A.T.


    On February 18, 1992, Louisiana State University with two technical subcontractors, BDM, Inc. and ICF, Inc., began a research program to estimate the potential oil and gas reserve additions that could result from the application of advanced secondary and enhanced oil recovery technologies and the exploitation of undeveloped and attic oil zones in the Gulf of Mexico oil fields that are related to piercement salt domes. This project is a one year continuation of this research and will continue work in reservoir description, extraction processes, and technology transfer. Detailed data will be collected for two previously studies reservoirs: a South Marsh Island reservoir operated by Taylor Energy and one additional Gulf of Mexico reservoir operated by Mobil. Additional reservoirs identified during the project will also be studied if possible. Data collected will include reprocessed 2-D seismic data, newly acquired 3-D data, fluid data, fluid samples, pressure data, well test data, well logs, and core data/samples. The new data will be used to refine reservoir and geologic characterization of these reservoirs. Further laboratory investigation will provide additional simulation input data in the form of PVT properties, relative permeabilities, capillary pressure, and water compatibility. Geological investigations will be conducted to refine the models of mud-rich submarine fan architectures used by seismic analysts and reservoir engineers. Research on advanced reservoir simulation will also be conducted. This report describes a review of fine-grained submarine fans and turbidite systems.

  15. Fractured reservoir modeling: From well data to dynamic flow. Methodology and application to a real case study in Illizi Basin (Algeria)

    Felici, Fabrizio; Alemanni, Annalisa; Bouacida, Djamil; de Montleau, Pierre


    Fault arrays and natural fractures distribution strongly influence subsurface fluids migration, trapping and production. It is critical to develop methodologies that can be used to accurately characterize reservoir volumes as present-day exploration and appraisal campaigns become increasingly focused on tight or low porosity reservoirs. A common method used to model the distribution and intensity of subsurface fracture sets is the Discrete Fracture Network (DFN) technique. Shortcomings of the DFN technique include the evaluation of fracture attributes, computational aspects in the case of large fields, and most importantly issues related to upscaling. Thus, the aim of this work is to present a simplified methodology for fractured reservoir characterization based on the distribution of fracture intensity as a continuous property. Fracture intensity was calculated from image well-logs data and then distributed in the reservoir according to specific fracture drivers. The case study is related to a large appraisal gas field located in the Illizi Basin, Southern Algeria, where Late Ordovician glacial deposits are the primary reservoir levels, in which the presence of faults and fractures strongly enhance well performances. The final fracture intensity model was obtained by implementing a workflow in a commonly used commercial geomodeling software and calibrated by means of well test data analysis. The implemented methodology is a useful tool for large fractured reservoir characterization when DFN technique is hardly applicable for computational reasons or the level of uncertainty does not support a performing discrete analysis.

  16. Warfarin dosing after bariatric surgery: a retrospective study of 10 patients previously stable on chronic warfarin therapy.

    Schullo-Feulner, A M; Stoecker, Z; Brown, G A; Schneider, J; Jones, T A; Burnett, B


    Many changes associated with bariatric surgery have the potential to affect warfarin dosing; yet current literature includes little data describing this phenomenon. Investigating this relationship may allow for determination of post-bariatric surgery warfarin dosing using stable pre-operative dosing levels. A retrospective chart review was completed for 10 patients stabilized on chronic warfarin therapy who underwent bariatric surgery. Data collection consisted of the following: warfarin requirement in mg/week, time in target range (TTR), creatinine, liver function, diarrhoea, medication changes, diet, and signs of bleeding and/or thrombosis. Three study patients underwent laparoscopic adjustable gastric banding procedures and seven patients underwent Roux-en-Y gastric bypass. The average (standard deviation) weekly warfarin dose required in the immediate post-operative interval was 64% (25%) of baseline dosing, corresponding to a TTR of 48%. At 6 months, patients required 85% (19%) of baseline weekly dosing, with TTR of 53.4%. At 1 year, dosing was 90% (16%) of baseline with TTR of 63.5%. Patients underwent medication changes as well as transient bouts of diarrhoea. Two patients suffered unspecified haemorrhages of the gastrointestinal tract (international normalized ratio [INR] = 2.3 and 9.8). This patient set demonstrated an initial drop in warfarin requirement, followed by escalating dosing trends that became more predictable as patients were farther out from procedure.

  17. An integrated geologic and engineering reservoir characterization of the North Robertson (Clearfork) unit: A case study, part 1

    Doublet, L.E.; Blasingame, T.A. [Texas A and M Univ., College Station, TX (United States); Pande, P.K.; Clark, M.B.; Nevans, J.W.


    Infill drilling of wells on a uniform spacing, without regard to reservoir performance and characterization, must become a process of the past. Such efforts do not optimize reservoir development as they fail to account for the complex nature of reservoir heterogeneities present in many low permeability carbonate reservoirs. New and emerging technologies such as cross-borehole tomography, geostatistical modeling, and rigorous decline type curve analysis can be used to quantify reservoir quality and the degree of interwell communication. These results can be used to develop a 3-D simulation model for prediction of infill locations. In this work, the authors will demonstrate the application of reservoir surveillance techniques to identify additional reservoir ``pay`` zones, and to monitor pressure and preferential fluid movement in the reservoir. These techniques are: long-term production and injection data analysis, pressure transient analysis, and advanced open and cased hole well log analysis. The major contribution of this paper is the summary of cost effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability carbonate reservoirs such as the North Robertson (Clearfork) Unit.


    Kevin M. Kostelnik; James H. Clarke; Jerry L. Harbour


    Environmental remediation efforts that are underway at hundreds of contaminated sites in the United States will not be able to remediate large portions of those sites to conditions that would permit unrestricted access. Rather, large volumes of waste materials, contaminated soils and cleanup residuals will have to be isolated either in place or in new, often on-site, disposal cells with long term monitoring, maintenance and institutional control needs. The challenge continues to be to provide engineering systems and controls that can ensure the protection of public health and the environment over very long time horizons (hundreds to perhaps thousands of years) with minimal intervention. Effective long term management of legacy hazardous and nuclear waste requires an integrated approach that addresses both the engineered containment and control system itself and the institutional controls and other responsibilities that are needed. Decisions concerning system design, monitoring and maintenance, and the institutional controls that will be employed are best done through a "risk-nformed, performance-based" approach. Such an approach should incorporate an analysis of potential "failure" modes and consequences for all important system features, together with lessons learned from experience with systems already in place. The authors will present the preliminary results of a case study approach that included several sites where contamination isolation systems including institutional controls have been implemented. The results are being used together with failure trees and logic diagrams that have been developed for both the engineered barriers and the institutional controls. The use of these analytical tools to evaluate the potential for different levels of failure and associated consequences will be discussed. Of special interest is the robustness of different approaches to providing long-term protection through redundancy and defense in depth.

  19. Variations of the accessory nerve: anatomical study including previously undocumented findings-expanding our misunderstanding of this nerve.

    Tubbs, R Shane; Ajayi, Olaide O; Fries, Fabian N; Spinner, Robert J; Oskouian, Rod J


    The anatomy of the accessory nerve has been well described but continued new clinical and anatomical findings exemplify our lack of a full understanding of the course of this nerve. Therefore, this study aimed to expand on our knowledge of the course of the 11th cranial nerve via anatomical dissections. Fifty-six cadavers (112 sides) underwent dissection of the accessory nerve from its cranial and spinal origins to its emergence into the posterior cervical triangle. Immunohistochemistry was performed when appropriate. Our findings included two cases (1.8%) where the nerve was duplicated, one intracranially and one extracranially. One accessory nerve (0.9%) was found to enter its own dural compartment within the jugular foramen. The majority of sides (80%) were found to have a cranial root of the accessory nerve. Thirty-one sides (28%) had connections to cervical dorsal roots medially and three sides (2.7%) laterally. Medial connections were most common with the C1 nerve. Medial components of these dorsal root connections were all sensory in nature. However, lateral components were motor on two sides (1.8%). Nerves traveled anterior to the internal jugular vein on 88% of sides. One (0.9%) left side nerve joined an interneural anastomosis between the dorsal rootlets. Macroganglia were found on the spinal part of the intracranial nerve on 13% of sides. The lesser occipital nerve arose directly from the accessory nerve on two sides (1.8%) and communicated with the accessory nerve on 5.4% of sides. One side (0.9%) was found to communicate with the facial nerve with both nerves innervating the sternocleidomastoid muscle. Additional anatomical knowledge of the variants of the accessory nerve may benefit patient care when this nerve is pathologically involved.

  20. Analysis of the return period and correlation between the reservoir-induced seismic frequency and the water level based on a copula: A case study of the Three Gorges reservoir in China

    Liu, Xiaofei; Zhang, Qiuwen


    Studies have considered the many factors involved in the mechanism of reservoir seismicity. Focusing on the correlation between reservoir-induced seismicity and the water level, this study proposes to utilize copula theory to build a correlation model to analyze their relationships and perform the risk analysis. The sequences of reservoir induced seismicity events from 2003 to 2011 in the Three Gorges reservoir in China are used as a case study to test this new methodology. Next, we construct four correlation models based on the Gumbel, Clayton, Frank copula and M-copula functions and employ four methods to test the goodness of fit: Q-Q plots, the Kolmogorov-Smirnov (K-S) test, the minimum distance (MD) test and the Akaike Information Criterion (AIC) test. Through a comparison of the four models, the M-copula model fits the sample better than the other three models. Based on the M-copula model, we find that, for the case of a sudden drawdown of the water level, the possibility of seismic frequency decreasing obviously increases, whereas for the case of a sudden rising of the water level, the possibility of seismic frequency increasing obviously increases, with the former being greater than the latter. The seismic frequency is mainly distributed in the low-frequency region (Y ⩽ 20) for the low water level and in the middle-frequency region (20 80) is the least likely. For the conditional return period, it can be seen that the period of the high-frequency seismicity is much longer than those of the normal and medium frequency seismicity, and the high water level shortens the periods.

  1. Integrated seismic stochastic inversion and multi-attributes to delineate reservoir distribution: Case study MZ fields, Central Sumatra Basin

    Haris, A.; Novriyani, M.; Suparno, S.; Hidayat, R.; Riyanto, A.


    This study presents the integration of seismic stochastic inversion and multi-attributes for delineating the reservoir distribution in term of lithology and porosity in the formation within depth interval between the Top Sihapas and Top Pematang. The method that has been used is a stochastic inversion, which is integrated with multi-attribute seismic by applying neural network Probabilistic Neural Network (PNN). Stochastic methods are used to predict the probability mapping sandstone as the result of impedance varied with 50 realizations that will produce a good probability. Analysis of Stochastic Seismic Tnversion provides more interpretive because it directly gives the value of the property. Our experiment shows that AT of stochastic inversion provides more diverse uncertainty so that the probability value will be close to the actual values. The produced AT is then used for an input of a multi-attribute analysis, which is used to predict the gamma ray, density and porosity logs. To obtain the number of attributes that are used, stepwise regression algorithm is applied. The results are attributes which are used in the process of PNN. This PNN method is chosen because it has the best correlation of others neural network method. Finally, we interpret the product of the multi-attribute analysis are in the form of pseudo-gamma ray volume, density volume and volume of pseudo-porosity to delineate the reservoir distribution. Our interpretation shows that the structural trap is identified in the southeastern part of study area, which is along the anticline.


    In the last three years, mercury contamination in North Mississippi flood control reservoirs has become a growing concern. Previous data indicate that three flood control reservoirs have similar total mercury sediment concentrations and that fish collected from one reservoir cont...


    In the last three years, mercury contamination in North Mississippi flood control reservoirs has become a growing concern. Previous data indicate that three flood control reservoirs have similar total mercury sediment concentrations and that fish collected from one reservoir cont...

  4. Periodontal pocket as a potential reservoir of high risk human papilloma virus: A pilot study

    Manjunath Mundoor Dayakar


    Full Text Available Aim: Human papilloma viruses (HPVs are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. HPV detection in periodontium has previously involved DNA detection. This study attempts to: (a Detect the presence or absence of high risk HPV in marginal periodontiun by identifying E6/E7 messenger RNA (mRNA in cells from samples obtained by periodontal pocket scraping. (b Detect the percentage of HPV E6/E7 mRNA in cells of pocket scrapings, which is responsible for producing oncoproteins E6 and E7. Materials and Methods: Pocket scrapings from the periodontal pockets of eight subjects with generalized chronic periodontitis were taken the detection of presence or absence of E6, E7 mRNA was performed using in situ hybridization and flow cytometry. Results: HPV E6/E7 mRNA was detected in four of the eight samples. Conclusion: Presence of high risk human papillomaviruses in periodontal pockets patients of diagnosed with chronic periodontitis, not suffering from head and neck squamous cell carcinoma in the present day could link periodontitis to HPV related squamous cell carcinoma. Prevalence studies are needed detecting the presence of HPV in marginal periodontium as well as prospective studies of HPV positive periodontitis patients are required to explore this possible link.

  5. Reasons for reservoir effect variability

    Philippsen, Bente


    Freshwater reservoir effects can be large and highly variable. I will present my investigations into the short-term variability of the freshwater reservoir effect in two Northern German rivers. The samples analysed in this study were collected between 2007 and 2012. Reservoir ages of water samples......, aquatic plants and fish from the rivers Alster and Trave range between zero and about 3,000 radiocarbon years. The reservoir age of water DIC depends to a large extent on the origin of the water and is for example correlated with precipitation amounts. These short-term variations are smoothed out in water...... plants. Their carbon should represent an average value of the entire growth season. However, there are large reservoir age variations in aquatic plants and animals as well. These can best be explained by the multitude of carbon sources which can be utilized by aquatic organisms, and which have...


    Mahmut FIRAT


    Full Text Available The circulation pattern in lakes and reservoirs varies according to many external factors. In situ measurement of the occuring flow pattern in every point of the lake is a very costly and hard task. For this reason, models determining the velocities and surface fluctuations are developed by using computers. The use of these models enables the generation of the foundation for the prediction of possible environmental problems and water pollution concentrations. Today, three dimensional models are widely used in the modelling of lakes and reservoirs. In this study, the velocity profiles and surface fluctuation values generated under various wind speed and directions at some sections in Gokpinar Lake in Denizli are obtained by applying artificial neural networks (ANN on the results of three dimensional hydrodynamic model of the lake made with Princeton Ocean Model (POM. The developed ANN model is applied to the same sections for different wind conditions and it is found that the results are in accordance with the results of POM. As a result of the comparisons of the models, the superiorities of the models on each other at the model generation and solution phases are determined and mentioned.

  7. Use of Cusp Catastrophe for Risk Analysis of Navigational Environment: A Case Study of Three Gorges Reservoir Area.

    Jiang, Dan; Hao, Guozhu; Huang, Liwen; Zhang, Dan


    A water traffic system is a huge, nonlinear, complex system, and its stability is affected by various factors. Water traffic accidents can be considered to be a kind of mutation of a water traffic system caused by the coupling of multiple navigational environment factors. In this study, the catastrophe theory, principal component analysis (PCA), and multivariate statistics are integrated to establish a situation recognition model for a navigational environment with the aim of performing a quantitative analysis of the situation of this environment via the extraction and classification of its key influencing factors; in this model, the natural environment and traffic environment are considered to be two control variables. The Three Gorges Reservoir area of the Yangtze River is considered as an example, and six critical factors, i.e., the visibility, wind, current velocity, route intersection, channel dimension, and traffic flow, are classified into two principal components: the natural environment and traffic environment. These two components are assumed to have the greatest influence on the navigation risk. Then, the cusp catastrophe model is employed to identify the safety situation of the regional navigational environment in the Three Gorges Reservoir area. The simulation results indicate that the situation of the navigational environment of this area is gradually worsening from downstream to upstream.

  8. Study on Relation between Hydrodynamic Feature Size of HPAM and Pore Size of Reservoir Rock in Daqing Oilfield

    Qing Fang


    Full Text Available The flow mechanism of the injected fluid was studied by the constant pressure core displacement experiments in the paper. It is assumed under condition of the constant pressure gradient in deep formation based on the characteristic of pressure gradient distribution between the injection and production wells and the mobility of different polymer systems in deep reservoir. Moreover, the flow rate of steady stream was quantitatively analyzed and the critical flow pressure gradient of different injection parameters polymer solutions in different permeability cores was measured. The result showed that polymer hydrodynamic feature size increases with the increasing molecular weight. If the concentration of polymer solutions overlaps beyond critical concentration, then molecular chains entanglement will be occur and cause the augment of its hydrodynamic feature size. The polymer hydrodynamic feature size decreased as the salinity of the dilution water increased. When the median radius of the core pore and throat was 5–10 times of the polymer system hydrodynamic feature size, the polymer solution had a better compatibility with the microscopic pore structure of the reservoir. The estimation of polymer solutions mobility in the porous media can be used to guide the polymer displacement plan and select the optimum injection parameters.

  9. Use of Cusp Catastrophe for Risk Analysis of Navigational Environment: A Case Study of Three Gorges Reservoir Area.

    Dan Jiang

    Full Text Available A water traffic system is a huge, nonlinear, complex system, and its stability is affected by various factors. Water traffic accidents can be considered to be a kind of mutation of a water traffic system caused by the coupling of multiple navigational environment factors. In this study, the catastrophe theory, principal component analysis (PCA, and multivariate statistics are integrated to establish a situation recognition model for a navigational environment with the aim of performing a quantitative analysis of the situation of this environment via the extraction and classification of its key influencing factors; in this model, the natural environment and traffic environment are considered to be two control variables. The Three Gorges Reservoir area of the Yangtze River is considered as an example, and six critical factors, i.e., the visibility, wind, current velocity, route intersection, channel dimension, and traffic flow, are classified into two principal components: the natural environment and traffic environment. These two components are assumed to have the greatest influence on the navigation risk. Then, the cusp catastrophe model is employed to identify the safety situation of the regional navigational environment in the Three Gorges Reservoir area. The simulation results indicate that the situation of the navigational environment of this area is gradually worsening from downstream to upstream.

  10. Modeling Alpine hydropower reservoirs management to study the water-energy nexus under change.

    Castelletti, A.; Giuliani, M.; Fumagalli, E.; Weber, E.


    Climate change and growing population are expected to severely affect freshwater availability by the end of 21th century. Many river basins, especially in the Mediterranean region, are likely to become more prone to periods of reduced water supply, risking considerable impacts on the society, the environment, and the economy, thus emphasizing the need to rethink the way water resources are distributed, managed, and used at the regional and river basin scale. This paradigm shift will be essential to cope with the undergoing global change, characterized by growing water demands and by increasingly uncertain hydrologic regimes. Most of the literature traditionally focused on predicting the impacts of climate change on water resources, while our understanding of the human footprint on the hydrological cycle is limited. For example, changes in the operation of the Alpine hydropower reservoirs induced by socio-economic drivers (e.g., development of renewable energy) were already observed over the last few years and produced relevant impacts on multiple water uses due to the altered distribution of water volumes in time and space. Modeling human decisions as well as the links between society and environmental systems becomes key to develop reliable projections on the co-evolution of the coupled human-water systems and deliver robust adaptation strategies This work contributes a preliminary model-based analysis of the behaviour of hydropower operators under changing energy market and climate conditions. The proposed approach is developed for the San Giacomo-Cancano reservoir system, Italy. The identification of the current operating policy is supported by input variable selection methods to select the most relevant hydrological and market based drivers to explain the observed release time series.. The identified model is then simulated under a set of future scenarios, accounting for both climate and socio-economic change (e.g. expansion of the electric vehicle sector, load

  11. Thermo-poroelastic numerical modelling for enhanced geothermal system performance: Case study of the Groß Schönebeck reservoir

    Jacquey, Antoine B.; Cacace, Mauro; Blöcher, Guido; Watanabe, Norihiro; Huenges, Ernst; Scheck-Wenderoth, Magdalena


    Significant pressure and temperature changes can occur within geothermal reservoirs caused by injection and production of fluid which can affect transport properties of the rocks and therefore alter reservoir performance and sustainability. To understand the coupling between transport properties evolution and state variable changes, a complete description of the mechanical behavior of the reservoir is required which should consider thermo- and poroelastic effects. This study aims to integrate transport properties evolution for coupled thermo-hydro-mechanical (THM) process modelling of fluid-bearing reservoirs. This approach is here applied to the geothermal research site of Groß Schönebeck (40 km north of Berlin, Germany) which consists of a doublet system at a target depth of about - 4100 m in which both injection and production wells have been hydraulically stimulated. A 3D reservoir model including the main geological units, major natural fault zones and hydraulic fractures is integrated in the finite-element method-based simulator OpenGeoSys for modelling coupled THM processes during geothermal activity. One challenge of this study is to integrate both hydro-geological and physical complexity to better describe the dynamic behavior of the geothermal reservoir. From the results of the simulation, thermal breakthrough is observed after 18 years of injection and life time of the system has been evaluated as 50 years. Furthermore, a 5.5% increase of porosity around the injection well is observed as well as an increase of the anisotropy ratio for permeability (kz/kxy) of about 2%. These transport properties enhancements lead to a decrease of the thermal breakthrough time (around - 8%) and life time of the system (- 14%) compared to classic thermo-hydro simulations with constant transport properties. The results presented here provide therefore valuable insights for understanding porosity and permeability distributions and evolutions during injection and production

  12. A study of infestation of Alburnoides bipunctatus with Ligula intestinalis in Latian reservoir Dam Lake, Tehran province, Iran: A histopathological stud

    Iraj Sohrabi Haghdoos


    Full Text Available . Objective: The objective of this study was to report infestation of the fish with Ligula intestinalis as a food borne zoonoses and to study its histopathological effects on one Alburnoides bipunctatus in Latian reservoir Dam Lake, Tehran province, Iran. Material and methods: In July 2010, 6 fish (Alburnoides bipunctatus from Latian reservoir Dam Lake, Tehran province, Iran were referred to Laboratory. After autopsy, two of them (Mature and Female were found infested with plerocercoid of Ligula intestinalis based on taxonomical features. For histopathological studies samples were stained with Haematoxylin and Eosin (H&E and observed under light microscopy. Results: Pathological findings showed inflammation of the reservoir adipose tissue (in the loose conjunctive tissue between lipocytes surrounding intestine. Severe atrophy in follicular cells of ovary was evident. In liver cholangiohepastitis with metaplastic hyperplasia was seen. Conclusion: Considering the importance ofLigula intestinalis as a food borne parasite, performance of other comprehensive studies is a necessity.

  13. Reservoir Cannulas for Pediatric Oxygen Therapy: A Proof-of-Concept Study

    Grace Wu


    Full Text Available Hypoxemia is a complication of pneumonia—the leading infectious cause of death in children worldwide. Treatment generally requires oxygen-enriched air, but access in low-resource settings is expensive and unreliable. We explored use of reservoir cannulas (RCs, which yield oxygen savings in adults but have not been examined in children. Toddler, small child, and adolescent breathing profiles were simulated with artificial lung and airway models. An oxygen concentrator provided flow rates of 0 to 5 L/min via a standard nasal cannula (NC or RC, and delivered oxygen fraction (FdO2 was measured. The oxygen savings ratio (SR and absolute flow savings (AFS were calculated, comparing NC and RC. We demonstrated proof-of-concept that pendant RCs could conserve oxygen during pediatric therapy. SR mean and standard deviation were 1.1±0.2 to 1.4±0.4, 1.1±0.1 to 1.7±0.3, and 1.3±0.1 to 2.4±0.3 for toddler, small child, and adolescent models, respectively. Maximum AFS observed were 0.3±0.3, 0.2±0.1, and 1.4±0.3 L/min for the same models. RCs have the potential to reduce oxygen consumption during treatment of hypoxemia in children; however, further evaluation of products is needed, followed by clinical analysis in patients.

  14. Laboratory study of fluid viscosity induced ultrasonic velocity dispersion in reservoir sandstones

    He, Tao; Zou, Chang-Chun; Pei, Fa-Gen; Ren, Ke-Ying; Kong, Fan-Da; Shi, Ge


    Ultrasonic velocities of a set of saturated sandstone samples were measured at simulated in-situ pressures in the laboratory. The samples were obtained from the W formation of the WXS Depression and covered low to nearly high porosity and permeability ranges. The brine and four different density oils were used as pore fluids, which provided a good chance to investigate fluid viscosity-induced velocity dispersion. The analysis of experimental observations of velocity dispersion indicates that (1) the Biot model can explain most of the small discrepancy (about 2-3%) between ultrasonic measurements and zero frequency Gassmann predictions for high porosity and permeability samples saturated by all the fluids used in this experiment and is also valid for medium porosity and permeability samples saturated with low viscosity fluids (less than approximately 3 mP·S) and (2) the squirt flow mechanism dominates the low to medium porosity and permeability samples when fluid viscosity increases and produces large velocity dispersions as high as about 8%. The microfracture aspect ratios were also estimated for the reservoir sandstones and applied to calculate the characteristic frequency of the squirt flow model, above which the Gassmann’ s assumptions are violated and the measured high frequency velocities cannot be directly used for Gassmann’s fluid replacement at the exploration seismic frequency band for W formation sandstones.

  15. Spectral decomposition aids AVO analysis in reservoir characterization: A case study of Blackfoot field, Alberta, Canada

    Jung Yoon, Wang; Farfour, Mohammed


    Blackfoot field, Alberta, Canada, has produced oil and gas from a Glauconitic compound incised valley-system. In this area channels can be filled with sands and/or shales. Differentiation of prospective channel sands and non-productive shales was always problematic due to the similarity in P-wave impedance of these two lithotypes. We study the spectral decomposition response to the hydrocarbons presence in the Glauconitic channel of Early Cretaceous age. From previous AVO analysis and modeling, a strong Class III AVO anomaly has been observed at the top of the porous sandstone in the upper valley, whereas shale had a very different AVO response. Furthermore, AVO inversion revealed additional information about lithology and fluid content in the channel. Our workflow starts from selecting a continuous horizon that was close and conforms to the channel interval; we then run spectral analyses for the channel area. Short Window Fourier Transform workflow could successfully image the channel's stratigraphic features and confirm results obtained from AVO analysis and inversion run on the data before being stacked. Additionally, the producing oil wells in the sand-fill channel were found to be correlating with high spectrum amplitude; while the dry wells in the shale-plugged channel fell in low amplitude anomaly.

  16. A Study on the Matching Relationship of Polymer Molecular Weight and Reservoir Permeability in ASP Flooding for Duanxi Reservoirs in Daqing Oil Field

    Bin Huang


    Full Text Available In order to determine the matching relationship of polymer molecular weight and reservoir permeability in ASP (alkaline/surfactant/polymer flooding, a number of core flooding experiments with different polymer molecular weights are performed. Two types of curves for the relationship between the pressure difference and the injection pore volume multiples are obtained. One describes the characteristics of the core plugging; the other describes the characteristics of the injection well. The relationship between the polymer molecular cyclotron radius and the pore throat radius used to describe the relationship between the polymer molecular weight and the core permeability. The results indicate that when the ratio of the pore throat radius (rh to the polymer molecular cyclotron radius (rp is greater than 7, the injection of ASP system with a variety of molecular weights will not be blocked; on contrary, when the ratio is less than 7, the core will be blocked. The range of water permeability of the core is determined by the value of the polymer molecular weight. The ratio between the pore throat radius (rh to the polymer molecular cyclotron radius (rp for the ASP system is greater than that of polymer system (rh/rp = 5. A scanning electron microscope (SEM is used to compare the morphology of polymer molecules in polymer solution and ASP solution, and shows that the dimension of polymer molecular coils in ASP solution is smaller than that in polymer solution, which is caused by the double effect of alkali and surfactant.

  17. Capacity sharing of water reservoirs

    Dudley, Norman J.; Musgrave, Warren F.


    The concept of a water use property right is developed which does not apply to water volumes as such but to a share of the capacity (not contents) of river storage reservoirs and their inflows. The shareholders can withdraw water from their share over time in accordance with their preferences for stability of water deliveries. The reservoir authority does not manage reservoir releases but keeps record of individual shareholder's withdrawals and net inflows to monitor the quantity of water in each shareholder's capacity share. A surplus of total reservoir contents over the sum of the contents of the individual shareholder's capacity shares will accrue over time. Two different criteria for its periodic distribution among shareholders are compared. A previous paper Dudley (this issue(b)) noted a loss of short-run economic efficiency as reservoir and farm management decision making become separated. This is largely overcome by capacity sharing which allows each user to integrate the management of their portion of the reservoir and their farming operations. The nonattenuated nature of the capacity sharing water rights also promotes long-run economic efficiency.

  18. Study on the connectivity of heavy oil reservoirs by ultraviolet spectrum technique in the western part of the QHD32-6 oilfield

    XU Yaohui; CHEN Dan


    As a new method, the ultraviolet spectrum technique is applied to studying the connectivity of biodegradable heavy oil reservoirs. The similarity of crude oils can be judged according to the extinction coefficient (E)because aromatic hydrocarbons and non-hydrocarbons have conjugated bonds and obvious absorption in the ultraviolet range, and different materials have different characteristics and additives. The relationship diagram is made in terms of the extinction coefficients (E) of the samples by taking E as the Y-axis and wavelength as the X-axis. The connectivity of oil reservoirs is estimated according to the curve positions and characteristic fingerprints of the samples. The connectivity of part of the reservoirs in the western part of the QHD32-6 oilfieid was studied with this method. The results showed that the connectivity of samples from wells F7 and F8 in the Nm-2 oil reservoir zone is good, that of samples from wells F17 and F20 in the Nm-1 oil reservoir zone also is good, and that of samples from wells F17, F19, and F20 is poor.

  19. Comparative Study of Effects of CO 2 Concentration and pH on Microbial Communities from a Saline Aquifer, a Depleted Oil Reservoir, and a Freshwater Aquifer

    Gulliver, Djuna M.; Lowry, Gregory V.; Gregory, Kelvin B.


    Injected CO2 from geologic carbon storage is expected to impact the microbial communities of proposed storage sites, such as depleted oil reservoirs and deep saline aquifers, as well as overlying freshwater aquifers at risk of receiving leaking CO2. Microbial community change in these subsurface sites may affect injectivity of CO2, permanence of stored CO2, and shallow subsurface water quality. The effect of CO2 concentration on the microbial communities in fluid collected from a depleted oil reservoir and a freshwater aquifer was examined at subsurface pressures and temperatures. The community was exposed to 0%, 1%, 10%, and 100% pCO2 for 56 days. Bacterial community structure was analyzed through 16S rRNA gene clone libraries, and total bacterial abundance was estimated through quantitative polymerase chain reaction. Changes in the microbial community observed in the depleted oil reservoir samples and freshwater samples were compared to previous results from CO2-exposed deep saline aquifer fluids. Overall, results suggest that CO2 exposure to microbial communities will result in pH-dependent population change, and the CO2-selected microbial communities will vary among sites. This is the first study to compare the response of multiple subsurface microbial communities at conditions expected during geologic carbon storage, increasing the understanding of environmental drivers for microbial community changes in CO2-exposed environments.

  20. Advanced waterflooding in chalk reservoirs: Understanding of underlying mechanisms

    Zahid, Adeel; Sandersen, Sara Bülow; Stenby, Erling Halfdan


    Over the last decade, a number of studies have shown SO42−, Ca2+ and Mg2+ to be potential determining ions, which may be added to the injected brine for improving oil recovery during waterflooding in chalk reservoirs. However the understanding of the mechanism leading to an increase in oil recove...... of a microemulsion phase could be the possible reasons for the observed increase in oil recovery with sulfate ions at high temperature in chalk reservoirs besides the mechanism of the rock wettability alteration, which has been reported in most previous studies.......Over the last decade, a number of studies have shown SO42−, Ca2+ and Mg2+ to be potential determining ions, which may be added to the injected brine for improving oil recovery during waterflooding in chalk reservoirs. However the understanding of the mechanism leading to an increase in oil recovery...

  1. A study on 4D inversion of time-lapse magnetotelluric data sets for monitoring geothermal reservoir

    Jang, H.; Nam, M. J.; Song, Y.


    The productivity of geothermal reservoir, which is function of pore-space and fluid-flow path of the reservoir, varies since the properties of reservoir changes with geothermal electricity generation. The variation in the reservoir properties causes changes in electrical resistivity, time-lapse (TL) three-dimensional (3D) magnetotelluric (MT) methods can be applied to monitor the productivity variation of geothermal reservoir thanks to its sensitive to the electrical resistivity of deep subsurface. For an accurate interpretation of TL 3D MT data, a 4D MT inversion algorithm has been developed to simultaneously invert all vintage data in a time-coupled way. However, the changes in electrical resistivity of deep geothermal reservoirs are usually small generating minimum variation in TL MT responses. In order to reduce TL inversion artifacts emphasizing the TL changes, we upgrade the TL coupling of the original 4D inversion algorithm with active time constraint (ATC), which has been verified to be efficient for resistivity monitoring based on TL electrical resistivity surveys. In order to maximize the sensitivity to reservoir-region resistivity changes, we further developed a focused 4D MT inversion method by considering the distribution of reservoir fractures. To analyze the validity of the 4D algorithms, we make 4D MT inversion of synthetic TL data sets applying ATC and focusing methods, respectively, and compare their results those from the original 4D algorithm. The numerical tests find that ATC 4D inversion can be useful for conventional geothermal reservoirs, while the focused inversion algorithm can be better for monitoring engineering geothermal system (EGS) reservoir, within which new fracture can be actively developed by fluid circulation during production. This work is supported by KETEP granted by MOTIE, KOREA (NO. 20133030000220).

  2. Study the effect of reservoir spatial heterogeneity on CO2 sequestration under an uncertainty quantification (UQ) software framework

    Fang, Y.; Hou, J.; Engel, D.; Lin, G.; Yin, J.; Han, B.; Fang, Z.; Fountoulakis, V.


    In this study, we introduce an uncertainty quantification (UQ) software framework for carbon sequestration, with the focus of studying being the effect of spatial heterogeneity of reservoir properties on CO2 migration. We use a sequential Gaussian method (SGSIM) to generate realizations of permeability fields with various spatial statistical attributes. To deal with the computational difficulties, we integrate the following ideas/approaches: 1) firstly, we use three different sampling approaches (probabilistic collocation, quasi-Monte Carlo, and adaptive sampling approaches) to reduce the required forward calculations while trying to explore the parameter space and quantify the input uncertainty; 2) secondly, we use eSTOMP as the forward modeling simulator. eSTOMP is implemented using the Global Arrays toolkit (GA) that is based on one-sided inter-processor communication and supports a shared memory programming style on distributed memory platforms. It provides highly-scalable performance. It uses a data model to partition most of the large scale data structures into a relatively small number of distinct classes. The lower level simulator infrastructure (e.g. meshing support, associated data structures, and data mapping to processors) is separated from the higher level physics and chemistry algorithmic routines using a grid component interface; and 3) besides the faster model and more efficient algorithms to speed up the forward calculation, we built an adaptive system infrastructure to select the best possible data transfer mechanisms, to optimally allocate system resources to improve performance, and to integrate software packages and data for composing carbon sequestration simulation, computation, analysis, estimation and visualization. We will demonstrate the framework with a given CO2 injection scenario in a heterogeneous sandstone reservoir.

  3. Stonemeal of amazon soils with sediments from reservoirs: a case study of remineralization of the tucuruí degraded land for agroforest reclamation



    Full Text Available This study suggests the employment of accumulated sediments in the reservoir of Tucuruí (Pará /Brazil to remineralize the surrounding degraded soils. The approach was based on the principles of stonemeal technology. It suggests that the soil can be rejuvenated by crushed rocks rich in macro and micronutrients. Removal of the sediments for agricultural use will bring benefits to family farmers and increase the life cycle of the reservoir and, therefore, energy generation. Geochemical data on retained sediments, soils and rocks in the area of influence of the reservoir were evaluated regarding nutrient transport mechanisms and soil-fertility potential. Results show that sediments from the reservoir contain nutrients levels at least one order of magnitude greater than average Amazon region soils. Our data on soil use and occupation in the region show the degradation areas which could be recovered by stonemeal techniques. Thence, an Agroforestry System was installed, with 12 plots where different mixtures of sediments removed from the reservoir were used, along with crushed rock with or without the addition of NPK and manure. The experiments showed that maximum crop yield and plant growth were attained in the plots where a mixture of sediments, crushed rocks and manure were added.

  4. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    Li, Jianzhu; Sun, Huafeng; Feng, Ping


    Several small reservoirs and a large number of check dams had been constructed in the Wangkuai reservoir watershed after 1970s, and flood time series lacked stationarity, which affected the original design flood hydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of the large number of check dams were unknown, we present a method to estimate their total storage capacities (TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basis of TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed under current conditions to obtain a stationary flood series. A frequency analysis was subsequently performed to assess the design flood peak and volume for both small and medium design floods with a 10-200 year return period. For large and catastrophic floods, it was assumed that the upstream check dams and small reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to the Wangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods with a 10-200 year return period when compared to the current design flood. But for large design floods with a return period exceeding 500 years, peak discharge increased. This study provides a new method for design flood calculation or modification of the original design flood in watersheds with a large number of check dams.

  5. Studying methane migration mechanisms at Walker Ridge, Gulf of Mexico, via 3D methane hydrate reservoir modeling

    Nole, Michael [University of Texas at Austin; Daigle, Hugh [University of Texas at Austin; Mohanty, Kishore [University of Texas at Austin; Cook, Ann [Ohio State University; Hillman, Jess [Ohio State University


    We have developed a 3D methane hydrate reservoir simulator to model marine methane hydrate systems. Our simulator couples highly nonlinear heat and mass transport equations and includes heterogeneous sedimentation, in-situ microbial methanogenesis, the influence of pore size contrast on solubility gradients, and the impact of salt exclusion from the hydrate phase on dissolved methane equilibrium in pore water. Using environmental parameters from Walker Ridge in the Gulf of Mexico, we first simulate hydrate formation in and around a thin, dipping, planar sand stratum surrounded by clay lithology as it is buried to 295mbsf. We find that with sufficient methane being supplied by organic methanogenesis in the clays, a 200x pore size contrast between clays and sands allows for a strong enough concentration gradient to significantly drop the concentration of methane hydrate in clays immediately surrounding a thin sand layer, a phenomenon that is observed in well log data. Building upon previous work, our simulations account for the increase in sand-clay solubility contrast with depth from about 1.6% near the top of the sediment column to 8.6% at depth, which leads to a progressive strengthening of the diffusive flux of methane with time. By including an exponentially decaying organic methanogenesis input to the clay lithology with depth, we see a decrease in the aqueous methane supplied to the clays surrounding the sand layer with time, which works to further enhance the contrast in hydrate saturation between the sand and surrounding clays. Significant diffusive methane transport is observed in a clay interval of about 11m above the sand layer and about 4m below it, which matches well log observations. The clay-sand pore size contrast alone is not enough to completely eliminate hydrate (as observed in logs), because the diffusive flux of aqueous methane due to a contrast in pore size occurs slower than the rate at which methane is supplied via organic methanogenesis

  6. Using underground gas storage to replace the swing capacity of the giant natural gas field of Groningen in the Netherlands. A reservoir performance feasibility study

    Juez-Larre, J.; Remmelts, G.; Breunese, J.N.; Gessel, S.F.; Leeuwenburgh, O.


    In this study we probe the ultimate potential Underground Gas Storage (UGS) capacity of the Netherlands by carrying out a detailed feasibility study on inflow performances of all onshore natura! gas reservoirs. The Netherlands is one of the largest natura! gas producers in Western Europe. The curren

  7. Using underground gas storage to replace the swing capacity of the giant natural gas field of Groningen in the Netherlands. A reservoir performance feasibility study

    Juez-Larre, J.; Remmelts, G.; Breunese, J.N.; Gessel, S.F.; Leeuwenburgh, O.


    In this study we probe the ultimate potential Underground Gas Storage (UGS) capacity of the Netherlands by carrying out a detailed feasibility study on inflow performances of all onshore natura! gas reservoirs. The Netherlands is one of the largest natura! gas producers in Western Europe. The curren

  8. Using underground gas storage to replace the swing capacity of the giant natural gas field of Groningen in the Netherlands. A reservoir performance feasibility study

    Juez-Larre, J.; Remmelts, G.; Breunese, J.N.; Gessel, S.F.; Leeuwenburgh, O.


    In this study we probe the ultimate potential Underground Gas Storage (UGS) capacity of the Netherlands by carrying out a detailed feasibility study on inflow performances of all onshore natura! gas reservoirs. The Netherlands is one of the largest natura! gas producers in Western Europe. The

  9. Missing osteoconductive effect of a resorbable PEO/PBT copolymer in human bone defects: a clinically relevant pilot study with contrary results to previous animal studies.

    Roessler, M; Wilke, A; Griss, P; Kienapfel, H


    PEO/PBT 70/30 (POLYACTIVE(R) 70/30), a degradable porous copolymer with elastic properties, was found to be osteoconductive in many animal studies. The aim of this study was to determine the osteoconductive effect in a human paired control iliac defect model. In seven patients undergoing anterior spinal interbody fusion surgery, two bicortical iliac defects for autograft harvesting were created. The defect size was identical for both defects measuring about 40 x 15 mm (group I). One defect was filled with the degradable implants, whereas the remaining one was left untreated as a control. The defect site for treatment was chosen randomly. In three further patients, only one defect measuring about 40 x 35 mm was created (group II). All patients were examined clinically and radiologically by spiral-CT after 1, 6, 12, 24, and 52 weeks. Three-dimensional reconstructions as well as CT-volumetric measurements using 1 mm sections were used as evaluation methods. In group I, a two-tailed paired t-test showed that the treated defects had significantly less formation of new bone than the untreated ones (p < 0.05 after 12 weeks, p < 0.01 after 52 weeks). Also, in group II, not much bone ingrowth could be observed. The histological evaluation of one patient in group I revealed no bone within the pores, and a fibrous layer between bone and implant was always present. Therefore, PEO/PBT 70/30 cannot be recommended as a bone substitute for clinical use. Differences in bone regeneration between humans and certain animal species as well as inapplicable defect models in previous animal studies are discussed as possible reasons for the failure.

  10. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim (University of Texas at Austin, Austin, TX); Gilbert, Bob (University of Texas at Austin, Austin, TX); Lake, Larry W. (University of Texas at Austin, Austin, TX); Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett (University of Texas at Austin, Austin, TX); Thomas, Sunil G. (University of Texas at Austin, Austin, TX); Rightley, Michael J.; Rodriguez, Adolfo (University of Texas at Austin, Austin, TX); Klie, Hector (University of Texas at Austin, Austin, TX); Banchs, Rafael (University of Texas at Austin, Austin, TX); Nunez, Emilio J. (University of Texas at Austin, Austin, TX); Jablonowski, Chris (University of Texas at Austin, Austin, TX)


    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  11. Quantifying the influence of previously burned areas on suppression effectiveness and avoided exposure: A case study of the Las Conchas Fire

    Matthew P. Thompson; Patrick Freeborn; Jon D. Rieck; Dave Calkin; Julie W. Gilbertson-Day; Mark A. Cochrane; Michael S. Hand


    We present a case study of the Las Conchas Fire (2011) to explore the role of previously burned areas (wildfires and prescribed fires) on suppression effectiveness and avoided exposure. Methodological innovations include characterisation of the joint dynamics of fire growth and suppression activities, development of a fire line effectiveness framework, and...

  12. Study of some physical aspects previous to design of an exponential experiment; Estudio de algunos aspectos fisicos previos al diseno de una experiencia exponencial

    Caro, R.; Francisco, J. L. de


    This report presents the theoretical study of some physical aspects previous to the design of an exponential facility. The are: Fast and slow flux distribution in the multiplicative medium and in the thermal column, slowing down in the thermal column, geometrical distribution and minimum needed intensity of sources access channels and perturbations produced by possible variations in its position and intensity. (Author) 4 refs.

  13. Phase II study of reintroduction of oxaliplatin for advanced colorectal cancer in patients previously treated with oxaliplatin and irinotecan: RE-OPEN study

    Suenaga M


    Full Text Available Mitsukuni Suenaga,1 Nobuyuki Mizunuma,1 Satoshi Matsusaka,1 Eiji Shinozaki,1 Masato Ozaka,1 Mariko Ogura,1 Toshiharu Yamaguchi21Department of Gastroenterology, 2Department of Gastroenterological Surgery, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, JapanBackground: The effectiveness of reintroducing oxaliplatin in patients with metastatic colorectal cancer refractory to standard chemotherapy has not been verified. We performed a single-arm, open-label, Phase II study to evaluate the safety and efficacy of reintroducing oxaliplatin. Methods: Eligible patients had received prior chemotherapy including oxaliplatin and irinotecan that achieved a response or stable disease followed by confirmed disease progression ≥6 months previously during prior oxaliplatin-based therapy. The primary endpoint was the disease control rate (DCR after 12 weeks of treatment starting. The DCR was defined as the sum of patients with complete response, partial response, and stable disease. Results: Thirty-three patients were enrolled. The median age was 62 (range: 35–77 years and the male/female ratio was 19/14. Eastern Cooperative Oncology Group performance status was 0 in 84.8%. Fourteen primary tumors were in the colon and 19 were in the rectum. All patients received modified FOLFOX6 as the protocol treatment. After 12 weeks of treatment starting, the DCR was 39.4% (95% confidence interval 21.8–57.0 and the response rate (complete response and partial response was 6.1%. The median number of chemotherapy cycles was five and the median total dose of oxaliplatin was 425 mg/m2. Median progression-free survival time was 98 days and median overall survival was 300 days. The incidence of grade ≥1 and grade ≥3 allergic reactions was 28.1% and 3.1%, respectively. The incidence of grade ≥1 and grade ≥3 peripheral sensory neuropathy was 53.1% and 0%, respectively. There were no other severe adverse events and no treatment

  14. Optimization and risk analyses for rule curves of reservoir operation: application to Tien-Hua-Hu Reservoir in Taiwan.

    Kuo, J T; Hsu, N S; Chiu, S K


    Tien-Hua-Hu Reservoir is currently under planning by the Water Resources Agency, Taiwan to meet the increasing water demands of central Taiwan arising from rapid growth of domestic water supply, and high-tech industrial parks. This study develops a simulation model for the ten-day period reservoir operation to calculate the ten-day water shortage index under varying rule curves. A genetic algorithm is coupled to the simulation model to find the optimal rule curves using the minimum ten-day water shortage index as an objective function. This study generates many sets of synthetic streamflows for risk, reliability, resiliency, and vulnerability analyses of reservoir operation. ARMA and disaggregation models are developed and applied to the synthetic streamflow generation. The optimal rule curves obtained from this study perform better in the ten-day shortage index when compared to the originally designed rule curves from a previous study. The optimal rule curves are also superior to the originally designed rule curves in terms of vulnerability. However, in terms of reliability and resiliency, the optimal rule curves are inferior to the those originally designed. Results from this study have provided in general a set of improved rule curves for operation of the Tien-Hua-Hu Reservoir. Furthermore, results from reliability, resiliency and vulnerability analyses offer much useful information for decision making in reservoir operation.

  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

    Christopher D. White


    Significant volumes of oil and gas occur in reservoirs formed by ancient river deltas. This has implications for the spatial distribution of rock types and the variation of transport properties. A between mudstones and sandstones may form baffles that influence productivity and recovery efficiency. Diagenetic processes such as compaction, dissolution, and cementation can also alter flow properties. A better understanding of these properties and improved methods 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 view of variability. Insights gleaned from these exposures can be used to model analogous reservoirs, for which data is sparser. The Frontier Formation in central Wyoming provides an opportunity for high-resolution models. The same rocks exposed in the Tisdale anticline are productive in nearby oil fields. Kilometers of exposure are accessible, and bedding-plane exposures allow use of high-resolution ground-penetrating radar. This study combined geologic interpretations, maps, vertical sections, core data, and ground-penetrating radar to construct geostatistical and flow models. Strata-conforming grids were use to reproduce the observed geometries. A new Bayesian method integrates outcrop, core, and radar amplitude and phase data. The proposed method propagates measurement uncertainty and yields an ensemble of plausible models for calcite concretions. These concretions affect flow significantly. Models which integrate more have different flow responses from simpler models, as demonstrated an exhaustive two-dimensional reference image and in three dimensions. This method is simple to implement within widely available geostatistics packages. Significant volumes of oil and gas occur in reservoirs that are inferred to have been formed by ancient river deltas. This geologic setting has implications for the spatial distribution of

  16. Outcrop analogue study of Permocarboniferous geothermal sandstone reservoir formations (northern Upper Rhine Graben, Germany): impact of mineral content, depositional environment and diagenesis on petrophysical properties

    Aretz, Achim; Bär, Kristian; Götz, Annette E.; Sass, Ingo


    The Permocarboniferous siliciclastic formations represent the largest hydrothermal reservoir in the northern Upper Rhine Graben in SW Germany and have so far been investigated in large-scale studies only. The Cenozoic Upper Rhine Graben crosses the Permocarboniferous Saar-Nahe Basin, a Variscan intramontane molasse basin. Due to the subsidence in this graben structure, the top of the up to 2-km-thick Permocarboniferous is located at a depth of 600-2900 m and is overlain by Tertiary and Quaternary sediments. At this depth, the reservoir temperatures exceed 150 °C, which are sufficient for geothermal electricity generation with binary power plants. To further assess the potential of this geothermal reservoir, detailed information on thermophysical and hydraulic properties of the different lithostratigraphical units and their depositional environment is essential. Here, we present an integrated study of outcrop analogues and drill core material. In total, 850 outcrop samples were analyzed, measuring porosity, permeability, thermal conductivity and thermal diffusivity. Furthermore, 62 plugs were taken from drillings that encountered or intersected the Permocarboniferous at depths between 1800 and 2900 m. Petrographic analysis of 155 thin sections of outcrop samples and samples taken from reservoir depth was conducted to quantify the mineral composition, sorting and rounding of grains and the kind of cementation. Its influence on porosity, permeability, the degree of compaction and illitization was quantified. Three parameters influencing the reservoir properties of the Permocarboniferous were detected. The strongest and most destructive influence on reservoir quality is related to late diagenetic processes. An illitic and kaolinitic cementation and impregnation of bitumina document CO2- and CH4-rich acidic pore water conditions, which are interpreted as fluids that migrated along a hydraulic contact from an underlying Carboniferous hydrocarbon source rock. Migrating

  17. Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.

    Leon Biscornet


    Full Text Available Leptospirosis is a bacterial zoonosis caused by pathogenic Leptospira for which rats are considered as the main reservoir. Disease incidence is higher in tropical countries, especially in insular ecosystems. Our objectives were to determine the current burden of leptospirosis in Seychelles, a country ranking first worldwide according to historical data, to establish epidemiological links between animal reservoirs and human disease, and to identify drivers of transmission.A total of 223 patients with acute febrile symptoms of unknown origin were enrolled in a 12-months prospective study and tested for leptospirosis through real-time PCR, IgM ELISA and MAT. In addition, 739 rats trapped throughout the main island were investigated for Leptospira renal carriage. All molecularly confirmed positive samples were further genotyped.A total of 51 patients fulfilled the biological criteria of acute leptospirosis, corresponding to an annual incidence of 54.6 (95% CI 40.7-71.8 per 100,000 inhabitants. Leptospira carriage in Rattus spp. was overall low (7.7% but dramatically higher in Rattus norvegicus (52.9% than in Rattus rattus (4.4%. Leptospira interrogans was the only detected species in both humans and rats, and was represented by three distinct Sequence Types (STs. Two were novel STs identified in two thirds of acute human cases while noteworthily absent from rats.This study shows that human leptospirosis still represents a heavy disease burden in Seychelles. Genotype data suggests that rats are actually not the main reservoir for human disease. We highlight a rather limited efficacy of preventive measures so far implemented in Seychelles. This could result from ineffective control measures of excreting animal populations, possibly due to a misidentification of the main contaminating reservoir(s. Altogether, presented data stimulate the exploration of alternative reservoir animal hosts.

  18. Reservoir compartmentalization assessment by using FTIR spectroscopy

    Permanyer, A. [Dept. Geoquimica, Petrologia i Prospeccio Geologica, Universitat de Barcelona, Marti i Franques, s/n, 08028 - Barcelona, Catalonia (Spain); Rebufa, C.; Kister, J. [Universite d' Aix - Marseille III, Faculte des Sciences et Techniques de St. Jerome, CNRS UMR 6171, Laboratoire de Geochimie Organique Analytique et Environnement (GOAE), Case 561, 13397 Marseille Cedex 20 (France)


    Reservoir geochemistry has traditionally used the gas chromatographic fingerprinting method and star diagrams to provide evidence of petroleum reservoir compartmentalization. Recently alternative techniques such as Fourier Transform Infra Red (FTIR) spectroscopy have been postulated to aid the evaluation of reservoir compartmentalization, and to characterize the geochemical evolution of oils from individual reservoirs. FTIR spectroscopy was applied successfully in the Tarragona Basin, Offshore N.E. Spain, validating the method to identify oils from different reservoirs. Moreover the method was successfully applied to provide evidence of compositional differences in oils from a faulted reservoir (El Furrial field, Venezuela), in which GC fingerprints failed to differentiate the oils. FTIR spectroscopy therefore, proves to be a complementary tool for reservoir compartmentalization studies. (author)

  19. 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

    Jaruchiewicz Ewelina


    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

  20. ATLANTIC-DIP: prevalence of metabolic syndrome and insulin resistance in women with previous gestational diabetes mellitus by International Association of Diabetes in Pregnancy Study Groups criteria.

    Noctor, Eoin; Crowe, Catherine; Carmody, Louise A; Kirwan, Breda; O'Dea, Angela; Glynn, Liam G; McGuire, Brian E; O'Shea, Paula M; Dunne, Fidelma P


    Women with previous gestational diabetes (GDM) are a high-risk group for future development of diabetes, metabolic syndrome, and cardiovascular disease. The new International Association of Diabetes in Pregnancy Study Groups (IADPSG) criteria significantly increase the number of women diagnosed with GDM. The long-term metabolic outcome in these women is unknown. We set out to determine the prevalence of metabolic syndrome, using adult treatment panel-III criteria; and insulin resistance, using HOMA2-IR, in white European women with previous GDM. Using a cohort design, we invited women meeting IADPSG GDM criteria across four Irish antenatal centres between 2007 and 2010 to participate. Two hundred and sixty-five women with previous values meeting IADPSG criteria for GDM participated (44 % of the population eligible for participation). Mean age was 36.7 years (SD 5.0). These women were compared with a randomly selected control group of 378 women (mean age 37.6 years, SD 5.1) known to have normal glucose tolerance (NGT) in pregnancy during the same period. A total of 25.3 % of women with previous IADPSG-defined GDM met metabolic syndrome criteria, compared to 6.6 % of women with NGT [at 2.6 (SD 1.0) vs. 3.3 years (SD 0.7) post-partum]. The prevalence of HOMA2-IR >1.8 was higher in women with previous IADPSG-defined GDM (33.6 vs. 9.1 % with NGT, p Women with previous GDM by IADPSG criteria demonstrate a greater than threefold prevalence of metabolic syndrome compared to women with NGT in pregnancy. Efforts to prevent projected long-term consequences of this should focus on interventions both in the preconception and post-partum periods.

  1. Pilot study of using UAV to reveal spatial patterns of indicator bacteria concentrations in ponds and reservoirs used for irrigation

    Determination of indicator bacteria concentrations in irrigation water recently became mandatory for farmers. These concentrations are known to have large spatial variability in ponds and reservoirs. This variability is partially attributed to affinity of indicator bacteria to algae accumulations. W...

  2. Exogenous processes study in the coastal zone of the large reservoirs in the archaeological monuments placement (Volga-Kama region)

    Gaynullin, Iskander; Usmanov, Bulat


    The problem of conservation of archaeological heritage is highly relevant for the Republic of Tatarstan (RT), because in its territory identified, studied and registered around 4,300 archaeological sites. Most of archaeological sites from the Mesolithic to the late Middle Ages, now situated in the coastal zone of reservoirs where archaeological objects destroying because of intensive abrasion processes. The Volga and Kama rivers region attracted people for millennia. This territory of the Russian Plain is abounding in archaeological sites of various ages. During the Upper Paleolithic study region was quite convenient for living activity of the first inhabitants because of its situation out of the glacier limits. The sites on the banks are deposited within deluvial sediments of the Late Valday glaciation which have been accumulated on the slope of the Volga and Kama valleys, placing the third terrace and the segmentations of the second terrace over the flood-plain and now completely or fragmentary destroyed by reservoir waters. The analysis of remote sensing (1958-2013) and field survey (2011-2013) data performed. Georeferencing and alignment of the historical maps with remote sensing data makes possible to reveal mistakes in old site plans and re-create the shape of the destroyed archaeological objects, as well to get the exact size of the monument and its correct orientation. Results showed also that the studying sites caused a great rate of destruction of coastline. Cultural heritage sites monitoring, with information about the chronology, cultural layer value, settlement specifics, etc., taking into account the methods used in landscape ecology and field archaeological survey, allows to evaluate damage and the intensity of archaeological sites destruction through the dangerous exogenous processes estimation. Exogenous processes data and archaeological GIS integration will form unified system of archaeological rescue works, will provide analysis of large amount

  3. Integrating Geographical Information Systems, Fuzzy Logic and Analytical Hierarchy Process in Modelling Optimum Sites for Locating Water Reservoirs. A Case Study of the Debub District in Eritrea

    Rodney G. Tsiko


    Full Text Available The aim of this study was to model water reservoir site selection for a real world application in the administrative district of Debub, Eritrea. This is a region were scarcity of water is a fundamental problem. Erratic rainfall, drought and unfavourable hydro-geological characteristics exacerbates the region’s water supply. Consequently, the population of Debub is facing severe water shortages and building reservoirs has been promoted as a possible solution to meet the future demand of water supply. This was the most powerful motivation to identify candidate sites for locating water reservoirs. A number of conflicting qualitative and quantitative criteria exist for evaluating alternative sites. Decisions regarding criteria are often accompanied by ambiguities and vagueness. This makes fuzzy logic a more natural approach to this kind of Multi-criteria Decision Analysis (MCDA problems. This paper proposes a combined two-stage MCDA methodology. The first stage involved utilizing the most simplistic type of data aggregation techniques known as Boolean Intersection or logical AND to identify areas restricted by environmental and hydrological constraints and therefore excluded from further study. The second stage involved integrating fuzzy logic with the Analytic Hierarchy Process (AHP to identify optimum and back-up candidate water reservoir sites in the area designated for further study.

  4. Drone photogrammetry for geological research: field digital stratigraphic logs for turbiditic reservoir analog studies in Calabria, Southern Italy.

    Guillois, Maxime; Brocheray, Sandra; Paron, Paolo


    Drone technology combined with new algorithms like Structure from Motion (SfM) has revived and expanded the uses of photogrammetry bringing new flexibility and the capacity to carry on close range photogrammetry to inaccessible areas. This characteristics are particularly appealing in field geology offering the option to reconstruct continuous digital outcrop models of vertical or difficult to reach outcrops. In this light we present the results of a digital outcrop modelling of a Miocene turbiditic system (mainly sandstone) in Calabria (Southern Italy) generated through field data collected by means of a light-weight commercial drone, a detailed geological field survey and cloud point photogrammetric analyses comparing different software for this purpose (Agisoft Photoscan, Drone deploy, Arc3D). The geological model has been used as an input for preliminary reservoir modelling. We generated digital geological sections (stratigraphic logs) of 1,200 m of sections using expert digital image and terrain model interprepation from the DTM generated with drone data, with the goal to reconstruct the real thickness of each layer. We then compared the results with previously created detailed field geological cross sections. The comparison between drone-derived sections and field-survey sections shows a global accuracy of the thickness ranging between 1% to 10%. Although this new methodology still has to be validated in other morpho-lithological context it already demonstrating its usefulness for preliminary geological outcrop investigation and modelling in remote areas. We also compared the different softwares used and we made recommendations for future deployment. This research has been made possible thanks to a collaboration between UNESCO-IHE, The Netherlands, and UniLaSalle Beauvais, France.

  5. Prevention and health promotion in undergraduate medical education: Preferences, attitudes and previous knowledge of medical students - a cross-sectional study

    Klement, Andreas; Bretschneider, Kristin; Lautenschläger, Christine; Stang, Andreas; Herrmann, Markus; Haerting, Johannes


    Objective: The interdisciplinary topic "prevention and health promotion" (Q10) was introduced into the medical training in Germany by the new medical licensing regulations in 2004. For the conception of an effective curriculum, it is helpful to know student preferences concerning teaching-formats, attitudes and self-estimated previous knowledge. Little is known concerning student perception of “prevention and health promotion” in Germany. Thus, this explorative cross-sectional study aims to p...

  6. Continous controversy about radiation oncologists' choice of treatment regimens for bone metatases: should we blame doctors, canser-related features, or design of previous clinical studies

    Nieder, Carsten; Pawinski, Adam; Dalhaug, Astrid


    Recent studies from Italy, Japan and Norway have confirmed previous reports, which found that a large variety of palliative radiotherapy regimens are used for painful bone metastases. Routine use of single fraction treatment might or might not be the preferred institutional approach. It is not entirely clear why inter-physician and inter-institution differences continue to persist despite numerous randomized trials, meta-analyses and guidelines, which recommend against more costly and inconve...

  7. The impact of smoking and previous periodontal disease on peri-implant microbiota and health: a retrospective study up to 7-year follow-up.

    Quaranta, Alessandro; Assenza, Bartolomeo; D'Isidoro, Orlando; Profili, Fabia; Polimeni, Antonella; Vozza, Iole


    To evaluate the impact of smoking and previous periodontal disease on peri-implant microbiota and health in medium to long-term maintained patients. A retrospective evaluation of partial edentulous patients restored with dental implants and enrolled in a regular supportive therapy was performed. Inclusion criteria were: medium to long-term periodontal and implant maintenance (at least 5 years), a minimum of 2 implants placed in each patient, absence of systemic diseases that may affect osseointegration. 30 implants in 15 patients were included in the study. Subjects were divided in smokers or non-smokers and between patients previously affected by periodontal disease and periodontally healthy. Peri-implant and periodontal parameters were assessed (PD,BoP, mPI). Microbiological samples were collected around implant and an adjacent tooth. Real- Time Polymerase Chain Reaction (RT-PCR) analysis was performed. In all the three groups no differences in bacterial counts between dental and implant sites were observed. Non smoker, healthy patients: healthy clinical parameters, significant counts of spirochetes in isolated patients. Non smokers with previous periodontal disease: occasional positive BoP values, significant high counts of pathogenic bacteria. Smokers with previous periodontal disease: clinical signs of inflammation including deep pockets and slight bone resorption, significant counts of pathogenic bacteria. Over a follow-up of 5 to 7 years, it is possible to state that the absence of smoking habit and previous periodontal disease positively influences the peri-implant microbiological and clinical conditions in partial edentulous patients restored with dental implants and enrolled in a strict regular supportive therapy.

  8. Radioactive Sediment Transport on Ogaki Dam Reservoir in Fukushima Evacuated Zone: Numerical Simulation Studies by 2-D River Simulation Code

    Yamada, Susumu; Kitamura, Akihiro; Kurikami, Hiroshi; Machida, Masahiko


    Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on March 2011 released significant quantities of radionuclides to atmosphere. The most significant nuclide is radioactive cesium isotopes. Therefore, the movement of the cesium is one of the critical issues for the environmental assessment. Since the cesium is strongly sorbed by soil particles, the cesium transport can be regarded as the sediment transport which is mainly brought about by the aquatic system such as a river and a lake. In this research, our target is the sediment transport on Ogaki dam reservoir which is located in about 16 km northwest from FDNPP. The reservoir is one of the principal irrigation dam reservoirs in Fukushima Prefecture and its upstream river basin was heavily contaminated by radioactivity. We simulate the sediment transport on the reservoir using 2-D river simulation code named Nays2D originally developed by Shimizu et al. (The latest version of Nays2D is available as a code included in iRIC (, which is a river flow and riverbed variation analysis software package). In general, a 2-D simulation code requires a huge amount of calculation time. Therefore, we parallelize the code and execute it on a parallel computer. We examine the relationship between the behavior of the sediment transport and the height of the reservoir exit. The simulation result shows that almost all the sand that enter into the reservoir deposit close to the entrance of the reservoir for any height of the exit. The amounts of silt depositing within the reservoir slightly increase by raising the height of the exit. However, that of the clay dramatically increases. Especially, more than half of the clay deposits, if the exit is sufficiently high. These results demonstrate that the water level of the reservoir has a strong influence on the amount of the clay discharged from the reservoir. As a result, we conclude that the tuning of the water level has a possibility for controlling the

  9. Role of previous hospitalization in clinically-significant MRSA infection among HIV-infected inpatients: results of a case-control study

    Festa Anna


    Full Text Available Abstract Background HIV-infected subjects have high incidence rates of Staphylococcus aureus infections, with both methicillin-susceptible and methicillin-resistant (MRSA strains. Possible explanations could include the high burden of colonization, the behavioral risk factors, and the frequent exposures to health care facilities of HIV-infected patients. The purpose of the study was to assess the risk factors for clinically- significant methicillin-resistant Staphylococcus aureus (CS-MRSA infections in HIV-infected patients admitted to Infectious Diseases Units. Methods From January 1, 2002 to December 31, 2005, we conducted a retrospective case-control (1:2 study. We identified all the cases of CS-MRSA infections in HIV-infected patients admitted to the National Institute for Infectious Diseases (INMI "Lazzaro Spallanzani" in the 4-year study period. A conditional logistic regression model was used to identify risk factors for CS-MRSA infection. Results We found 27 CS-MRSA infections, i.e. 0.9 CS-MRSA infections per 100 HIV-infected individuals cared for in our Institute. At multivariate analysis, independent predictors of CS-MRSA infection were cumulative hospital stay, invasive procedures in the previous year, and low CD4 cell count. Particularly, the risk for CS-MRSA increased by 14% per an increase of 5 days hospitalization in the previous year. Finally, we identified a low frequency of community-acquired MRSA infections (only 1 of 27; 3.7% among HIV-infected patients. Conclusion Clinicians should be aware of the risk for CS-MRSA infection in the clinical management of HIV-infected patients, especially in those patients with a low CD4 cell count, longer previous hospital stay, and previous invasive procedures.

  10. Role of previous hospitalization in clinically-significant MRSA infection among HIV-infected inpatients: results of a case-control study

    Drapeau, Cecilia MJ; Angeletti, Claudio; Festa, Anna; Petrosillo, Nicola


    Background HIV-infected subjects have high incidence rates of Staphylococcus aureus infections, with both methicillin-susceptible and methicillin-resistant (MRSA) strains. Possible explanations could include the high burden of colonization, the behavioral risk factors, and the frequent exposures to health care facilities of HIV-infected patients. The purpose of the study was to assess the risk factors for clinically- significant methicillin-resistant Staphylococcus aureus (CS-MRSA) infections in HIV-infected patients admitted to Infectious Diseases Units. Methods From January 1, 2002 to December 31, 2005, we conducted a retrospective case-control (1:2) study. We identified all the cases of CS-MRSA infections in HIV-infected patients admitted to the National Institute for Infectious Diseases (INMI) "Lazzaro Spallanzani" in the 4-year study period. A conditional logistic regression model was used to identify risk factors for CS-MRSA infection. Results We found 27 CS-MRSA infections, i.e. 0.9 CS-MRSA infections per 100 HIV-infected individuals cared for in our Institute. At multivariate analysis, independent predictors of CS-MRSA infection were cumulative hospital stay, invasive procedures in the previous year, and low CD4 cell count. Particularly, the risk for CS-MRSA increased by 14% per an increase of 5 days hospitalization in the previous year. Finally, we identified a low frequency of community-acquired MRSA infections (only 1 of 27; 3.7%) among HIV-infected patients. Conclusion Clinicians should be aware of the risk for CS-MRSA infection in the clinical management of HIV-infected patients, especially in those patients with a low CD4 cell count, longer previous hospital stay, and previous invasive procedures. PMID:17470274

  11. Large spatial variations in coastal 14C reservoir age – a case study from the Baltic Sea

    B. C. Lougheed


    Full Text Available Coastal locations are highly influenced by input from freshwater river runoff, including sources of terrestrial carbon, which can be expected to modify the 14C reservoir age, or R (t, associated with marine water. In this Baltic Sea case study, pre-bomb museum collection mollusc shells of known calendar age, from 30 locations across a strategic salinity transect of the Baltic Sea, were analysed for 14C, δ13C and δ18O. R (t was calculated for all 30 locations. Seven locations, of which six are within close proximity of the coast, were found to have relatively higher R (t values, indicative of hard-water effects. Whenever possible, the Macoma genus of mollusc was selected from the museum collections, in order to exclude species specific reservoir age effects as much as possible. When the Macoma samples are exclusively considered, and samples from hard-water locations excluded, a statistically significant correlation between Macoma R (t and average salinity is found, indicating a two end-member linear mixing model between 14Cmarine and 14Crunoff. A map of Baltic Sea Macoma aragonite R (t for the late 19th and early 20th centuries is produced. Such a map can provide an estimate for contemporary Baltic Sea Macoma R (t, although one must exercise caution when applying such estimates back in time or to 14C dates obtained from different sample material. A statistically significant correlation is found between δ18Oaragonite and Macoma R (t, suggesting that δ18Oaragonite can be used to estimate Macoma palaeo-R (t, due to the δ18Oaragonite signal being dominated by the salinity gradient of the Baltic Sea. A slightly increased correlation can be expected when δ18Oaragonite is corrected for temperature fractionation effects. The results of this Baltic Sea case study, which show that R (t is affected by hydrographic conditions and local carbon inputs, have important consequences for other coastal and estuarine locations, where R (t is also likely to

  12. Surface-water and suspended-sediment inflow and outflow for Nutria Reservoir No 3, Zuni Indian Reservation, New Mexico, March 1994 to September 1995

    Gellis, A.C.


    Surface-water and suspended-sediment inflow to and outflow from Nutria Reservoir No. 3 on the Zuni Indian Reservation, western New Mexico, were calculated. The period of study was March 3, 1994, to September 30, 1995. Total runoff into Nutria Reservoir No. 3 during the study period was 6,812 acre-feet. During the study period, 24,310 tons of suspended sediment was transported into Nutria Reservoir No. 3, and 259 tons of suspended sediment was transported out of Nutria Reservoir No. 3. Runoff during the study period, recorded at an upstream gage with 25 years of record, was 137 percent higher than that for a 19-month period similar to the study period. This may indicate that suspended-sediment loads transported into Nutria Reservoir No. 3 also were larger than average. Based on the difference between inflow and outflow of suspended sediment, 24,050 tons of suspended sediment was deposited in Nutria Reservoir No. 3. From March 1994 to May 1994 the spillway elevation of Nutria Reservoir No. 3 was raised to allow water to be diverted into an adjacent reservoir, Nutria Reservoir No. 4. This flow and sediment transported into Nutria Reservoir No. 4 were not recorded. If the elevation of the spillway had not been raised, suspended- sediment loads recorded downstream from Nutria Reservoir No. 3 would have been larger and the calculated amount of sediment deposited in Nutria Reservoir would have been smaller. Of the total suspended-sediment load entering Nutria Reservoir No. 3 during the study period, 94 percent was transported by an arroyo, Garcia Draw. Garcia Draw drains only 15 percent of the total drainage area of Nutria Reservoir No. 3 and contributed less than 5 percent of the total surface runoff to the reservoir. The average annual amount of sediment deposited in Nutria Reservoir No. 3 during the study was 15,355 tons. By using a dry-weight density of 99.4 pounds per cubic foot for the deposited sediment, the annual volume of sediment deposited in Nutria Reservoir

  13. Soil erosion and sediment fluxes analysis: a watershed study of the Ni Reservoir, Spotsylvania County, VA, USA.

    Pope, Ian C; Odhiambo, Ben K


    Anthropogenic forces that alter the physical landscape are known to cause significant soil erosion, which has negative impact on surface water bodies, such as rivers, lakes/reservoirs, and coastal zones, and thus sediment control has become one of the central aspects of catchment management planning. The revised universal soil loss equation empirical model, erosion pins, and isotopic sediment core analyses were used to evaluate watershed erosion, stream bank erosion, and reservoir sediment accumulation rates for Ni Reservoir, in central Virginia. Land-use and land cover seems to be dominant control in watershed soil erosion, with barren land and human-disturbed areas contributing the most sediment, and forest and herbaceous areas contributing the least. Results show a 7 % increase in human development from 2001 (14 %) to 2009 (21.6 %), corresponding to an increase in soil loss of 0.82 Mg ha(-1) year(-1) in the same time period. (210)Pb-based sediment accumulation rates at three locations in Ni Reservoir were 1.020, 0.364, and 0.543 g cm(-2) year(-1) respectively, indicating that sediment accumulation and distribution in the reservoir is influenced by reservoir configuration and significant contributions from bedload. All three locations indicate an increase in modern sediment accumulation rates. Erosion pin results show variability in stream bank erosion with values ranging from 4.7 to 11.3 cm year(-1). These results indicate that urban growth and the decline in vegetative cover has increased sediment fluxes from the watershed and poses a significant threat to the long-term sustainability of the Ni Reservoir as urbanization continues to increase.

  14. Understanding the True Strimulated Reservoir Volume in Shale Reservoirs

    Hussain, Maaruf


    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically-induced fractures that connect the wellbore to a larger fracture surface area within the reservoir rock volume. Thus, accurate estimation of the stimulated reservoir volume (SRV) becomes critical for the reservoir performance simulation and production analysis. Micro-seismic events (MS) have been commonly used as a proxy to map out the SRV geometry, which could be erroneous because not all MS events are related to hydraulic fracture propagation. The case studies discussed here utilized a fully 3-D simulation approach to estimate the SRV. The simulation approach presented in this paper takes into account the real-time changes in the reservoir\\'s geomechanics as a function of fluid pressures. It is consisted of four separate coupled modules: geomechanics, hydrodynamics, a geomechanical joint model for interfacial resolution, and an adaptive re-meshing. Reservoir stress condition, rock mechanical properties, and injected fluid pressure dictate how fracture elements could open or slide. Critical stress intensity factor was used as a fracture criterion governing the generation of new fractures or propagation of existing fractures and their directions. Our simulations were run on a Cray XC-40 HPC system. The studies outcomes proved the approach of using MS data as a proxy for SRV to be significantly flawed. Many of the observed stimulated natural fractures are stress related and very few that are closer to the injection field are connected. The situation is worsened in a highly laminated shale reservoir as the hydraulic fracture propagation is significantly hampered. High contrast in the in-situ stresses related strike-slip developed thereby shortens the extent of SRV. However, far field nature fractures that were not connected to

  15. How to update design floods after the construction of small reservoirs and check dams: A case study from the Daqinghe river basin, China

    Jianzhu Li; Huafeng Sun; Ping Feng


    Several small reservoirs and a large number of check dams had been constructed in theWangkuai reservoirwatershed after 1970s, and flood time series lacked stationarity, which affected the original design floodhydrographs for the Wangkuai reservoir. Since the location, storage capacity and drainage area of thelarge number of check dams were unknown, we present a method to estimate their total storage capacities(TSC) and total drainage areas (TDA) by using the recorded rainstorm and flood data. On the basisof TSC and TDA, the flood events which occurred in an undisturbed period were reconstructed undercurrent conditions to obtain a stationary flood series. A frequency analysis was subsequently performedto assess the design flood peak and volume for both small and medium design floods with a 10–200year return period. For large and catastrophic floods, it was assumed that the upstream check dams andsmall reservoirs would be destroyed, and water stored in these hydraulic structures were re-routed to theWangkuai reservoir by unit hydrograph. The modified flood peak and volume decreased for floods witha 10–200 year return period when compared to the current design flood. But for large design floods witha return period exceeding 500 years, peak discharge increased. This study provides a new method fordesign flood calculation or modification of the original design flood in watersheds with a large numberof check dams.

  16. Formation of abnormal high pressure and its application in the study of oil-bearing property of lithologic hydrocarbon reservoirs in the Dongying Sag

    ZHANG ShanWen; ZHANG LinYe; ZHANG ShouChun; LIU Qing; ZHU RiFang; BAO YouShu


    The mechanisms of abnormal high pressures are studied in this paper, and it is concluded that the undercompaction, hydrocarbon generation and stratum denudation are obviously effective to fluid pressure buildup. Because of the episodic difference, the hydrocarbon generation and stratum denu-dation are the main factors influencing oil-gas migration. On the basis of basin evolutionary analysis in the Dongying Sag, it is considered that the undercompaction mainly caused the abnormal pressure before the first denudation by the uplift in Late Paleogene, while hydrocarbon generation was the main factor of abnormal pressure after the denudation. The second denudation occurred in Late Neogene, which changed the pressure field and induced the fluid migration. The development of overpressures is the necessary condition to the formation of lithologic hydrocarbon reservoirs, which have positive correlations to overpressures. According to the fullness of the present reservoirs, the quantitative re-lations between oil-bearing property and driving forces of reservoir formation were determined, the latter were decided by dynamic source, reservoir capillary pressure, fluid pressure of surrounding rocks and the dynamic attenuation in different conducting systems.

  17. A method for the assessment of long-term changes in carbon stock by construction of a hydropower reservoir.

    Bernardo, Julio Werner Yoshioka; Mannich, Michael; Hilgert, Stephan; Fernandes, Cristovão Vicente Scapulatempo; Bleninger, Tobias


    Sustainability of hydropower reservoirs has been questioned since the detection of their greenhouse gas (GHG) emissions which are mainly composed of carbon dioxide and methane. A method to assess the impact on the carbon cycle caused by the transition from a natural river system into a reservoir is presented and discussed. The method evaluates the long term changes in carbon stock instead of the current approach of monitoring and integrating continuous short term fluxes. A case study was conducted in a subtropical reservoir in Brazil, showing that the carbon content within the reservoir exceeds that of the previous landuse. The average carbon sequestration over 43 years since damming was 895 mg C m[Formula: see text] and found to be mainly due to storage of carbon in sediments. These results demonstrate that reservoirs have two opposite effects on the balance of GHGs. By storing organic C in sediments, reservoirs are an important carbon sink. On the other hand, reservoirs increase the flux of methane into the atmosphere. If the sediments of reservoirs could be used for long term C storage, reservoirs might have a positive effect on the balance of GHGs.

  18. Large reservoirs: Chapter 17

    Miranda, Leandro E.; Bettoli, Phillip William


    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

  19. Modeling of fault activation and seismicity by injection directly into a fault zone associated with hydraulic fracturing of shale-gas reservoirs

    LBNL, in consultation with the EPA, expanded upon a previous study by injecting directly into a 3D representation of a hypothetical fault zone located in the geologic units between the shale-gas reservoir and the drinking water aquifer.

  20. Compensation for Land Loss in Reservoir Resettlement: A Case Study of The Three Gorges Project, China

    Wang Yi-qian; Tan Yan


    This paper studies current policies in compensation for land lost due to construction of the Three Gorges project (TGP), China. In the case study of Kaixian County, the value of land in the peri-urban areas is underestimated. Some losses in land are tangible and thus measurable, but some losses are intangible and thus immeasurable. The land available in the resettlement areas is scarce and rarely of equivalent quality. This study suggests that the loss of agricultural land be compensated with alternative land and/or non-land-based livelihood strategies, including part compensation in monetary terms and preferential policies.

  1. Compensation for Land Loss in Reservoir Resettlement: A Case Study of The Three Gorges Project, China

    WangYi-qian; TanYan


    This paper studies current policies in compensation for land lost due to construction of the Three Gorges project (TGP), China. In the case study of Kaixian County, the value of land in the peri-urban areas is underestimated. Some losses in land are tangible and thus measurable, but some losses are intangible and thus immeasurable. The land available in the resettlement areas is scarce and rarely of equivalent quality. This study suggests that the loss of agricultural land be compensated with alternative land and/or non-land-based livelihood strategies, including part compensation in monetary terms and preferential policies.

  2. Phase II study of capecitabine as palliative treatment for patients with recurrent and metastatic squamous head and neck cancer after previous platinum-based treatment

    Martinez-Trufero, J; Isla, D; Adansa, J C; Irigoyen, A; Hitt, R; Gil-Arnaiz, I; Lambea, J; Lecumberri, M J; Cruz, J J


    Background: Platinum-based therapy (PBT) is the standard therapy for recurrent and/or metastatic head and neck cancer (HNC), but the incidence of recurrence remains high. This study evaluates the efficacy and tolerability of capecitabine as palliative monotherapy for recurrent HNC previously treated with PBT. Methods: Patients aged 18–75 years, with Eastern Cooperative Oncology Group performance status 0–2, squamous HNC with locoregional and/or metastatic recurrence previously treated with PBT and adequate organ functions, were included. Capecitabine (1.250 mg m−2 BID) was administered on days 1–14 every 21 days for at least two cycles. Results: A total of 40 male patients with a median age of 58 years were analysed. All patients received a median number of four cycles of capecitabine (range: 1–9) and the median relative dose intensity was 91%. Seven patients were not evaluable for response. Overall response rate was 24.2%. Median time to progression and overall survival were 4.8 and 7.3 months, respectively. Haematological adverse events (AEs) grade 3/4 were reported in six patients. Most common grade 3/4 non-haematological AEs were asthenia (12.5%), palmar-plantar eritrodisestesia (10%), mucositis (10%), dysphagia (10%) and diarrhoea (7.5%). Conclusions: Capecitabine seems to be an active, feasible and well-tolerated mode of palliative treatment for advanced HNC patients who have previously received PBT schedules. PMID:20485287

  3. Deriving Design Flood Hydrograph Based on Conditional Distribution: A Case Study of Danjiangkou Reservoir in Hanjiang Basin

    Changjiang Xu


    Full Text Available Design flood hydrograph (DFH for a dam is the flood of suitable probability and magnitude adopted to ensure safety of the dam in accordance with appropriate design standards. Estimated quantiles of peak discharge and flood volumes are necessary for deriving the DFH, which are mutually correlated and need to be described by multivariate analysis methods. The joint probability distributions of peak discharge and flood volumes were established using copula functions. Then the general formulae of conditional most likely composition (CMLC and conditional expectation composition (CEC methods that consider the inherent relationship between flood peak and volumes were derived for estimating DFH. The Danjiangkou reservoir in Hanjiang basin was selected as a case study. The design values of flood volumes and 90% confidence intervals with different peak discharges were estimated by the proposed methods. The performance of CMLC and CEC methods was also compared with conventional flood frequency analysis, and the results show that CMLC method performs best for both bivariate and trivariate distributions which has the smallest relative error and root mean square error. The proposed CMLC method has strong statistical basis with unique design flood composition scheme and provides an alternative way for deriving DFH.

  4. Risk for High Depressive Symptoms in Diagnosed and Previously Undetected Diabetes: 5-Year Follow-Up Results of the Heinz Nixdorf Recall Study

    Icks, Andrea; Albers, Bernd; Haastert, Burkhard; Pechlivanis, Sonali; Pundt, Noreen; Slomiany, Uta; Erbel, Raimund; Jöckel, Karl-Heinz; Kruse, Johannes; Kulzer, Bernd; Nowotny, Bettina; Herder, Christian; Giani, Guido; Moebus, Susanne


    Objective The objective of this study was to determine the risk for the development of high depressive symptoms in study participants with diagnosed and previously undetected diabetes mellitus compared to those without diabetes in a prospective population-based cohort study in Germany. Methods We estimated the 5-year cumulative incidence of high depressive symptoms in participants without high depressive symptoms at baseline (n = 3,633, 51.4% men, mean age (SD) 59.1 (7.6) years, 7.0% diagnosed diabetes, 5.3% previously undetected diabetes) from the population-based Heinz Nixdorf Recall study. Diabetes was assessed by self-report, medication, and blood glucose. High depressive symptoms were assessed using CES-D. We calculated odds ratios and their corresponding 95% confidence interval, using multiple logistic regression analyses. Result Cumulative 5-year incidences (95% CI) of high depressive symptoms in participants with diagnosed, undetected, and without diabetes were 7.1 (4.2–10.9), 4.1 (1.8–8.0), and 6.5 (5.6–7.4), respectively. The age-sex-adjusted OR for developing high depressive symptoms was 1.22 (0.74–2.03) in participants with diagnosed compared to those without diabetes, and 1.00 (0.59–1.68) after adjustment for BMI, physical activity, education, stroke, and myocardial infarction. The age-sex adjusted OR for developing high depressive symptoms in participants with previously undetected diabetes compared to those without diabetes was 0.72; 0.35–1.48; and fully adjusted 0.62; 0.30–1.30. Conclusion We found no significant associations, maybe due to low power. However, our results are in line with a recent meta-analysis suggesting that risk of developing high depressive symptoms in patients with diagnosed diabetes may be moderately higher than in those without diabetes, and that comorbidity may explain in part this association. In participants with previously undetected diabetes, this first longitudinal study indicates that the risk is not

  5. Risk for high depressive symptoms in diagnosed and previously undetected diabetes: 5-year follow-up results of the Heinz Nixdorf Recall study.

    Andrea Icks

    Full Text Available OBJECTIVE: The objective of this study was to determine the risk for the development of high depressive symptoms in study participants with diagnosed and previously undetected diabetes mellitus compared to those without diabetes in a prospective population-based cohort study in Germany. METHODS: We estimated the 5-year cumulative incidence of high depressive symptoms in participants without high depressive symptoms at baseline (n = 3,633, 51.4% men, mean age (SD 59.1 (7.6 years, 7.0% diagnosed diabetes, 5.3% previously undetected diabetes from the population-based Heinz Nixdorf Recall study. Diabetes was assessed by self-report, medication, and blood glucose. High depressive symptoms were assessed using CES-D. We calculated odds ratios and their corresponding 95% confidence interval, using multiple logistic regression analyses. RESULT: Cumulative 5-year incidences (95% CI of high depressive symptoms in participants with diagnosed, undetected, and without diabetes were 7.1 (4.2-10.9, 4.1 (1.8-8.0, and 6.5 (5.6-7.4, respectively. The age-sex-adjusted OR for developing high depressive symptoms was 1.22 (0.74-2.03 in participants with diagnosed compared to those without diabetes, and 1.00 (0.59-1.68 after adjustment for BMI, physical activity, education, stroke, and myocardial infarction. The age-sex adjusted OR for developing high depressive symptoms in participants with previously undetected diabetes compared to those without diabetes was 0.72; 0.35-1.48; and fully adjusted 0.62; 0.30-1.30. CONCLUSION: We found no significant associations, maybe due to low power. However, our results are in line with a recent meta-analysis suggesting that risk of developing high depressive symptoms in patients with diagnosed diabetes may be moderately higher than in those without diabetes, and that comorbidity may explain in part this association. In participants with previously undetected diabetes, this first longitudinal study indicates that the risk is not

  6. Improved reservoir exploitation

    Thomassen, P.R. [IKU Petroleumsforskning A/S, Trondheim (Norway)


    This paper deals with reservoir exploitation and it highlights some ideas on how to improve exploitive skills to optimise the recovery of a field. The author looks closer at what needs to be done to optimise the reservoir data and the exploitation tools, and what are the needs of the reservoir production management. 2 refs., 3 figs.

  7. Evaluating the Implications of Climate Phenomenon Indices in Supporting Reservoir Operation Using the Artificial Neural Network and Decision-Tree Methods: A Case Study on Trinity Lake in Northern California

    Yang, T.; Akbari Asanjan, A.; Gao, X.; Sorooshian, S.


    Reservoirs are fundamental human-built infrastructures that collect, store, and deliver fresh surface water in a timely manner for all kinds of purposes, including residential and industrial water supply, flood control, hydropower, and irrigation, etc. Efficient reservoir operation requires that policy makers and operators understand how reservoir inflows, available storage, and discharges are changing under different climatic conditions. Over the last decade, the uses of Artificial Intelligence and Data Mining (AI & DM) techniques in assisting reservoir management and seasonal forecasts have been increasing. Therefore, in this study, two distinct AI & DM methods, Artificial Neural Network (ANN) and Random Forest (RF), are employed and compared with respect to their capabilities of predicting monthly reservoir inflow, managing storage, and scheduling reservoir releases. A case study on Trinity Lake in northern California is conducted using long-term (over 50 years) reservoir operation records and 17 known climate phenomenon indices, i.e. PDO and ENSO, etc., as predictors. Results show that (1) both ANN and RF are capable of providing reasonable monthly reservoir storage, inflow, and outflow prediction with satisfactory statistics, and (2) climate phenomenon indices are useful in assisting monthly or seasonal forecasts of reservoir inflow and outflow. It is also found that reservoir storage has a consistent high autocorrelation effect, while inflow and outflow are more likely to be influenced by climate conditions. Using a Gini diversity index, RF method identifies that the reservoir discharges are associated with Southern Oscillation Index (SOI) and reservoir inflows are influenced by multiple climate phenomenon indices during different seasons. Furthermore, results also show that, during the winter season, reservoir discharges are controlled by the storage level for flood-control purposes, while, during the summer season, the flood-control operation is not as

  8. Marine Vibrionaceae as a reservoir for bioprospecting and ecology studies

    Giubergia, Sonia

    The exploration of biodiversity (“bioprospecting”) provides mankind with an immense pool of novel organisms, molecules and information, which can be exploited for the development of innovative biotechnological processes and new ways to treat diseases. In the past decades, the marine environment...... environment. Studying microbial eco-physiology is important not only for the development of ecological models, but also as foundation for bioprospecting studies, where this knowledge may be used, for example, to elicit silent biosynthetic gene clusters during natural product discovery....


    M. H. Nazarifar


    previous history of annual water entrance during the past and present years(40 years. The algorithm developed covers both, the overflow and non-overflow conditions in the reservoir. Result of this study shows that in non-overflow conditions the most exigency case is equal to 75%. This means that, if the reservoir is empty (the stored water is less than 100 MCM this year, it would be also empty by 75% next year. The stored water in the reservoir would be less than 300 MCM by 85% next year if the reservoir is empty this year. This percentage decreases to 70% next year if the water of reservoir is less than 300 MCM this year. The percentage also decreases to 5% next year if the reservoir is full this year. In overflow conditions the most exigency case is equal to 75% again. The reservoir volume would be less than 150 MCM by 90% next year, if it is empty this year. This percentage decreases to 70% if its water volume is less than 300 MCM and 55% if the water volume is less than 500 MCM this year. Result shows that too, if the probability matrix of water rates to a reservoir is multiplied by itself repeatedly; it converges to a constant probability matrix, which could be used to predict the long-term water rate of the reservoir. In other words, the probability matrix of series of water rates is changed to a steady probability matrix in the course of time, which could reflect the hydrological behavior of the watershed and could be easily used for the long-term prediction of water storage in the down stream reservoirs.

  10. Study on Productivity Numerical Simulation of Highly Deviated and Fractured Wells in Deep Oil and Gas Reservoirs

    Li Liangchuan


    Full Text Available This paper establishes the model of sandstone, porosity and permeability on single well in allusion to 10 highly deviated and fractured wells in deep oil and gas reservoirs of Jidong Oilfield, which forms a numerical simulation method of highly deviated and fractured wells in deep oil and gas reservoirs of Jidong Oilfield. The numerical simulation results of highly deviated and fractured wells productivity in deep oil and gas reservoirs are given out under different layers (layer ES1, layer ES3, layer ED2,and layer ED3, different deviation angles(60° and 75°, different fracture parameters and producing pressure drops. Through the comparison with testing data getting from exploration wells, we know that the calculation results of numerical simulation are consistent with practical testing results.

  11. A Study on the Reservoir Capacity to Control Mud Flood Derived from Mud Volcano: A Phenomenon in Sidoarjo

    Sholihin Sholihin


    Full Text Available This paper is an extended research of Coastal Zone Management of Sidoarjo mud phenomenon. The idea is to find special concept of management to control mud flood using reservoir system. This method, in the mud fluid, is intentionally used to make separation of the solid materials from water. The concept is to calculate sediment velocity in order to find the time of sedimentation then to estimate the volume of mud. Therefore, the reservoir will be determined from this calculation. The result of this research is the dimension of the reservoir: area of 3,704,144.36 m2, the depth of 5.94 m, and the volume 22.018.856.07 m3. The time of sedimentation is calculated of 28.33 hours for 42.2 % of material volume sedimentation. Consequently, the suspension material is 57.8 %. The correction of calculation is depending on the calculation of the velocity of sedimentation, about 2 %.

  12. Improving Geologic and Engineering Models of Midcontinent Fracture and Karst-Modified Reservoirs Using New 3-D Seismic Attributes

    Susan Nissen; Saibal Bhattacharya; W. Lynn Watney; John Doveton


    Our project goal was to develop innovative seismic-based workflows for the incremental recovery of oil from karst-modified reservoirs within the onshore continental United States. Specific project objectives were: (1) to calibrate new multi-trace seismic attributes (volumetric curvature, in particular) for improved imaging of karst-modified reservoirs, (2) to develop attribute-based, cost-effective workflows to better characterize karst-modified carbonate reservoirs and fracture systems, and (3) to improve accuracy and predictiveness of resulting geomodels and reservoir simulations. In order to develop our workflows and validate our techniques, we conducted integrated studies of five karst-modified reservoirs in west Texas, Colorado, and Kansas. Our studies show that 3-D seismic volumetric curvature attributes have the ability to re-veal previously unknown features or provide enhanced visibility of karst and fracture features compared with other seismic analysis methods. Using these attributes, we recognize collapse features, solution-enlarged fractures, and geomorphologies that appear to be related to mature, cockpit landscapes. In four of our reservoir studies, volumetric curvature attributes appear to delineate reservoir compartment boundaries that impact production. The presence of these compartment boundaries was corroborated by reservoir simulations in two of the study areas. Based on our study results, we conclude that volumetric curvature attributes are valuable tools for mapping compartment boundaries in fracture- and karst-modified reservoirs, and we propose a best practices workflow for incorporating these attributes into reservoir characterization. When properly calibrated with geological and production data, these attributes can be used to predict the locations and sizes of undrained reservoir compartments. Technology transfer of our project work has been accomplished through presentations at professional society meetings, peer-reviewed publications

  13. Shallow landslide susceptibility model for the Oria river basin, Gipuzkoa province (North of Spain). Application of the logistic regression and comparison with previous studies.

    Bornaetxea, Txomin; Antigüedad, Iñaki; Ormaetxea, Orbange


    In the Oria river basin (885 km2) shallow landslides are very frequent and they produce several roadblocks and damage in the infrastructure and properties, causing big economic loss every year. Considering that the zonification of the territory in different landslide susceptibility levels provides a useful tool for the territorial planning and natural risk management, this study has the objective of identifying the most prone landslide places applying an objective and reproducible methodology. To do so, a quantitative multivariate methodology, the logistic regression, has been used. Fieldwork landslide points and randomly selected stable points have been used along with Lithology, Land Use, Distance to the transport infrastructure, Altitude, Senoidal Slope and Normalized Difference Vegetation Index (NDVI) independent variables to carry out a landslide susceptibility map. The model has been validated by the prediction and success rate curves and their corresponding area under the curve (AUC). In addition, the result has been compared to those from two landslide susceptibility models, covering the study area previously applied in different scales, such as ELSUS1000 version 1 (2013) and Landslide Susceptibility Map of Gipuzkoa (2007). Validation results show an excellent prediction capacity of the proposed model (AUC 0,962), and comparisons highlight big differences with previous studies.

  14. Food intake during the previous 24 h as a percentage of usual intake: a marker of hypoxia in infants with bronchiolitis: an observational, prospective, multicenter study

    Corrard François


    Full Text Available Abstract Background Hypoxia associated with bronchiolitis is not always easy to assess on clinical grounds alone. The aim of this study was to determine the value of food intake during the previous 24 hours (bottle and spoon feeding, as a percentage of usual intake (24h FI, as a marker of hypoxia, and to compare its diagnostic value with that of usual clinical signs. Methods In this observational, prospective, multicenter study, 18 community pediatricians, enrolled 171 infants, aged from 0 to 6 months, with bronchiolitis (rhinorrhea + dyspnea + cough + expiratory sounds. Infants with risk factors (history of prematurity, chronic heart or lung disorders, breast-fed infants, and infants having previously been treated for bronchial disorders were excluded. The 24h FI, subcostal, intercostal, supracostal retractions, nasal flaring, respiratory rate, pauses, cyanosis, rectal temperature and respiratory syncytial virus test results were noted. The highest stable value of transcutaneous oxygen saturation (SpO2 was recorded. Hypoxia was noted if SpO2 was below 95% and verified. Results 24h FI ≥ 50% was associated with a 96% likelihood of SpO2 ≥ 95% [95% CI, 91–99]. In univariate analysis, 24h FI  Conclusion In practice, the measure of 24 h FI may be useful in identifying hypoxia and deserves further study.

  15. Study to determine the feasibility of obtaining true samples of oil and gas reservoirs. Final report

    Ward, C.E.; Sinclair, A.R.


    The study concludes that a feasible solution is possible which would provide up to about 90 percent information accuracy under many operating conditions, well within the economic range for most oil and gas operations. The study also concludes that there is potential feasibility for the development of systems to approach 100 percent information accuracy under many operating situations. However, the cost of such a system is far beyond those considered practical within the economics of the competitive oil and gas industry. The justification of such a system has been likened to that of a ''moon shot'' approach and would take several years of development before true feasibility and probability of success could be assessed.

  16. Qualitative simulation of bathymetric changes due to reservoir sedimentation: A Japanese case study.

    Bilal, Ahmed; Dai, Wenhong; Larson, Magnus; Beebo, Qaid Naamo; Xie, Qiancheng


    Sediment-dynamics modeling is a useful tool for estimating a dam's lifespan and its cost-benefit analysis. Collecting real data for sediment-dynamics analysis from conventional field survey methods is both tedious and expensive. Therefore, for most rivers, the historical record of data is either missing or not very detailed. Available data and existing tools have much potential and may be used for qualitative prediction of future bathymetric change trend. This study shows that proxy approaches may be used to increase the spatiotemporal resolution of flow data, and hypothesize the river cross-sections and sediment data. Sediment-dynamics analysis of the reach of the Tenryu River upstream of Sakuma Dam in Japan was performed to predict its future bathymetric changes using a 1D numerical model (HEC-RAS). In this case study, only annually-averaged flow data and the river's longitudinal bed profile at 5-year intervals were available. Therefore, the other required data, including river cross-section and geometry and sediment inflow grain sizes, had to be hypothesized or assimilated indirectly. The model yielded a good qualitative agreement, with an R2 (coefficient of determination) of 0.8 for the observed and simulated bed profiles. A predictive simulation demonstrated that the useful life of the dam would end after the year 2035 (±5 years), which is in conformity with initial detailed estimates. The study indicates that a sediment-dynamic analysis can be performed even with a limited amount of data. However, such studies may only assess the qualitative trends of sediment dynamics.

  17. An Integrated Study of the Grayburg/San Andres Reservoir, Foster and South Cowden Fields, Ector County, Texas, Class II

    Trentham, Robert C.; Weinbrandt, Richard; Robinson, William C.; Widner, Kevin


    The objectives of the project were to: (1) Thoroughly understand the 60-year history of the field. (2) Develop a reservoir description using geology and 3D seismic. (3) Isolate the upper Grayburg in wells producing from multiple intervals to stop cross flow. (4) Re-align and optimize the upper Grayburg waterflood. (5) Determine well condition, identify re-frac candidates, evaluate the effectiveness of well work and obtain bottom hole pressure data for simulation utilizing pressure transient testing field wide. (6) Quantitatively integrate all the data to guide the field operations, including identification of new well locations utilizing reservoir simulation.

  18. Experimental and molecular modeling study of the three-phase behavior of (n-decane + carbon dioxide + Water) at reservoir conditions

    E. Forte; Galindo, A.; Trusler, JPM


    Knowledge of the phase behavior of mixtures of oil with carbon dioxide and water is essential for reservoir engineering, especially in the processes of enhanced oil recovery and geological storage of carbon dioxide. However, for a comprehensive understanding, the study of simpler systems needs to be completed. In this work the system (n-decane + carbon dioxide + water) was studied as a model (oil + carbon dioxide + water) mixture. To accomplish our aim, a new analytical apparatus to measure p...

  19. Study on temperature distribution along wellbore of fracturing horizontal wells in oil reservoir

    Junjun Cai


    Full Text Available The application of distributed temperature sensors (DTS to monitor producing zones of horizontal well through a real-time measurement of a temperature profile is becoming increasingly popular. Those parameters, such as flow rate along wellbore, well completion method, skin factor, are potentially related to the information from DTS. Based on mass-, momentum-, and energy-balance equations, this paper established a coupled model to study on temperature distribution along wellbore of fracturing horizontal wells by considering skin factor in order to predict wellbore temperature distribution and analyze the factors influencing the wellbore temperature profile. The models presented in this paper account for heat convective, fluid expansion, heat conduction, and viscous dissipative heating. Arriving temperature and wellbore temperature curves are plotted by computer iterative calculation. The non-perforated and perforated sections show different temperature distribution along wellbore. Through the study on the sensitivity analysis of skin factor and flow rate, we come to the conclusion that the higher skin factor generates larger temperature increase near the wellbore, besides, temperature along wellbore is related to both skin factors and flow rate. Temperature response type curves show that the larger skin factor we set, the less temperature augmenter from toe to heel could be. In addition, larger flow rate may generate higher wellbore temperature.

  20. Status of Wheeler Reservoir


    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.

  1. Status of Cherokee Reservoir


    This is the first in a series of reports prepared by Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overviews of Cherokee Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports, publications, and data available, and interviews with water resource professionals in various Federal, state, and local agencies and in public and private water supply and wastewater treatment facilities. 11 refs., 4 figs., 1 tab.

  2. Status of Cherokee Reservoir


    This is the first in a series of reports prepared by Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overviews of Cherokee Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports, publications, and data available, and interviews with water resource professionals in various Federal, state, and local agencies and in public and private water supply and wastewater treatment facilities. 11 refs., 4 figs., 1 tab.

  3. Geochemical monitoring using noble gases and carbon isotopes: study of a natural reservoir; Monitoring geochimique par couplage entre les gaz rares et les isotopes du carbone: etude d'un reservoir naturel

    Jeandel, E


    To limit emissions of greenhouse gases in the atmosphere, CO{sub 2} geological sequestration appears as a solution in the fight against climate change. The development of reliable monitoring tools to ensure the sustainability and the safety of geological storage is a prerequisite for the implementation of such sites. In this framework, a geochemical method using noble gas and carbon isotopes geochemistry has been tested on natural and industrial analogues. The study of natural analogues from different geological settings showed systematic behaviours of the geochemical parameters, depending on the containment sites, and proving the effectiveness of these tools in terms of leak detection and as tracers of the behaviour of CO{sub 2}. Moreover, an experience of geochemical tracing on a natural gas storage has demonstrated that it is possible to identify the physical-chemical processes taking place in the reservoir to a human time scale, increasing interest in the proposed tool and providing general information on its use. (author)

  4. The experimental study of heat extraction of supercritical CO2 in the geothermal reservoir

    Huang Cyun-Jie


    Full Text Available The heat transfer phenomena of supercritical CO2 are experimentally investigated in a horizontal tube for improving the efficiency of CO2-EGS.This study discuss the experimental verification of the numerical simulations. The experiment is conducted for the pressure, the flow rate, and particle size 1.54mm. In addition, the experiment and simulation that the maximum heat extraction is occurred at the 9MPa pressure and mass flow rate of 0.00109 kg/s. The maximum specific heat extraction at 9MPa and flow rate of 0.00082 kg/s. The results show that the numerical model has been experimentally verified of the feasibility. Furthermore, the pseudo-critical point had a significant influence on the heat extraction, temperature difference and specific heat extraction.

  5. Optimization of Well Configuration for a Sedimentary Enhanced Geothermal Reservoir

    Zhou, Mengnan; Cho, JaeKyoung; Zerpa, Luis E.; Augustine, Chad


    The extraction of geothermal energy in the form of hot water from sedimentary rock formations could expand the current geothermal energy resources toward new regions. From previous work, we observed that sedimentary geothermal reservoirs with relatively low permeability would require the application of enhancement techniques (e.g., well hydraulic stimulation) to achieve commercial production/injection rates. In this paper we extend our previous work to develop a methodology to determine the optimum well configuration that maximizes the hydraulic performance of the geothermal system. The geothermal systems considered consist of one vertical well doublet system with hydraulic fractures, and three horizontal well configurations with open-hole completion, longitudinal fractures and transverse fractures, respectively. A commercial thermal reservoir simulation is used to evaluate the geothermal reservoir performance using as design parameters the well spacing and the length of the horizontal wells. The results obtained from the numerical simulations are used to build a response surface model based on the multiple linear regression method. The optimum configuration of the sedimentary geothermal systems is obtained from the analysis of the response surface model. The proposed methodology is applied to a case study based on a reservoir model of the Lyons sandstone formation, located in the Wattenberg field, Denver-Julesburg basin, Colorado.

  6. Delineating gas bearing reservoir by using spectral decomposition attribute: Case study of Steenkool formation, Bintuni Basin

    Haris, A.; Pradana, G. S.; Riyanto, A.


    Tectonic setting of the Bird Head Papua Island becomes an important model for petroleum system in Eastern part of Indonesia. The current exploration has been started since the oil seepage finding in Bintuni and Salawati Basin. The biogenic gas in shallow layer turns out to become an interesting issue in the hydrocarbon exploration. The hydrocarbon accumulation appearance in a shallow layer with dry gas type, appeal biogenic gas for further research. This paper aims at delineating the sweet spot hydrocarbon potential in shallow layer by applying the spectral decomposition technique. The spectral decomposition is decomposing the seismic signal into an individual frequency, which has significant geological meaning. One of spectral decomposition methods is Continuous Wavelet Transform (CWT), which transforms the seismic signal into individual time and frequency simultaneously. This method is able to make easier time-frequency map analysis. When time resolution increases, the frequency resolution will be decreased, and vice versa. In this study, we perform low-frequency shadow zone analysis in which the amplitude anomaly at a low frequency of 15 Hz was observed and we then compare it to the amplitude at the mid (20 Hz) and the high-frequency (30 Hz). The appearance of the amplitude anomaly at a low frequency was disappeared at high frequency, this anomaly disappears. The spectral decomposition by using CWT algorithm has been successfully applied to delineate the sweet spot zone.

  7. The freshwater reservoir effect in radiocarbon dating

    Philippsen, Bente


    of magnitude and degree of variability of the freshwater reservoir effect over short and long timescales. Radiocarbon dating of recent water samples, aquatic plants, and animals, shows that age differences of up to 2000 14C years can occur within one river. The freshwater reservoir effect has also implications...... for radiocarbon dating of Mesolithic pottery from inland sites of the Ertebølle culture in Northern Germany. The surprisingly old ages of the earliest pottery most probably are caused by a freshwater reservoir effect. In a sediment core from the Limfjord, northern Denmark, the impact of the freshwater reservoir...... effect on radiocarbon dating in an estuarine environment is examined. Here, freshwater influence causes reservoir ages to vary between 250 and 700 14C years during the period 5400 BC - AD 700. The examples in this study show clearly that the freshwater reservoir effect can seriously corrupt radiocarbon...

  8. Water Quality of the Weija Reservoir after 28 Years of Impoundment


    ... previous studies on the Weija Reservoir, results of the study show a slight increase in ... was well mixed and aerated but less transparent with high phytoplankton ... station was sampled 10 times in the year, from March to December. ..... Preliminary physico-chemical studies of estuaries along the Gulf of Guinea in Ghana.

  9. basement reservoir geometry and properties

    Walter, bastien; Geraud, yves; Diraison, marc


    Basement reservoirs are nowadays frequently investigated for deep-seated fluid resources (e.g. geothermal energy, groundwater, hydrocarbons). The term 'basement' generally refers to crystalline and metamorphic formations, where matrix porosity is negligible in fresh basement rocks. Geothermal production of such unconventional reservoirs is controlled by brittle structures and altered rock matrix, resulting of a combination of different tectonic, hydrothermal or weathering phenomena. This work aims to characterize the petro-structural and petrophysical properties of two basement surface analogue case studies in geological extensive setting (the Albert Lake rift in Uganda; the Ifni proximal margin of the South West Morocco Atlantic coast). Different datasets, using field structural study, geophysical acquisition and laboratory petrophysical measurements, were integrated to describe the multi-scale geometry of the porous network of such fractured and weathered basement formations. This study points out the multi-scale distribution of all the features constituting the reservoir, over ten orders of magnitude from the pluri-kilometric scale of the major tectonics structures to the infra-millimetric scale of the secondary micro-porosity of fractured and weathered basements units. Major fault zones, with relatively thick and impermeable fault core structures, control the 'compartmentalization' of the reservoir by dividing it into several structural blocks. The analysis of these fault zones highlights the necessity for the basement reservoirs to be characterized by a highly connected fault and fracture system, where structure intersections represent the main fluid drainage areas between and within the reservoir's structural blocks. The suitable fluid storage areas in these reservoirs correspond to the damage zone of all the fault structures developed during the tectonic evolution of the basement and the weathered units of the basement roof developed during pre

  10. Four Forensic Entomology Case Studies: Records and Behavioral Observations on Seldom Reported Cadaver Fauna With Notes on Relevant Previous Occurrences and Ecology.

    Lindgren, Natalie K; Sisson, Melissa S; Archambeault, Alan D; Rahlwes, Brent C; Willett, James R; Bucheli, Sibyl R


    A yearlong survey of insect taxa associated with human decomposition was conducted at the Southeast Texas Applied Forensic Science (STAFS) facility located in the Center for Biological Field Studies of Sam Houston State University in Huntsville, TX. During this study, four insect-cadaver interactions were observed that represent previously poorly documented yet forensically significant interactions: Syrphidae maggots colonized a corpse in an aquatic situation; Psychodidae adults mated and oviposited on an algal film that was present on a corpse that had been recently removed from water; several Panorpidae were the first insects to feed upon a freshly placed corpse in the autumn; and a noctuid caterpillar was found chewing and ingesting dried human skin. Baseline knowledge of insect-cadaver interactions is the foundation of forensic entomology, and unique observations have the potential to expand our understanding of decomposition ecology.

  11. Operational reservoir inflow forecasting with radar altimetry: the Zambezi case study

    Michailovsky, C. I.; Bauer-Gottwein, P.


    River basin management can greatly benefit from short-term river discharge predictions. In order to improve model produced discharge forecasts, data assimilation allows for the integration of current observations of the hydrological system to produce improved forecasts and reduce prediction uncertainty. Data assimilation is widely used in operational applications to update hydrological models with in situ discharge or level measurements. In areas where timely access to in situ data is not possible, remote sensing data products can be used in assimilation schemes. While river discharge itself cannot be measured from space, radar altimetry can track surface water level variations at crossing locations between the satellite ground track and the river system called virtual stations (VS). Use of radar altimetry versus traditional monitoring in operational settings is complicated by the low temporal resolution of the data (between 10 and 35 days revisit time at a VS depending on the satellite) as well as the fact that the location of the measurements is not necessarily at the point of interest. However, combining radar altimetry from multiple VS with hydrological models can help overcome these limitations. In this study, a rainfall runoff model of the Zambezi River basin is built using remote sensing data sets and used to drive a routing scheme coupled to a simple floodplain model. The extended Kalman filter is used to update the states in the routing model with data from 9 Envisat VS. Model fit was improved through assimilation with the Nash-Sutcliffe model efficiencies increasing from 0.19 to 0.62 and from 0.82 to 0.88 at the outlets of two distinct watersheds, the initial NSE (Nash-Sutcliffe efficiency) being low at one outlet due to large errors in the precipitation data set. However, model reliability was poor in one watershed with only 58 and 44% of observations falling in the 90% confidence bounds, for the open loop and assimilation runs respectively, pointing to

  12. Vitamin D deficiency in medical patients at a central hospital in Malawi: a comparison with TB patients from a previous study.

    Yamikani Mastala

    Full Text Available OBJECTIVES: To determine the prevalence of vitamin D deficiency (VDD in adult medical, non-tuberculous (non-TB patients. To investigate associations with VDD. To compare the results with a similar study in TB patients at the same hospital. DESIGN: Cross-sectional sample. SETTING: Central hospital in Malawi. PARTICIPANTS: Adult non-TB patients (n = 157, inpatients and outpatients. OUTCOME MEASURES: The primary outcome was the prevalence of VDD. Potentially causal associations sought included nutritional status, in/outpatient status, HIV status, anti-retroviral therapy (ART and, by comparison with a previous study, a diagnosis of tuberculosis (TB. RESULTS: Hypovitaminosis D (≤75 nmol/L occurred in 47.8% (75/157 of patients, 16.6% (26/157 of whom had VDD (≤50 nmol/L. None had severe VDD (≤25 nmol/L. VDD was found in 22.8% (23/101 of in-patients and 5.4% (3/56 of out-patients. In univariable analysis in-patient status, ART use and low dietary vitamin D were significant predictors of VDD. VDD was less prevalent than in previously studied TB patients in the same hospital (68/161 = 42%. In multivariate analysis of the combined data set from both studies, having TB (OR 3.61, 95%CI 2.02-6.43 and being an in-patient (OR 2.70, 95%CI 1.46-5.01 were significant independent predictors of VDD. CONCLUSIONS: About half of adult medical patients without TB have suboptimal vitamin D status, which is more common in in-patients. VDD is much more common in TB patients than non-TB patients, even when other variables are controlled for, suggesting that vitamin D deficiency is associated with TB.

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

    Pachytel, Radomir; Jarosiński, Marek; Bobek, Kinga


    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

  14. Myocardial adaptation to high-intensity (interval) training in previously untrained men with a longitudinal cardiovascular magnetic resonance imaging study (Running Study and Heart Trial).

    Scharf, Michael; Schmid, Axel; Kemmler, Wolfgang; von Stengel, Simon; May, Matthias S; Wuest, Wolfgang; Achenbach, Stephan; Uder, Michael; Lell, Michael M


    To prospectively evaluate whether short-term high-intensity (interval) training (HI(I)T) induces detectable morphological cardiac changes in previously untrained men in cardiovascular magnetic resonance imaging. Eighty-four untrained volunteers were randomly assigned to a HI(I)T group (n=42; 44.1±4.7 years) or an inactive control group (n=42; 42.3±5.6 years). HI(I)T focused on interval runs (intensity: 95%-105% of individually calculated heart rate at the anaerobic threshold). Before and after 16 weeks, all subjects underwent physiological examination, stepwise treadmill test with blood lactate analysis, and contrast-enhanced cardiovascular magnetic resonance imaging (cine, tagging, and delayed enhancement). Indexed left ventricular (LV) and right ventricular (RV) volume (LV, 77.1±8.5-83.9±8.6; RV, 80.5±8.5-86.6±8.1) and mass (LV, 58.2±6.4-63.4±8.1; RV, 14.8±1.7-16.1±2.1) significantly increased with HI(I)T. Changes in LV and RV morphological parameters with HI(I)T were highly correlated with an increase in maximal aerobic capacity (VO2max) and a decrease in blood lactate concentration at the anaerobic threshold. Mean LV and RV remodeling index of HI(I)T group did not alter with training (0.76 ±0.09 and 0.24±0.10 g/mL, respectively [P=0.97 and P=0.72]), indicating balanced cardiac adaptation. Myocardial circumferential strain decreased after HI(I)T within all 6 basal segments (anteroseptal, P=0.01 and anterolateral, PHeart Association, Inc.

  15. Studies and support for the EGS reservoirs at Soultz-sous-Forets. April 2004 - May 2009. Final report

    Portier, S.; Vuataz, F.-D. [Centre de Recherche en Geothermie (CREGE), Neuchatel (Switzerland)


    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at the activities carried out during the period from April 2004 up to May 2009 at Soultz-sous-Forets, France, in connection with the enhanced geothermal systems (EGS) at that location. The report describes the work performed by the Swiss EGS Research and Development group involved in the Soultz project. The principal target set was to install and operate a power plant, enabling the deep reservoir/heat exchanger to be operated, evaluated and improved under realistic conditions. The Swiss contributors have been participating in several work packages: Short and long term tests and medium-term tests of the three-well reservoir/heat exchanger system, development and up-scaling, technical and economic design of larger, industrial, EGS units and the development of stimulation methodology for EGS. The exchange of findings obtained during this project phase is discussed, as is the state-of-the-art of EGS stimulation methods, the interpretation of logging data. Also, seismic /-hydraulic factors, the evaluation of the production/injection performance of the boreholes and reservoir development strategies are discussed as are the modelling of geochemical impact of forced fluid circulation in the deep geothermal reservoir and the results of chemical stimulation tests performed on site.

  16. Gravimetric monitoring of water influx into a gas reservoir: A numerical study based on the ensemble kalman filter

    Glegola, M.; Ditmar, P.; Hanea, R.G.; Vossepoel, F.C.; Arts, R.; Klees, R.


    Water influx into gas fields can reduce recovery factors by 10-40%. Therefore, information about the magnitude and spatial distribution of water influx is essential for efficient management of waterdrive gas reservoirs. Modern geophysical techniques such as gravimetry may provide a direct measure of

  17. A multi-scale case study of natural fracture systems in outcrops and boreholes with applications to reservoir modelling

    Taal-van Koppen, J.K.J.


    Fractured reservoirs are notoriously difficult to characterize because the resolution of seismic data is too low to detect fractures whereas borehole data is detailed but sparse. Therefore, outcrops can be of great support in gaining knowledge of the three-dimensional geometry of fracture networks,

  18. CBM in 3-D: coalbed methane multicomponent 3-D reservoir characterisation study, Cedar Hill Field, San Juan Basin, New Mexico

    Davis, T.; Shuck, E.; Benson, R. [Colorado School of Mines, Golden, CO (United States). Dept. of Geophysics


    The article explains how 3-D multicomponent seismic surveys could substantially improve the production and development of fractured coalbed methane reservoirs. The technique has been used by Northern Geophysical for the detection of geological faults and zones of enhanced fracture permeability proximal to the fault in the western side of the Cedar Hill field in San Juan Basin, NM, USA. 3 figs.

  19. Biomechanical jumping differences among elite female handball players with and without previous anterior cruciate ligament reconstruction: a novel inertial sensor unit study.

    Setuain, Igor; Millor, Nora; González-Izal, Miriam; Gorostiaga, Esteban M; Gómez, Marisol; Alfaro-Adrián, Jesús; Maffiuletti, Nicola A; Izquierdo, Mikel


    Persistent biomechanical and jumping capacity alterations have been observed among female athletes who have sustained anterior cruciate ligament (ACL) injuries. The purpose of this study was to examine if biomechanical jumping differences persist among a cohort of elite female handball players with previous ACL reconstruction several years after return to top-level competition. In order to achieve this goal, a direct mechanics simplified analysis by using a single Inertial Sensor Unit (IU) was used. Twenty-one elite female (6 anterior cruciate ligament reconstructed and 15 uninjured control players) handball players were recruited and evaluated 6.0 ± 3.5 years after surgical anterior cruciate ligament reconstruction. Bilateral and unilateral vertical jumps were performed to evaluate the functional performance and a single inertial sensor unit was employed in order to collect 3D acceleration and 3D orientation data. Previously ACL-reconstructed analysed athletes demonstrated significant (p reconstruction. Identification of the encountered deficits through the use of an IU devise could provide clinicians with a new reliable tool for movement analysis in a clinical setting.

  20. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 8: Design approaches. UPH. Appendix E: Lower reservoir


    Operational, construction, and geotechnical requirements were examined. Overriding considerations including operating range, volume, construction methods, cavern cross section and reservoir layout were studied within the context of minimizing facility costs and optimizing the plant layout. The study led to a preliminary arrangement of fourteen parallel caverns, each 60 ft wide by 85 ft high in cross section and 3610 ft in length. The requirements for and preliminary design of the intermediate reservoir in the case of a two step UPH facility is also described. The design and the cost estimates presented are based on the requirements for a 2000 MW plant providing 20,000 MWh of storage at a nominal head of 4600 ft.

  1. Geology, reservoir engineering and methane hydrate potential of the Walakpa Gas Field, North Slope, Alaska

    Glenn, R.K.; Allen, W.W.


    The Walakpa Gas Field, located near the city of Barrow on Alaska's North Slope, has been proven to be methane-bearing at depths of 2000--2550 feet below sea level. The producing formation is a laterally continuous, south-dipping, Lower Cretaceous shelf sandstone. The updip extent of the reservoir has not been determined by drilling, but probably extends to at least 1900 feet below sea level. Reservoir temperatures in the updip portion of the reservoir may be low enough to allow the presence of in situ methane hydrates. Reservoir net pay however, decreases to the north. Depths to the base of permafrost in the area average 940 feet. Drilling techniques and production configuration in the Walakpa field were designed to minimize formation damage to the reservoir sandstone and to eliminate methane hydrates formed during production. Drilling development of the Walakpa field was a sequential updip and lateral stepout from a previously drilled, structurally lower confirmation well. Reservoir temperature, pressure, and gas chemistry data from the development wells confirm that they have been drilled in the free-methane portion of the reservoir. Future studies in the Walakpa field are planned to determine whether or not a component of the methane production is due to the dissociation of updip in situ hydrates.

  2. 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

    McMechan, G.A.; Soegaard, K.


    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.

  3. Geothermal reservoir management

    Scherer, C.R.; Golabi, K.


    The optimal management of a hot water geothermal reservoir was considered. The physical system investigated includes a three-dimensional aquifer from which hot water is pumped and circulated through a heat exchanger. Heat removed from the geothermal fluid is transferred to a building complex or other facility for space heating. After passing through the heat exchanger, the (now cooled) geothermal fluid is reinjected into the aquifer. This cools the reservoir at a rate predicted by an expression relating pumping rate, time, and production hole temperature. The economic model proposed in the study maximizes discounted value of energy transferred across the heat exchanger minus the discounted cost of wells, equipment, and pumping energy. The real value of energy is assumed to increase at r percent per year. A major decision variable is the production or pumping rate (which is constant over the project life). Other decision variables in this optimization are production timing, reinjection temperature, and the economic life of the reservoir at the selected pumping rate. Results show that waiting time to production and production life increases as r increases and decreases as the discount rate increases. Production rate decreases as r increases and increases as the discount rate increases. The optimal injection temperature is very close to the temperature of the steam produced on the other side of the heat exchanger, and is virtually independent of r and the discount rate. Sensitivity of the decision variables to geohydrological parameters was also investigated. Initial aquifer temperature and permeability have a major influence on these variables, although aquifer porosity is of less importance. A penalty was considered for production delay after the lease is granted.

  4. A longitudinal study of relationships between previous academic achievement, emotional intelligence and personality traits with psychological health of medical students during stressful periods.

    Yusoff, Muhamad Saiful Bahri; Esa, Ab Rahman; Mat Pa, Mohamad Najib; Mey, See Ching; Aziz, Rosniza Abdul; Abdul Rahim, Ahmad Fuad


    There is considerable evidence that emotional intelligence, previous academic achievement (i.e. cumulative grade point average (GPA)) and personality are associated with success in various occupational settings. This study evaluated the relationships of these variables with psychological health of first year medical students during stressful periods. A 1-year prospective study was done with students accepted into the School of Medical Sciences, Universiti Sains Malaysia. Information on emotional intelligence, GPA and personality traits were obtained prior to admission. The validated Universiti Sains Malaysia Emotional Quotient Inventory and Universiti Sains Malaysia Personality Inventory were used to measure emotional intelligence and personality traits, respectively. Stress, anxiety and depression were measured by the 21-item Depression Anxiety Stress Scale during the end-of-course (time 1) and final (time 2) examinations. At the less stressful period (time 1), stress level was associated with agreeableness and the final GPA, anxiety level was associated with emotional control and emotional conscientiousness and depression level was associated with the final GPA and extraversion. At the more stressful period (time 2), neuroticism associated with stress level, anxiety level was associated with neuroticism and emotional expression, and depression level was associated with neuroticism. This study found that neuroticism was the strongest associated factor of psychological health of medical students during their most stressful testing period. Various personality traits, emotional intelligence and previous academic performance were associated factors of psychological health during a less stressful period. These data suggest that early identification of medical students who are vulnerable to the stressful environment of medical schools might help them maintain psychological well-being during medical training.

  5. Method of extracting heat from dry geothermal reservoirs

    Potter, R.M.; Robinson, E.S.; Smith, M.C.


    Hydraulic fracturing is used to interconnect two or more holes that penetrate a previously dry geothermal reservoir, and to produce within the reservoir a sufficiently large heat-transfer surface so that heat can be extracted from the reservoir at a usefully high rate by a fluid entering it through one hole and leaving it through another. Introduction of a fluid into the reservoir to remove heat from it and establishment of natural (unpumped) convective circulation through the reservoir to accomplish continuous heat removal are important and novel features of the method. (auth)

  6. Study on Evaporation Suppression for Arid Regions Reservoir%旱区水库水面防蒸发研究

    王正中; 袁国清; 李博颖; 金晶; 洪慧兰; 罗彬


    This paper studies the anti-evaporation efects of the two schemes:using polystyrene plates and floating bals cover the water surface.The results show that:using the method of covering the water surface to suppres evaporation is feasibil for arid regions reservoir;anti-evaporation rate is not proportional to the wate surface coverage rate;when using polystyrene plates cover the water surface,the coverage rate is 81% and the average anti-evaporation rate is 49.4%;when using floating bals cover the water surface,the coverage rate is 90.8% and the average anti-evaporation rate is 61.2%;the efect of using floating bals cover the water surface to supres evaporation is beter under the same conditions.%采用聚苯乙烯板、浮球覆盖水面,研究两种覆盖水面条件下的水面防蒸发效果。研究结果表明:旱区水库采用覆盖水面来抑制水面蒸发是可行的;水面蒸发抑制率与水面覆盖率不成正比;水面覆盖聚苯乙烯板后的水面覆盖率为81%,平均水面蒸发抑制率为49.4%;水面覆盖浮球后的水面覆盖率为约为90.8%,平均水面蒸发抑制率为61.2%;相同条件下采用浮球覆盖水面抑制水面蒸发效果较好。

  7. Multilevel techniques for Reservoir Simulation

    Christensen, Max la Cour

    The subject of this thesis is the development, application and study of novel multilevel methods for the acceleration and improvement of reservoir simulation techniques. The motivation for addressing this topic is a need for more accurate predictions of porous media flow and the ability to carry...... Full Approximation Scheme) • Variational (Galerkin) upscaling • Linear solvers and preconditioners First, a nonlinear multigrid scheme in the form of the Full Approximation Scheme (FAS) is implemented and studied for a 3D three-phase compressible rock/fluids immiscible reservoir simulator...... based on element-based Algebraic Multigrid (AMGe). In particular, an advanced AMGe technique with guaranteed approximation properties is used to construct a coarse multilevel hierarchy of Raviart-Thomas and L2 spaces for the Galerkin coarsening of a mixed formulation of the reservoir simulation...

  8. Study on the Properties of TiN Coatings on Previously Ion-Implanted Pure Magnesium Surface by MEVVA Ion Implantation

    ZHOU Hai; CHEN Fei; WANG Jian-ping


    A metal vapor vacuum arc (MEVVA) is used in ion implantation for substrate preparation before the deposition process which would ensure the improvement of mechanical properties of the coating.Ti ion is implanted into pure magnesium surface by MEVVA implanter operated with a modified cathode.Implanting energy is kept at 45 keV and dose is set at 3×1017 cm-2.TiN coatings are deposited by magnetically filtered vacuum-arc plasma source on unimplanted and previously implanted substrates.Microstructure and phase composition are analysed using scanning electron microscopy (SEM) and X-ray diffraction (XRD).The property of corrosion resistance of TiN coatings was studied by CS300P electrochemistry-corrosion workstation,and the main impact factor of the corrosion resistance was also analyzed.

  9. Phase II study of a 3-day schedule with topotecan and cisplatin in patients with previously untreated small cell lung cancer and extensive disease

    Sorensen, M.; Lassen, Ulrik Niels; Jensen, Peter Buhl;


    and cisplatin are needed. The aim of this phase II study was to establish the response rate and response duration in chemo-naive patients with SCLC receiving a 3-day topotecan and cisplatin schedule. METHODS: Simons optimal two-stage design was used. Patients with previously untreated extensive disease SCLC......, adequate organ functions and performance status less than 3 were eligible. Topotecan (2.0 mg/m, intravenously) was administered on days 1 to 3 with cisplatin (50 mg/m, intravenously) on day 3 every 3 weeks for a total of six cycles. RESULTS: Forty-three patients received 219 cycles of chemotherapy. Median.......3-7.7), respectively. CONCLUSION: Three-day topotecan with cisplatin on day 3 is active and safe in extensive disease SCLC. An ongoing phase III randomized trial compares this combination to standard treatment Udgivelsesdato: 2008/8...

  10. Effects of CO2-rich fluids on a redbed reservoir: outcrop analogue study from the Buntsandstein (Germany)

    Kasch, N.; Kley, J.; Koester, J.; van Geldern, R.; Wehrer, M.; Wendler, J.


    Carbon capture and storage (CCS) in saline aquifers will induce fluid-rock interactions, with effects on the mineralogy and physical properties of the reservoir. These effects are difficult to study in real reservoirs. Outcrop analogues provide access to relatively large rock volumes, but it may be difficult to prove that CO2 was involved in the mineral reactions observed. We present circumstantial evidence for the presence of CO2-rich fluids during the alteration of Triassic Buntsandstein redbeds from Germany. Fluid-rock interaction there is evidenced by localized bleaching of the red sandstones in fringes of a few mm to a few cm width along joints and fine cracks. The fringes can be traced along individual joints for a few dm to m. 3D geometric analysis on a cm scale shows that the bleached cracks form a complex interconnected network. On the outcrop scale, bleaching is essentially restricted to one north-trending joint set which is parallel to Miocene basalt dikes in the area. In underground salt mines, the dikes have caused bleaching of potassium salt minerals along their contacts. In the same mines CO2 is found trapped within rock salt along north-trending fractures, sometimes causing violent gas eruptions during mining operations. Together, these observations suggest that bleaching along north-trending joints in the Buntsandstein is causally related to the migration of CO2-rich fluids associated with the basalt volcanism. Today, CO2 ascends in CO2-enriched waters. We analyzed 12 samples of such waters. Their δ18O values correspond to meteoric waters. The δ13C (DIC) values of four water samples show signatures typical of volcanogenic CO2. Five samples contain mixed signals of volcanogenic and carbonatic CO2 or biogenic CO2 from soil. Volcanogenic and carbonatic CO2 are restricted to waters interpreted to rise along NW-SE striking basement faults. The switch of preferential fluid channeling from N-trending fractures in Tertiary time to NW-trending fractures


    Hausmann, Jennifer C; Wack, Allison N; Allender, Matthew C; Cranfield, Mike R; Murphy, Kevin J; Barrett, Kevin; Romero, Jennell L; Wellehan, James F X; Blum, Stella A; Zink, M Christine; Bronson, Ellen


    The Maryland Zoo in Baltimore experienced an outbreak of Frog virus-3 (FV3)-like ranavirus during the summer of 2011, during which 14 of 27 (52%) of its captive eastern box turtles (Terrapene carolina carolina) survived. To assess survival, immunity, and viral shedding, an experimental challenge study was performed in which the surviving, previously infected turtles were reinfected with the outbreak strain of FV3-like ranavirus. Seven turtles were inoculated with virus intramuscularly and four control turtles received saline intramuscularly. The turtles were monitored for 8 wk with blood and oral swabs collected for quantitative polymerase chain reaction (qPCR). During that time, one of seven (14%) inoculated turtles and none of the controls (0%) died; there was no significant difference in survival. Clinical signs of the inoculated turtles, except for the turtle that died, were mild compared to the original outbreak. Quantitative PCR for FV3-like ranavirus on blood and oral swabs was positive for all inoculated turtles and negative for all controls. The turtle that died had intracytoplasmic inclusion bodies in multiple organs. Three inoculated and two control turtles were euthanized at the end of the study. No inclusion bodies were present in any of the organs. Quantitative PCR detected FV3-like ranavirus in the spleen of a control turtle, which suggested persistence of the virus. The surviving five turtles were qPCR-negative for FV3-like ranavirus from blood and oral swabs after brumation. Quantitative PCR for Terrapene herpesvirus 1 found no association between ranavirus infection and herpesvirus loads. In conclusion, previously infected eastern box turtles can be reinfected with the same strain of FV3-like ranavirus and show mild to no clinical signs but can shed the virus from the oral cavity.

  12. Clinical evaluation of balloon occlusion of the lower abdominal aorta in patients with placenta previa and previous cesarean section: A retrospective study on 43 cases.

    Chen, Manru; Xie, Lan


    This study investigated the efficacy of balloon occlusion of the lower abdominal aorta in cesarean section surgery for the patients with placenta previa and previous cesarean section. The patients who had placenta previa and underwent cesarean section (CS) were evaluated. The patients treated with CS to terminate the pregnancy were used as control group (23 cases); the patients treated with the preset abdominal aorta balloon before CS was taken as study group (20 cases). The investigated indicators included the intraoperative blood loss, blood loss within postoperative 24 h, the transfusion amount of red cell suspension (RCS), hospital stay, incidence rate of disseminated intravascular coagulation (DIC), the asphyxia, premature delivery and the mortality of the newborns. The two groups are comparable. The intraoperative blood loss, blood loss within postoperative 24 h, the transfusion amount of RCS and the percentage of uterus resection in the study group were significantly lower (P < 0.05) than that in the control group. The percentage of uterine cavity filling with ribbon gauze in the study group was higher than the control group (P < 0.05). The balloon occlusion of lower abdominal aorta seems effective in reducing postpartum hemorrhage and the blood transfusion and decreasing the risk of hysterectomy without harming the newborns. Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  13. Algae community and trophic state of subtropical reservoirs in southeast Fujian, China.

    Yang, Jun; Yu, Xiaoqing; Liu, Lemian; Zhang, Wenjing; Guo, Peiyong


    Fujian reservoirs in southeast China are important water resources for economic and social sustainable development, although few have been studied previously. In recent years, growing population and increasing demands for water shifted the focus of many reservoirs from flood control and irrigation water to drinking water. However, most of them showed a rapid increase in the level of eutrophication, which is one of the most serious and challenging environmental problems. In this study, we investigated the algae community characteristics, trophic state, and eutrophication control strategies for typical subtropical reservoirs in southeast Fujian. Surface water samples were collected using polyvinyl chloride (PVC) plastic bottles from 11 Fujian reservoirs in summer 2010. Planktonic algae were investigated by optical microscopy. Water properties were determined according to the national standard methods. Shallow reservoirs generally have higher values of trophic state index (TSI) and appear to be more susceptible to anthropogenic disturbance than deeper reservoirs. A total of 129 taxa belonging to eight phyla (i.e., Bacillariophyta, Chlorophyta, Chrysophyta, Cryptophyta, Cyanophyta, Euglenophyta, Pyrrophyta, Xanthophyta) were observed and the most diverse groups were Chlorophyta (52 taxa), Cyanophyta (20 taxa), Euglenophyta (17 taxa), Chrysophyta (14 taxa). The dominant groups were Chlorophyta (40.58%), Cyanophyta (22.91%), Bacillariophyta (21.61%), Chrysophyta (6.91%). The species richness, abundance, diversity, and evenness of algae varied significantly between reservoirs. TSI results indicated that all 11 reservoirs were eutrophic, three of them were hypereutrophic, six were middle eutrophic, and two were light eutrophic. There was a strong positive correlation between algal diversity and TSI at P affecting the distribution of algae communities. The transparency and chlorophyll a were the strongest environmental factors in explaining the community data. Furthermore

  14. Study of the water quality parameters in the Pena del Aguila reservoir, Villar del Rey, Badajoz. Spain; Estudio de los paametros de calidad del agua del embalse de Pena del Aguila, Villar del Rey (Badaojoz)

    Gala Marquez, M. M.; Gomez Crisostomo, C.


    Limnological studies of reservoirs that supply drinking water are essential in view of their practical interest and usefulness. This led Aqualia, Gestion Integral de Agua, the company running the water supply service in Badajoz, to carry out such a study on the Pena del Aguila reservoir supplying the town. The study presented here covers the period from May 2003 to April 2004. the results concerning the organoleptic, physico-chemical and undesirable substances parameters show that the surface water in the reservoir is of optimum quality and so the installation of a floating intake is proposed as a way of improving the water captured. (Author) 13 refs.

  15. Development of gas and gas condensate reservoirs



    In the study of gas reservoir development, the first year topics are restricted on reservoir characterization. There are two types of reservoir characterization. One is the reservoir formation characterization and the other is the reservoir fluid characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. The results of conditional simulation has higher confidence level than the unconditional simulation because conditional simulation considers the sample location as well as distance correlation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. From the liquid volume fraction with pressure drop, the phase behavior of reservoir fluid can be estimated. The calculation results of fluid recombination, constant composition expansion, and constant volume depletion are matched very well with the experimental data. In swelling test of the reservoir fluid with lean gas, the accuracy of dew point pressure forecast depends on the component characterization. (author). 28 figs., 10 tabs.

  16. Biomarker-driven trial in metastatic pancreas cancer: feasibility in a multicenter study of saracatinib, an oral Src inhibitor, in previously treated pancreatic cancer.

    Arcaroli, John; Quackenbush, Kevin; Dasari, Arvind; Powell, Rebecca; McManus, Martine; Tan, Aik-Choon; Foster, Nathan R; Picus, Joel; Wright, John; Nallapareddy, Sujatha; Erlichman, Charles; Hidalgo, Manuel; Messersmith, Wells A


    Src tyrosine kinases are overexpressed in pancreatic cancers, and the oral Src inhibitor saracatinib has shown antitumor activity in preclinical models of pancreas cancer. We performed a CTEP-sponsored Phase II clinical trial of saracatinib in previously treated pancreas cancer patients, with a primary endpoint of 6-month survival. A Simon MinMax two-stage phase II design was used. Saracatinib (175 mg/day) was administered orally continuously in 28-day cycles. In the unselected portion of the study, 18 patients were evaluable. Only two (11%) patients survived for at least 6 months, and three 6-month survivors were required to move to second stage of study as originally designed. The study was amended as a biomarker-driven trial (leucine rich repeat containing protein 19 [LRRC19] > insulin-like growth factor-binding protein 2 [IGFBP2] "top scoring pairs" polymerase chain reaction [PCR] assay, and PIK3CA mutant) based on preclinical data in a human pancreas tumor explant model. In the biomarker study, archival tumor tissue or fresh tumor biopsies were tested. Biomarker-positive patients were eligible for the study. Only one patient was PIK3CA mutant in a 3' untranslated region (UTR) portion of the gene. This patient was enrolled in the study and failed to meet the 6-month survival endpoint. As the frequency of biomarker-positive patients was very low (pancreatic cancer patients treated with a Src inhibitor based on a biomarker would improve 6-month survival, we demonstrate that testing pancreatic tumor samples for a biomarker-driven, multicenter study in metastatic pancreas cancer is feasible.

  17. A Phase III Study of Durvalumab (MEDI4736) With or Without Tremelimumab for Previously Treated Patients With Advanced NSCLC: Rationale and Protocol Design of the ARCTIC Study.

    Planchard, David; Yokoi, Takashi; McCleod, Michael J; Fischer, Jürgen R; Kim, Young-Chul; Ballas, Marc; Shi, Kelvin; Soria, Jean-Charles


    Anti-programmed cell death-1 and anti-programmed cell death ligand-1 (PD-L1) monotherapies have shown promising clinical activity in advanced, refractory non-small-cell lung cancer (NSCLC), but antitumor activity appears to be greater in patients with PD-L1(+) tumors compared with patients harboring PD-L1(-) tumors. Combining the anti-PD-L1 antibody durvalumab and the anti-cytotoxic T-lymphocyte antigen 4 antibody tremelimumab offers the potential for antitumor activity in patients with advanced NSCLC, regardless of PD-L1 tumor status. ARCTIC (NCT02352948) is a global, phase III, randomized, open-label multicenter study in patients with advanced NSCLC assessing the safety and clinical activity of durvalumab versus standard of care (SoC; erlotinib, gemcitabine, or vinorelbine) in patients with PD-L1(+) tumors (≥25% of tumor cells with membrane staining using VENTANA PD-L1 [SP263] CDx Assay) (Sub-study A) and the combination of durvalumab + tremelimumab or either agent as monotherapy versus SoC in patients with PD-L1(-) tumors (Sub-study B). Eligible patients are those with locally advanced or metastatic NSCLC (Stage IIIB/IV), without epidermal growth factor receptor tyrosine kinase activating mutations or anaplastic lymphoma kinase rearrangements, who have received at least 2 prior systemic regimens, including 1 platinum-based chemotherapy regimen. Co-primary endpoints are progression-free survival and overall survival. Secondary endpoints include the proportion of patients alive at 12 months, objective response rate, duration of response, progression-free survival at 6 and 12 months, safety and tolerability, pharmacokinetics, immunogenicity, and quality of life. The exploratory endpoints will assess potential biomarkers of treatment response. Recruitment started in January 2015 and is ongoing.

  18. Phase III study of 5FU, etoposide and leucovorin (FELV) compared to epirubicin, cisplatin and 5FU (ECF) in previously untreated patients with advanced biliary cancer.

    Rao, S; Cunningham, D; Hawkins, R E; Hill, M E; Smith, D; Daniel, F; Ross, P J; Oates, J; Norman, A R


    The purpose of this study was to determine whether epirubicin, cisplatin and infused 5FU (ECF) improves overall survival (OS) compared to 5FU, etoposide and leucovorin (FELV) in patients with previously untreated advanced biliary cancer in a prospective randomised study. Patients were randomly assigned to receive epirubicin, cisplatin and infused 5FU ECF or bolus 5FU etoposide and leucovorin (FELV). The primary end point was OS with secondary end points of objective response rate (ORR), failure-free survival (FFS), quality of life (QOL) and toxicity. In all, 54 patients were recruited with 27 randomly assigned to each arm. The median OS for ECF was 9.02 months (95% confidence interval (CI): 6.46-11.51) and FELV 12.03 months (95% CI: 9.3-14.7), P=0.2059. Objective response rates were similar for both arms: ECF 19.2% (95% CI: 6.55-39.3); FELV 15% (95% CI: 3.2-37.9), P=0.72. There was significantly increased grade 3/4 neutropenia with FELV vs ECF (53.8 vs 29.5%, respectively, P=0.020). Symptom resolution was impressive for both regimens. This is the largest reported randomised study to date in this setting. ECF did not improve OS compared to FELV, but was associated with less acute toxicity. These data suggest that chemotherapy can prolong OS and achieve good symptomatic relief in advanced biliary cancer.

  19. Deepwater turbidite system analysis : From outcrops studies to basin scale depositional elements. Key learnings for reservoir occurence and characterisation.

    Navarre, J.-C.; Dattilo, P.; Crumeyrolle, P.


    Decisions on exploration and production in the deepwater domain rely mostly on seismic data (2D or 3D) with limited amount of well geological data. This limited information has to be supplemented by models derived from analogues at different scales, in order to derisk the reservoir presence and infer the reservoir architecture within a larger stratigraphic framework from shelf to deep basin. The fundamental outcrop analysis carried in the 70's and the 80's contributed to identify and characterize the main deep water depositional elements. Outcrop observations are the best way to appraise the architectural and faciological complexity of the subsurface depositional systems within their stratigraphic framework. The lessons learned in the Earth surface provide the key to the subsurface data understanding: core analysis, well-logs correlations and detailed 3D seismic interpretations. Subsurface data is in turn bringing key insights on large scale depositional system; 3D geometry and sediment nature of the depositional elements and processes. Research derived from 3D seismic subsurface data interpretations with tentative continuity between shelf to basin improved the understanding of shelf to deep basin sediment transfer mechanisms. In particular, it has been accompanied by a renewal of interest in the processes associated with hyperpycnal flows in the various deepwater settings. Outcrop and Subsurface integration appears as a powerful tool to characterize and predict reservoir occurence. A seismic based approach on the recognition of depositional elements defined at different scales honoring the stratigraphical architecture of turbidites deposits is systematically applied in our evaluations at a similar scale than the elementary depositional sequences recognized by Mutti (1994). Despite common depositional processes, a large diversity of systems and geobodies will be illustrated from regional scale to reservoir scale from a worldwide portfolio of assets in turbidite

  20. Plantar pressure in diabetic peripheral neuropathy patients with active foot ulceration, previous ulceration and no history of ulceration: a meta-analysis of observational studies.

    Malindu Eranga Fernando

    Full Text Available AIMS: Elevated dynamic plantar pressures are a consistent finding in diabetes patients with peripheral neuropathy with implications for plantar foot ulceration. This meta-analysis aimed to compare the plantar pressures of diabetes patients that had peripheral neuropathy and those with neuropathy with active or previous foot ulcers. METHODS: Published articles were identified from Medline via OVID, CINAHL, SCOPUS, INFORMIT, Cochrane Central EMBASE via OVID and Web of Science via ISI Web of Knowledge bibliographic databases. Observational studies reporting barefoot dynamic plantar pressure in adults with diabetic peripheral neuropathy, where at least one group had a history of plantar foot ulcers were included. Interventional studies, shod plantar pressure studies and studies not published in English were excluded. Overall mean peak plantar pressure (MPP and pressure time integral (PTI were primary outcomes. The six secondary outcomes were MPP and PTI at the rear foot, mid foot and fore foot. The protocol of the meta-analysis was published with PROPSERO, (registration number CRD42013004310. RESULTS: Eight observational studies were included. Overall MPP and PTI were greater in diabetic peripheral neuropathy patients with foot ulceration compared to those without ulceration (standardised mean difference 0.551, 95% CI 0.290-0.811, p<0.001; and 0.762, 95% CI 0.303-1.221, p = 0.001, respectively. Sub-group analyses demonstrated no significant difference in MPP for those with neuropathy with active ulceration compared to those without ulcers. A significant difference in MPP was found for those with neuropathy with a past history of ulceration compared to those without ulcers; (0.467, 95% CI 0.181- 0.753, p = 0.001. Statistical heterogeneity between studies was moderate. CONCLUSIONS: Plantar pressures appear to be significantly higher in patients with diabetic peripheral neuropathy with a history of foot ulceration compared to those with diabetic

  1. A Comparative Study between a Pseudo-Forward Equation (PFE and Intelligence Methods for the Characterization of the North Sea Reservoir

    Saeed Mojeddifar


    Full Text Available This paper presents a comparative study between three versions of adaptive neuro-fuzzy inference system (ANFIS algorithms and a pseudo-forward equation (PFE to characterize the North Sea reservoir (F3 block based on seismic data. According to the statistical studies, four attributes (energy, envelope, spectral decomposition and similarity are known to be useful as fundamental attributes in porosity estimation. Different ANFIS models were constructed using three clustering methods of grid partitioning (GP, subtractive clustering method (SCM and fuzzy c-means clustering (FCM. An experimental equation, called PFE and based on similarity attributes, was also proposed to estimate porosity values of the reservoir. When the validation set derived from training wells was used, the R-square coefficient between two variables (actual and predicted values was obtained as 0.7935 and 0.7404 for the ANFIS algorithm and the PFE model, respectively. But when the testing set derived from testing wells was used, the same coefficients decreased to 0.252 and 0.5133 for the ANFIS algorithm and the PFE model, respectively. According to these results, and the geological characteristics observed in the F3 block, it seems that the ANFIS algorithms cannot estimate the porosity acceptably. By contrast, in the outputs of PFE, the ability to detect geological structures such as faults (gas chimney, folds (salt dome, and bright spots, alongside the porosity estimation of sandstone reservoirs, could help in determining the drilling target locations. Finally, this work proposes that the developed PFE could be a good technique for characterizing the reservoir of the F3 block.

  2. The influence of previous infections and antichlamydia pneumoniae seropositivity on functional outcome in ischemic stroke patients: results from the IN2 study.

    Consoli, Domenico; Vidale, Simone; Aguglia, Umberto; Bassi, Pietro; Cavallini, Anna; Consoli, Arturo; Galati, Franco; Guidetti, Donata; Micieli, Giuseppe; Neri, Giuseppe; Rasura, Maurizia; Sterzi, Roberto; Toni, Danilo; Inzitari, Domenico


    Although a growing attention is being paid to acute ischemic stroke patients, the correlation between clinical outcome and infectious events in this population has been poorly investigated. 749 ischemic stroke (mean age 71 years old, males 56%) patients were enrolled in this prospective case-control study by 11 Italian Stroke Units. Demographic data, vascular risk factors, previous infections and post-stroke infections (PSIs) were recorded. Blood samples were collected and the enzyme-linked immunoassay was chosen to measure Chlamydia pneumoniae IgG and IgA plasma antibodies (antibody titers were classified with specific cut-off levels: IgA > 1:16 and IgG > 1:64). Early poor outcome was defined as mRS score >2 at discharge, while poor outcome at 6-month follow-up. Univariate and multivariate analyses were performed. Median NIHSS was 7, IgA and IgG antichlamydia pneumoniae seropositivities were observed in 308 (37.1%) and 207 (23.6%) patients, respectively. Multivariate analyses showed significant correlations between PSIs and NIHSS (RR: 1.06; 95% CI 1.02-1.09; p < 0.001) and PSIs and IgA antichlamydia pneumoniae seropositivity (RR: 3.84; 95% CI 2.53-5.84; p < 0.001). Significant disability was associated with baseline NIHSS (RR: 1.32; 95% CI 1.16-1.50; p < 0.001), IgA (RR: 2.67; 95% CI 1.06-6.70; p = 0.035) and IgG antichlamydia (RR: 5.75; 95% CI 1.83-18.03; p = 0.003) seropositivity and atrial fibrillation (RR: 2.58; 95% CI 1.81-3.67; p < 0.001). While previous infections were not associated with functional outcome, antichlamydia antibodies play a negative role in ischemic stroke patients. Preventive strategies may reduce the stroke burden and improve the clinical outcome.

  3. Rapid proliferation of an endemic galaxiid following eradication of an alien piscivore (Perca fluviatilis) from a reservoir.

    Beatty, S J; Morgan, D L


    Following the complete eradication of the alien piscivorous perch Perca fluviatilis from a potable reservoir, the abundance of the endemic western minnow Galaxias occidentalis, which was previously undetectable prior to the initial eradication event, increased dramatically. The study reveals the potential of reservoirs to act as ecological refuges and has implications for understanding the relative effects of alien fishes v. habitat alteration on native freshwater fishes.

  4. Methodology Measuring Rare Earth Elements in High TDS Reservoir Brines Application as Natural Tracers in CCUS Studies

    Smith, W.; Mcling, T. L.; Smith, R. W.; Neupane, H.


    In recent years rare earth elements (REE) have been demonstrated to be useful natural tracers for geochemical processes in aqueous environments. The application of REE's to carbon dioxide utilization and storage (CCUS) could provide researchers with a sensitive, inexpensive tool for tracking the movement of CO2 and displaced formation brines. By definition, geologic reservoirs that have been deemed suitable for carbon capture and storage contain formation brine with total dissolved solids (TDS) greater than 10,000 ppm and often these formation brines exceed 75,000 ppm TDS. This high TDS water makes it very difficult to measure REE, which typically occur at part per trillion concentrations. Critical to the use of REE for CCUS studies is the development of a procedure, which allows for the pre-concentration of REE's across a wide range of water quality. Additionally, due to the large number of samples that will need analysis, any developed procedure must be inexpensive, reproducible, and quick to implement. As part of the Big Sky Carbon Sequestration Project the INL's Center for Advance Energy Studies is developing REE pre-concentration procedures based on methods reported in the literature. While there are many REE pre-concentration procedures in the literature, our tests have shown these methods have difficulty at TDS greater than seawater (roughly 35,000 ppm TDS). Therefore, the ability to quantitatively measure REE's in formation brines with very high TDS has required the modification of an already developed procedure. After careful consideration and testing we selected methods modified after those described by Kingston et al., 1978 and Strachan et al., 1989 utilizing chelating media for very high TDS waters and ion-exchange media as detailed by Crock et al., 1984; Robinson et al., 1985; and Stetzenbach et al., 1994 for low TDS (<10,000 ppm TDS) waters. These modified procedures have been successfully tested in our laboratory and have proven effective in greatly

  5. The role of petroleum engineering on geothermal reservoir assessments

    Alkan, H. [ISTec, Koeln (Germany)


    Reservoir assessment is the most critical issue of the risk analysis on the use of a geothermal energy source and requires a multi disciplinary survey of the underground objective. Petroleum reservoir engineering with its methodology and its actual technology level fits well with the needs of geothermal reservoir assessments. In this study similarities and differences of the hydrocarbon and geothermal reservoirs are discussed briefly in terms of exploration and production. Furthermore the petroleum reservoir engineering techniques which are currently used and which can be used in geothermal reservoir assessments are summarized. (orig.)


    Mohammad Hashem Kanani


    Full Text Available The data collected from the operation of existing storage reservoirs, could offer valuable information for the better allocation and management of fresh water rates for future use to mitigation droughts effect. In this paper the long-term Dez reservoir (IRAN water rate prediction is presented using probability matrix method. Data is analyzed to find the probability matrix of water rates in Dez reservoir based on the previous history of annual water entrance during the past and present years(40 years. The algorithm developed covers both, the overflow and non-overflow conditions in the reservoir. Result of this study shows that in non-overflow conditions the most exigency case is equal to 75%. This means that, if the reservoir is empty (the stored water is less than 100 MCM this year, it would be also empty by 75% next year. The stored water in the reservoir would be less than 300 MCM by 85% next year if the reservoir is empty this year. This percentage decreases to 70% next year if the water of reservoir is less than 300 MCM this year. The percentage also decreases to 5% next year if the reservoir is full this year. In overflow conditions the most exigency case is equal to 75% again. The reservoir volume would be less than 150 MCM by 90% next year, if it is empty this year. This percentage decreases to 70% if its water volume is less than 300 MCM and 55% if the water volume is less than 500 MCM this year. Result shows that too, if the probability matrix of water rates to a reservoir is multiplied by itself repeatedly; it converges to a constant probability matrix, which could be used to predict the long-term water rate of the reservoir. In other words, the probability matrix of series of water rates is changed to a steady probability matrix in the course of time, which could reflect the hydrological behavior of the watershed and could be easily used for the long-term prediction of water storage in the down stream reservoirs.

  7. 页岩气成藏理论及资源评价方法%The Study of Shale Gas Reservoir Theory and Resources Evaluation

    王伟锋; 刘鹏; 陈晨; 王会丽; 姜帅; 张志超


    Based on the investigation of shale gas at home and abroad,this article systematically studies the basic characteristics of shale gas reservoir,analyzes formation mechanism of shale gas reservoir and its controlling factors.In addition,it discusses the matching identification method and resource assessment methods aiming at the shale gas reservoir's special accumulation characteristics.Studies show that shale gas reservoir generally has characteristics such as self-generation and self-storage,fine particle size,low porosity and low permeability,fracture development,big reservoir area,continuous distribution,wide formation temperature and burial depth,abnormal formation pressure,low capacity,low recovery ratio,long production period and its occurrence mode is mainly adsorption state.Shale gas reservoir formation has transitional characteristic,with reservoir formation mechanism of both source-contacting gas and conventional natural gas.The type,content and maturity of organic matters,the fracture,porosity and permeability,mineral composition,thickness,humidity,burial depth of shale,as well as the temperature and pressure have certain controlling effect on the formation of shale gas reservoir.Shale gas can be identified qualitatively or quantitatively with core analysis method,geophysical method and new logging techniques such as ECS logging and imaging logging.According to the difference of principles,there are mainly four shale gas resource assessment methods for different geological and data conditions,which are analogy method,statistic method,genetic method,comprehensive analytical method.%在调研了国内外页岩气研究成果的基础上,系统地研究了页岩气藏基本特征,分析了页岩气藏的成藏机理及成藏控制因素,并针对页岩气藏特殊的成藏特征,探讨了相应的识别方法和资源评价方法.研究表明,页岩气藏通常具有自生自储、储层粒度细、低孔低渗、裂缝发育、储层面积大、连续分

  8. Transport of reservoir fines

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...... dispersion equation in modeling the transport and the deposition of reservoir fines. It successfully predicts the unsymmetrical concentration profiles and the hyperexponential deposition in experiments....

  9. Development Study of Turbulent Kappa-Epsilon Model for Recirculation flow III : Two Dimension Recirculation Flow in a Reservoir

    M. Syahril B. Kusuma


    Full Text Available An assessment of recirculation flow in Jatiluhur reservoir is conducted based on two dimensions turbulent K-e model. The numerical model was developed using finite difference method where hydrodynamic equation was solved by the combination of Mc Cormack and splitting methods. The K-e equation is solved using quickest scheme in convection term, central scheme in diffusion term and Euler scheme in reaction term. The simulations were done for maximum incoming flow during the rainy season and the dry season. Model results for the rainy season case have shown good agreement with those found by field measurement. The rainy season case generated a much recirculted flow and higher concentration of DO in the reservoir than that of the dry season case. Denser grid and high courant number is needed to avoid it from becoming oscillating and unstable and for achieving a more accurate results for the case with less average velocity.

  10. Study of the environmental degradation of Bodocongó Reservoir in Campina Grande, State of Paraiba, Brasil.

    Dany Geraldo Kramer Cavalcanti e Silva


    Full Text Available Nowadays the environmental resources has been suffering intense transformations impelled by the urbanization and industrial development, through the installation of industries and construction of homes, facts that can endanger the sustainability of any ecosystem. This work had as objective to diagnose the degradation processes practiced along the Bodocongó reservoir and to monitor the quality of the water of this reservoir. For this purpose were used: geoprocessing, digital analysis of images, photographic registrations, field visits. The results showed an absence of administration polices and, in this way a system for the management should be implanted for containing the environmental degradation and prevent the pollution in this aquatic ecosystem.Key-words: environmental degradation, water resource, pollution.

  11. Dynamic study of the upper Sao Francisco River and the Tres Marias reservoir using MSS/LANDSAT images. [Brazil

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


    The use of LANDSAT multispectral ban scanner imagery to verify the relationship between the behavior of the Tres Marias reservoir and the dynamics of the Sao Francisco River supply basin is described. The dispersion of suspended sediments and their concentration in the surface layers of the water are considered. A five year survey of the region during both dry and rainy seasons was performed. The drainage network was analyzed based on the patterns of dessication, water rises and soil use in the supply basin. Surface layers of the reservoir were tabulated as a function of the levels of gray in the imagery. In situ observations of water depth and reflectance were performed. Ground truth and LANDSAT data were correlated to determine the factors affecting the dynamics of the supply basin.

  12. A Retrospective Case-Control Study Evaluating the Role of Mifepristone for Induction of Labor in Women with Previous Cesarean Section.

    Sharma, Chanderdeep; Soni, Anjali; Soni, Pawan K; Verma, Suresh; Verma, Ashok; Gupta, Amit


    To investigate the role of "mifepristone" for induction of labor (IOL) in pregnant women with prior cesarean section (CS). In this retrospective study, all pregnant women with prior CS who received oral mifepristone (400 mg) for IOL (as per clear obstetric indications) [group 1] were compared with pregnant women with prior CS who had spontaneous onset of labor (SOL) [group 2], with respect to incidence of vaginal delivery, CS, duration of labor, and various maternal and fetal outcomes. During the study period, 72 women received mifepristone (group 1) for IOL and 346 had SOL (group 2). In group 1 after mifepristone administration, 40 (55.6 %) women had labor onset, and 24 (33.3 %) women had cervical ripening (Bishop Score ≥ 8) within 48 h. There were no statistically significant differences with respect to duration of labor (p value: 0.681), mode of delivery (i.e., normal delivery or CS-p value: 0.076 or 0.120, respectively), or maternal (blood loss or scar dehiscence/rupture uterus), or fetal outcomes (NICU admission) compared to women with previous CS with SOL (group 2). However, the need of oxytocin (p value 0.020) and dose of oxytocin requirement (p value 0.008) were more statistically significant in group 1. Mifepristone may be considered as an agent for IOL in women with prior CS.

  13. Immunogenicity and safety of tetravalent dengue vaccine in 2-11 year-olds previously vaccinated against yellow fever: randomized, controlled, phase II study in Piura, Peru.

    Lanata, Claudio F; Andrade, Teresa; Gil, Ana I; Terrones, Cynthia; Valladolid, Omar; Zambrano, Betzana; Saville, Melanie; Crevat, Denis


    In a randomized, placebo-controlled, monocenter, observer blinded study conducted in an area where dengue is endemic, we assessed the safety and immunogenicity of a recombinant, live, attenuated, tetravalent dengue vaccine candidate (CYD-TDV) in 2-11 year-olds with varying levels of pre-existing yellow-fever immunity due to vaccination 1-7 years previously. 199 children received 3 injections of CYD-TDV (months 0, 6 and 12) and 99 received placebo (months 0 and 6) or pneumococcal polysaccharide vaccine (month 12). One month after the third dengue vaccination, serotype specific neutralizing antibody GMTs were in the range of 178-190 (1/dil) (versus 16.7-38.1 in the control group), a 10-20 fold-increase from baseline, and 94% of vaccines were seropositive to all four serotypes (versus 39% in the control group). There were no vaccine-related SAEs. The observed reactogenicity profile was consistent with phase I studies, with severity grade 1-2 injection site pain, headache, malaise and fever most frequently reported and no increase after subsequent vaccinations. Virologically confirmed dengue cases were seen after completion of the 3 doses: 1 in the CYD-TDV group (N=199), and 3 in the control group (N=99). A 3-dose regimen of CYD-TDV had a good safety profile in 2-11 year olds with a history of YF vaccination and elicited robust antibody responses that were balanced against the four serotypes.

  14. Effect of the Latent Reservoir on the Evolution of HIV at the Within- and Between-Host Levels

    Doekes, Hilje M.; Fraser, Christophe; Lythgoe, Katrina A.


    The existence of long-lived reservoirs of latently infected CD4+ T cells is the major barrier to curing HIV, and has been extensively studied in this light. However, the effect of these reservoirs on the evolutionary dynamics of the virus has received little attention. Here, we present a within-host quasispecies model that incorporates a long-lived reservoir, which we then nest into an epidemiological model of HIV dynamics. For biologically plausible parameter values, we find that the presence of a latent reservoir can severely delay evolutionary dynamics within a single host, with longer delays associated with larger relative reservoir sizes and/or homeostatic proliferation of cells within the reservoir. These delays can fundamentally change the dynamics of the virus at the epidemiological scale. In particular, the delay in within-host evolutionary dynamics can be sufficient for the virus to evolve intermediate viral loads consistent with maximising transmission, as is observed, and not the very high viral loads that previous models have predicted, an effect that can be further enhanced if viruses similar to those that initiate infection are preferentially transmitted. These results depend strongly on within-host characteristics such as the relative reservoir size, with the evolution of intermediate viral loads observed only when the within-host dynamics are sufficiently delayed. In conclusion, we argue that the latent reservoir has important, and hitherto under-appreciated, roles in both within- and between-host viral evolution. PMID:28103248

  15. Ichthyofauna of the reservoirs of Central Vietnam

    I. A. Stolbunov


    Full Text Available Species composition, distribution and abundance of fish in the pelagic and littoral zone of four reservoirs of Central Vietnam (Suoi Chau, Kam Lam, Da Ban and Suoi Dau were studied first. According to the research data the fish community of the reservoirs is represented by 43 species of 19 fish families.


    Wenxue LI; Yuanfeng ZHANG; Cuiping ZHANG


    Observation of the operation of the Sanmenxia Reservoir on the Yellow River has led to the conclusion that to preserve a certain effective storage volume for reservoirs built on heavily silt-laden rivers is feasible if the reservoir is operated according to the principle known as "storing the clear water and discharging the muddy flow". The relative stability of the bed elevation at the end of the backwater and the reservoir's erosion and deposition equilibrium depend on the compatibility of the pool level maintained in non-flood seasons with the conditions of flow and sediment load during flood seasons. Operating the reservoir to regulate the flood and sediment load during flood seasons can reduce the rate of aggradation in the Lower Yellow River. The basic condition for applying the operation mode of "storing the clear water and discharging the muddy flow" is that a sufficient amount of water should be used for discharging sediment during flood seasons. Under the condition of extremely low flow years, reservoir sedimentation cannot be avoided even if this operation mode is adopted.

  17. Studies on the Optimal behavior of Energy Storage in Reservoirs of a Hydroelectric system; Estudios sobre el comportamiento optimo del almacenamiento de energia en embalses de sistema hidroelectrico

    Macedo Faria, Breno; Franco Barbosa, Paulo Sergio [Universidad Estatal de Campinas (Brazil)


    This work aims at studying the results of an optimisation model applied to the Paranaiba river basin, Brazil. This system is made by the junction of three river branches located in a region with a well-defined seasonal hydrological behavior. The ratio between the total energy storage in the system and the active storage for every reservoir is evaluated from the optimal operational results. This relationship allows recognizing systematic patterns on the relative use for every reservoir, when compared to the entire system. The main parameters that define reservoir behavior are identified, with highlights on the position of the power station in the cascade, the relationship between the river flow and the active storage, and the installed capacity of the power station. In addition, the parameter hydrological scenario is also another factor that defines the relative use of the reservoirs. [Spanish] El modelo del presente trabajo tiene como objetivo estudiar los resultados de una optimizacion para el sistema hidroelectrico de la cuenca del rio Paranaiba, Brasil, la cual esta formada por la confluencia de tres rios en una region de distribucion de lluvias bien definidas en terminos hidrologicos. Se analiza la relacion entre la energia total almacenada en el sistema y el volumen util de cada embalse a partir de los resultados operativos optimos. Esta relacion permite identificar resultados sistematicos en lo que se refiere a la utilizacion de cada embalse, en comparacion con el uso del sistema como un todo. Se identifican los principales parametros responsables por el comportamiento de los embalses, destacando la influencia de la posicion de la central hidroelectrica en la cascada, de la relacion caudal/volumen util y de la potencia de central. Ademas, el parametro escenario hidrologico tambien es otro factor determinante en el uso relativo de los embalses.

  18. Land Use Zoning in Three-Gorge Reservoir Region:A Case Study of Fengdu County in Chongqing Municipality

    Xueqin; HUANG


    Taking Fengdu County in Three-Gorge Reservoir region as an example,this paper applies the dynamic clustering analysis model, and divides land resource utilization of Fengdu County into three zones: Yangtze River valley economic zone,low mountains and hills agricultural zone,and low and middle agricultural,forestry and animal husbandry zone. It also analyzes current situation and existing problems in the land utilization of every zone,and finally puts forward corresponding recommendations.

  19. Construction of a novel water quality index and quality indicator for reservoir water quality evaluation: A case study in the Amazon region

    Lobato, T. C.; Hauser-Davis, R. A.; Oliveira, T. F.; Silveira, A. M.; Silva, H. A. N.; Tavares, M. R. M.; Saraiva, A. C. F.


    A novel Quality Indicator (QI) and Water Quality Index (WQI) were constructed in the present study for the evaluation of the water quality of a Hydroelectric Plant reservoir in the Amazon area, Brazil, taking into account the specific characteristics of the Amazon area. Factor analyses were applied in order to select the relevant parameters to be included in the construction of both indices. Quality curves for each selected parameter were then created and the constructed QI and WQI were then applied to investigate the water quality at the reservoir. The hydrological cycle was shown by the indices to directly affect reservoir water quality, and the WQI was further useful in identifying anthropogenic impacts in the area, since water sampling stations suffering different anthropogenic impacts were categorized differently, with poorer water quality, than stations near the dam and the environmental preservation area, which suffer significantly less anthropogenic impacts, and were categorized as presenting better water quality. The constructed indices are thus helpful in investigating environmental conditions in areas that show well-defined hydrological cycles, in addition to being valuable tools in the detection of anthropogenic impacts. The statistical techniques applied in the construction of these indices may also be used to construct other indices in different geographical areas, taking into account the specificities for each area.

  20. Application of multivariate statistical approach to identify trace elements sources in surface waters: a case study of Kowalskie and Stare Miasto reservoirs, Poland.

    Siepak, Marcin; Sojka, Mariusz


    The paper reports the results of measurements of trace elements concentrations in surface water samples collected at the lowland retention reservoirs of Stare Miasto and Kowalskie (Poland). The samples were collected once a month from October 2011 to November 2012. Al, As, Cd, Co, Cr, Cu, Li, Mn, Ni, Pb, Sb, V, and Zn were determined in water samples using the inductively coupled plasma with mass detection (ICP-QQQ). To assess the chemical composition of surface water, multivariate statistical methods of data analysis were used, viz. cluster analysis (CA), principal components analysis (PCA), and discriminant analysis (DA). They made it possible to observe similarities and differences in the chemical composition of water in the points of water samples collection, to uncover hidden factors accounting for the structure of the data, and to assess the impact of natural and anthropogenic sources on the content of trace elements in the water of retention reservoirs. The conducted statistical analyses made it possible to distinguish groups of trace elements allowing for the analysis of time and spatial variation of water in the studied reservoirs.

  1. Estimation of reservoir inflow in data scarce region by using Sacramento rainfall runoff model - A case study for Sittaung River Basin, Myanmar

    Myo Lin, Nay; Rutten, Martine


    The Sittaung River is one of four major rivers in Myanmar. This river basin is developing fast and facing problems with flood, sedimentation, river bank erosion and salt intrusion. At present, more than 20 numbers of reservoirs have already been constructed for multiple purposes such as irrigation, domestic water supply, hydro-power generation, and flood control. The rainfall runoff models are required for the operational management of this reservoir system. In this study, the river basin is divided into (64) sub-catchments and the Sacramento Soil Moisture Accounting (SAC-SMA) models are developed by using satellite rainfall and Geographic Information System (GIS) data. The SAC-SMA model has sixteen calibration parameters, and also uses a unit hydrograph for surface flow routing. The Sobek software package is used for SAC-SMA modelling and simulation of river system. The models are calibrated and tested by using observed discharge and water level data. The statistical results show that the model is applicable to use for data scarce region. Keywords: Sacramento, Sobek, rainfall runoff, reservoir

  2. South Asia as a Reservoir for the Global Spread of Ciprofloxacin-Resistant Shigella sonnei: A Cross-Sectional Study

    Pham Thanh, Duy; De Lappe, Niall; Cormican, Martin; Howden, Benjamin P.; Wangchuk, Sonam; Bodhidatta, Ladaporn; Nguyen Thi Nguyen, To; Thompson, Corinne N.; Phu Huong Lan, Nguyen; Voong Vinh, Phat; Ha Thanh, Tuyen; Turner, Paul; Sar, Poda; Thwaites, Guy; Thomson, Nicholas R.; Holt, Kathryn E.; Baker, Stephen


    Background Antimicrobial resistance is a major issue in the Shigellae, particularly as a specific multidrug-resistant (MDR) lineage of Shigella sonnei (lineage III) is becoming globally dominant. Ciprofloxacin is a recommended treatment for Shigella infections. However, ciprofloxacin-resistant S. sonnei are being increasingly isolated in Asia and sporadically reported on other continents. We hypothesized that Asia is a primary hub for the recent international spread of ciprofloxacin-resistant S. sonnei. Methods and Findings We performed whole-genome sequencing on a collection of 60 contemporaneous ciprofloxacin-resistant S. sonnei isolated in four countries within Asia (Vietnam, n = 11; Bhutan, n = 12; Thailand, n = 1; Cambodia, n = 1) and two outside of Asia (Australia, n = 19; Ireland, n = 16). We reconstructed the recent evolutionary history of these organisms and combined these data with their geographical location of isolation. Placing these sequences into a global phylogeny, we found that all ciprofloxacin-resistant S. sonnei formed a single clade within a Central Asian expansion of lineage III. Furthermore, our data show that resistance to ciprofloxacin within S. sonnei may be globally attributed to a single clonal emergence event, encompassing sequential gyrA-S83L, parC-S80I, and gyrA-D87G mutations. Geographical data predict that South Asia is the likely primary source of these organisms, which are being regularly exported across Asia and intercontinentally into Australia, the United States and Europe. Our analysis was limited by the number of S. sonnei sequences available from diverse geographical areas and time periods, and we cannot discount the potential existence of other unsampled reservoir populations of antimicrobial-resistant S. sonnei. Conclusions This study suggests that a single clone, which is widespread in South Asia, is likely driving the current intercontinental surge of ciprofloxacin-resistant S. sonnei and is capable of establishing

  3. Effect of Streamflow Forecast Uncertainty on Real-Time Reservoir Operation

    Zhao, T.; Cai, X.; Yang, D.


    Various hydrological forecast products have been applied to real-time reservoir operation, including deterministic streamflow forecast (DSF), DSF-based probabilistic streamflow forecast (DPSF), and ensemble streamflow forecast (ESF), which represent forecast uncertainty in the form of deterministic forecast error, deterministic forecast error-based uncertainty distribution, and ensemble forecast errors, respectively. Compared to previous studies that treat these forecast products as ad hoc inputs for reservoir operation models, this paper attempts to model the uncertainties involved in the various forecast products and explores their effect on real-time reservoir operation decisions. In hydrology, there are various indices reflecting the magnitude of streamflow forecast uncertainty; meanwhile, few models illustrate the forecast uncertainty evolution process. This research introduces Martingale Model of Forecast Evolution (MMFE) from supply chain management and justifies its assumptions for quantifying the evolution of uncertainty in streamflow forecast as time progresses. Based on MMFE, this research simulates the evolution of forecast uncertainty in DSF, DPSF, and ESF, and applies the reservoir operation models (dynamic programming, DP; stochastic dynamic programming, SDP; and standard operation policy, SOP) to assess the effect of different forms of forecast uncertainty on real-time reservoir operation. Through a hypothetical single-objective real-time reservoir operation model, the results illustrate that forecast uncertainty exerts significant effects. Reservoir operation efficiency, as measured by a utility function, decreases as the forecast uncertainty increases. Meanwhile, these effects also depend on the type of forecast product being used. In general, the utility of reservoir operation with ESF is nearly as high as the utility obtained with a perfect forecast; the utilities of DSF and DPSF are similar to each other but not as efficient as ESF. Moreover

  4. ACTG-HIV symptoms changes in patients switched to RPV/FTC/TDF due to previous intolerance to CART. Interim analysis of the PRO-STR study

    Daniel Podzamczer


    Full Text Available Introduction: Tolerability and convenience are crucial aspects for the long-term success of combined antiretroviral therapy (cART. The aim of this study was to investigate the impact in routine clinical practice of switching to the single tablet regimen (STR RPV/FTC/TDF in patients with intolerance to previous cART, in terms of patients’ well-being, assessed by several validated measures. Methods: Prospective, multicenter study. Adult HIV-infected patients with viral load under 1.000 copies/mL while receiving a stable ART for at least the last three months and switched to RPV/FTC/TDF due to intolerance of previous regimen, were included. Analyses were performed by ITT. Presence/magnitude of symptoms (ACTG-HIV Symptom Index, quality of life (EQ-5D, EUROQoL & MOS-HIV, adherence (SMAQ, preference of treatment and perceived ease of medication (ESTAR through 48 weeks were performed. Results: Interim analysis of 125 patients with 16 weeks of follow up was performed. 100 (80% were male, mean age 46 years. Mean CD4 at baseline was 629.5±307.29 and 123 (98.4% had viral load <50 copies/mL; 15% were HCV co-infected. Ninety two (73.6% patients switched from a NNRTI (84.8% from EFV/FTC/TDF and 33 (26.4% from a PI/r. The most frequent reasons for switching were psychiatric disorders (51.2%, CNS adverse events (40.8%, gastrointestinal (19.2% and metabolic disorders (19.2%. At the time of this analysis (week 16, four patients (3.2% discontinued treatment: one due to adverse events, two virologic failures and one with no data. A total of 104 patients (83.2% were virologically suppressed (<50 copies/mL. The average degree of discomfort in the ACTG-HIV Symptom Index significantly decreased from baseline (21±15.55 to week 4 (10.89±12.36 & week 16 (10.81±12.62, p<0.001. In all the patients, quality of life tools showed a significant benefit in well-being of the patients (Table 1. Adherence to therapy significantly and progressively increased (SMAQ from

  5. Perturbation of lipids and glucose metabolism associated with previous 2,4-D exposure: a cross-sectional study of NHANES III data, 1988-1994

    Schreinemachers Dina M


    Full Text Available Abstract Background Results from previous population studies showed that mortality rates from acute myocardial infarction and type-2 diabetes during the 1980s and 1990s in rural, agricultural counties of Minnesota, Montana, North and South Dakota, were higher in counties with a higher level of spring wheat farming than in counties with lower levels of this crop. Spring wheat, one of the major field crops in these four states, was treated for 85% or more of its acreage with chlorophenoxy herbicides. In the current study NHANES III data were reviewed for associations of 2,4-dichlorophenoxy acetic acid (2,4-D exposure, one of the most frequently used chlorophenoxy herbicides, with risk factors that are linked to the pathogenesis of acute myocardial infarction and type-2 diabetes, such as dyslipidemia and impaired glucose metabolism. Methods To investigate the toxicity pattern of chlorophenoxy herbicides, effects of a previous 2,4-D exposure were assessed by comparing levels of lipids, glucose metabolism, and thyroid stimulating hormone in healthy adult NHANES III subjects with urinary 2,4-D above and below the level of detection, using linear regression analysis. The analyses were conducted for all available subjects and for two susceptible subpopulations characterized by high glycosylated hemoglobin (upper 50th percentile and low thyroxine (lower 50th percentile. Results Presence of urinary 2,4-D was associated with a decrease of HDL levels: 8.6% in the unadjusted data (p-value = 0.006, 4.8% in the adjusted data (p-value = 0.08, and 9% in the adjusted data for the susceptible subpopulation with low thyroxine (p-value = 0.02. An effect modification of the inverse triglycerides-HDL relation was observed in association with 2,4-D. Among subjects with low HDL, urinary 2,4-D was associated with increased levels of triglycerides, insulin, C-peptide, and thyroid stimulating hormone, especially in the susceptible subpopulations. In contrast, subjects with

  6. Late tamoxifen in patients previously operated for breast cancer without postoperative tamoxifen: 5-year results of a single institution randomised study

    Bidoli Ettore


    Full Text Available Abstract Background A population of breast cancer patients exists who, for various reasons, never received adjuvant post-operative tamoxifen (TAM. This study was aimed to evaluate the role of late TAM in these patients. Methods From 1997 to 2003, patients aged 35 to 75 years, operated more than 2 years previously for monolateral breast cancer without adjuvant TAM, with no signs of metastases and no contraindication to TAM were randomized to TAM 20 mg/day orally for 2 years or follow-up alone. Events were categorized as locoregional relapse, distant metastases, metachronous breast cancer, tumours other than breast cancer and death from any causes, whichever occurred first. The sample size (197 patients per arm, plus 10% allowance was based on the assumption of a 30% decrease in the number of events occurring at a rate of 5% annually in the 10 years following randomization. Four hundred and thirty-three patients were randomized in the study (TAM 217, follow-up 216. Patients characteristics (TAM/follow-up included: median age 55/55 years, median time from surgery 25/25 months (range, 25-288/25-294, in situ carcinoma 18/24, oestrogen receptor (ER positive in 75/68, negative in 70/57, unknown in 72/91 patients. Previous adjuvant treatment included chemotherapy in 131/120 and an LHRH analogue in 11/13 patients. Results Thirty-six patients prematurely discontinued TAM after a median of 1 month, mostly because of subjective intolerance. Eighty-three events (TAM 39, follow-up 44 occurred: locoregional relapse in 10/8, distant metastases in 14/16, metachronous breast cancer in 4/10, other tumours in 11/10 patients. Less ER-positive secondary breast cancers occurred in the TAM treated patients than in follow-up patients (1 vs 10, p = 0.005. Event-free survival was similar in both groups of patients. Conclusions This 5-year analysis revealed significantly less metachronous ER-positive breast cancers in the TAM treated patients. No other statistically

  7. An Integrated Study of the Grayburg/San Andres Reservoir, Foster and South Cowden Fields, Ector County Texas

    Weinbrandt, Richard; Trentham, Robert C; Robinson, William


    For a part of the Foster and South Cowden (Grayburg-San Andres) oil fields, improvement in oil production has been accomplished, in part, by using "pipeline fracturing" technology in the most recent completion to improve fluid flow rates, and filtration of waterflood injection water to preserve reservoir permeability. The 3D seismic survey acquired in conjunction with this DOE project has been used to calculate a 3D seismic inversion model, which has been analyzed to provide detailed maps of porosity within the productive upper 250 feet of the Grayburg Formation. Geologic data, particularly from logs and cores, have been combined with the geophysical interpretation and production history information to develop a model of the reservoir that defines estimations of remaining producible oil. The integrated result is greater than the sum of its parts, since no single data form adequately describes the reservoir. Each discipline relies upon computer software that runs on PC-type computers, allowing virtually any size company to affordably access the technology required to achieve similar results.

  8. An Experimental and Modeling Study on the Response to Varying Pore Pressure and Reservoir Fluids in the Morrow A Sandstone

    Aaron V. Wandler


    Full Text Available In mature oil fields undergoing enhanced oil recovery methods, such as CO2 injection, monitoring the reservoir changes becomes important. To understand how reservoir changes influence compressional wave (P and shear wave (S velocities, we conducted laboratory core experiments on five core samples taken from the Morrow A sandstone at Postle Field, Oklahoma. The laboratory experiments measured P- and S-wave velocities as a function of confining pressure, pore pressure, and fluid type (which included CO2 in the gas and supercritical phase. P-wave velocity shows a response that is sensitive to both pore pressure and fluid saturation. However, S-wave velocity is primarily sensitive to changes in pore pressure. We use the fluid and pore pressure response measured from the core samples to modify velocity well logs through a log facies model correlation. The modified well logs simulate the brine- and CO2-saturated cases at minimum and maximum reservoir pressure and are inputs for full waveform seismic modeling. Modeling shows how P- and S-waves have a different time-lapse amplitude response with offset. The results from the laboratory experiments and modeling show the advantages of combining P- and S-wave attributes in recognizing the mechanism responsible for time-lapse changes due to CO2 injection.

  9. Numerical Study on the Permeability of the Hydraulic-Stimulated Fracture Network in Naturally-Fractured Shale Gas Reservoirs

    Zhaobin Zhang


    Full Text Available As hydraulic fracturing is a fluid-rock coupling process, the permeability of the hydraulic-stimulated fracture network in the initial stage has great effects on the propagation of the hydraulic fracture network in the following stages. In this work, the permeability of the hydraulic-stimulated fracture network in shale gas reservoirs is investigated by a newly-proposed model based on the displacement discontinuity method. The permeability of the fracture network relies heavily on fracture apertures, which can be calculated with high precision by the displacement discontinuity method. The hydraulic fracturing processes are simulated based on the natural fracture networks reconstructed from the shale samples in the Longmaxi formation of China. The flow fields are simulated and the permeability is calculated based on the fracture configurations and fracture apertures after hydraulic fracturing treatment. It is found that the anisotropy of the permeability is very strong, and the permeability curves have similar shapes. Therefore, a fitting equation of the permeability curve is given for convenient use in the future. The permeability curves under different fluid pressures and crustal stress directions are obtained. The results show that the permeability anisotropy is stronger when the fluid pressure is higher. Moreover, the permeability anisotropy reaches the minimum value when the maximum principle stress direction is perpendicular to the main natural fracture direction. The investigation on the permeability is useful for answering how the reservoirs are hydraulically stimulated and is useful for predicting the propagation behaviors of the hydraulic fracture network in shale gas reservoirs.

  10. Study and application on the evaluation method of porous formation for long-term waterflooding sand reservoir

    Wang Changjiang; Jiang Hanqiao; Chen Minfeng; Geng Zhanli; Liu Pengfei


    Nine targets which stand both for the static characteristic of produced formations and the dynamic parameter of wells including the average permeability, variation coefficient of permeability, moving capability, remaining recoverable reserves, coefficient of flooding, daily oil production, increasing rate of water cut, cumulative liquid production per unit meter and efficiency index of oil production are selected as the evaluation indexes, a novel model to evaluate the porous formations in long-term waterflooding sand reservoir was established by using the support vector machine and clustering analysis. Data of 57 wefts from Shentuo 21 block Shengli oilfield was analyzed by using the model. Four kinds of forma-tion groups were gained. According to the analysis result, different adjustment solutions were put forward to develop the relevant formations. The Monthly oil production increased 7.6 % and the water cut decreased 8.9 % after the adjusted solutions. Good results indicate that the learning from this method gained will be valuable adding to other long-term wa-terflooding sand reservoirs in Shengli oilfield and other similar reservoirs worldwide.

  11. Problems in the Labor Export of Western Rural Areas——A Case Study of Three Gorges Reservoir Area


    The thesis gives a brief account of the status of the labor economy in Three Gorges Reservoir area,which indicates that the labor economy in this area has made certain development and is characterized by fragile ecology,backward economic development and weak capacity to absorb employment,the Three Gorges Reservoir area is densely populated and has lots of rural surplus labors which need to be transferred.Then the thesis analyzes the problems in the labor export of this region,which can be manifested in the following aspects:the exported labors are with low quality and single skill;they are narrow-minded and have strong intention for their employment regions;they have low income but high risk to get employed;the government does not provide strong supporting services for exported labors.In order to solve these problems,the thesis proposes the suggestions and measures to develop the labor economy in Three Gorges Reservoir area,say,to perfect and ameliorate the training mechanism and improve the quality and skills of labors;to build the platform of employment network and solve the problems of the asymmetric employment information;to actively develop the intermediary organizations and promote the a proper movement of labor forces;to fully exert the function of government in logistic services and resolve the difficulties of the exported workers.

  12. In vitro evaluation of oestrogenic/androgenic activity of the serum organochlorine pesticide mixtures previously described in a breast cancer case–control study

    Rivero, Javier; Luzardo, Octavio P., E-mail:; Henríquez-Hernández, Luis A.; Machín, Rubén P.; Pestano, José; Zumbado, Manuel; Boada, Luis D.; Camacho, María; Valerón, Pilar F.


    Some organochlorine pesticides (OCs) have been individually linked to breast cancer (BC) because they exert oestrogenic effects on mammary cells. However, humans are environmentally exposed to more or less complex mixtures of these organochlorines, and the biological effects of these mixtures must be elucidated. In this work we evaluated the in vitro effects exerted on human BC cells by the OC mixtures that were most frequently detected in two groups of women who participated in a BC case–control study developed in Spain: healthy women and women diagnosed with BC. The cytotoxicity, oestrogenicity, and androgenicity of the most prevalent OC mixtures found in healthy women (H-mixture) and in BC patients (BC-mixture) were tested at concentrations that resembled those found in the serum of the evaluated women. Our results showed that both OC mixtures presented a similar oestrogenic activity and effect on cell viability, but BC-mixture showed an additional anti-androgenic effect. These results indicate that although the proliferative effect exerted by these mixtures on human breast cells seems to depend mainly on their oestrogenic action, the BC-mixture might additionally induce cell proliferation due to its anti-androgenic activity, therefore increasing the carcinogenic potential of this mixture. The findings of this study demonstrate that subtle variations in the composition of a mixture may induce relevant changes in its biological action. - Highlights: • E-screen and A-screen of two mixtures of organochlorine pesticides (OCP) • Assay concentrations based on a previous breast cancer case–control study • Only non-cytotoxic concentrations assayed • Both OCP mixtures induce proliferation mediated by oestrogen receptor. • OCP mixture of breast cancer patients exhibits additional androgenic activity.

  13. Evaluation of the Widal tube agglutination test for the diagnosis of typhoid fever among children admitted to a rural hdospital in Tanzania and a comparison with previous studies

    Malahiyo Rajabu


    Full Text Available Abstract Background The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi. However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability. Methods We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV, and negative predictive value (NPV of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives." Results We found that 16 (1% of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies. Conclusion Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of ≥ 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable.

  14. Effects of testosterone replacement therapy on nocturia and quality of life in men with hypogonadism: a subanalysis of a previous prospective randomized controlled study in Japan.

    Shigehara, Kazuyoshi; Konaka, Hiroyuki; Koh, Eitetsu; Izumi, Koji; Kitagawa, Yasuhide; Mizokami, Atsushi; Nakashima, Takao; Shimamura, Masayoshi; Iwamoto, Teruaki; Namiki, Mikio


    We investigated the effects of testosterone replacement therapy (TRT) on nocturia and general health among men with hypogonadism and nocturia. From our previous EARTH study population, 64 patients with a clinical diagnosis of nocturia (two or more times per one night) and hypogonadism, comprising the TRT group (n = 31) and controls (n = 33), were included in this analysis. The TRT group was administered 250 mg of testosterone enanthate as an intramuscular injection every 4 weeks for 6 months. All patients responded to the following questionnaires: International Prostatic Symptoms Score (IPSS), Aging Male Symptoms (AMS) score and Short Form-36 health survey at baseline and 6-month visit. These categories were compared based on changes from baseline to the 6-month visit between TRT and control groups. At the 6-month visit, the TRT group had a significant decrease in IPSS question no. 7 and AMS question no. 4, whereas no significant changes were observed in the control group. Additionally, role limitation because of health program, vitality and mental health domains were significantly improved in the TRT group. Six-month TRT may improve nocturia, sleep conditions and quality of life among men with hypogonadism and nocturia.

  15. Reservoir stimulation techniques to minimize skin factor of Longwangmiao Fm gas reservoirs in the Sichuan Basin

    Guo Jianchun


    Full Text Available The Lower Cambrian Longwangmiao Fm carbonatite gas reservoirs in the Leshan-Longnüsi Paleouplift in the Sichuan Basin feature strong heterogeneity, well-developed fractures and caverns, and a high content of H2S, so these reservoirs are prone to reservoir damages caused by the invasion of drilling fluid or the improper well completion, so to minimize the reservoir skin factor is key to achieving high yield of oil and gas in this study area. Therefore, based on the geological characteristics of the Longwangmiao reservoirs, the binomial productivity equation was applied to demonstrate the possibility and scientificity of minimizing the skin factor. According to the current status of reservoir stimulation, the overall skin factors of reservoir damage caused by drilling fluid invasion, improper drilling and completion modes etc were analyzed, which shows there is still potential for skin factor reduction. Analysis of reservoir damage factors indicates that the main skin factor of Longwangmiao Fm reservoirs consists of that caused by drilling fluid and by improper completion modes. Along with the minimization of skin factor caused by drilling and improper completion, a fracture-network acidizing process to achieve “non-radial & network-fracture” plug-removal by making good use of natural fractures was proposed according to the characteristics of Longwangmiao Fm carbonatite reservoirs.

  16. Efficacy of confrontational counselling for smoking cessation in smokers with previously undiagnosed mild to moderate airflow limitation: study protocol of a randomized controlled trial

    Huibers Marcus JH


    Full Text Available Abstract Background The use of spirometry for early detection of chronic obstructive pulmonary disease (COPD is still an issue of debate, particularly because of a lack of convincing evidence that spirometry has an added positive effect on smoking cessation. We hypothesise that early detection of COPD and confrontation with spirometry for smoking cessation may be effective when applying an approach we have termed "confrontational counselling"; a patient-centred approach which involves specific communication skills and elements of cognitive therapy. An important aspect is to confront the smoker with his/her airflow limitation during the counselling sessions. The primary objective of this study is to test the efficacy of confrontational counselling in comparison to regular health education and promotion for smoking cessation delivered by specialized respiratory nurses in current smokers with previously undiagnosed mild to moderate airflow limitation. Methods/Design The study design is a randomized controlled trial comparing confrontational counselling delivered by a respiratory nurse combined with nortriptyline for smoking cessation (experimental group, health education and promotion delivered by a respiratory nurse combined with nortriptyline for smoking cessation (control group 1, and "care as usual" delivered by the GP (control group 2. Early detection of smokers with mild to moderate airflow limitation is achieved by means of a telephone interview in combination with spirometry. Due to a comparable baseline risk of airflow limitation and motivation to quit smoking, and because of the standardization of number, duration, and scheduling of counselling sessions between the experimental group and control group 1, the study enables to assess the "net" effect of confrontational counselling. The study has been ethically approved and registered. Discussion Ethical as well as methodological considerations of the study are discussed in this protocol. A

  17. The Study of Clay Minerals Distribution in Lianhua Reservoir%莲花油层中粘土矿物分布规律研究

    唐洪明; 曾凡刚; 陈忠; 赵敬松; 沈明道; 唐清山; 柴利文; 魏桂萍


    The Lianhua reservoir of Shahejie group(geology period E1) in Gaosheng Oil field , located in Liaohe granen faulting basin, is rich in heavy crude oil, with the burial depth being 1 450~1 700 m.The reservoirs have been under development for 22 years. The company has made great profit from the reservoir development by means of steam-flooding technology, but some problems have been found in the reservo i r with the technology application, because the difficulty in reservoir developme nt is increasing with the frequency of applying the technology. By the end of 19 98 the average steam flooding for every well has been four times, but the more s team-flooding, the less satisfactory the efforts to increase the production.   Therefore, a more comprehensive study of the types, content, and the horizonta l and vertical distribution characteristics of the clay minerals in the reservoi r is of most important consequence to the design of the heavy crude oil developme nt, reservoir protection, reservoir evaluation, and enhanced oil recovery (EOR) etc. The clay minerals in Lianhua reservoir are systematically studied by means of X-ray diffraction, scan electronic microscope and heat simulation experiment s.   The Lianhua reservoir is a sediment by gravity flow, with the rock types bein g gravel, sandstone, and mudstone, and the sedimentary depth being 50~600 m. L ian hua reservoir has excellent physical property, with the porosity being 20%~26% and the permeability being 1~4 μm2.   The studies show that the major clay minerals in Lianhua reservoir are montmoril lonite(60%~85%), illite (8%~20%), kaolinite (5%~25%), and chlorite (<5%). T he montm orillonite content decreases with the increase of the burial depth, but the kaol inite and illite content are just the opposite, because the porosity fluid in sa ndstone and gravels more easily circulative than that in mudstone, and the mont morillonite in sandstone can more easily convert into other

  18. Prevention of Reservoir Interior Discoloration

    Arnold, K.F.


    Contamination is anathema in reservoir production. Some of the contamination is a result of welding and some appears after welding but existed before. Oxygen was documented to be a major contributor to discoloration in welding. This study demonstrates that it can be controlled and that some of the informal cleaning processes contribute to contamination.

  19. Worldwide Experience of Sediment Flushing Through Reservoirs

    Muhammad Asif Chaudhry


    Full Text Available Globally there are about 25,500 storage reservoirs with total storage volume of about 6,464 Bcm. The maximum number of reservoirs are in North America, i.e. 7205 with the total storage volume of about 1,844 Bcm, whereas minimum number of reservoirs are in Central Asia, i.e. 44, with the total storage volume of about 148 Bcm. Over the globe, average annual reservoir storage loss due to sedimentation varies from 0.1-2.3%, however, average annual world storage loss is about 1.0%. In order to combat the storage loss, the techniques used globally are: watershed management, dredging of deposited sediments, sediment routing/sluicing, sediment bypassing, density current venting and sediment flushing through reservoir, separately and also in combination. Each approach has its own limitations, depending on the site conditions. Sediment flushing technique is used by two ways i.e. Drawdown flushing and Emptying and Flushing. In Emptying and Flushing, the reservoir is emptied before the flood season, resulting in the creation of river-like flow conditions in the reservoir. The flow velocities in the reservoir are increased to such an extent that deposited sediments are remobilized and transported through the low level outlets provided slightly above the original riverbed level with sufficient flow capacity. Flushing is not a new technique and has been experienced for the last 6 decades on several reservoirs of the world. The results of the study reveal that there are about 50 reservoirs which are flushed, out of which flushing data is available for about 22 reservoirs only. However 6 reservoirs have been found with successful application of flushing operation and all other are flushed with low flushing efficiency. Flushing has been successfully implemented at Baira-India, Gebidem-Switzerland, Gmund-Austria, Hengshan-China, Palagnedraswitzerland, Santo-Domingo-Venezuela Reservoirs, while the unsuccessfully flushed reservoirs are: Chinese reservoirs, Gaunting

  20. Ground-water quality in Geauga County, Ohio; review of previous studies, status in 1999, and comparison of 1986 and 1999 data

    Jagucki, Martha L.; Darner, Robert A.


    Most residents in Geauga County, Ohio, rely on ground water as their primary source of drinking water. With population growing at a steady rate, the possibility that human activity will affect ground-water quality becomes considerable. This report presents the results of a study by the U.S. Geological Survey (USGS), in cooperation with the Geauga County Planning Commission and Board of County Commissioners, to provide a brief synopsis of work previously done within the county, to assess the present (1999) ground-water quality, and to determine any changes in ground-water quality between 1986 and 1999. Previous studies of ground-water quality in the county have consistently reported that manganese and iron concentrations in ground water in Geauga County often exceed the U.S. Environmental Protection Agency (USEPA) Secondary Maximum Contaminant Level (SMCL). Road salt and, less commonly, oil-field brines and volatile organic compounds (VOCs) have been found in ground water at isolated locations. Nitrate has not been detected above the USEPA Maximum Contaminant Level (MCL) of 10 milligrams per liter as N; however, nitrate has been found in some locations at levels that may indicate the effects of fertilizer application or effluent from septic systems. Between June 7 and July 1, 1999, USGS personnel collected a total of 31 water-quality samples from wells completed in glacial deposits, the Pottsville Formation, the Cuyahoga Group, and the Berea Sandstone. All samples were analyzed for VOCs, sulfide, dissolved organic carbon, major ions, trace elements, alkalinity, total coliforms, and Escherichia coli bacteria. Fourteen of the samples also were analyzed for tritium. Water-quality data were used to determine (1) suitability of water for drinking, (2) age of ground water, (3) stratigraphic variation in water quality, (4) controls on water quality, and (5) temporal variation in water quality. Water from 16 of the 31 samples exceeded the Geauga County General Health

  1. Distribution of interferon lambda-3 gene polymorphisms in Australian patients with previously untreated genotype 1 chronic hepatitis C: Analysis from the PREDICT and CHARIOT studies.

    Roberts, Stuart K; Mitchell, Joanne; Leung, Reynold; Booth, David; Bollipo, Steven; Ostapowicz, George; Sloss, Andrew; McCaughan, Geoffrey W; Dore, Gregory J; Thompson, Alexander; Crawford, Darrell Hg; Sievert, William; Weltman, Martin; Cheng, Wendy; George, Jacob


    The aim of this study was to examine the distribution of interferon lambda-3 (IFN-λ3) gene polymorphisms in previously untreated Australian patients with genotype 1 (Gt1) chronic hepatitis C (CHC) and to compare the IFN-λ3 genotype frequency among the different ethnic populations. This was a prospective, multicenter, observational study undertaken by the Australian Liver Association Clinical Research Network. Eligible subjects had Gt1 CHC and were being considered for and/or undergoing treatment. IFN-λ3 single nucleotide polymorphisms were genotyped by the Applied Biosystems's Taqman single nucleotide polymorphism genotyping assay. Between May 2012 and June 2012, 1132 patients were recruited from 38 treatment clinics across Australia. Also, 561 subjects from the CHARIOT (collaborative group hepatitis C study using high dose Pegasys RBV Induction dose in genotype one) study of high-dose interferon who had baseline serum available were retrospectively tested. The overall frequency of IFN-λ3 rs12979860 CC/CT/TT genotypes was 36%, 52%, and 12%, and that of rs8099917 TT/TG/GG genotypes was 54%, 41%, and 5%, respectively. The prevalence of the favorable IFN-λ3 rs12979860 CC and rs8099917 TT genotypes in Causcasians, Asians, Aboriginals, Maori/Pacific Islanders, and Mediterraneans was 32% and 52%, 80% and 86%, 33% and 63%, 77% and 88%, and 19% and 29%, respectively. Compared with Caucasians, the frequency of IFN-λ3 CC was significantly higher among Asians (P < 0.0001) and Maori/Pacific Islander subjects (P < 0.0001). The distribution of IFN-λ3 polymorphisms among untreated patients with Gt1 CHC in Australia appears similar to that reported from North America. The frequency of the favorable response alleles varies considerably according to ethnicity, being more common in self-reported Asians and Maori/Pacific Islanders than Caucasians, Aboriginals, and Mediterraneans. © 2013 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty

  2. Sweet spot identification and smart development -An integrated reservoir characterization study of a posidonia shale of a posidonia shale outcrop analogue

    Veen, J.H. ten; Verreussel, R.M.C.H.; Ventra, D.; Zijp, M.H.A.A.


    Shale gas reservoir stimulation procedures (e.g. hydraulic fracturing) require upfront prediction and planning that should be supported by a comprehensive reservoir characterization. Therefore, understanding shale depositional processes and associated vertical and lateral sedimentological variabilit

  3. Reservoir-flooded river mouth areas as sediment traps revealing erosion from peat mining areas - Jukajoki case study in eastern Finland

    Tahvanainen, Teemu; Meriläinen, Henna-Kaisa; Haraguchi, Akira; Simola, Heikki


    Many types of soil-disturbing land use have caused excess sedimentation in Finnish lakes. Identification and quantification of catchment sources of sediment material is crucial in cases where demands for remediation measures are considered. We studied recent (50 yr) sediments of four small rivers, all draining to a reservoir impounded in 1971. Catchments of two of the rivers had had peat mining activities from early 1980s until recently, exposing large areas of peat surfaces to erosion. The water level of the reservoir had risen to the river mouth areas of all rivers, while in each case, the river mouth areas still form riverine narrows separable from the main reservoir, hence collecting sedimentation from their own catchments. The original soils under the reservoir water level could readily be observed in core samples, providing a dated horizon under recent sediments. In addition, we used 137Cs-stratigraphies for dating of samples from original river bed locations. As expected, recent sediments of rivers with peat mining influence differed from others e.g. by high organic content and C:N ratios. Stable isotopes 13C and 15N both correlated with C:N (r = 0.799 and r = -0.717, respectively) and they also differentiated the peat-mining influenced samples from other river sediments. Principal components of the physical-chemical variables revealed clearer distinction than any variables separately. Light-microscopy revealed abundance of leafs of Sphagnum mosses in peat-mining influenced river sediments that were nearly absent from other rivers. Spores of Sphagnum were, however, abundant in all river sediments indicating their predominantly airborne origin. We find that combination of several physical-chemical characters rather than any single variable and microscopy of plant remains can result in reliable recognition of peatland-origin of sediment material when non-impacted sites are available for comparison. Dating of disturbed recent sediments is challenging. River

  4. Reservoir Engineering Management Program

    Howard, J.H.; Schwarz, W.J.


    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  5. Dynamic reservoir well interaction

    Sturm, W.L.; Belfroid, S.P.C.; Wolfswinkel, O. van; Peters, M.C.A.M.; Verhelst, F.J.P.C.M.


    In order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady s

  6. 三座店水库与二道河子水库供水调度规则研究%The study of scheduling rules of the water supply in Sanzhuodian reservoir and Erdaohezi reservoir



    For Sanzhuodian reservoir and Erdaohezi reservoir joint scheduling problem ,the use of a single database operation chart plus two joint scheduling method to determine the rules of joint water reservoir rule , two water reservoir scheduling model were established.Particle swarm optimization algorithm through the water rules and analog two-reservoir operation run under the rules ,and the results and compensation adjustment rule corresponding results were compared to verify that the scheduling rules of rationality and effectiveness.%针对三座店水库与二道河子水库联合调度问题,采用单库调度图加联合调度规则法确定两水库联合供水规则,建立了两水库供水调度模型。通过粒子群算法优化该供水规则,并模拟两水库在该规则下的调度运行,将其结果与补偿调节规则对应结果进行对比,检验该调度规则的合理性和有效性。

  7. Identifying and Evaluating of Oil Reservoir

    Yang Haixia


    The identification and evaluation of oil reservoir with logging data are one of most important ways in geologic logging services. For the last decades, with the further development of the oil & gas exploration, great advances have been achieved in techniques on the acquisition, processing and interpretative evaluation of logging data. How to identify fluid characteristics and evaluate the productivity in light oil reservoir (the crude density being between 0.74g/cm3 and 0.82g/cm3)has become one of the difficulties.With the establishment of the regional interpretation criterion of the study blocks, the optimized logging parameters that reflect the reservoir characteristics have been used to establish the chart for the interpretation of oil-water reservoir combining with well logging parameters. Then, to begin with geologic reserves of crude in single well, we establish evaluation criterion for productivity in oil reservoir with determining lower limit value of the reservoir and applying the relationship between chart parameters. The techniques are verified in production and get better effect.On the basis of the reservoir characteristics analysis of both basin A and B, We established the evaluation method of static productivity on light oil reservoir with getting quantitative evaluation parameters after quantitatively evaluating the date of core, pyrolysis chromatogram and gas chromatogram. It provides new technique 7 for new well interpretation and old well review, as well as evidence for of well testing.


    Abbas Firoozabadi


    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly

  9. Modeling vapor dominated geothermal reservoirs

    Marconcini, R.; McEdwards, D.; Neri, G.; Ruffilli, C.; Schroeder, R.; Weres, O.; Witherspoon, P.


    The unresolved questions with regard to vapor-dominated reservoir production and longevity are reviewed. The simulation of reservoir behavior and the LBL computer program are discussed. The geology of Serrazzano geothermal field and its reservoir simulation are described. (MHR)

  10. Exact propagation of open quantum systems in a system-reservoir context

    Stockburger, Jürgen T


    A stochastic representation of the dynamics of open quantum systems, suitable for non-perturbative system-reservoir interaction, non-Markovian effects and arbitrarily driven systems is presented. It includes the case of driving on timescales comparable to or shorter than the reservoir correlation time, a notoriously difficult but relevant case in the context of quantum information processing and quantum thermodynamics. A previous stochastic approach is re-formulated for the case of finite reservoir correlation and response times, resulting in a numerical simulation strategy exceeding previous ones by orders of magnitude in efficiency. Although the approach is based on a memory formalism, the dynamical equations propagated in the simulations are time-local. This leaves a wide range of choices in selecting the system to be studied and the numerical method used for propagation. For a series of tests, the dynamics of the spin-boson system is computed in various settings including strong external driving and Landa...

  11. A feasibility study on the expected seismic AVA signatures of deep fractured geothermal reservoirs in an intrusive basement

    Aleardi, Mattia; Mazzotti, Alfredo


    The deep geothermal reservoirs in the Larderello-Travale field (southern Tuscany) are found in intensively fractured portions of intrusive/metamorphic rocks. Therefore, the geothermal exploration has been in search of possible fracture signatures that could be retrieved from the analysis of geophysical data. In the present work we assess the feasibility of finding seismic markers in the pre-stack domain which may pinpoint fractured levels. Thanks to the availability of data from boreholes that ENEL GreenPower drilled in the deep intrusive basement of this geothermal field, we derived the expected amplitude versus angle (AVA) responses of the vapour reservoirs found in some intensely, but very localized, fractured volumes within the massive rocks. The information we have available limit us to build 1D elastic and isotropic models only and thus anisotropy effects related to the presence of fractures cannot be properly modelled. We analysed the velocities and the density logs pertaining to three wells which reached five deep fractured zones in the basement. The AVA response of the fractured intervals is modelled downscaling the log data to seismic scale and comparing the analytical AVA response (computed with the Aki and Richards approximation) and the AVA extracted from a synthetic common mid point (calculated making use of a reflectivity algorithm). The results show that the amplitude of the reflections from the fractured level is characterized by negative values at vertical incidence and by decreasing absolute amplitudes with the increase of the source to receiver offset. This contrasts with many observations from hydrocarbon exploration in clastic reservoirs where gas-sand reflections often exhibit negative amplitudes at short offsets but increasing absolute amplitudes for increasing source to receiver offsets. Thereby, some common AVA attributes considered in silicoclastic lithologies would lead to erroneous fracture localization. For this reason we propose a

  12. Kansas environmental and resource study: A Great Plains model. Monitoring fresh water resources. [water quality of reservoirs

    Yarger, H. L. (Principal Investigator); Mccauley, J. R.


    The author has identified the following significant results. Processing and analysis of CCT's for numerous ground truth supported passes over Kansas reservoirs has demonstrated that sun angle and atmospheric conditions are strong influences on water reflectance levels as detected by ERTS-1 and can suppress the contributions of true water quality factors. Band ratios, on the other hand, exhibit very little dependence on sun angle and sky conditions and thus are more directly related to water quality. Band ratio levels can be used to reliably determine suspended load. Other water quality indicators appear to have little or no affect on reflectance levels.

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