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Sample records for storage reservoirs analogs

  1. Evaluating Potential for Large Releases from CO2 Storage Reservoirs: Analogs, Scenarios, and Modeling Needs

    International Nuclear Information System (INIS)

    Birkholzer, Jens; Pruess, Karsten; Lewicki, Jennifer; Tsang, Chin-Fu; Karimjee, Anhar

    2005-01-01

    While the purpose of geologic storage of CO 2 in deep saline formations is to trap greenhouse gases underground, the potential exists for CO 2 to escape from the target reservoir, migrate upward along permeable pathways, and discharge at the land surface. Such discharge is not necessarily a serious concern, as CO 2 is a naturally abundant and relatively benign gas in low concentrations. However, there is a potential risk to health, safety and environment (HSE) in the event that large localized fluxes of CO 2 were to occur at the land surface, especially where CO 2 could accumulate. In this paper, we develop possible scenarios for large CO 2 fluxes based on the analysis of natural analogues, where large releases of gas have been observed. We are particularly interested in scenarios which could generate sudden, possibly self-enhancing, or even eruptive release events. The probability for such events may be low, but the circumstances under which they might occur and potential consequences need to be evaluated in order to design appropriate site selection and risk management strategies. Numerical modeling of hypothetical test cases is needed to determine critical conditions for such events, to evaluate whether such conditions may be possible at designated storage sites, and, if applicable, to evaluate the potential HSE impacts of such events and design appropriate mitigation strategies

  2. Analog storage integrated circuit

    Science.gov (United States)

    Walker, J.T.; Larsen, R.S.; Shapiro, S.L.

    1989-03-07

    A high speed data storage array is defined utilizing a unique cell design for high speed sampling of a rapidly changing signal. Each cell of the array includes two input gates between the signal input and a storage capacitor. The gates are controlled by a high speed row clock and low speed column clock so that the instantaneous analog value of the signal is only sampled and stored by each cell on coincidence of the two clocks. 6 figs.

  3. Fast multichannel analog storage system

    International Nuclear Information System (INIS)

    Freytag, D.R.

    1982-11-01

    A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. = 11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

  4. Analog readout for optical reservoir computers

    OpenAIRE

    Smerieri, Anteo; Duport, François; Paquot, Yvan; Schrauwen, Benjamin; Haelterman, Marc; Massar, Serge

    2012-01-01

    Reservoir computing is a new, powerful and flexible machine learning technique that is easily implemented in hardware. Recently, by using a time-multiplexed architecture, hardware reservoir computers have reached performance comparable to digital implementations. Operating speeds allowing for real time information operation have been reached using optoelectronic systems. At present the main performance bottleneck is the readout layer which uses slow, digital postprocessing. We have designed a...

  5. Reflection Phenomena in Underground Pumped Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Elena Pummer

    2018-04-01

    Full Text Available Energy storage through hydropower leads to free surface water waves in the connected reservoirs. The reason for this is the movement of water between reservoirs at different elevations, which is necessary for electrical energy storage. Currently, the expansion of renewable energies requires the development of fast and flexible energy storage systems, of which classical pumped storage plants are the only technically proven and cost-effective technology and are the most used. Instead of classical pumped storage plants, where reservoirs are located on the surface, underground pumped storage plants with subsurface reservoirs could be an alternative. They are independent of topography and have a low surface area requirement. This can be a great advantage for energy storage expansion in case of environmental issues, residents’ concerns and an unusable terrain surface. However, the reservoirs of underground pumped storage plants differ in design from classical ones for stability and space reasons. The hydraulic design is essential to ensure their satisfactory hydraulic performance. The paper presents a hybrid model study, which is defined here as a combination of physical and numerical modelling to use the advantages and to compensate for the disadvantages of the respective methods. It shows the analysis of waves in ventilated underground reservoir systems with a great length to height ratio, considering new operational aspects from energy supply systems with a great percentage of renewable energies. The multifaceted and narrow design of the reservoirs leads to complex free surface flows; for example, undular and breaking bores arise. The results show excessive wave heights through wave reflections, caused by the impermeable reservoir boundaries. Hence, their knowledge is essential for a successful operational and constructive design of the reservoirs.

  6. Beyond peak reservoir storage? A global estimate of declining water storage capacity in large reservoirs

    NARCIS (Netherlands)

    Wisser, D.; Frolking, S.; Hagen, Stephen; Bierkens, M.F.P.|info:eu-repo/dai/nl/125022794

    2013-01-01

    Water storage is an important way to cope with temporal variation in water supply anddemand. The storage capacity and the lifetime of water storage reservoirs can besignificantly reduced by the inflow of sediments. A global, spatially explicit assessment ofreservoir storage loss in conjunction with

  7. A fast multichannel analog storage system

    International Nuclear Information System (INIS)

    Freytag, D.R.

    1983-01-01

    A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. =11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

  8. Performance Analysis of Depleted Oil Reservoirs for Underground Gas Storage

    Directory of Open Access Journals (Sweden)

    Dr. C.I.C. Anyadiegwu

    2014-02-01

    Full Text Available The performance of underground gas storage in depleted oil reservoir was analysed with reservoir Y-19, a depleted oil reservoir in Southern region of the Niger Delta. Information on the geologic and production history of the reservoir were obtained from the available field data of the reservoir. The verification of inventory was done to establish the storage capacity of the reservoir. The plot of the well flowing pressure (Pwf against the flow rate (Q, gives the deliverability of the reservoir at various pressures. Results of the estimated properties signified that reservoir Y-19 is a good candidate due to its storage capacity and its flow rate (Q of 287.61 MMscf/d at a flowing pressure of 3900 psig

  9. Deriving Area-storage Curves of Global Reservoirs

    Science.gov (United States)

    Mu, M.; Tang, Q.

    2017-12-01

    Basic information including capacity, dam height, and largest water area on global reservoirs and dams is well documented in databases such as GRanD (Global Reservoirs and Dams), ICOLD (International Commission on Large Dams). However, though playing a critical role in estimating reservoir storage variations from remote sensing or hydrological models, area-storage (or elevation-storage) curves of reservoirs are not publicly shared. In this paper, we combine Landsat surface water extent, 1 arc-minute global relief model (ETOPO1) and GRanD database to derive area-storage curves of global reservoirs whose area is larger than 1 km2 (6,000 more reservoirs are included). First, the coverage polygon of each reservoir in GRanD is extended to where water was detected by Landsat during 1985-2015. Second, elevation of each pixel in the reservoir is extracted from resampled 30-meter ETOPO1, and then relative depth and frequency of each depth value is calculated. Third, cumulative storage is calculated with increasing water area by every one percent of reservoir coverage area and then the uncalibrated area-storage curve is obtained. Finally, the area-storage curve is linearly calibrated by the ratio of calculated capacity over reported capacity in GRanD. The derived curves are compared with in-situ reservoir data collected in Great Plains Region in US, and the results show that in-situ records are well captured by the derived curves even in relative small reservoirs (several square kilometers). The new derived area-storage curves have the potential to be employed in global monitoring or modelling of reservoirs storage and area variations.

  10. Reservoir storage and containment of greenhouse gases

    Energy Technology Data Exchange (ETDEWEB)

    Weir, G.J.; White, S.P.; Kissling, W.M. [Industrial Research Ltd., Lower Hutt (New Zealand)

    1995-03-01

    This paper considers the injection of CO{sub 2} into underground reservoirs. Computer models are used to investigate the disposal of CO{sub 2} generated by an 800 MW power station. A number of scenarios are considered, some of which result in containment of the CO{sub 2} over very long time scales and others result in the escape of the CO{sub 2} after a few hundred years.

  11. Microbial Life in an Underground Gas Storage Reservoir

    Science.gov (United States)

    Bombach, Petra; van Almsick, Tobias; Richnow, Hans H.; Zenner, Matthias; Krüger, Martin

    2015-04-01

    While underground gas storage is technically well established for decades, the presence and activity of microorganisms in underground gas reservoirs have still hardly been explored today. Microbial life in underground gas reservoirs is controlled by moderate to high temperatures, elevated pressures, the availability of essential inorganic nutrients, and the availability of appropriate chemical energy sources. Microbial activity may affect the geochemical conditions and the gas composition in an underground reservoir by selective removal of anorganic and organic components from the stored gas and the formation water as well as by generation of metabolic products. From an economic point of view, microbial activities can lead to a loss of stored gas accompanied by a pressure decline in the reservoir, damage of technical equipment by biocorrosion, clogging processes through precipitates and biomass accumulation, and reservoir souring due to a deterioration of the gas quality. We present here results from molecular and cultivation-based methods to characterize microbial communities inhabiting a porous rock gas storage reservoir located in Southern Germany. Four reservoir water samples were obtained from three different geological horizons characterized by an ambient reservoir temperature of about 45 °C and an ambient reservoir pressure of about 92 bar at the time of sampling. A complementary water sample was taken at a water production well completed in a respective horizon but located outside the gas storage reservoir. Microbial community analysis by Illumina Sequencing of bacterial and archaeal 16S rRNA genes indicated the presence of phylogenetically diverse microbial communities of high compositional heterogeneity. In three out of four samples originating from the reservoir, the majority of bacterial sequences affiliated with members of the genera Eubacterium, Acetobacterium and Sporobacterium within Clostridiales, known for their fermenting capabilities. In

  12. Development and operation of Northern Natural's aquifer gas storage reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Martinson, E V

    1969-01-01

    There are no depleted (or nondepleted) oil and gas fields in Northern Natural Gas Co.'s market area. Consequently, when the search was started for a possible underground field, the company had to resort to the possibility of locating a water-filled, porous-rock formation (aquifer) in a geological structure which would form a suitable trap for gas storage. Geological research and exploratory drilling was carried on in S. Minnesota, E. Nebraska, and W.-central Iowa. An area located about 40 miles northwest of Des Moines, Iowa, near Redfield, appeared to have the most desirable characteristics for development of a gas-storage field. Drilling of deep developmental wells was started in late 1953 on a double- plunging anticline. The geological structure is similar to that of many oil and gas fields, but the porous formations contained only fresh water. To date, 2 major reservoirs and a minor reservoir have been developed in this structure. As much as 120 billion cu ft has been stored in the 3 reservoirs which supplied 43 billion cu ft gas withdrawals this past season from a total of 85 wells. A second aquifer gas-storage field is under development in N.-central Iowa about 15 miles northeast of Ft. Dodge.

  13. Carbon dioxide storage in unconventional reservoirs workshop: summary of recommendations

    Science.gov (United States)

    Jones, Kevin B.; Blondes, Madalyn S.

    2015-01-01

    “Unconventional reservoirs” for carbon dioxide (CO2) storage—that is, geologic reservoirs in which changes to the rock trap CO2 and therefore contribute to CO2 storage—including coal, shale, basalt, and ultramafic rocks, were the focus of a U.S. Geological Survey (USGS) workshop held March 28 and 29, 2012, at the National Conservation Training Center in Shepherdstown, West Virginia. The goals of the workshop were to determine whether a detailed assessment of CO2 storage capacity in unconventional reservoirs is warranted, and if so, to build a set of recommendations that could be used to develop a methodology to assess this storage capacity. Such an assessment would address only the technically available resource, independent of economic or policy factors. At the end of the workshop, participants agreed that sufficient knowledge exists to allow an assessment of the potential CO2 storage resource in coals, organic-rich shales, and basalts. More work remains to be done before the storage resource in ultramafic rocks can be meaningfully assessed.

  14. Thermal reservoir sizing for adiabatic compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Kere, Amelie; Goetz, Vincent; Py, Xavier; Olives, Regis; Sadiki, Najim [Perpignan Univ. (France). PROMES CNRS UPR 8521; Mercier-Allart, Eric [EDF R et D, Chatou (France)

    2012-07-01

    Despite the operation of the two existing industrial facilities to McIntosh (Alabama), and for more than thirty years, Huntorf (Germany), electricity storage in the form of compressed air in underground cavern (CAES) has not seen the development that was expected in the 80s. The efficiency of this form of storage was with the first generation CAES, less than 50%. The evolving context technique can significantly alter this situation. The new generation so-called Adiabatic CAES (A-CAES) is to retrieve the heat produced by the compression via thermal storage, thus eliminating the necessity of gas to burn and would allow consideration efficiency overall energy of the order of 70%. To date, there is no existing installation of A-CAES. Many studies describe the principal and the general working mode of storage systems by adiabatic compression of air. So, efficiencies of different configurations of adiabatic compression process were analyzed. The aim of this paper is to simulate and analyze the performances of a thermal storage reservoir integrated in the system and adapted to the working conditions of a CAES.

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

    Science.gov (United States)

    Lenhardt, Nils; Götz, Annette E.

    2011-07-01

    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.

  16. Integrated Sedimentological Approach to Assess Reservoir Quality and Architecture of Khuff Carbonates: Outcrop Analog, Central Saudi Arabia

    Science.gov (United States)

    Osman, Mutsim; Abdullatif, Osman

    2017-04-01

    The Permian to Triassic Khuff carbonate reservoirs (and equivalents) in the Middle East are estimated to contain about 38.4% of the world's natural gas reserves. Excellent exposed outcrops in central Saudi Arabia provide good outcrop equivalents to subsurface Khuff reservoirs. This study conduct high resolution outcrop scale investigations on an analog reservoir for upper Khartam of Khuff Formation. The main objective is to reconstruct litho- and chemo- stratigraphic outcrop analog model that may serve to characterize reservoir high resolution (interwell) heterogeneity, continuity and architecture. Given the fact of the limitation of subsurface data and toolsin capturing interwell reservoir heterogeneity, which in turn increases the value of this study.The methods applied integrate sedimentological, stratigraphic petrographic, petrophysical data and chemical analyses for major, trace and rare earth elements. In addition, laser scanning survey (LIDAR) was also utilized in this study. The results of the stratigraphic investigations revealed that the lithofacies range from mudstone, wackestone, packestone and grainstone. These lithofacies represent environments ranging from supratidal, intertidal, subtidal and shoal complex. Several meter-scale and less high resolution sequences and composite sequences within 4th and 5th order cycles were also recognized in the outcrop analog. The lithofacies and architectural analysis revealed several vertically and laterally stacked sequences at the outcrop as revealed from the stratigraphic sections and the lidar scan. Chemostratigraphy is effective in identifying lithofacies and sequences within the outcrop analog. Moreover, different chemical signatures were also recognized and allowed establishing and correlating high resolution lithofacies, reservoir zones, layers and surfaces bounding reservoirs and non-reservoir zones at scale of meters or less. The results of this high resolution outcrop analog study might help to understand

  17. Thermodynamic analysis of a compressed carbon dioxide energy storage system using two saline aquifers at different depths as storage reservoirs

    International Nuclear Information System (INIS)

    Liu, Hui; He, Qing; Borgia, Andrea; Pan, Lehua; Oldenburg, Curtis M.

    2016-01-01

    Highlights: • A compressed CO_2 energy storage system using two storage reservoirs is presented. • Compressed CO_2 energy storage density is higher than that of CAES. • The effects of storage reservoir pressure on the system performance are studied. - Abstract: Compressed air energy storage (CAES) is one of the leading large-scale energy storage technologies. However, low thermal efficiency and low energy storage density restrict its application. To improve the energy storage density, we propose a two-reservoir compressed CO_2 energy storage system. We present here thermodynamic and parametric analyses of the performance of an idealized two-reservoir CO_2 energy storage system under supercritical and transcritical conditions using a steady-state mathematical model. Results show that the transcritical compressed CO_2 energy storage system has higher round-trip efficiency and exergy efficiency, and larger energy storage density than the supercritical compressed CO_2 energy storage. However, the configuration of supercritical compressed CO_2 energy storage is simpler, and the energy storage densities of the two systems are both higher than that of CAES, which is advantageous in terms of storage volume for a given power rating.

  18. Assessing reservoir performance risk in CO2 storage projects

    International Nuclear Information System (INIS)

    Bowden, A.R.; Rigg, A.

    2005-01-01

    One of the main issues for researchers involved with geological storage of carbon dioxide (CO 2 ) has been the development of a proper methodology to assess and compare alternative CO 2 injection projects on the basis of risk. Consideration needs to be given to technical aspects, such as the risk of leakage and the effectiveness of the intended reservoir, as well as less tangible aspects such as the value and safety of geological storage of CO 2 , and potential impacts on the community and environment. The Geological Disposal of Carbon Dioxide (GEODISC), was a research program of the Australian Petroleum Cooperative Research Centre which identified 56 potential environmentally sustainable sites for CO 2 injection (ESSCIs) within Australia. Several studies were carried out, involving detailed evaluation of the suitability of 4 selected sites, including Dongara, Petrel, Gippsland and Carnarvon. The GEODISC program included a risk assessment research module which required a complete and quantified risk assessment of CO 2 injection as a storage option. Primary goals were to assess the risk of leakage, to assess the effectiveness of the intended reservoir, and to assess negative consequences to facilitate comparison of alternative sites. This paper discussed the background and risk assessment model. Key performance indicators (KPIs) were also developed to address the purpose of risk assessment. It was concluded that the RISQUE method is an appropriate approach and that potential injection projects can be measured against six KPIs including containment; effectiveness; self-funding potential; wider community benefits; community safety and community amenity. 6 refs., 3 tabs., 3 figs

  19. Myocardial imaging with a radioiodinated norepinephrine storage analog

    International Nuclear Information System (INIS)

    Wieland, D.M.; Brown, L.E.; Rogers, W.L.; Worthington, K.C.; Wu, J.L.; Clinthorne, N.H.; Otto, C.A.; Swanson, D.P.; Beierwaltes, W.H.

    1981-01-01

    Meta-iodobenzylguanidine (M-IBG), an iodinated aromatic analog of the hypotensive drug guanethidine, localizes in the heart of the rat, dog, and rhesus monkey. A comparative study of tissue distribution in the dog has been performed with five myocardiophilic agents: thallium-201, I-125 16-iodohexadecanoic acid, H-3 norepinephrine, C-14 guanethidine and I-125 M-IBG. The last two compounds give heart concentrations and heart-to-blood concentration ratios similar to those of thallium-201. Planar and tomographic images of the hearts of the dog and rhesus monkey were obtained using I-131 or I-123 labeled M-IBG. Blocking studies with reserpine suggest that a major component of myocardial retention of M-IBG is sequestration within the norepinephrine storage vesicles of the adrenergic nerves. The localization of M-IBG in other organs with rich sympathetic innervation and the relative insensitivity of myocardial uptake to a wide range of loading doses lend additional support for a neuronal mode of retention

  20. 18 CFR 1304.407 - Development within flood control storage zones of TVA reservoirs.

    Science.gov (United States)

    2010-04-01

    ... flood control storage zones of TVA reservoirs. 1304.407 Section 1304.407 Conservation of Power and Water... documentation related to flood control storage, provided the loss of flood control storage caused by the project... control storage. If this determination can be made, the applicant must then demonstrate how the loss of...

  1. Storage Capacity and Sedimentation of Loch Lomond Reservoir, Santa Cruz, California, 1998

    Science.gov (United States)

    McPherson, Kelly R.; Harmon, Jerry G.

    2000-01-01

    In 1998, a bathymetric survey was done to determine the storage capacity and the loss of capacity owing to sedimentation of Loch Lomond Reservoir in Santa Cruz County, California. Results of the survey indicate that the maximum capacity of the reservoir is 8,991 acre-feet in November 1998. The results of previous investigations indicate that storage capacity of the reservoir is less than 8,991 acre-feet. The storage capacity determined from those investigations probably were underestimated because of limitations of the methods and the equipment used. The volume of sedimentation in a reservoir is considered equal to the decrease in storage capacity. To determine sedimentation in Loch Lomond Reservoir, change in storage capacity was estimated for an upstream reach of the reservoir. The change in storage capacity was determined by comparing a 1998 thalweg profile (valley floor) of the reservoir with thalweg profiles from previous investigations; results of the comparison indicate that sedimentation is occurring in the upstream reach. Cross sections for 1998 and 1982 were compared to determine the magnitude of sedimentation in the upstream reach of the reservoir. Results of the comparison, which were determined from changes in the cross-sectional areas, indicate that the capacity of the reservoir decreased by 55 acre-feet.

  2. Radwaste storage in crystalline rocks: a natural analog

    International Nuclear Information System (INIS)

    Brookins, D.G.; Abashian, M.S.; Cohen, L.H.; Wollenberg, H.A.

    1982-01-01

    The Eldora-Bryan Stock (Colorado) intruded the 1.4-1.6 billion year old metamorphic rocks of the Idaho Springs Formation 55 million years ago. The stock may be considered a giant analog of a radwaste form without canister or engineered backfill barriers. The authors' lanthanide studies show the following: (1) The intrusive rocks remained as a closed system. (2) Lanthanide/chondrite versus ionic radius plots show only local redistribution in the immediate contact zone, and that rocks in this zone have not gained lanthanides from the magma. (3) No whole rock perturbations for the lanthanides are noted at distances greater than 3 m from the contact. Stable oxygen isotopic variations show a narrow 9.0 +- 0.3 per mille range for the intrusive rocks and whole rock values from 7.6 to 10.0 per mille for the intruded rocks. The authors conclude: (1) The Idaho Springs Formation was not penetrated by hydrothermal fluids from the Eldora-Bryan magma except possibly on a local scale within 3 m of the contact. (2) The light lanthanides may be locally redistributed in the immediate contact zone, but without additions from the magma. (3) The oxygen isotopic data imply lack of hydrothermal fluids from the magma penetrating the intruded rocks, even in the highest temperature contact zones. Whole rock data imply closed system conditions for Rb, Sr, Th, U, Pb even where mineral ages have been lowered. Data for Co, Cr, Sc, Fe, Cs also indicate retention in whole rock systems and no exchange with the magma. The combined chemical, isotopic, petrographic and theoretical data and calculations indicate suitability of rocks of the Idaho Springs Formation, and thus of many types of crystalline rocks as well, for possible use for the storage of radioactive waste

  3. Effects of Formation Damage on Productivity of Underground Gas Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    C.I.C. Anyadiegwu

    2013-12-01

    Full Text Available Analysis of the effects of formation damage on the productivity of gas storage reservoirs was performed with depleted oil reservoir (OB-02, located onshore, Niger Delta, Nigeria. Information on the reservoir and the fluids from OB-02 were collected and used to evaluate the deliverabilities of the gas storage reservoir over a 10-year period of operation. The results obtained were used to plot graphs of deliverability against permeability and skin respectively. The graphs revealed that as the permeability decreased, the skin increased, and hence a decrease in deliverability of gas from the reservoir during gas withdrawal. Over the ten years of operating the reservoir for gas storage, the deliverability and permeability which were initially 2.7 MMscf/d and 50 mD, with a skin of 0.2, changed to new values of 0.88 MMscf/d and 24 mD with the skin as 4.1 at the tenth year.

  4. CO2 storage in depleted gas reservoirs: A study on the effect of residual gas saturation

    Directory of Open Access Journals (Sweden)

    Arshad Raza

    2018-03-01

    Full Text Available Depleted gas reservoirs are recognized as the most promising candidate for carbon dioxide storage. Primary gas production followed by injection of carbon dioxide after depletion is the strategy adopted for secondary gas recovery and storage practices. This strategy, however, depends on the injection strategy, reservoir characteristics and operational parameters. There have been many studies to-date discussing critical factors influencing the storage performance in depleted gas reservoirs while little attention was given to the effect of residual gas. In this paper, an attempt was made to highlight the importance of residual gas on the capacity, injectivity, reservoir pressurization, and trapping mechanisms of storage sites through the use of numerical simulation. The results obtained indicated that the storage performance is proportionally linked to the amount of residual gas in the medium and reservoirs with low residual fluids are a better choice for storage purposes. Therefore, it would be wise to perform the secondary recovery before storage in order to have the least amount of residual gas in the medium. Although the results of this study are useful to screen depleted gas reservoirs for the storage purpose, more studies are required to confirm the finding presented in this paper.

  5. STRUCTURAL HETEROGENEITIES AND PALEO FLUID FLOW IN AN ANALOG SANDSTONE RESERVOIR 2001-2004

    International Nuclear Information System (INIS)

    Pollard, David; Aydin, Atilla

    2005-01-01

    Fractures and faults are brittle structural heterogeneities that can act both as conduits and barriers with respect to fluid flow in rock. This range in the hydraulic effects of fractures and faults greatly complicates the challenges faced by geoscientists working on important problems: from groundwater aquifer and hydrocarbon reservoir management, to subsurface contaminant fate and transport, to underground nuclear waste isolation, to the subsurface sequestration of CO2 produced during fossil-fuel combustion. The research performed under DOE grant DE-FG03-94ER14462 aimed to address these challenges by laying a solid foundation, based on detailed geological mapping, laboratory experiments, and physical process modeling, on which to build our interpretive and predictive capabilities regarding the structure, patterns, and fluid flow properties of fractures and faults in sandstone reservoirs. The material in this final technical report focuses on the period of the investigation from July 1, 2001 to October 31, 2004. The Aztec Sandstone at the Valley of Fire, Nevada, provides an unusually rich natural laboratory in which exposures of joints, shear deformation bands, compaction bands and faults at scales ranging from centimeters to kilometers can be studied in an analog for sandstone aquifers and reservoirs. The suite of structures there has been documented and studied in detail using a combination of low-altitude aerial photography, outcrop-scale mapping and advanced computational analysis. In addition, chemical alteration patterns indicative of multiple paleo fluid flow events have been mapped at outcrop, local and regional scales. The Valley of Fire region has experienced multiple episodes of fluid flow and this is readily evident in the vibrant patterns of chemical alteration from which the Valley of Fire derives its name. We have successfully integrated detailed field and petrographic observation and analysis, process-based mechanical modeling, and numerical

  6. A numerical investigation of combined heat storage and extraction in deep geothermal reservoirs

    DEFF Research Database (Denmark)

    Major, Márton; Poulsen, Søren Erbs; Balling, Niels

    2018-01-01

    Heat storage capabilities of deep sedimentary geothermal reservoirs are evaluated through numerical model simulations. We combine storage with heat extraction in a doublet well system when storage phases are restricted to summer months. The effects of stored volume and annual repetition on energy...... recovery are investigated. Recovery factors are evaluated for several different model setups and we find that storing 90 °C water at 2500 m depth is capable of reproducing, on average 67% of the stored energy. In addition, ambient reservoir temperature of 75 °C is slightly elevated leading to increased...... efficiency. Additional simulations concerning pressure build-up in the reservoir are carried out to show that safety levels may not be reached. Reservoir characteristics are inspired by Danish geothermal conditions, but results are assumed to have more general validity. Thus, deep sedimentary reservoirs...

  7. Analysis of the influence of input data uncertainties on determining the reliability of reservoir storage capacity

    Directory of Open Access Journals (Sweden)

    Marton Daniel

    2015-12-01

    Full Text Available The paper contains a sensitivity analysis of the influence of uncertainties in input hydrological, morphological and operating data required for a proposal for active reservoir conservation storage capacity and its achieved values. By introducing uncertainties into the considered inputs of the water management analysis of a reservoir, the subsequent analysed reservoir storage capacity is also affected with uncertainties. The values of water outflows from the reservoir and the hydrological reliabilities are affected with uncertainties as well. A simulation model of reservoir behaviour has been compiled with this kind of calculation as stated below. The model allows evaluation of the solution results, taking uncertainties into consideration, in contributing to a reduction in the occurrence of failure or lack of water during reservoir operation in low-water and dry periods.

  8. Compressed air energy storage system reservoir size for a wind energy baseload power plant

    Energy Technology Data Exchange (ETDEWEB)

    Cavallo, A.J.

    1996-12-31

    Wind generated electricity can be transformed from an intermittent to a baseload resource using an oversized wind farm in conjunction with a compressed air energy storage (CAES) system. The size of the storage reservoir for the CAES system (solution mined salt cavern or porous media) as a function of the wind speed autocorrelation time (C) has been examined using a Monte Carlo simulation for a wind class 4 (wind power density 450 W m{sup -2} at 50 m hub height) wind regime with a Weibull k factor of 2.5. For values of C typically found for winds over the US Great Plains, the storage reservoir must have a 60 to 80 hour capacity. Since underground reservoirs account for only a small fraction of total system cost, this larger storage reservoir has a negligible effect on the cost of energy from the wind energy baseload system. 7 refs., 2 figs., 1 tab.

  9. MOSFET analog memory circuit achieves long duration signal storage

    Science.gov (United States)

    1966-01-01

    Memory circuit maintains the signal voltage at the output of an analog signal amplifier when the input signal is interrupted or removed. The circuit uses MOSFET /Metal Oxide Semiconductor Field Effect Transistor/ devices as voltage-controlled switches, triggered by an external voltage-sensing device.

  10. Monitoring small reservoirs' storage with satellite remote sensing in inaccessible areas

    Science.gov (United States)

    Avisse, Nicolas; Tilmant, Amaury; François Müller, Marc; Zhang, Hua

    2017-12-01

    In river basins with water storage facilities, the availability of regularly updated information on reservoir level and capacity is of paramount importance for the effective management of those systems. However, for the vast majority of reservoirs around the world, storage levels are either not measured or not readily available due to financial, political, or legal considerations. This paper proposes a novel approach using Landsat imagery and digital elevation models (DEMs) to retrieve information on storage variations in any inaccessible region. Unlike existing approaches, the method does not require any in situ measurement and is appropriate for monitoring small, and often undocumented, irrigation reservoirs. It consists of three recovery steps: (i) a 2-D dynamic classification of Landsat spectral band information to quantify the surface area of water, (ii) a statistical correction of DEM data to characterize the topography of each reservoir, and (iii) a 3-D reconstruction algorithm to correct for clouds and Landsat 7 Scan Line Corrector failure. The method is applied to quantify reservoir storage in the Yarmouk basin in southern Syria, where ground monitoring is impeded by the ongoing civil war. It is validated against available in situ measurements in neighbouring Jordanian reservoirs. Coefficients of determination range from 0.69 to 0.84, and the normalized root-mean-square error from 10 to 16 % for storage estimations on six Jordanian reservoirs with maximal water surface areas ranging from 0.59 to 3.79 km2.

  11. Modeling of Single and Dual Reservoir Porous Media Compressed Gas (Air and CO2) Storage Systems

    Science.gov (United States)

    Oldenburg, C. M.; Liu, H.; Borgia, A.; Pan, L.

    2017-12-01

    Intermittent renewable energy sources are causing increasing demand for energy storage. The deep subsurface offers promising opportunities for energy storage because it can safely contain high-pressure gases. Porous media compressed air energy storage (PM-CAES) is one approach, although the only facilities in operation are in caverns (C-CAES) rather than porous media. Just like in C-CAES, PM-CAES operates generally by injecting working gas (air) through well(s) into the reservoir compressing the cushion gas (existing air in the reservoir). During energy recovery, high-pressure air from the reservoir is mixed with fuel in a combustion turbine to produce electricity, thereby reducing compression costs. Unlike in C-CAES, the storage of energy in PM-CAES occurs variably across pressure gradients in the formation, while the solid grains of the matrix can release/store heat. Because air is the working gas, PM-CAES has fairly low thermal efficiency and low energy storage density. To improve the energy storage density, we have conceived and modeled a closed-loop two-reservoir compressed CO2 energy storage system. One reservoir is the low-pressure reservoir, and the other is the high-pressure reservoir. CO2 is cycled back and forth between reservoirs depending on whether energy needs to be stored or recovered. We have carried out thermodynamic and parametric analyses of the performance of an idealized two-reservoir CO2 energy storage system under supercritical and transcritical conditions for CO2 using a steady-state model. Results show that the transcritical compressed CO2 energy storage system has higher round-trip efficiency and exergy efficiency, and larger energy storage density than the supercritical compressed CO2 energy storage. However, the configuration of supercritical compressed CO2 energy storage is simpler, and the energy storage densities of the two systems are both higher than that of PM-CAES, which is advantageous in terms of storage volume for a given

  12. The role of rainfall variability in reservoir storage management at ...

    African Journals Online (AJOL)

    Reservoir operation and management is usually patterned after the background of long standing water resources management experience. Reservoir management for optimum power production at any hydropower station requires constant assessment of the quantity of available water. The hydrographic responses of flow ...

  13. Simulation-optimization model of reservoir operation based on target storage curves

    Directory of Open Access Journals (Sweden)

    Hong-bin Fang

    2014-10-01

    Full Text Available This paper proposes a new storage allocation rule based on target storage curves. Joint operating rules are also proposed to solve the operation problems of a multi-reservoir system with joint demands and water transfer-supply projects. The joint operating rules include a water diversion rule to determine the amount of diverted water in a period, a hedging rule based on an aggregated reservoir to determine the total release from the system, and a storage allocation rule to specify the release from each reservoir. A simulation-optimization model was established to optimize the key points of the water diversion curves, the hedging rule curves, and the target storage curves using the improved particle swarm optimization (IPSO algorithm. The multi-reservoir water supply system located in Liaoning Province, China, including a water transfer-supply project, was employed as a case study to verify the effectiveness of the proposed join operating rules and target storage curves. The results indicate that the proposed operating rules are suitable for the complex system. The storage allocation rule based on target storage curves shows an improved performance with regard to system storage distribution.

  14. How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

    Science.gov (United States)

    Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

    2014-05-01

    Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

  15. Horizontal drilling in a natural gas storage horizon of 4 m thickness using reservoir navigation technology

    Energy Technology Data Exchange (ETDEWEB)

    Bastert, Thomas [E.ON Gas Storage GmbH, Essen (Germany); Liewert, Mathias; Rohde, Uwe [Baker Hughes INTEQ GmbH, Celle (Germany); Haberland, Joachim

    2010-09-15

    With a working gas capacity of 1,44 billion m{sup 3} (Vn) the natural gas storage facility at Bierwang is one of the largest storage facilities of E.ON Gas Storage (in Germany) and also one of the largest porous rock storages in Germany. The natural gas is stored in the tertiary storage horizons of the Chattian Hauptsand and Nebensand. To increase the storage capacity a second development well was planned for the Chattian Nebensand II (approx. 1680 m below ground). Following a comprehensive technical investigation the BW 502 well was planned as a horizontal well intended to provide a 300 m exposed section length through the reservoir. In a first step a pilot well was drilled to examine the Nebensand II which had been explored only to a limited extent before; the pilot well was also to provide accurate data on depth, thickness and dip. The results obtained indicated that the Nebensand II was only 4 m thick instead of 6 m as originally assumed. An azimuthal LWD resistivity tool was therefore used for reservoir navigation to allow horizontal drilling despite the lower thickness found. The technology allowed drilling of the horizontal well over its entire length of 315 m within a max. 1.5 m corridor relative to the reservoir top. Drilling confirmed that the actual formation found corresponded to the reservoir formation plan. Drilling operations were completed successfully. The well has been commissioned in the spring of 2010. (orig.)

  16. Monitoring small reservoirs' storage with satellite remote sensing in inaccessible areas

    Directory of Open Access Journals (Sweden)

    N. Avisse

    2017-12-01

    Full Text Available In river basins with water storage facilities, the availability of regularly updated information on reservoir level and capacity is of paramount importance for the effective management of those systems. However, for the vast majority of reservoirs around the world, storage levels are either not measured or not readily available due to financial, political, or legal considerations. This paper proposes a novel approach using Landsat imagery and digital elevation models (DEMs to retrieve information on storage variations in any inaccessible region. Unlike existing approaches, the method does not require any in situ measurement and is appropriate for monitoring small, and often undocumented, irrigation reservoirs. It consists of three recovery steps: (i a 2-D dynamic classification of Landsat spectral band information to quantify the surface area of water, (ii a statistical correction of DEM data to characterize the topography of each reservoir, and (iii a 3-D reconstruction algorithm to correct for clouds and Landsat 7 Scan Line Corrector failure. The method is applied to quantify reservoir storage in the Yarmouk basin in southern Syria, where ground monitoring is impeded by the ongoing civil war. It is validated against available in situ measurements in neighbouring Jordanian reservoirs. Coefficients of determination range from 0.69 to 0.84, and the normalized root-mean-square error from 10 to 16 % for storage estimations on six Jordanian reservoirs with maximal water surface areas ranging from 0.59 to 3.79 km2.

  17. Potential hazards of compressed air energy storage in depleted natural gas reservoirs.

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Paul W.; Grubelich, Mark Charles; Bauer, Stephen J.

    2011-09-01

    This report is a preliminary assessment of the ignition and explosion potential in a depleted hydrocarbon reservoir from air cycling associated with compressed air energy storage (CAES) in geologic media. The study identifies issues associated with this phenomenon as well as possible mitigating measures that should be considered. Compressed air energy storage (CAES) in geologic media has been proposed to help supplement renewable energy sources (e.g., wind and solar) by providing a means to store energy when excess energy is available, and to provide an energy source during non-productive or low productivity renewable energy time periods. Presently, salt caverns represent the only proven underground storage used for CAES. Depleted natural gas reservoirs represent another potential underground storage vessel for CAES because they have demonstrated their container function and may have the requisite porosity and permeability; however reservoirs have yet to be demonstrated as a functional/operational storage media for compressed air. Specifically, air introduced into a depleted natural gas reservoir presents a situation where an ignition and explosion potential may exist. This report presents the results of an initial study identifying issues associated with this phenomena as well as possible mitigating measures that should be considered.

  18. Optimizing and Quantifying CO2 Storage Resource in Saline Formations and Hydrocarbon Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Bosshart, Nicholas W. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Ayash, Scott C. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Azzolina, Nicholas A. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Peck, Wesley D. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Gorecki, Charles D. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Ge, Jun [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Jiang, Tao [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Burton-Kelly, Matthew E. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Anderson, Parker W. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Dotzenrod, Neil W. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center; Gorz, Andrew J. [Univ. of North Dakota, Grand Folks, ND (United States). Energy & Environmental Research Center

    2017-06-30

    In an effort to reduce carbon dioxide (CO2) emissions from large stationary sources, carbon capture and storage (CCS) is being investigated as one approach. This work assesses CO2 storage resource estimation methods for deep saline formations (DSFs) and hydrocarbon reservoirs undergoing CO2 enhanced oil recovery (EOR). Project activities were conducted using geologic modeling and simulation to investigate CO2 storage efficiency. CO2 storage rates and efficiencies in DSFs classified by interpreted depositional environment were evaluated at the regional scale over a 100-year time frame. A focus was placed on developing results applicable to future widespread commercial-scale CO2 storage operations in which an array of injection wells may be used to optimize storage in saline formations. The results of this work suggest future investigations of prospective storage resource in closed or semiclosed formations need not have a detailed understanding of the depositional environment of the reservoir to generate meaningful estimates. However, the results of this work also illustrate the relative importance of depositional environment, formation depth, structural geometry, and boundary conditions on the rate of CO2 storage in these types of systems. CO2 EOR occupies an important place in the realm of geologic storage of CO2, as it is likely to be the primary means of geologic CO2 storage during the early stages of commercial implementation, given the lack of a national policy and the viability of the current business case. This work estimates CO2 storage efficiency factors using a unique industry database of CO2 EOR sites and 18 different reservoir simulation models capturing fluvial clastic and shallow shelf carbonate depositional environments for reservoir depths of 1219 and 2438 meters (4000 and 8000 feet) and 7.6-, 20-, and 64-meter (25-, 66

  19. Hybrid Multi-Objective Optimization of Folsom Reservoir Operation to Maximize Storage in Whole Watershed

    Science.gov (United States)

    Goharian, E.; Gailey, R.; Maples, S.; Azizipour, M.; Sandoval Solis, S.; Fogg, G. E.

    2017-12-01

    The drought incidents and growing water scarcity in California have a profound effect on human, agricultural, and environmental water needs. California experienced multi-year droughts, which have caused groundwater overdraft and dropping groundwater levels, and dwindling of major reservoirs. These concerns call for a stringent evaluation of future water resources sustainability and security in the state. To answer to this call, Sustainable Groundwater Management Act (SGMA) was passed in 2014 to promise a sustainable groundwater management in California by 2042. SGMA refers to managed aquifer recharge (MAR) as a key management option, especially in areas with high variation in water availability intra- and inter-annually, to secure the refill of underground water storage and return of groundwater quality to a desirable condition. The hybrid optimization of an integrated water resources system provides an opportunity to adapt surface reservoir operations for enhancement in groundwater recharge. Here, to re-operate Folsom Reservoir, objectives are maximizing the storage in the whole American-Cosumnes watershed and maximizing hydropower generation from Folsom Reservoir. While a linear programing (LP) module tends to maximize the total groundwater recharge by distributing and spreading water over suitable lands in basin, a genetic based algorithm, Non-dominated Sorting Genetic Algorithm II (NSGA-II), layer above it controls releases from the reservoir to secure the hydropower generation, carry-over storage in reservoir, available water for replenishment, and downstream water requirements. The preliminary results show additional releases from the reservoir for groundwater recharge during high flow seasons. Moreover, tradeoffs between the objectives describe that new operation performs satisfactorily to increase the storage in the basin, with nonsignificant effects on other objectives.

  20. Determination of turnover and cushion gas volume of a prospected gas storage reservoir under uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Gubik, A. [RAG-AG Wien (Austria); Baffoe, J.; Schulze-Riegert, R. [SPT Group GmbH, Hamburg (Germany)

    2013-08-01

    Gas storages define a key contribution for building a reliable gas supply chain from production to consumers. In a competitive gas market with short reaction times to seasonal and other gas injection and extraction requirements, gas storages also receive a strong focus on availability and precise prediction estimates for future operation scenarios. Reservoir management workflows are increasingly built on reservoir simulation support for optimizing production schemes and estimating the impact of subsurface uncertainties on field development scenarios. Simulation models for gas storages are calibrated to geological data and accurate reproduction of historical production data are defined as a prerequisite for reliable production and performance forecasts. The underlying model validation process is called history matching, which potentially generates alternative simulation models due to prevailing geological uncertainties. In the past, a single basecase reference model was used to predict production capacities of a gas storage. The working gas volume was precisely defined over a contracted plateau delivery and the required cushion gas volume maintains the reservoir pressure during the operation. Cushion and working gas Volume are strongly dependent on reservoir parameters. In this work an existing depleted gas reservoir and the operation target as a gas storage is described. Key input data to the reservoir model description and simulation is reviewed including production history and geological uncertainties based on large well spacing, limited core and well data and a limited seismic resolution. Target delivery scenarios of the prospected gas storage are evaluated under uncertainty. As one key objective, optimal working gas and cushion gas volumes are described in a probabilistic context reflecting geological uncertainties. Several work steps are defined and included in an integrated workflow design. Equiprobable geological models are generated and evaluated based on

  1. Prediction of the thermohydraulic performance of porous-media reservoirs for compressed-air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.; McCann, R.A.

    1981-09-01

    The numerical modeling capability that has been developed at the Pacific Northwest Laboratory (PNL) for the prediction of the thermohydraulic performance of porous media reservoirs for compressed air energy storage (CAES) is described. The capability of the numerical models was demonstrated by application to a variety of parametric analyses and the support analyses for the CAES porous media field demonstration program. The demonstration site analyses include calculations for the displacement of aquifer water to develop the air storage zone, the potential for water coning, thermal development in the reservoir, and the dehydration of the near-wellbore region. Unique features of the demonstration site reservoir that affect the thermohydraulic performance are identified and contrasted against the predicted performance for conditions that would be considered more typical of a commercial CAES site.

  2. An analog RF gap voltage regulation system for the Advanced Photon Source storage ring

    International Nuclear Information System (INIS)

    Horan, D.

    1999-01-01

    An analog rf gap voltage regulation system has been designed and built at Argonne National Laboratory to maintain constant total storage ring rf gap voltage, independent of beam loading and cavity tuning effects. The design uses feedback control of the klystron mod-anode voltage to vary the amount of rf power fed to the storage ring cavities. The system consists of two independent feedback loops, each regulating the combined rf gap voltages of eight storage ring cavities by varying the output power of either one or two rf stations, depending on the mode of operation. It provides full operator control and permissive logic to permit feedback control of the rf system output power only if proper conditions are met. The feedback system uses envelope-detected cavity field probe outputs as the feedback signal. Two different methods of combining the individual field probe signals were used to generate a relative DC level representing one-half of the total storage ring rf voltage, an envelope-detected vector sum of the field probe rf signals, and the DC sum of individual field probe envelope detector outputs. The merits of both methods are discussed. The klystron high-voltage power supply (HVPS) units are fitted with an analog interface for external control of the mod-anode voltage level, using a four-quadrant analog multiplier to modulate the HVPS mod-anode voltage regulator set-point in response to feedback system commands

  3. modelling for optimal number of line storage reservoirs in a water

    African Journals Online (AJOL)

    user

    RESERVOIRS IN A WATER DISTRIBUTION SYSTEM. By. B.U. Anyata. Department ... water distribution systems, in order to balance the ... distribution line storage systems to meet peak demands at .... Evaluation Method. The criteria ... Pipe + Energy Cost (N). 191, 772 ... Economic Planning Model for Distributed information ...

  4. Characteristics of phytoplankton in Lake Karachay, a storage reservoir of medium-level radioactive waste.

    Science.gov (United States)

    Atamanyuk, Natalia I; Osipov, Denis I; Tryapitsina, Galina A; Deryabina, Larisa V; Stukalov, Pavel M; Ivanov, Ivan A; Pryakhin, Evgeny A

    2012-07-01

    The status of the phytoplankton community in Lake Karachay, a storage reservoir of liquid medium-level radioactive waste from the Mayak Production Association, Chelyabinsk Region, Russia, is reviewed. In 2010, the concentration of Sr in water of this reservoir was found to be 6.5 × 10(6) Bq L, the concentration of 137Cs was 1.6 × 10(7) Bq L, and total alpha activity amounted to 3.0 × 10(3) Bq L. An increased level of nitrates was observed in the reservoir-4.4 g L. It has been demonstrated that in this reservoir under the conditions of the maximum contamination levels known for aquatic ecosystems in the entire biosphere, a phytoplankton community exists that has a pronounced decline in species diversity, almost to the extent of a monoculture of widely-spread thread eurytopic cyanobacteria Geitlerinema amphibium.

  5. Microflora of hydrobionts digestive tract in Kaunas water storage reservoir

    International Nuclear Information System (INIS)

    Shyvokiene, J.; Mickiene, L.; Mileriene, E.

    1996-01-01

    Microbiological and ichthiological investigations carried out in 1990 and 1992 showed the variability of bacterial cenoses in the digestive tract of hydrobionts before and after setting in motion Kruonis hydro pumped storage. The studies also showed that microorganisms of the digestive tract of the hydrobionts investigated were involved in the degradation of nutritional substrates and could serve as indicators of an anthropogenic effect. Before setting in motion the hydro pumped storage hydrocarbon-degrading bacteria (HDB) were detected in the digestive tract of the freshwater shrimps, opossum shrimps, sticklebacks, zebra mussels and roaches. The greatest number of HDB was found in the digestive tract of the roach while in perches they were not detected. However after setting in motion the hydro pumped storage , high numbers of HDB were determined in the digestive tracts of all the hydrobionts investigated. It has been shown that the function of bacterial digestion is conditioned not only by the nutrition specificity of the macroorganism, but on its environment as well. With the aid of enzymes secreted by microorganisms organic compounds difficult to assimilate are transformed into valuable nutrients. Besides, the functional activity of microorganisms of the digestive tract of the hydrobionts indicate the intensity of the digestive process and physiological state of their organism. Therefore, when investigating fish stocks in hydrosystems one must evaluate inner resources of their organism, i.e. functional activities and the activity of digestive tract microorganisms, their quantitative and qualitative composition, relationship with the macroorganism, its growth rate and environment. (author). 15 refs., 5 tabs

  6. Water coning in porous media reservoirs for compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.; McCann, R.A.

    1981-06-01

    The general purpose of this work is to define the hydrodynamic and thermodynamic response of a CAES porous media reservoir subjected to simulated air mass cycling. This research will assist in providing design guidelines for the efficient and stable operation of the air storage reservoir. This report presents the analysis and results for the two-phase (air-water), two-dimensional, numerical modeling of CAES porous media reservoirs. The effects of capillary pressure and relative permeability were included. The fluids were considered to be immisicible; there was no phase change; and the system was isothermal. The specific purpose of this analysis was to evaluate the reservoir parameters that were believed to be important to water coning. This phenomenon may occur in reservoirs in which water underlies the air storage zone. It involves the possible intrusion of water into the wellbore or near-wellbore region. The water movement is in response to pressure gradients created during a reservoir discharge cycle. Potential adverse effects due to this water movement are associated with the pressure response of the reservoir and the geochemical stability of the near-wellbore region. The results obtained for the simulated operation of a CAES reservoir suggest that water coning should not be a severe problem, due to the slow response of the water to the pressure gradients and the relatively short duration in which those gradients exist. However, water coning will depend on site-specific conditions, particularly the fluid distributions following bubble development, and, therefore, a water coning analysis should be included as part of site evaluation.

  7. Spatially pooled depth-dependent reservoir storage, elevation, and water-quality data for selected reservoirs in Texas, January 1965-January 2010

    Science.gov (United States)

    Burley, Thomas E.; Asquith, William H.; Brooks, Donald L.

    2011-01-01

    The U.S. Geological Survey (USGS), in cooperation with Texas Tech University, constructed a dataset of selected reservoir storage (daily and instantaneous values), reservoir elevation (daily and instantaneous values), and water-quality data from 59 reservoirs throughout Texas. The period of record for the data is as large as January 1965-January 2010. Data were acquired from existing databases, spreadsheets, delimited text files, and hard-copy reports. The goal was to obtain as much data as possible; therefore, no data acquisition restrictions specifying a particular time window were used. Primary data sources include the USGS National Water Information System, the Texas Commission on Environmental Quality Surface Water-Quality Management Information System, and the Texas Water Development Board monthly Texas Water Condition Reports. Additional water-quality data for six reservoirs were obtained from USGS Texas Annual Water Data Reports. Data were combined from the multiple sources to create as complete a set of properties and constituents as the disparate databases allowed. By devising a unique per-reservoir short name to represent all sites on a reservoir regardless of their source, all sampling sites at a reservoir were spatially pooled by reservoir and temporally combined by date. Reservoir selection was based on various criteria including the availability of water-quality properties and constituents that might affect the trophic status of the reservoir and could also be important for understanding possible effects of climate change in the future. Other considerations in the selection of reservoirs included the general reservoir-specific period of record, the availability of concurrent reservoir storage or elevation data to match with water-quality data, and the availability of sample depth measurements. Additional separate selection criteria included historic information pertaining to blooms of golden algae. Physical properties and constituents were water

  8. System-level modeling for economic evaluation of geological CO2 storage in gas reservoirs

    International Nuclear Information System (INIS)

    Zhang, Yingqi; Oldenburg, Curtis M.; Finsterle, Stefan; Bodvarsson, Gudmundur S.

    2007-01-01

    One way to reduce the effects of anthropogenic greenhouse gases on climate is to inject carbon dioxide (CO 2 ) from industrial sources into deep geological formations such as brine aquifers or depleted oil or gas reservoirs. Research is being conducted to improve understanding of factors affecting particular aspects of geological CO 2 storage (such as storage performance, storage capacity, and health, safety and environmental (HSE) issues) as well as to lower the cost of CO 2 capture and related processes. However, there has been less emphasis to date on system-level analyses of geological CO 2 storage that consider geological, economic, and environmental issues by linking detailed process models to representations of engineering components and associated economic models. The objective of this study is to develop a system-level model for geological CO 2 storage, including CO 2 capture and separation, compression, pipeline transportation to the storage site, and CO 2 injection. Within our system model we are incorporating detailed reservoir simulations of CO 2 injection into a gas reservoir and related enhanced production of methane. Potential leakage and associated environmental impacts are also considered. The platform for the system-level model is GoldSim [GoldSim User's Guide. GoldSim Technology Group; 2006, http://www.goldsim.com]. The application of the system model focuses on evaluating the feasibility of carbon sequestration with enhanced gas recovery (CSEGR) in the Rio Vista region of California. The reservoir simulations are performed using a special module of the TOUGH2 simulator, EOS7C, for multicomponent gas mixtures of methane and CO 2 . Using a system-level modeling approach, the economic benefits of enhanced gas recovery can be directly weighed against the costs and benefits of CO 2 injection

  9. A comparative study of gas-gas miscibility processes in underground gas storage reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rafiee, M.M.; Schmitz, S. [DBI - Gastechnologisches Institut gGmbH, Freiberg (Germany)

    2013-08-01

    Intermixture of gases in underground gas reservoirs have had great weight for natural gas storage in UGS projects with substitution of cushion gas by inert gases or changing the stored gas quality or origin, as for the replacement of town gas by natural gas. It was also investigated during the last years for Enhanced Gas Recovery (EGR) and Carbon Capture and Storage (CCS) projects. The actual importance of its mechanisms is discussed for the H{sub 2} storage in Power to Gas to Power projects (PGP). In these approaches miscibility of the injected gas with the gas in place in the reservoir plays an important role in the displacement process. The conditions and parameters for the gas-gas displacement and mixing have been investigated in previous projects, as e.g. the miscibility of CO{sub 2} with natural gas (CLEAN). Furthermore the miscibility process of town gas with natural gas and sauer gas with sweet gas were also previously measured and compared in laboratory. The objective of this work is to investigate the miscibility of H{sub 2} injection into natural gas reservoirs using a compositional and a black oil reservoir simulator. Three processes of convection, dispersion and diffusion are considered precisely. The effect of gas miscibility is studied for both simulators and the results are compared to find optimum miscibility parameters. The findings of this work could be helpful for further pilot and field case studies to predict and monitor the changes in gas composition and quality. In future this monitoring might become more important when PGP together with H{sub 2}-UGS, as storage technology, will help to successfully implement the change to an energy supply from more renewable sources. Similarly the method confirms the use of the black oil simulator as an alternative for gas-gas displacement and sequestration reservoir simulation in comparison to the compositional simulator. (orig.)

  10. Response of littoral macrophytes to water level fluctuations in a storage reservoir

    Directory of Open Access Journals (Sweden)

    Krolová M.

    2013-05-01

    Full Text Available Lakes and reservoirs that are used for water supply and/or flow regulations have usually poorly developed littoral macrophyte communities, which impairs ecological potential in terms of the EU Water Framework Directive. The aim of our study was to reveal controlling factors for the growth of littoral macrophytes in a storage reservoir with fluctuating water level (Lipno Reservoir, Czech Republic. Macrophytes occurred in this reservoir only in the eulittoral zone i.e., the shoreline region between the highest and the lowest seasonal water levels. Three eulittoral sub-zones could be distinguished: the upper eulittoral with a stable community of perennial species with high cover, the middle eulittoral with relatively high richness of emergent and amphibious species present at low cover values, and the lower eulittoral devoid of permanent vegetation. Cover and species composition in particular sub-zones were primarily influenced by the duration and timing of flooding, followed by nutrient limitation and strongly reducing conditions in the flooded organic sediment. Our results stress the ecological importance of eulittoral zone in reservoirs with fluctuating water levels where macrophyte growth can be supported by targeted management of water level, thus helping reservoir managers in improving the ecological potential of this type of water bodies.

  11. A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

    Directory of Open Access Journals (Sweden)

    Iskahar

    2018-01-01

    Full Text Available Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

  12. Strategies to diagnose and control microbial souring in natural gas storage reservoirs and produced water systems

    Energy Technology Data Exchange (ETDEWEB)

    Morris, E.A.; Derr, R.M.; Pope, D.H.

    1995-12-31

    Hydrogen sulfide production (souring) in natural gas storage reservoirs and produced water systems is a safety and environmental problem that can lead to operational shutdown when local hydrogen sulfide standards are exceeded. Systems affected by microbial souring have historically been treated using biocides that target the general microbial community. However, requirements for more environmentally friendly solutions have led to treatment strategies in which sulfide production can be controlled with minimal impact to the system and environment. Some of these strategies are based on microbial and/or nutritional augmentation of the sour environment. Through research sponsored by the Gas Research Institute (GRI) in Chicago, Illinois, methods have been developed for early detection of microbial souring in natural gas storage reservoirs, and a variety of mitigation strategies have been evaluated. The effectiveness of traditional biocide treatment in gas storage reservoirs was shown to depend heavily on the methods by which the chemical is applied. An innovative strategy using nitrate was tested and proved ideal for produced water and wastewater systems. Another strategy using elemental iodine was effective for sulfide control in evaporation ponds and is currently being tested in microbially sour natural gas storage wells.

  13. Frictional and transport properties of simulated faults in CO2 storage reservoirs and clay-rich caprocks

    NARCIS (Netherlands)

    Bakker, Elisenda

    2017-01-01

    In order to mitigate and meet CO2 emission regulations, long-term CO2 storage in hydrocarbon reservoirs is one of the most attractive large-scale options. To ensure save anthropogenic storage, it is important to maintain the sealing integrity of potential storage complexes. It is therefore

  14. Potential petrophysical and chemical property alterations in a compressed air energy storage porous rock reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Stottlemyre, J.A.; Erikson, R.L.; Smith, R.P.

    1979-10-01

    Successful commercialization of Compressed Air Energy Storage (CAES) systems depends on long-term stability of the underground reservoirs subjected to somewhat unique operating conditions. Specifically, these conditions include elevated and time varying temperatures, effective stresses, and air humidities. To minimize the requirements for premium fuels, it may be desirable to retain the thermal energy of compression. Porous media, e.g., sandstone, may hold promise as elevated temperature reservoirs. In this study, a reservoir composed of clean quartz sandstone and injection air temperatures of 300 to 575/sup 0/K are assumed. Numerical modeling is used to estimate temperature, stress, and humidity conditions within this reference porous media reservoir. A discussion on relative importance to CAES of several potential porous media damage mechanisms is presented. In this context, damage is defined as a reduction in intrinsic permeability (measure of air transport capability), a decrease in effective porosity (measure of storage capability), or an increase in elastic and/or inelastic deformation of the porous material. The potential damage mechanisms presented include: (1) disaggregation, (2) particulate plugging, (3) boundary layer viscosity anomalies, (4) inelastic microstructural consolidation, (5) clay swelling and dispersion, (6) hydrothermal mineral alteration, (7) oxidation reactions, and (8) well casing corrosion. These mechanisms are placed in perspective with respect to anticipated CAES conditions and mechanisms suggested are: (1) of academic interest only, (2) readily identified and controlled via engineering, or (3) potential problem areas requiring additional investigation.

  15. Potential evaluation of CO2 storage and enhanced oil recovery of tight oil reservoir in the Ordos Basin, China.

    Science.gov (United States)

    Tian, Xiaofeng; Cheng, Linsong; Cao, Renyi; Zhang, Miaoyi; Guo, Qiang; Wang, Yimin; Zhang, Jian; Cui, Yu

    2015-07-01

    Carbon -di-oxide (CO2) is regarded as the most important greenhouse gas to accelerate climate change and ocean acidification. The Chinese government is seeking methods to reduce anthropogenic CO2 gas emission. CO2 capture and geological storage is one of the main methods. In addition, injecting CO2 is also an effective method to replenish formation energy in developing tight oil reservoirs. However, exiting methods to estimate CO2 storage capacity are all based on the material balance theory. This was absolutely correct for normal reservoirs. However, as natural fractures widely exist in tight oil reservoirs and majority of them are vertical ones, tight oil reservoirs are not close. Therefore, material balance theory is not adaptive. In the present study, a new method to calculate CO2 storage capacity is presented. The CO2 effective storage capacity, in this new method, consisted of free CO2, CO2 dissolved in oil and CO2 dissolved in water. Case studies of tight oil reservoir from Ordos Basin was conducted and it was found that due to far lower viscosity of CO2 and larger solubility in oil, CO2 could flow in tight oil reservoirs more easily. As a result, injecting CO2 in tight oil reservoirs could obviously enhance sweep efficiency by 24.5% and oil recovery efficiency by 7.5%. CO2 effective storage capacity of Chang 7 tight oil reservoir in Longdong area was 1.88 x 10(7) t. The Chang 7 tight oil reservoir in Ordos Basin was estimated to be 6.38 x 10(11) t. As tight oil reservoirs were widely distributed in Songliao Basin, Sichuan Basin and so on, geological storage capacity of CO2 in China is potential.

  16. Aging Reservoirs in a Changing Climate: Examining Storage Loss of Large Reservoirs and Variability of Sedimentation Rate in a Dominant Cropland Region

    Science.gov (United States)

    Rahmani, V.; Kastens, J.; deNoyelles, F.; Huggins, D.; Martinko, E.

    2015-12-01

    Dam construction has multiple environmental and hydrological consequences including impacts on upstream and downstream ecosystems, water chemistry, and streamflow. Behind the dam the reservoir can trap sediment from the stream and fill over time. With increasing population and drinking and irrigation water demands, particularly in the areas that have highly variable weather and extended drought periods such as the United States Great Plains, reservoir sedimentation escalates water management concerns. Under nearly all projected climate change scenarios we expect that reservoir water storage and management will come under intense scrutiny because of the extensive use of interstate river compacts in the Great Plains. In the state of Kansas, located in the Great Plains, bathymetric surveys have been completed during the last decade for many major lakes by the Kansas Biological Survey, Kansas Water Office, and the U.S. Army Corps of Engineers. In this paper, we studied the spatial and temporal changes of reservoir characteristics including sedimentation yield, depletion rate, and storage capacity loss for 24 federally-operated reservoirs in Kansas. These reservoirs have an average age of about 50 years and collectively have lost approximately 15% of their original capacity, with the highest annual observed single-reservoir depletion rate of 0.84% and sedimentation yield of 1,685 m3 km-2 yr-1.

  17. Quantification of dissolved organic carbon (DOC) storage in lakes and reservoirs of mainland China.

    Science.gov (United States)

    Song, Kaishan; Wen, Zhidan; Shang, Yingxing; Yang, Hong; Lyu, Lili; Liu, Ge; Fang, Chong; Du, Jia; Zhao, Ying

    2018-04-04

    As a major fraction of carbon in inland waters, dissolved organic carbon (DOC) plays a crucial role in carbon cycling on a global scale. However, the quantity of DOC stored in lakes and reservoirs was not clear to date. In an attempt to examine the factors that determine the DOC storage in lakes and reservoirs across China, we assembled a large database (measured 367 lakes, and meta-analyzed 102 lakes from five limnetic regions; measured 144 reservoirs, and meta-analyzed 272 reservoirs from 31 provincial units) of DOC concentrations and water storages for lakes and reservoirs that are used to determine DOC storage in static inland waters. We found that DOC concentrations in saline waters (Mean/median ± S.D: 50.5/30.0 ± 55.97 mg/L) are much higher than those in fresh waters (8.1/5.9 ± 6.8 mg/L), while lake DOC concentrations (25.9/11.5 ± 42.04 mg/L) are much higher than those in reservoirs (5.0/3.8 ± 4.5 mg/L). In terms of lake water volume and DOC storage, the Tibet-Qinghai lake region has the largest water volume (552.8 km 3 ), 92% of which is saline waters, thus the largest DOC (13.39 Tg) is stored in these alpine lake region; followed by the Mengxin lake region, having a water volume of 99.4 km 3 in which 1.75 Tg DOC was stored. Compared to Mengxin lake region, almost the same amount of water was stored in East China lake region (91.9 km 3 ), however, much less DOC was stored in this region (0.43 Tg) due to the lower DOC concentration (Ave: 3.45 ± 2.68 mg/L). According to our investigation, Yungui and Northeast lake regions had water storages of 32.14 km 3 and 19.44 km 3 respectively, but relatively less DOC was stored in Yungui (0.13 Tg) than in Northeast lake region (0.19 Tg). Due to low DOC concentration in reservoirs, especially these large reservoirs having lower DOC concentration (V > 1.0 km 3 : 2.31 ± 1.48 mg/L), only 1.54 Tg was stored in a 485.1 km 3 volume of water contained

  18. Demonstrating storage of CO2 in geological reservoirs: the Sleipner and SACS projects

    International Nuclear Information System (INIS)

    Torp, T.A.; Gale, J.

    2004-01-01

    At the Sleipner gas field in the North Sea, CO 2 has been stripped from the produced natural gas and injected into a sand layer called the Utsira formation. Injection started in October 1996, to date nearly 8 million tonnes of CO 2 have been injected without any significant operational problems observed in the capture plant or in the injection well. The Sleipner project is the first commercial application of CO 2 storage in deep saline aquifers in the world. To monitor the injected CO 2 , a separate project called the saline aquifer CO 0 2 storage (SACS) project was established in 1998. As part of the SACS project, 3D seismic surveying has been used to successfully monitor the CO 2 in the Utsira formation, an industry first. Repeat seismic surveys have successfully imaged movement of the injected CO 2 within the reservoir. Reservoir simulation tools have been successfully adapted to describe the migration of the CO 2 in the reservoir. The simulation packages have been calibrated against the repeat seismic surveys and shown themselves to be capable of replicating the position of the CO 2 in the reservoir. The possible reactions between minerals within the reservoir sand and the injected CO 2 have been studied by laboratory experiments and simulations. The cumulative experiences of the Sleipner and SACS projects will be embodied in a Best Practice Manual to assist other organisations planning CO 2 injection projects to take advantage of the learning processes undertaken and to assist in facilitating new projects of this type. (author)

  19. Preliminary formation analysis for compressed air energy storage in depleted natural gas reservoirs :

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, William Payton

    2013-06-01

    The purpose of this study is to develop an engineering and operational understanding of CAES performance for a depleted natural gas reservoir by evaluation of relative permeability effects of air, water and natural gas in depleted natural gas reservoirs as a reservoir is initially depleted, an air bubble is created, and as air is initially cycled. The composition of produced gases will be evaluated as the three phase flow of methane, nitrogen and brine are modeled. The effects of a methane gas phase on the relative permeability of air in a formation are investigated and the composition of the produced fluid, which consists primarily of the amount of natural gas in the produced air are determined. Simulations of compressed air energy storage (CAES) in depleted natural gas reservoirs were carried out to assess the effect of formation permeability on the design of a simple CAES system. The injection of N2 (as a proxy to air), and the extraction of the resulting gas mixture in a depleted natural gas reservoir were modeled using the TOUGH2 reservoir simulator with the EOS7c equation of state. The optimal borehole spacing was determined as a function of the formation scale intrinsic permeability. Natural gas reservoir results are similar to those for an aquifer. Borehole spacing is dependent upon the intrinsic permeability of the formation. Higher permeability allows increased injection and extraction rates which is equivalent to more power per borehole for a given screen length. The number of boreholes per 100 MW for a given intrinsic permeability in a depleted natural gas reservoir is essentially identical to that determined for a simple aquifer of identical properties. During bubble formation methane is displaced and a sharp N2methane boundary is formed with an almost pure N2 gas phase in the bubble near the borehole. During cycling mixing of methane and air occurs along the boundary as the air bubble boundary moves. The extracted gas mixture changes as a

  20. Assessment of CO2 Storage Potential in Naturally Fractured Reservoirs With Dual-Porosity Models

    Science.gov (United States)

    March, Rafael; Doster, Florian; Geiger, Sebastian

    2018-03-01

    Naturally Fractured Reservoirs (NFR's) have received little attention as potential CO2 storage sites. Two main facts deter from storage projects in fractured reservoirs: (1) CO2 tends to be nonwetting in target formations and capillary forces will keep CO2 in the fractures, which typically have low pore volume; and (2) the high conductivity of the fractures may lead to increased spatial spreading of the CO2 plume. Numerical simulations are a powerful tool to understand the physics behind brine-CO2 flow in NFR's. Dual-porosity models are typically used to simulate multiphase flow in fractured formations. However, existing dual-porosity models are based on crude approximations of the matrix-fracture fluid transfer processes and often fail to capture the dynamics of fluid exchange accurately. Therefore, more accurate transfer functions are needed in order to evaluate the CO2 transfer to the matrix. This work presents an assessment of CO2 storage potential in NFR's using dual-porosity models. We investigate the impact of a system of fractures on storage in a saline aquifer, by analyzing the time scales of brine drainage by CO2 in the matrix blocks and the maximum CO2 that can be stored in the rock matrix. A new model to estimate drainage time scales is developed and used in a transfer function for dual-porosity simulations. We then analyze how injection rates should be limited in order to avoid early spill of CO2 (lost control of the plume) on a conceptual anticline model. Numerical simulations on the anticline show that naturally fractured reservoirs may be used to store CO2.

  1. Influence of Chemical, Mechanical, and Transport Processes on Wellbore Leakage from Geologic CO2 Storage Reservoirs.

    Science.gov (United States)

    Carroll, Susan A; Iyer, Jaisree; Walsh, Stuart D C

    2017-08-15

    Wells are considered to be high-risk pathways for fluid leakage from geologic CO 2 storage reservoirs, because breaches in this engineered system have the potential to connect the reservoir to groundwater resources and the atmosphere. Given these concerns, a few studies have assessed leakage risk by evaluating regulatory records, often self-reported, documenting leakage in gas fields. Leakage is thought to be governed largely by initial well-construction quality and the method of well abandonment. The geologic carbon storage community has raised further concerns because acidic fluids in the CO 2 storage reservoir, alkaline cement meant to isolate the reservoir fluids from the overlying strata, and steel casings in wells are inherently reactive systems. This is of particular concern for storage of CO 2 in depleted oil and gas reservoirs with numerous legacy wells engineered to variable standards. Research suggests that leakage risks are not as great as initially perceived because chemical and mechanical alteration of cement has the capacity to seal damaged zones. Our work centers on defining the coupled chemical and mechanical processes governing flow in damaged zones in wells. We have developed process-based models, constrained by experiments, to better understand and forecast leakage risk. Leakage pathways can be sealed by precipitation of carbonate minerals in the fractures and deformation of the reacted cement. High reactivity of cement hydroxides releases excess calcium that can precipitate as carbonate solids in the fracture network under low brine flow rates. If the flow is fast, then the brine remains undersaturated with respect to the solubility of calcium carbonate minerals, and zones depleted in calcium hydroxides, enriched in calcium carbonate precipitates, and made of amorphous silicates leached of original cement minerals are formed. Under confining pressure, the reacted cement is compressed, which reduces permeability and lowers leakage risks. The

  2. Mines as lower reservoir of an UPSH (Underground Pumping Storage Hydroelectricity): groundwater impacts and feasibility

    Science.gov (United States)

    Bodeux, Sarah; Pujades, Estanislao; Orban, Philippe; Dassargues, Alain

    2016-04-01

    The energy framework is currently characterized by an expanding use of renewable sources. However, their intermittence could not afford a stable production according to the energy demand. Pumped Storage Hydroelectricity (PSH) is an efficient possibility to store and release electricity according to the demand needs. Because of the topographic and environmental constraints of classical PSH, new potential suitable sites are rare in countries whose topography is weak or with a high population density. Nevertheless, an innovative alternative is to construct Underground Pumped Storage Hydroelectricity (UPSH) plants by using old underground mine works as lower reservoir. In that configuration, large amount of pumped or injected water in the underground cavities would impact the groundwater system. A representative UPSH facility is used to numerically determine the interactions with surrounding aquifers Different scenarios with varying parameters (hydrogeological and lower reservoir characteristics, boundaries conditions and pumping/injection time-sequence) are computed. Analysis of the computed piezometric heads around the reservoir allows assessing the magnitude of aquifer response and the required time to achieve a mean pseudo-steady state under cyclic solicitations. The efficiency of the plant is also evaluated taking the leakage into the cavity into account. Combining these two outcomes, some criterions are identified to assess the feasibility of this type of projects within potential old mine sites from a hydrogeological point of view.

  3. Freshwater Algal Bloom Prediction by Support Vector Machine in Macau Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Zhengchao Xie

    2012-01-01

    Full Text Available Understanding and predicting dynamic change of algae population in freshwater reservoirs is particularly important, as algae-releasing cyanotoxins are carcinogens that would affect the health of public. However, the high complex nonlinearity of water variables and their interactions makes it difficult to model the growth of algae species. Recently, support vector machine (SVM was reported to have advantages of only requiring a small amount of samples, high degree of prediction accuracy, and long prediction period to solve the nonlinear problems. In this study, the SVM-based prediction and forecast models for phytoplankton abundance in Macau Storage Reservoir (MSR are proposed, in which the water parameters of pH, SiO2, alkalinity, bicarbonate (HCO3 -, dissolved oxygen (DO, total nitrogen (TN, UV254, turbidity, conductivity, nitrate, total nitrogen (TN, orthophosphate (PO4 3−, total phosphorus (TP, suspended solid (SS and total organic carbon (TOC selected from the correlation analysis of the 23 monthly water variables were included, with 8-year (2001–2008 data for training and the most recent 3 years (2009–2011 for testing. The modeling results showed that the prediction and forecast powers were estimated as approximately 0.76 and 0.86, respectively, showing that the SVM is an effective new way that can be used for monitoring algal bloom in drinking water storage reservoir.

  4. Groundwater storage and water security: making better use of our largest reservoir.

    Science.gov (United States)

    Tuinhof, A; Olsthoorn, T; Heederik, J P; de Vries, J

    2005-01-01

    Provision of sufficient storage capacity under growing water demands and increasing climate variability is one the main concerns for water managers in the coming decades. It is expected that 150-300 km3 of additional storage capacity will be needed by 2025 especially in semi-arid and arid regions where changes in climate variability will have most impact on rainfall and drought. Storage of substantial amounts of water can either be above ground, in reservoirs behind dams or underground in aquifers (sub-surface storage). Recharge enhancement through management of aquifer recharge (MAR) and sub-surface storage (SSS) is a known technology and already successfully applied in a number of countries for many years at different scales. MAR-SSS is a flexible and cost-effective means to increase storage capacity both at village level and in modern water management schemes. A dialogue and information exchange between climate experts and water managers can provide an effective contribution to the planning, design and operation of MAR-SSS schemes.

  5. Characterization of biocenoses in the storage reservoirs of liquid radioactive wastes of Mayak PA. Initial descriptive report

    International Nuclear Information System (INIS)

    Pryakhin, E.A.; Mokrov, Yu.G.; Tryapitsina, G.A.; Ivanov, I.A.; Osipov, D.I.; Atamanyuk, N.I.; Deryabina, L.V.; Shaposhnikova, I.A.; Shishkina, E.A.; Obvintseva, N.A.; Egoreichenkov, E.A.; Styazhkina, E.V.; Osipova, O.F.; Mogilnikova, N.I.; Andreev, S.S.; Tarasov, O.V.; Geras'kin, S.A.; Trapeznikov, A.V.; Akleyev, A.V.

    2016-01-01

    As a result of operation of the Mayak Production Association (Mayak PA), Chelyabinsk Oblast, Russia, an enterprise for production and separation of weapon-grade plutonium in the Soviet Union, ecosystems of a number of water bodies have been radioactively contaminated. The article presents information about the current state of ecosystems of 6 special industrial storage reservoirs of liquid radioactive waste from Mayak PA: reservoirs R-3, R-4, R-9, R-10, R-11 and R-17. At present the excess of the radionuclide content in the water of the studied reservoirs and comparison reservoirs (Shershnyovskoye and Beloyarskoye reservoirs) is 9 orders of magnitude for 90 Sr and 137 Cs, and 6 orders of magnitude for alpha-emitting radionuclides. According to the level of radioactive contamination, the reservoirs of the Mayak PA could be arranged in the ascending order as follows: R-11, R-10, R-4, R-3, R-17 and R-9. In 2007–2012 research of the status of the biocenoses of these reservoirs in terms of phytoplankton, zooplankton, bacterioplankton, zoobenthos, aquatic plants, ichthyofauna, avifauna parameters was performed. The conducted studies revealed decrease in species diversity in reservoirs with the highest levels of radioactive and chemical contamination. This article is an initial descriptive report on the status of the biocenoses of radioactively contaminated reservoirs of the Mayak PA, and is the first article in a series of publications devoted to the studies of the reaction of biocenoses of the fresh-water reservoirs of the Mayak PA to a combination of natural and man-made factors, including chronic radiation exposure. - Highlights: • The current state of storage reservoirs of liquid radioactive waste of the Mayak Production Association is presented. • Radionuclides contents in water and sediments of the reservoirs of Mayak PA are presented. • The status of the major ecological groups of hydrobionts of the given reservoirs is described.

  6. Sustainable Irrigation Allocation Model for Dry and Wet Periods using Reservoir Storage and Inflow

    Science.gov (United States)

    Surianarayanan, S.; Suribabu, C. R.; Ramakrishnan, K.

    2017-07-01

    The dry period agriculture is inevitable both for the farmers for their earning, and for the soil for its fertility by crop-rotation. In tropical countries like INDIA, dry period agriculture becomes difficult because of less (or) no rain fall. Hence a simple water balancing model for irrigation scheduling, using the measure “Volumetric Reliability” is prepared in this paper, with the storage and inflow of a reservoir both for the dry and wet periods. The case-study is done for a reservoir in INDIA with thirty one years of hydrological data(from 1982 to 2012). The objective of this paper is to prepare a simple water balance model taking 10 days periods of demand and supply for ID crop(Irrigated Dry crop, ground nut) with usage of volumetric reliability concept for the periods of deficiency and adoption of less water requirement crops to reduce the water-stress during critical periods of crop growth, and finally arrive at a feasible allocation schedule for the success of agriculture and the yield throughout the year both for wet and dry crops with the available storage on the start of irrigation for a particular year. The reservoir is divided for storages such as full, deficient and critical storages. The starting storage for the dry period from January is used after adequate allocation for wet crops, the quantity for riparian rights and for drinking water, for the sustainability. By the water-balancing, the time-series for thirty one years, it is found that for twenty two years the demand for the ID crops is satisfied with the storage in the reservoir, and in the remaining years of deficient inflows, for three years (1986,1996,2004)the demand is managed by using the safe reliability factor for demand which can nullify the deficit in demand for the whole supply period. But it is genuine to assure that the reduction in the amount of water for each 10 days periods should not exceed the survival limit of the crop. Necessary soil-moisture must be ensured in the crop

  7. Intelligent monitoring system for real-time geologic CO2 storage, optimization and reservoir managemen

    Science.gov (United States)

    Dou, S.; Commer, M.; Ajo Franklin, J. B.; Freifeld, B. M.; Robertson, M.; Wood, T.; McDonald, S.

    2017-12-01

    Archer Daniels Midland Company's (ADM) world-scale agricultural processing and biofuels production complex located in Decatur, Illinois, is host to two industrial-scale carbon capture and storage projects. The first operation within the Illinois Basin-Decatur Project (IBDP) is a large-scale pilot that injected 1,000,000 metric tons of CO2 over a three year period (2011-2014) in order to validate the Illinois Basin's capacity to permanently store CO2. Injection for the second operation, the Illinois Industrial Carbon Capture and Storage Project (ICCS), started in April 2017, with the purpose of demonstrating the integration of carbon capture and storage (CCS) technology at an ethanol plant. The capacity to store over 1,000,000 metric tons of CO2 per year is anticipated. The latter project is accompanied by the development of an intelligent monitoring system (IMS) that will, among other tasks, perform hydrogeophysical joint analysis of pressure, temperature and seismic reflection data. Using a preliminary radial model assumption, we carry out synthetic joint inversion studies of these data combinations. We validate the history-matching process to be applied to field data once CO2-breakthrough at observation wells occurs. This process will aid the estimation of permeability and porosity for a reservoir model that best matches monitoring observations. The reservoir model will further be used for forecasting studies in order to evaluate different leakage scenarios and develop appropriate early-warning mechanisms. Both the inversion and forecasting studies aim at building an IMS that will use the seismic and pressure-temperature data feeds for providing continuous model calibration and reservoir status updates.

  8. Modeling CO2 Storage in Fractured Reservoirs: Fracture-Matrix Interactions of Free-Phase and Dissolved CO2

    Science.gov (United States)

    Oldenburg, C. M.; Zhou, Q.; Birkholzer, J. T.

    2017-12-01

    The injection of supercritical CO2 (scCO2) in fractured reservoirs has been conducted at several storage sites. However, no site-specific dual-continuum modeling for fractured reservoirs has been reported and modeling studies have generally underestimated the fracture-matrix interactions. We developed a conceptual model for enhanced CO2 storage to take into account global scCO2 migration in the fracture continuum, local storage of scCO2 and dissolved CO2 (dsCO2) in the matrix continuum, and driving forces for scCO2 invasion and dsCO2 diffusion from fractures. High-resolution discrete fracture-matrix models were developed for a column of idealized matrix blocks bounded by vertical and horizontal fractures and for a km-scale fractured reservoir. The column-scale simulation results show that equilibrium storage efficiency strongly depends on matrix entry capillary pressure and matrix-matrix connectivity while the time scale to reach equilibrium is sensitive to fracture spacing and matrix flow properties. The reservoir-scale modeling results shows that the preferential migration of scCO2 through fractures is coupled with bulk storage in the rock matrix that in turn retards the fracture scCO2 plume. We also developed unified-form diffusive flux equations to account for dsCO2 storage in brine-filled matrix blocks and found solubility trapping is significant in fractured reservoirs with low-permeability matrix.

  9. Reservoir Engineering Optimization Strategies for Subsurface CO{sub 2} Storage

    Energy Technology Data Exchange (ETDEWEB)

    Mclntire, Blayde; McPherson, Brian

    2013-09-30

    The purpose of this report is to outline a methodology for calculating the optimum number of injection wells for geologic CCS. The methodology is intended primarily for reservoir pressure management, and factors in cost as well. Efficiency may come in many forms depending on project goals; therefore, various results are presented simultaneously. The developed methodology is illustrated via application in a case study of the Rocky Mountain Carbon Capture and Storage (RMCCS) project, including a CCS candidate site near Craig, Colorado, USA. The forecasting method provided reasonable estimates of cost and injection volume when compared to simulated results.

  10. Doomed reservoirs in Kansas, USA? Climate change and groundwater mining on the Great Plains lead to unsustainable surface water storage

    Science.gov (United States)

    Brikowski, T. H.

    2008-06-01

    SummaryStreamflow declines on the Great Plains of the US are causing many Federal reservoirs to become profoundly inefficient, and will eventually drive them into unsustainability as negative annual reservoir water budgets become more common. The streamflow declines are historically related to groundwater mining, but since the mid-1980s correlate increasingly with climate. This study highlights that progression toward unsustainability, and shows that future climate change will continue streamflow declines at historical rates, with severe consequences for surface water supply. An object lesson is Optima Lake in the Oklahoma Panhandle, where streamflows have declined 99% since the 1960s and the reservoir has never been more than 5% full. Water balances for the four westernmost Federal reservoirs in Kansas (Cedar Bluff, Keith Sebelius, Webster and Kirwin) show similar tendencies. For these four, reservoir inflow has declined by 92%, 73%, 81% and 64% respectively since the 1950s. Since 1990 total evaporated volumes relative to total inflows amounted to 68%, 83%, 24% and 44% respectively. Predictions of streamflow and reservoir performance based on climate change models indicate 70% chance of steady decline after 2007, with a ˜50% chance of failure (releases by gravity flow impossible) of Cedar Bluff Reservoir between 2007 and 2050. Paradoxically, a 30% chance of storage increase prior 2020 is indicated, followed by steady declines through 2100. Within 95% confidence the models predict >50% decline in surface water resources between 2007 and 2050. Ultimately, surface storage of water resources may prove unsustainable in this region, forcing conversion to subsurface storage.

  11. Rapid cooling and cold storage in a silicic magma reservoir recorded in individual crystals.

    Science.gov (United States)

    Rubin, Allison E; Cooper, Kari M; Till, Christy B; Kent, Adam J R; Costa, Fidel; Bose, Maitrayee; Gravley, Darren; Deering, Chad; Cole, Jim

    2017-06-16

    Silicic volcanic eruptions pose considerable hazards, yet the processes leading to these eruptions remain poorly known. A missing link is knowledge of the thermal history of magma feeding such eruptions, which largely controls crystallinity and therefore eruptability. We have determined the thermal history of individual zircon crystals from an eruption of the Taupo Volcanic Zone, New Zealand. Results show that although zircons resided in the magmatic system for 10 3 to 10 5 years, they experienced temperatures >650° to 750°C for only years to centuries. This implies near-solidus long-term crystal storage, punctuated by rapid heating and cooling. Reconciling these data with existing models of magma storage requires considering multiple small intrusions and multiple spatial scales, and our approach can help to quantify heat input to and output from magma reservoirs. Copyright © 2017, American Association for the Advancement of Science.

  12. Bathymetry and Sediment-Storage Capacity Change in Three Reservoirs on the Lower Susquehanna River, 1996-2008

    Science.gov (United States)

    Langland, Michael J.

    2009-01-01

    The Susquehanna River transports a substantial amount of the sediment and nutrient load to the Chesapeake Bay. Upstream of the bay, three large dams and their associated reservoirs trap a large amount of the transported sediment and associated nutrients. During the fall of 2008, the U.S. Geological Survey in cooperation with the Pennsylvania Department of Environmental Protection completed bathymetric surveys of three reservoirs on the lower Susquehanna River to provide an estimate of the remaining sediment-storage capacity. Previous studies indicated the upper two reservoirs were in equilibrium with long-term sediment storage; only the most downstream reservoir retained capacity to trap sediments. A differential global positioning system (DGPS) instrument was used to provide the corresponding coordinate position. Bathymetry data were collected using a single beam 210 kHz (kilohertz) echo sounder at pre-defined transects that matched previous surveys. Final horizontal (X and Y) and vertical (Z) coordinates of the geographic positions and depth to bottom were used to create bathymetric maps of the reservoirs. Results indicated that from 1996 to 2008 about 14,700,000 tons of sediment were deposited in the three reservoirs with the majority (12,000,000 tons) being deposited in Conowingo Reservoir. Approximately 20,000 acre-feet or 30,000,000 tons of remaining storage capacity is available in Conowingo Reservoir. At current transport (3,000,000 tons per year) and deposition (2,000,000 tons per year) rates and with no occurrence of major scour events due to floods, the remaining capacity may be filled in 15 to 20 years. Once the remaining sediment-storage capacity in the reservoirs is filled, sediment and associated phosphorus loads entering the Chesapeake Bay are expected to increase.

  13. Geophysical assessments of renewable gas energy compressed in geologic pore storage reservoirs.

    Science.gov (United States)

    Al Hagrey, Said Attia; Köhn, Daniel; Rabbel, Wolfgang

    2014-01-01

    Renewable energy resources can indisputably minimize the threat of global warming and climate change. However, they are intermittent and need buffer storage to bridge the time-gap between production (off peak) and demand peaks. Based on geologic and geochemical reasons, the North German Basin has a very large capacity for compressed air/gas energy storage CAES in porous saltwater aquifers and salt cavities. Replacing pore reservoir brine with CAES causes changes in physical properties (elastic moduli, density and electrical properties) and justify applications of integrative geophysical methods for monitoring this energy storage. Here we apply techniques of the elastic full waveform inversion FWI, electric resistivity tomography ERT and gravity to map and quantify a gradually saturated gas plume injected in a thin deep saline aquifer within the North German Basin. For this subsurface model scenario we generated different synthetic data sets without and with adding random noise in order to robust the applied techniques for the real field applications. Datasets are inverted by posing different constraints on the initial model. Results reveal principally the capability of the applied integrative geophysical approach to resolve the CAES targets (plume, host reservoir, and cap rock). Constrained inversion models of elastic FWI and ERT are even able to recover well the gradual gas desaturation with depth. The spatial parameters accurately recovered from each technique are applied in the adequate petrophysical equations to yield precise quantifications of gas saturations. Resulting models of gas saturations independently determined from elastic FWI and ERT techniques are in accordance with each other and with the input (true) saturation model. Moreover, the gravity technique show high sensitivity to the mass deficit resulting from the gas storage and can resolve saturations and temporal saturation changes down to ±3% after reducing any shallow fluctuation such as that of

  14. Carbon capture and storage at scale: Lessons from the growth of analogous energy technologies

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Varun, E-mail: varun@stanford.ed [Program on Energy and Sustainable Development, Stanford University, Stanford, 616 Serra St., Encina Hall, Room E419, CA 94305 (United States); Victor, David G. [School of International Relations and Pacific Studies, University of California, San Diego, La Jolla, CA 92093-0519 (United States); Thurber, Mark C. [Program on Energy and Sustainable Development, Stanford University, Stanford, 616 Serra St., Encina Hall, Room E419, CA 94305 (United States)

    2010-08-15

    At present carbon capture and storage (CCS) is very expensive and its performance is highly uncertain at the scale of commercial power plants. Such challenges to deployment, though, are not new to students of technological change. Several successful technologies, including energy technologies, have faced similar challenges as CCS faces now. To draw lessons for the CCS industry from the history of other energy technologies that, as with CCS today, were risky and expensive early in their commercial development, we have analyzed the development of the US nuclear-power industry, the US SO{sub 2}-scrubber industry, and the global liquefied natural gas (LNG) industry. Through analyzing the development of the analogous industries we arrive at three principal observations. First, government played a decisive role in the development of all of these analogous technologies. Second, diffusion of these technologies beyond the early demonstration and niche projects hinged on the credibility of incentives for industry to invest in commercial-scale projects. Third, the conventional wisdom that experience with technologies inevitably reduces costs does not necessarily hold. Risky and capital-intensive technologies may be particularly vulnerable to diffusion without accompanying reductions in cost.

  15. Carbon capture and storage at scale. Lessons from the growth of analogous energy technologies

    Energy Technology Data Exchange (ETDEWEB)

    Rai, Varun; Thurber, Mark C. [Program on Energy and Sustainable Development, Stanford University, Stanford, 616 Serra St., Encina Hall, Room E419, CA 94305 (United States); Victor, David G. [School of International Relations and Pacific Studies, University of California, San Diego, La Jolla, CA 92093-0519 (United States)

    2010-08-15

    At present carbon capture and storage (CCS) is very expensive and its performance is highly uncertain at the scale of commercial power plants. Such challenges to deployment, though, are not new to students of technological change. Several successful technologies, including energy technologies, have faced similar challenges as CCS faces now. To draw lessons for the CCS industry from the history of other energy technologies that, as with CCS today, were risky and expensive early in their commercial development, we have analyzed the development of the US nuclear-power industry, the US SO{sub 2}-scrubber industry, and the global liquefied natural gas (LNG) industry. Through analyzing the development of the analogous industries we arrive at three principal observations. First, government played a decisive role in the development of all of these analogous technologies. Second, diffusion of these technologies beyond the early demonstration and niche projects hinged on the credibility of incentives for industry to invest in commercial-scale projects. Third, the conventional wisdom that experience with technologies inevitably reduces costs does not necessarily hold. Risky and capital-intensive technologies may be particularly vulnerable to diffusion without accompanying reductions in cost. (author)

  16. Carbon capture and storage at scale: Lessons from the growth of analogous energy technologies

    International Nuclear Information System (INIS)

    Rai, Varun; Victor, David G.; Thurber, Mark C.

    2010-01-01

    At present carbon capture and storage (CCS) is very expensive and its performance is highly uncertain at the scale of commercial power plants. Such challenges to deployment, though, are not new to students of technological change. Several successful technologies, including energy technologies, have faced similar challenges as CCS faces now. To draw lessons for the CCS industry from the history of other energy technologies that, as with CCS today, were risky and expensive early in their commercial development, we have analyzed the development of the US nuclear-power industry, the US SO 2 -scrubber industry, and the global liquefied natural gas (LNG) industry. Through analyzing the development of the analogous industries we arrive at three principal observations. First, government played a decisive role in the development of all of these analogous technologies. Second, diffusion of these technologies beyond the early demonstration and niche projects hinged on the credibility of incentives for industry to invest in commercial-scale projects. Third, the conventional wisdom that experience with technologies inevitably reduces costs does not necessarily hold. Risky and capital-intensive technologies may be particularly vulnerable to diffusion without accompanying reductions in cost.

  17. Precision analog signal processor for beam position measurements in electron storage rings

    International Nuclear Information System (INIS)

    Hinkson, J.A.; Unser, K.B.

    1995-05-01

    Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y position entirely by analog means at nominally 1 V/mm. No computers are involved. No software is required. Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design m their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this paper we report on the architecture and performance of the ALS prototype BPM

  18. Precision analog signal processor for beam position measurements in electron storage rings

    International Nuclear Information System (INIS)

    Hinkson, J.A.; Unser, K.B.

    1995-01-01

    Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y posit ion entirely by analog means at nominally 1 V/mm. No computers are involved. No software is required. Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design m their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this paper we report on the architecture and performance of the ALS prototype BPM

  19. On-farm irrigation reservoirs for surface water storage in eastern Arkansas: Trends in construction in response to aquifer depletion

    Science.gov (United States)

    Yaeger, M. A.; Reba, M. L.; Massey, J. H.; Adviento-Borbe, A.

    2017-12-01

    On-farm surface water storage reservoirs have been constructed to address declines in the Mississippi River Valley Alluvial aquifer, the primary source of irrigation for most of the row crops grown in eastern Arkansas. These reservoirs and their associated infrastructure represent significant investments in financial and natural resources, and may cause producers to incur costs associated with foregone crop production and long-term maintenance. Thus, an analysis of reservoir construction trends in the Grand Prairie Critical Groundwater Area (GPCGA) and Cache River Critical Groundwater Area (CRCGA) was conducted to assist future water management decisions. Between 1996 and 2015, on average, 16 and 4 reservoirs were constructed per year, corresponding to cumulative new reservoir surface areas of 161 and 60 ha yr-1, for the GPCGA and the CRCGA, respectively. In terms of reservoir locations relative to aquifer status, after 1996, 84.5% of 309 total reservoirs constructed in the GPCGA and 91.0% of 78 in the CRCGA were located in areas with remaining saturated aquifer thicknesses of 50% or less. The majority of new reservoirs (74% in the GPCGA and 63% in the CRCGA) were constructed on previously productive cropland. The next most common land use, representing 11% and 15% of new reservoirs constructed in the GPCGA and CRCGA, respectively, was the combination of a field edge and a ditch, stream, or other low-lying area. Less than 10% of post-1996 reservoirs were constructed on predominately low-lying land, and the use of such lands decreased in both critical groundwater areas during the past 20 years. These disparities in reservoir construction rates, locations, and prior land uses is likely due to groundwater declines being first observed in the GPCGA as well as the existence of two large-scale river diversion projects under construction in the GPCGA that feature on-farm storage as a means to offset groundwater use.

  20. Energy optimization through probabilistic annual forecast water release technique for major storage hydroelectric reservoir

    International Nuclear Information System (INIS)

    Abdul Bahari Othman; Mohd Zamri Yusoff

    2006-01-01

    One of the important decisions to be made by the management of hydroelectric power plant associated with major storage reservoir is to determine the best turbine water release decision for the next financial year. The water release decision enables firm energy generated estimation for the coming financial year to be done. This task is usually a simple and straightforward task provided that the amount of turbine water release is known. The more challenging task is to determine the best water release decision that is able to resolve the two conflicting operational objectives which are minimizing the drop of turbine gross head and maximizing upper reserve margin of the reservoir. Most techniques from literature emphasize on utilizing the statistical simulations approach. Markovians models, for example, are a class of statistical model that utilizes the past and the present system states as a basis for predicting the future [1]. This paper illustrates that rigorous solution criterion can be mathematically proven to resolve those two conflicting operational objectives. Thus, best water release decision that maximizes potential energy for the prevailing natural inflow is met. It is shown that the annual water release decision shall be made in such a manner that annual return inflow that has return frequency smaller than critical return frequency (f c ) should not be considered. This criterion enables target turbine gross head to be set to the well-defined elevation. In the other words, upper storage margin of the reservoir shall be made available to capture magnitude of future inflow that has return frequency greater than or equal to f c. A case study is shown to demonstrate practical application of the derived mathematical formulas

  1. Reservoir operations under climate change: Storage capacity options to mitigate risk

    Science.gov (United States)

    Ehsani, Nima; Vörösmarty, Charles J.; Fekete, Balázs M.; Stakhiv, Eugene Z.

    2017-12-01

    Observed changes in precipitation patterns, rising surface temperature, increases in frequency and intensity of floods and droughts, widespread melting of ice, and reduced snow cover are some of the documented hydrologic changes associated with global climate change. Climate change is therefore expected to affect the water supply-demand balance in the Northeast United States and challenge existing water management strategies. The hydrological implications of future climate will affect the design capacity and operating characteristics of dams. The vulnerability of water resources systems to floods and droughts will increase, and the trade-offs between reservoir releases to maintain flood control storage, drought resilience, ecological flow, human water demand, and energy production should be reconsidered. We used a Neural Networks based General Reservoir Operation Scheme to estimate the implications of climate change for dams on a regional scale. This dynamic daily reservoir module automatically adapts to changes in climate and re-adjusts the operation of dams based on water storage level, timing, and magnitude of incoming flows. Our findings suggest that the importance of dams in providing water security in the region will increase. We create an indicator of the Effective Degree of Regulation (EDR) by dams on water resources and show that it is expected to increase, particularly during drier months of year, simply as a consequence of projected climate change. The results also indicate that increasing the size and number of dams, in addition to modifying their operations, may become necessary to offset the vulnerabilities of water resources systems to future climate uncertainties. This is the case even without considering the likely increase in future water demand, especially in the most densely populated regions of the Northeast.

  2. Feasibility study of an aeration treatment system in a raw water storage reservoir used as a potable water source

    OpenAIRE

    Fronk, Robert Charles

    1996-01-01

    The systems engineering process has been utilized to determine the feasibility of an aeration treatment system for a raw water storage reservoir used as a potable water source. This system will be used to ensure a consistently high quality of raw water by the addition of dissolved oxygen into the reservoir. A needs analysis establishes the importance and requirements for a consistently high quality of raw water used as a source for a potable water treatment facility. This s...

  3. Assessing reservoir performance risk in CO{sub 2} storage projects

    Energy Technology Data Exchange (ETDEWEB)

    Bowden, A.R. [URS Corp., San Francisco, CA (United States); Rigg, A. [CRC for Greenhouse Gas Technologies, Canberra (Australia)

    2005-07-01

    One of the main issues for researchers involved with geological storage of carbon dioxide (CO{sub 2}) has been the development of a proper methodology to assess and compare alternative CO{sub 2} injection projects on the basis of risk. Consideration needs to be given to technical aspects, such as the risk of leakage and the effectiveness of the intended reservoir, as well as less tangible aspects such as the value and safety of geological storage of CO{sub 2}, and potential impacts on the community and environment. The Geological Disposal of Carbon Dioxide (GEODISC), was a research program of the Australian Petroleum Cooperative Research Centre which identified 56 potential environmentally sustainable sites for CO{sub 2} injection (ESSCIs) within Australia. Several studies were carried out, involving detailed evaluation of the suitability of 4 selected sites, including Dongara, Petrel, Gippsland and Carnarvon. The GEODISC program included a risk assessment research module which required a complete and quantified risk assessment of CO{sub 2} injection as a storage option. Primary goals were to assess the risk of leakage, to assess the effectiveness of the intended reservoir, and to assess negative consequences to facilitate comparison of alternative sites. This paper discussed the background and risk assessment model. Key performance indicators (KPIs) were also developed to address the purpose of risk assessment. It was concluded that the RISQUE method is an appropriate approach and that potential injection projects can be measured against six KPIs including containment; effectiveness; self-funding potential; wider community benefits; community safety and community amenity. 6 refs., 3 tabs., 3 figs.

  4. Underground storage at Saint-Illiers-la-Ville. Initial results of filling. Reservoir control problems

    Energy Technology Data Exchange (ETDEWEB)

    Vernet, D

    1968-01-01

    The underground storage at Saint-Illiers-la-Ville (Yvelines in the Paris area) was discussed by Toche at the time when it was filled with gas in 1965. Now, 2-1/2 yr after the initial input, the volume of storage has reached 500 million cu m, and the first industrial withdrawals took place during the winter of 1967-1968. The results obtained in the operation of this underground storage are extremely satisfactory. In spite of differences in the composition of the sand layer, the gas bubble developed in a very regular way, horizontally and vertically, and the full penetration well equipment made a high output rate easy to obtain. Reservoir control was handled efficiently and the movements of the bubble contour were shown for every fluctuation of the injection and withdrawal volumes. Tests for production capacity showed the low extent to which the wells were affected by the phenomenon of water- coning and indicated measures to be taken to prevent the formation of hydrates. The measures effected and the conclusions which can be derived are discussed.

  5. Structural analysis of porous rock reservoirs subjected to conditions of compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Friley, J.R.

    1980-01-01

    Investigations are described which were performed to assess the structural behavior of porous rock compressed air energy storage (CAES) reservoirs subjected to loading conditions of temperature and pressure felt to be typical of such an operation. Analyses performed addressed not only the nominal or mean reservoir response but also the cyclic response due to charge/discharge operation. The analyses were carried out by assuming various geometrical and material related parameters of a generic site. The objective of this study was to determine the gross response of a generic porous reservoir. The site geometry for this study assumed a cylindrical model 122 m in dia and 57 m high including thicknesses for the cap, porous, and base rock formations. The central portion of the porous zone was assumed to be at a depth of 518 m and at an initial temperature of 20/sup 0/C. Cyclic loading conditions of compressed air consisted of pressure values in the range of 4.5 to 5.2 MPa and temperature values between 143 and 204/sup 0/C.Various modes of structural behavior were studied. These response modes were analyzed using loading conditions of temperature and pressure (in the porous zone) corresponding to various operational states during the first year of simulated site operation. The results of the structural analyses performed indicate that the most severely stressed region will likely be in the wellbore vicinity and hence highly dependent on the length of and placement technique utilized in the well production length. Analyses to address this specific areas are currently being pursued.

  6. The HYDROMED model and its application to semi-arid Mediterranean catchments with hill reservoirs 3: Reservoir storage capacity and probability of failure model

    Directory of Open Access Journals (Sweden)

    R. Ragab

    2001-01-01

    Full Text Available This paper addresses the issue of "what reservoir storage capacity is required to maintain a yield with a given probability of failure?". It is an important issue in terms of construction and cost. HYDROMED offers a solution based on the modified Gould probability matrix method. This method has the advantage of sampling all years data without reference to the sequence and is therefore particularly suitable for catchments with patchy data. In the HYDROMED model, the probability of failure is calculated on a monthly basis. The model has been applied to the El-Gouazine catchment in Tunisia using a long rainfall record from Kairouan together with the estimated Hortonian runoff, class A pan evaporation data and estimated abstraction data. Generally, the probability of failure differed from winter to summer. Generally, the probability of failure approaches zero when the reservoir capacity is 500,000 m3. The 25% probability of failure (75% success is achieved with a reservoir capacity of 58,000 m3 in June and 95,000 m3 in January. The probability of failure for a 240,000 m3 capacity reservoir (closer to storage capacity of El-Gouazine 233,000 m3, is approximately 5% in November, December and January, 3% in March, and 1.1% in May and June. Consequently there is no high risk of El-Gouazine being unable to meet its requirements at a capacity of 233,000 m3. Subsequently the benefit, in terms of probability of failure, by increasing the reservoir volume of El-Gouazine to greater than the 250,000 m3 is not high. This is important for the design engineers and the funding organizations. However, the analysis is based on the existing water abstraction policy, absence of siltation rate data and on the assumption that the present climate will prevail during the lifetime of the reservoir. Should these conditions change, a new analysis should be carried out. Keywords: HYDROMED, reservoir, storage capacity, probability of failure, Mediterranean

  7. Gas-water-rock interactions induced by reservoir exploitation, CO2 sequestration, and other geological storage

    International Nuclear Information System (INIS)

    Lecourtier, J.

    2005-01-01

    Here is given a summary of the opening address of the IFP International Workshop: 'gas-water-rock interactions induced by reservoir exploitation, CO 2 sequestration, and other geological storage' (18-20 November 2003). 'This broad topic is of major interest to the exploitation of geological sites since gas-water-mineral interactions determine the physicochemical characteristics of these sites, the strategies to adopt to protect the environment, and finally, the operational costs. Modelling the phenomena is a prerequisite for the engineering of a geological storage, either for disposal efficiency or for risk assessment and environmental protection. During the various sessions, several papers focus on the great achievements that have been made in the last ten years in understanding and modelling the coupled reaction and transport processes occurring in geological systems, from borehole to reservoir scale. Remaining challenges such as the coupling of mechanical processes of deformation with chemical reactions, or the influence of microbiological environments on mineral reactions will also be discussed. A large part of the conference programme will address the problem of mitigating CO 2 emissions, one of the most important issues that our society must solve in the coming years. From both a technical and an economic point of view, CO 2 geological sequestration is the most realistic solution proposed by the experts today. The results of ongoing pilot operations conducted in Europe and in the United States are strongly encouraging, but geological storage will be developed on a large scale in the future only if it becomes possible to predict the long term behaviour of stored CO 2 underground. In order to reach this objective, numerous issues must be solved: - thermodynamics of CO 2 in brines; - mechanisms of CO 2 trapping inside the host rock; - geochemical modelling of CO 2 behaviour in various types of geological formations; - compatibility of CO 2 with oil-well cements

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

    Directory of Open Access Journals (Sweden)

    Vaher, Rein

    2009-12-01

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

  9. The role of reservoir storage in large-scale surface water availability analysis for Europe

    Science.gov (United States)

    Garrote, L. M.; Granados, A.; Martin-Carrasco, F.; Iglesias, A.

    2017-12-01

    A regional assessment of current and future water availability in Europe is presented in this study. The assessment was made using the Water Availability and Adaptation Policy Analysis (WAAPA) model. The model was built on the river network derived from the Hydro1K digital elevation maps, including all major river basins of Europe. Reservoir storage volume was taken from the World Register of Dams of ICOLD, including all dams with storage capacity over 5 hm3. Potential Water Availability is defined as the maximum amount of water that could be supplied at a certain point of the river network to satisfy a regular demand under pre-specified reliability requirements. Water availability is the combined result of hydrological processes, which determine streamflow in natural conditions, and human intervention, which determines the available hydraulic infrastructure to manage water and establishes water supply conditions through operating rules. The WAAPA algorithm estimates the maximum demand that can be supplied at every node of the river network accounting for the regulation capacity of reservoirs under different management scenarios. The model was run for a set of hydrologic scenarios taken from the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP), where the PCRGLOBWB hydrological model was forced with results from five global climate models. Model results allow the estimation of potential water stress by comparing water availability to projections of water abstractions along the river network under different management alternatives. The set of sensitivity analyses performed showed the effect of policy alternatives on water availability and highlighted the large uncertainties linked to hydrological and anthropological processes.

  10. Quantification of oil recovery efficiency, CO 2 storage potential, and fluid-rock interactions by CWI in heterogeneous sandstone oil reservoirs

    DEFF Research Database (Denmark)

    Seyyedi, Mojtaba; Sohrabi, Mehran; Sisson, Adam

    2017-01-01

    Significant interest exists in improving recovery from oil reservoirs while addressing concerns about increasing CO2 concentrations in the atmosphere. The combination of Enhanced Oil Recovery (EOR) and safe geologic storage of CO2 in oil reservoirs is appealing and can be achieved by carbonated (CO...... for oil recovery and CO2 storage potential on heterogeneous cores. Since not all the oil reservoirs are homogenous, understanding the potential of CWI as an integrated EOR and CO2 storage scenario in heterogeneous oil reservoirs is essential....

  11. Geological storage of carbon dioxide in the coal seams: from material to the reservoir

    International Nuclear Information System (INIS)

    Nikoosokhan, S.

    2012-01-01

    CO 2 emissions into the atmosphere are recognized to have a significant effect on global warming. Geological storage of CO 2 is widely regarded as an essential approach to reduce the impact of such emissions on the environment. Moreover, injecting carbon dioxide in coal bed methane reservoirs facilitates the recovery of the methane naturally present, a process known as enhanced coal bed methane recovery (ECBM). But the swelling of the coal matrix induced by the preferential adsorption by coal of carbon dioxide over the methane in place leads to a closure of the cleat system (a set of small natural fractures) of the reservoir and therefore to a loss of injectivity. This PhD thesis is dedicated to a study of how this injectivity evolves in presence of fluids. We derive two poro-mechanical dual-porosity models for a coal bed reservoir saturated by a pure fluid. The resulting constitutive equations enable to better understand and model the link between the injectivity of a coal seam and the adsorption-induced swelling of coal. For both models, the pore space of the reservoir is considered to be divided into the macroporous cleats and the pores of the coal matrix. The two models differ by how adsorption of fluid is taken into account: the first model is restricted to surface adsorption, while the second model can be applied for adsorption in a medium with a generic pore size distribution and thus in a microporous medium such as coal, in which adsorption mostly occurs by micropore filling. The latter model is calibrated on two coals with different sorption and swelling properties. We then perform simulations at various scales (Representative Elementary Volume, coal sample, coal seam). In particular, we validate our model on experimental data of adsorption-induced variations of permeability of coal. We also perform simulations of seams from which methane would be produced (CBM) or of methane-free seams into which CO 2 would be injected. We study the effect of various

  12. Hybrid Stochastic Forecasting Model for Management of Large Open Water Reservoir with Storage Function

    Science.gov (United States)

    Kozel, Tomas; Stary, Milos

    2017-12-01

    all numbers from interval. Resulted course of management was compared with course, which was obtained from using GE + real flow series. Comparing results showed that fuzzy model with forecasted values has been able to manage main malfunction and artificially disorders made by model were founded essential, after values of water volume during management were evaluated. Forecasting model in combination with fuzzy model provide very good results in management of water reservoir with storage function and can be recommended for this purpose.

  13. Synthesis and structure-distribution study of radioiodinated norepinephrine storage analogs

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, D.M.; Inbasekaran, M.; Brown, L.E.; Marsh, D.D.; Beierwaltes, W.H. (Michigan Univ., Ann Arbor (USA). Medical Center)

    Unlabelled analogs of norepinephrine have been synthesised and then labelled with /sup 125/I in an attempt to find an agent with heart uptake and neuronal specificity greater than metaiodobenzylguanidine (MIBG). The analogs of norepinephrine were injected intravenously into dogs and showed a heart concentration similar to MIBG. Neuronal specificity of some analogs is being evaluated in rat heart.

  14. Synthesis and structure-distribution study of radioiodinated norepinephrine storage analogs

    International Nuclear Information System (INIS)

    Wieland, D.M.; Inbasekaran, M.; Brown, L.E.; Marsh, D.D.; Beierwaltes, W.H.

    1982-01-01

    Unlabelled analogs of norepinephrine have been synthesised and then labelled with 125 I in an attempt to find an agent with heart uptake and neuronal specificity greater than metaiodobenzylguanidine (MIBG). The analogs of norepinephrine were injected intravenously into dogs and showed a heart concentration similar to MIBG. Neuronal specificity of some analogs is being evaluated in rat heart. (U.K.)

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

    NARCIS (Netherlands)

    Ali, M.; Sterk, G.

    2010-01-01

    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

  16. Environmental effects of storage preservation practices: controlled flushing of fine sediment from a small hydropower reservoir.

    Science.gov (United States)

    Espa, Paolo; Castelli, Elena; Crosa, Giuseppe; Gentili, Gaetano

    2013-07-01

    Sediment flushing may be effective in mitigating loss of reservoir storage due to siltation, but flushing must be controlled to limit the impact on the downstream environment. A reliable prediction of the environmental effects of sediment flushing is hindered by the limited scientific information currently available. Consequently, there may be some controversy as regards to management decisions, planning the work, and monitoring strategies. This paper summarizes the main results of a monitoring campaign on the stream below a small alpine hydropower reservoir subjected to annual flushing between 2006 and 2009. The removed sediment was essentially silt, and the suspended solid concentration (SSC) of the discharged water was controlled to alleviate downstream impact. Control was achieved through hydraulic regulation and mechanical digging, alternating daytime sediment evacuation, and nocturnal clear water release. The four operations lasted about two weeks each and had an average SSC of about 4 g L(-1). Maximum values of SSC were generally kept below 10 g L(-1). Downstream impact was quantified through sampling of fish fauna (brown trout) and macroinvertebrate in the final reach of the effluent stream. The benthic community was severely impaired by the flushing operations, but recovered to pre-flushing values in a few months. As expected, the impact on brown trout was heavier on juveniles. While data biasing due to fish removal and re-stocking cannot be ruled out, the fish community seems to have reached a state of equilibrium characterized by a lower density than was measured before the flushing operations.

  17. Some open issues in the analysis of the storage and migration properties of fractured carbonate reservoirs

    Science.gov (United States)

    Agosta, Fabrizio

    2017-04-01

    Underground CO2 storage in depleted hydrocarbon reservoirs may become a common practice in the future to lower the concentration of greenhouse gases in the atmosphere. Results from the first experiments conducted in carbonate rocks, for instance the Lacq integrated CCS Pilot site, SW France, are quite exciting. All monitored parameters, such as the CO2 concentration at well sites, well pressures, cap rock integrity and environmental indicators show the long-term integrity of this type of geological reservoirs. Other positive news arise from the OXY-CFB-300 Compostilla Project, NW Spain, where most of the injected CO2 dissolved into the formation brines, suggesting the long-term security of this method. However, in both cases, the CO2- rich fluids partially dissolved the carbonate minerals during their migration through the fractured reservoir, modifying the overall pore volume and pressure regimes. These results support the growing need for a better understanding of the mechanical behavior of carbonate rocks over geological time of scales. In fact, it is well known that carbonates exhibit a variety of deformation mechanisms depending upon many intrinsic factors such as composition, texture, connected pore volume, and nature of the primary heterogeneities. Commonly, tight carbonates are prone to opening-mode and/or pressure solution deformation. The interplay between these two mechanisms likely affects the petrophysical properties of the fault damage zones, which form potential sites for CO2 storage due to their high values of both connected porosity and permeability. On the contrary, cataclastic deformation produces fault rocks that often form localized fluid barriers for cross-fault fluid flow. Nowadays, questions on the conditions of sealing/leakage of carbonate fault rocks are still open. In particular, the relative role played by bulk crushing, chipping, cementation, and pressure solution on connected porosity of carbonate fault rocks during structural

  18. Depth limit of littoral vegetation in a storage reservoir: A case study of Lipno Reservoir (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Krolová, M.; Čížková, Hana; Hejzlar, Josef

    2012-01-01

    Roč. 42, č. 2 (2012), s. 165-174 ISSN 0075-9511 R&D Projects: GA ČR(CZ) GA206/09/1764 EU Projects: European Commission(XE) 244121 - REFRESH Institutional research plan: CEZ:AV0Z60170517; CEZ:AV0Z60870520 Keywords : macrophyte * littoral * reservoir * shore erosion * ecological potential * European Water Framework Directive Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.565, year: 2012

  19. Geology of the Roswell artesian basin, New Mexico, and its relation to the Hondo Reservoir and Effect on artesian aquifer storage of flood water in Hondo Reservoir

    Science.gov (United States)

    Bean, Robert T.; Theis, Charles V.

    1949-01-01

    In the Roswell Basin in southeastern New Mexico artesian water is produced from cavernous zones in the carbonate rocks of the San Andres formation and the lower part of the Chalk Bluff formation, both of Permian age. The Hondo Reservoir, 9 miles west-southwest of Roswell, was completed by the U. S. Bureau of Reclamation in 1907, to store waters of the Rio Hondo for irrigation. The project was not successful, as the impounded water escaped rapidly through holes in the gypsum and limestone of the San Andres formation constituting its floor. Of 27,000 acre~feet that entered the reservoir between 1908 and 1913, only 1,100 acre-feet was drawn Ollt for use, the remainder escaping through the floor of the reservoir. Since 1939, plans have been drawn up by the State Engineer and by Federal agencies to utilize the reservoir to protect Roswell from floods. It has also been suggested that water from the Pecos River might be diverted into underground storage through the reservoir. Sinkholes in the Roswell Basin are largely clustered in areas where gypsum occurs in the bedrock. Collapse of strata is due to solution of underlying rock commonly containing gypsum. Domes occur in gypsiferous strata near Salt Creek. The Bottomless Lakes, sinkhole lakes in the escarpment on the east side of the Pecos, are believed to have developed in north-south hinge-line fractures opened when the westernmost beds in the escarpment collapsed. Collapse was due to solution and removal of gypsiferous rock by artesian water which now fills the lakes.

  20. Quantifying Fracture Heterogeneity in Different Domains of Folded Carbonate Rocks to Improve Fractured Reservoir Analog Fluid Flow Models

    NARCIS (Netherlands)

    Bisdom, K.; Bertotti, G.; Gauthier, B.D.M.; Hardebol, N.J.

    2013-01-01

    Fluid flow in carbonate reservoirs is largely controlled by multiscale fracture networks. Significant variations of fracture network porosity and permeability are caused by the 3D heterogeneity of the fracture network characteristics, such as intensity, orientation and size. Characterizing fracture

  1. Characterization of biocenosis in the storage-reservoirs of liquid radioactive wastes of 'Mayak' PA

    Energy Technology Data Exchange (ETDEWEB)

    Pryakhin, E.; Tryapitsina, G.; Andreyev, S.; Akleyev, A. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Mokrov, Y.; Ivanov, I. [Mayak PA (Russian Federation)

    2014-07-01

    A number of storage-reservoirs of liquid radioactive wastes of 'Mayak' Production Association ('Mayak' PA) with different levels of radioactive contamination: reservoir R-17 ('Staroye Boloto'), reservoir R-9 (Lake Karachay), reservoirs of the Techa Cascade R-3 (Koksharov pond), R-4 (Metlinsky pond), R-10 and R-11 is located in Chelyabinsk Oblast (Russia). The operation of these reservoirs began in 1949-1964. Full-scale hydro-biological studies of these reservoirs were started in 2007. The research into the status of biocenosis of these storage reservoirs of liquid radioactive wastes of 'Mayak' PA was performed in 2007 - 2011. The status of biocenosis was evaluated in accordance with the status of following communities: bacterio-plankton, phytoplankton, zooplankton, zoo-benthos, macrophytes and ichthyofauna. The status of ecosystems was determined by radioactive and chemical contamination of water bodies. The results of hydro-biological investigations showed that no changes in the status of biota in reservoir R-11 were revealed as compared to the biological parameters of the water bodies of this geographical zone. In terms of biological parameters the status of the ecosystem of the reservoir R-11 is characterized by a sufficient biological diversity, and can be considered acceptable. The ecosystem of the reservoir R-10 maintains its functional integrity, although there were registered negative effects in the zoo-benthos community associated with the decrease in the parameters of the development of pelophylic mollusks that live at the bottom of the water body throughout the entire life cycle. In reservoir R-4 the parameters of the development of phytoplankton did not differ from those in Reservoirs R-11 and R-10; however, a significant reduction in the quantity of Cladocera and Copepoda was registered in the zooplankton community, while in the zoo-benthos there were no small mollusks that live aground throughout the entire life

  2. Geochemical Impacts of Leaking CO2 from Subsurface Storage Reservoirs to Unconfined and Confined Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla; Brown, Christopher F.; Wang, Guohui; Sullivan, E. C.; Lawter, Amanda R.; Harvey, Omar R.; Bowden, Mark

    2013-04-15

    Experimental research work has been conducted and is undergoing at Pacific Northwest National Laboratory (PNNL) to address a variety of scientific issues related with the potential leaks of the carbon dioxide (CO2) gas from deep storage reservoirs. The main objectives of this work are as follows: • Develop a systematic understanding of how CO2 leakage is likely to influence pertinent geochemical processes (e.g., dissolution/precipitation, sorption/desorption and redox reactions) in the aquifer sediments. • Identify prevailing environmental conditions that would dictate one geochemical outcome over another. • Gather useful information to support site selection, risk assessment, policy-making, and public education efforts associated with geological carbon sequestration. In this report, we present results from experiments conducted at PNNL to address research issues related to the main objectives of this effort. A series of batch and column experiments and solid phase characterization studies (quantitative x-ray diffraction and wet chemical extractions with a concentrated acid) were conducted with representative rocks and sediments from an unconfined, oxidizing carbonate aquifer, i.e., Edwards aquifer in Texas, and a confined aquifer, i.e., the High Plains aquifer in Kansas. These materials were exposed to a CO2 gas stream simulating CO2 gas leaking scenarios, and changes in aqueous phase pH and chemical composition were measured in liquid and effluent samples collected at pre-determined experimental times. Additional research to be conducted during the current fiscal year will further validate these results and will address other important remaining issues. Results from these experimental efforts will provide valuable insights for the development of site-specific, generation III reduced order models. In addition, results will initially serve as input parameters during model calibration runs and, ultimately, will be used to test model predictive capability and

  3. Reservoir characterization and final pre-test analysis in support of the compressed-air-energy-storage Pittsfield aquifer field test in Pike County, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.; McCann, R.A.

    1983-06-01

    The work reported is part of a field experimental program to demonstrate and evaluate compressed air energy storage in a porous media aquifer reservoir near Pittsfield, Illinois. The reservoir is described. Numerical modeling of the reservoir was performed concurrently with site development. The numerical models were applied to predict the thermohydraulic performance of the porous media reservoir. This reservoir characterization and pre-test analysis made use of evaluation of bubble development, water coning, thermal development, and near-wellbore desaturation. The work was undertaken to define the time required to develop an air storage bubble of adequate size, to assess the specification of instrumentation and above-ground equipment, and to develop and evaluate operational strategies for air cycling. A parametric analysis was performed for the field test reservoir. (LEW)

  4. Preservation of artifacts in salt mines as a natural analog for the storage of transuranic wastes at the WIPP repository

    International Nuclear Information System (INIS)

    Martell, M.A.; Hansen, F.; Weiner, R.

    1998-01-01

    Use of nature's laboratory for scientific analysis of complex systems is a largely untapped resource for understanding long-term disposal of hazardous materials. The Waste Isolation Pilot Plant (WIPP) in the US is a facility designed and approved for storage of transuranic waste in a salt medium. Isolation from the biosphere must be ensured for 10,000 years. Natural analogs provide a means to interpret the evolution of the underground disposal setting. Investigations of ancient sites where manmade materials have experienced mechanical and chemical processes over millennia provide scientific information unattainable by conventional laboratory methods. This paper presents examples of these pertinent natural analogs, provides examples of features relating to the WIPP application, and identifies potential avenues of future investigations. This paper cites examples of analogical information pertaining to the Hallstatt salt mine in Austria and Wieliczka salt mine in Poland. This paper intends to develop an appreciation for the applicability of natural analogs to the science and engineering of a long-term disposal facility in geomedia

  5. Preservation of artifacts in salt mines as a natural analog for the storage of transuranic wastes at the WIPP repository

    Energy Technology Data Exchange (ETDEWEB)

    Martell, M.A.; Hansen, F.; Weiner, R.

    1998-10-01

    Use of nature`s laboratory for scientific analysis of complex systems is a largely untapped resource for understanding long-term disposal of hazardous materials. The Waste Isolation Pilot Plant (WIPP) in the US is a facility designed and approved for storage of transuranic waste in a salt medium. Isolation from the biosphere must be ensured for 10,000 years. Natural analogs provide a means to interpret the evolution of the underground disposal setting. Investigations of ancient sites where manmade materials have experienced mechanical and chemical processes over millennia provide scientific information unattainable by conventional laboratory methods. This paper presents examples of these pertinent natural analogs, provides examples of features relating to the WIPP application, and identifies potential avenues of future investigations. This paper cites examples of analogical information pertaining to the Hallstatt salt mine in Austria and Wieliczka salt mine in Poland. This paper intends to develop an appreciation for the applicability of natural analogs to the science and engineering of a long-term disposal facility in geomedia.

  6. Long-term evolution of radio-active waste storage in geological formations: analogy with the weathering of mineral deposits

    International Nuclear Information System (INIS)

    Cantinolle, P.; Griffault, L.; Jebrak, M.

    1986-01-01

    The aim of this study was to select examples of mineral deposits and their weathering environment, showing the long-term behaviour, in geological time, measuring (area, volume) some constituent elements of radio-active waste storage subject to the hazards of hydrogeochemical weathering. Initially, a feasibility study was made to collate data available within the BRGM (mining group and public service) and from literature dealing with weathering of deposits. It was thus discovered that the analogy between radio-active waste storage and mineral deposits could be approached in two different yet complementary ways: - one approach is to observe the behaviour of a mineral deposit in relation to the country rocks. For this a bibliographic metallogenic study was made. The other approach is to observe the behaviour of chemical elements during deposition of a mineral deposit whose genesis is similar to the spatial and thermal environment of a deposit of radio-active waste in a geological formation. For this two sites were selected corresponding to hydrothermal systems showing strong analogies to those expected in the neighbourhood of the storage sites. These two sites, Langenberg in the Vosges and La Telhaie in Brittany, were the subject of complementary analytical work [fr

  7. Assessing Reservoir Depositional Environments to Develop and Quantify Improvements in CO2 Storage Efficiency. A Reservoir Simulation Approach

    Energy Technology Data Exchange (ETDEWEB)

    Okwen, Roland [University of Illinois, Champaign, IL (United States); Frailey, Scott [University of Illinois, Champaign, IL (United States); Leetaru, Hannes [University of Illinois, Champaign, IL (United States); Moulton, Sandy [Illinois State Geological Survey, Champaign, IL (United States)

    2014-09-30

    The storage potential and fluid movement within formations are dependent on the unique hydraulic characteristics of their respective depositional environments. Storage efficiency (E) quantifies the potential for storage in a geologic depositional environment and is used to assess basinal or regional CO2 storage resources. Current estimates of storage resources are calculated using common E ranges by lithology and not by depositional environment. The objectives of this project are to quantify E ranges and identify E enhancement strategies for different depositional environments via reservoir simulation studies. The depositional environments considered include deltaic, shelf clastic, shelf carbonate, fluvial deltaic, strandplain, reef, fluvial and alluvial, and turbidite. Strategies considered for enhancing E include CO2 injection via vertical, horizontal, and deviated wells, selective completions, water production, and multi-well injection. Conceptual geologic and geocellular models of the depositional environments were developed based on data from Illinois Basin oil fields and gas storage sites. The geologic and geocellular models were generalized for use in other US sedimentary basins. An important aspect of this work is the development of conceptual geologic and geocellular models that reflect the uniqueness of each depositional environment. Different injection well completions methods were simulated to investigate methods of enhancing E in the presence of geologic heterogeneity specific to a depositional environment. Modeling scenarios included horizontal wells (length, orientation, and inclination), selective and dynamic completions, water production, and multiwell injection. A Geologic Storage Efficiency Calculator (GSECalc) was developed to calculate E from reservoir simulation output. Estimated E values were normalized to diminish their dependency on fluid relative permeability. Classifying depositional environments according to

  8. SILTATION IN RESERVOIRS

    African Journals Online (AJOL)

    Keywords: reservoir model, siltation, sediment, catchment, sediment transport. 1. Introduction. Sediment ... rendered water storage structures useless in less than 25 years. ... reservoir, thus reducing the space available for water storage and ...

  9. Integrated Reservoir Modeling of CO2-EOR Performance and Storage Potential in the Farnsworth Field Unit, Texas.

    Science.gov (United States)

    Ampomah, W.; Balch, R. S.; Cather, M.; Dai, Z.

    2017-12-01

    We present a performance assessment methodology and storage potential for CO2 enhanced oil recovery (EOR) in partially depleted reservoirs. A three dimensional heterogeneous reservoir model was developed based on geological, geophysics and engineering data from Farnsworth field Unit (FWU). The model aided in improved characterization of prominent rock properties within the Pennsylvanian aged Morrow sandstone reservoir. Seismic attributes illuminated previously unknown faults and structural elements within the field. A laboratory fluid analysis was tuned to an equation of state and subsequently used to predict the thermodynamic minimum miscible pressure (MMP). Datasets including net-to-gross ratio, volume of shale, permeability, and burial history were used to model initial fault transmissibility based on Sperivick model. An improved history match of primary and secondary recovery was performed to set the basis for a CO2 flood study. The performance of the current CO2 miscible flood patterns was subsequently calibrated to historical production and injection data. Several prediction models were constructed to study the effect of recycling, addition of wells and /or new patterns, water alternating gas (WAG) cycles and optimum amount of CO2 purchase on incremental oil production and CO2 storage in the FWU. The history matching study successfully validated the presence of the previously undetected faults within FWU that were seen in the seismic survey. The analysis of the various prediction scenarios showed that recycling a high percentage of produced gas, addition of new wells and a gradual reduction in CO2 purchase after several years of operation would be the best approach to ensure a high percentage of recoverable incremental oil and sequestration of anthropogenic CO2 within the Morrow reservoir. Larger percentage of stored CO2 were dissolved in residual oil and less amount existed as supercritical free CO2. The geomechanical analysis on the caprock proved to an

  10. Exploring trade-offs between carbon storage, yield and biodiversity in analog forestry. A case study in the Peruvian Amazon

    Science.gov (United States)

    Recanati, F.; Saini, M.; Guariso, G.; Melia, P.

    2016-12-01

    Creation and management of agro-ecosystems can considerably influence the greenhouse gas exchange between terrestrial ecosystems and atmosphere. This is especially evident for tropical areas, where the expansion of agricultural lands for monoculture is among the main causes of deforestation and consequent CO2 emissions. In these contexts, agro-ecological approaches, such as analog forestry, seem promising alternatives to intensive ones. Analog forestry is usually created for reforestation purposes through the combination of ecological succession and architecture of natural forests (i.e., inclusion of species from shrubs to higher trees). Besides provisioning a variety of food and medicinal products, they provide high levels of biodiversity (compared to other agricultural practices) and important ecosystem services, like carbon storage. Given the complexity of such agro-ecosystems, this study aims to estimate the quantity of carbon that can be stored in an analog forest as a function of its species composition. Consequently, trade-offs between performances in terms of carbon storage, productivity and biodiversity are explored. The analysis focuses on the Peruvian region of Madre de Dios, where native forest and its biodiversity is threatened by intensive agriculture. To quantify plant above- and belowground biomass and the related carbon content, we feed appropriate allometric models with plant morphological information gathered in the field. Relying on our database of productive plant species suitable for the region, we formulate an optimization problem aimed at the selection of plant population under different constraint systems. The latter are defined according to possible farmers' preferences (e.g., average profitability or multi-functionality). The analysis refers to the farm-scale and is performed over medium-term horizon (i.e., 40 years), in order to take into account important plant dynamics (species growth and the evolution of shade interaction

  11. Economic feasibility of pipe storage and underground reservoir storage options for power-to-gas load balancing

    International Nuclear Information System (INIS)

    Budny, Christoph; Madlener, Reinhard; Hilgers, Christoph

    2015-01-01

    Highlights: • Study of cost effectiveness of power-to-gas and storage of H 2 and renewable methane. • NPV analysis and Monte Carlo simulation to address fuel and electricity price risks. • Gas sale is compared with power and gas market arbitrage and balancing market gains. • Power-to-gas for linking the balancing markets for power and gas is not profitable. • Pipe storage is the preferred option for temporal arbitrage and balancing energy. - Abstract: This paper investigates the economic feasibility of power-to-gas (P2G) systems and gas storage options for both hydrogen and renewable methane. The study is based on a techno-economic model in which the net present value (NPV) method and Monte Carlo simulation of risks and price forward curves for the electricity and the gas market are used. We study three investment cases: a Base Case where the gas is directly sold in the market, a Storage & Arbitrage Case where temporal arbitrage opportunities between the electricity and the gas market are exploited, and a Storage & Balancing Case where the balancing markets (secondary reserve market for electricity, external balancing market for natural gas) are addressed. The optimal type and size of different centralized and decentralized storage facilities are determined and compared with each other. In a detailed sensitivity and cost analysis, we identify the key factors which could potentially improve the economic viability of the technological concepts assessed. We find that the P2G system used for bridging the balancing markets for power and gas cannot be operated profitably. For both, temporal arbitrage and balancing energy, pipe storage is preferred. Relatively high feed-in tariffs (100 € MW −1 for hydrogen, 130 € MW −1 for methane) are required to render pipe storage for P2G economically viable

  12. Archaeological analogous and industrials for deep storage: study of the archaeological metallic piece

    International Nuclear Information System (INIS)

    Criado Portal, A. J.; Martinez Garcia, J. A.; Calabres Molina, R.; Garcia abajo, A.; Penco Valenzuela, F.; Lecanda Esteban, J. A.; Garcia Bartual, M.; Jimenez Gonzalez, J. M.; Bravo Munoz, E.; Rodriguez Lobo, L. M.; Fernandez Cascos, T.; Fernandes Cordero, O.; Montero Ruiz, I.

    2000-01-01

    The aim of present research is to obtain information about archaeological analogous of iron and steel, useful for the model of deep geological repository (AGP). The analogous examined have remained buried between 1400 and 2400 years, in very assorted geochemical environments. The extraction of the archaeological pieces has been accomplished according to normalised protocols, trying to carry to the laboratory so the piece as its burial environment, avoiding all possible pollution. Trying to the archaeological analogous could provide valuable information to the AGP model, the study has been directed to related the physical-chemical characteristics of the terrain respect to the deterioration of the archaeological metallic piece. The geology of the surrounding terrain to the archaeological deposit, the geomorphological study of the terrain and data from the analysis of ground: pH, wetness, porosity, organic matter contents, bacteria presence, sulphates, carbonates, chlorides, etc., have allowed to explain the physical-chemical phenomena suffered by the archaeological iron and steel pieces. Also, an exhaustive study of the archaeological piece has been accomplished, concerning the microstructure of the corrosion layer and of the not deteriorated metallic rest. Obtained information concerns different items, such as corrosion velocity and formations of oxide layers, diffusion of chemical elements from the corrosion layer to the metal and viceversa, and structural changes in oxide layers and in the metallic remains by structural ageing. Obtained data have allowed to develop a mathematical model for calculation of corrosion velocity in buried iron and steels, based on physical-chemical variables of grounds, chemical composition and thermomechanical treatment given to the metal during its manufacture. (Author)

  13. 3D Sedimentological and geophysical studies of clastic reservoir analogs: Facies architecture, reservoir properties, and flow behavior within delta front facies elements of the Cretaceous Wall Creek Member, Frontier Formation, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Christopher D. White

    2009-12-21

    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

  14. The Role of Energy Reservoirs in Distributed Computing: Manufacturing, Implementing, and Optimizing Energy Storage in Energy-Autonomous Sensor Nodes

    Science.gov (United States)

    Cowell, Martin Andrew

    The world already hosts more internet connected devices than people, and that ratio is only increasing. These devices seamlessly integrate with peoples lives to collect rich data and give immediate feedback about complex systems from business, health care, transportation, and security. As every aspect of global economies integrate distributed computing into their industrial systems and these systems benefit from rich datasets. Managing the power demands of these distributed computers will be paramount to ensure the continued operation of these networks, and is elegantly addressed by including local energy harvesting and storage on a per-node basis. By replacing non-rechargeable batteries with energy harvesting, wireless sensor nodes will increase their lifetimes by an order of magnitude. This work investigates the coupling of high power energy storage with energy harvesting technologies to power wireless sensor nodes; with sections covering device manufacturing, system integration, and mathematical modeling. First we consider the energy storage mechanism of supercapacitors and batteries, and identify favorable characteristics in both reservoir types. We then discuss experimental methods used to manufacture high power supercapacitors in our labs. We go on to detail the integration of our fabricated devices with collaborating labs to create functional sensor node demonstrations. With the practical knowledge gained through in-lab manufacturing and system integration, we build mathematical models to aid in device and system design. First, we model the mechanism of energy storage in porous graphene supercapacitors to aid in component architecture optimization. We then model the operation of entire sensor nodes for the purpose of optimally sizing the energy harvesting and energy reservoir components. In consideration of deploying these sensor nodes in real-world environments, we model the operation of our energy harvesting and power management systems subject to

  15. A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

    OpenAIRE

    Iskahar; Suripin; Isdiyana

    2018-01-01

    Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of ...

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

    Science.gov (United States)

    Melo, D. D.; Wendland, E.

    2017-12-01

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

  17. THE OHIO RIVER VALLEY CO2 STORAGE PROJECT - PRELIMINARY ASSESSMENT OF DEEP SALINE RESERVOIRS AND COAL SEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Mudd; Howard Johnson; Charles Christopher; T.S. Ramakrishnan, Ph.D.

    2003-08-01

    This report describes the geologic setting for the Deep Saline Reservoirs and Coal Seams in the Ohio River Valley CO{sub 2} Storage Project area. The object of the current project is to site and design a CO{sub 2} injection facility. A location near New Haven, WV, has been selected for the project. To assess geologic storage reservoirs at the site, regional and site-specific geology were reviewed. Geologic reports, deep well logs, hydraulic tests, and geologic maps were reviewed for the area. Only one well within 25 miles of the site penetrates the deeper sedimentary rocks, so there is a large amount of uncertainty regarding the deep geology at the site. New Haven is located along the Ohio River on the border of West Virginia and Ohio. Topography in the area is flat in the river valley but rugged away from the Ohio River floodplain. The Ohio River Valley incises 50-100 ft into bedrock in the area. The area of interest lies within the Appalachian Plateau, on the western edge of the Appalachian Mountain chain. Within the Appalachian Basin, sedimentary rocks are 3,000 to 20,000 ft deep and slope toward the southeast. The rock formations consist of alternating layers of shale, limestone, dolomite, and sandstone overlying dense metamorphic continental shield rocks. The Rome Trough is the major structural feature in the area, and there may be some faults associated with the trough in the Ohio-West Virginia Hinge Zone. The area has a low earthquake hazard with few historical earthquakes. Target injection reservoirs include the basal sandstone/Lower Maryville and the Rose Run Sandstone. The basal sandstone is an informal name for sandstones that overlie metamorphic shield rock. Regional geology indicates that the unit is at a depth of approximately 9,100 ft below the surface at the project site and associated with the Maryville Formation. Overall thickness appears to be 50-100 ft. The Rose Run Sandstone is another potential reservoir. The unit is located approximately 1

  18. Information retrieval system: impacts of water-level changes on uses of federal storage reservoirs of the Columbia River.

    Energy Technology Data Exchange (ETDEWEB)

    Fickeisen, D.H.; Cowley, P.J.; Neitzel, D.A.; Simmons, M.A.

    1982-09-01

    A project undertaken to provide the Bonneville Power Administration (BPA) with information needed to conduct environmental assessments and meet requirements of the National Environmental Policy Act (NEPA) and the Pacific Northwest Electric Power Planning and Conservation Act (Regional Act) is described. Access to information on environmental effects would help BPA fulfill its responsibilities to coordinate power generation on the Columbia River system, protect uses of the river system (e.g., irrigation, recreation, navigation), and enhance fish and wildlife production. Staff members at BPA identified the need to compile and index information resources that would help answer environmental impact questions. A computer retrieval system that would provide ready access to the information was envisioned. This project was supported by BPA to provide an initial step toward a compilation of environmental impact information. Scientists at Pacific Northwest Laboratory (PNL) identified, gathered, and evaluated information related to environmental effects of water level on uses of five study reservoirs and developed and implemented and environmental data retrieval system, which provides for automated storage and retrieval of annotated citations to published and unpublished information. The data retrieval system is operating on BPA's computer facility and includes the reservoir water-level environmental data. This project was divided into several tasks, some of which were conducted simultaneously to meet project deadlines. The tasks were to identify uses of the five study reservoirs, compile and evaluate reservoir information, develop a data entry and retrieval system, identify and analyze research needs, and document the data retrieval system and train users. Additional details of the project are described in several appendixes.

  19. Maximizing Storage Rate and Capacity and Insuring the Environmental Integrity of Carbon Dioxide Sequestration in Geological Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    L.A. Davis; A.L. Graham; H.W. Parker; J.R. Abbott; M.S. Ingber; A.A. Mammoli; L.A. Mondy; Quanxin Guo; Ahmed Abou-Sayed

    2005-12-07

    Maximizing Storage Rate and Capacity and Insuring the Environmental Integrity of Carbon Dioxide Sequestration in Geological Formations The U.S. and other countries may enter into an agreement that will require a significant reduction in CO2 emissions in the medium to long term. In order to achieve such goals without drastic reductions in fossil fuel usage, CO2 must be removed from the atmosphere and be stored in acceptable reservoirs. The research outlined in this proposal deals with developing a methodology to determine the suitability of a particular geologic formation for the long-term storage of CO2 and technologies for the economical transfer and storage of CO2 in these formations. A novel well-logging technique using nuclear-magnetic resonance (NMR) will be developed to characterize the geologic formation including the integrity and quality of the reservoir seal (cap rock). Well-logging using NMR does not require coring, and hence, can be performed much more quickly and efficiently. The key element in the economical transfer and storage of the CO2 is hydraulic fracturing the formation to achieve greater lateral spreads and higher throughputs of CO2. Transport, compression, and drilling represent the main costs in CO2 sequestration. The combination of well-logging and hydraulic fracturing has the potential of minimizing these costs. It is possible through hydraulic fracturing to reduce the number of injection wells by an order of magnitude. Many issues will be addressed as part of the proposed research to maximize the storage rate and capacity and insure the environmental integrity of CO2 sequestration in geological formations. First, correlations between formation properties and NMR relaxation times will be firmly established. A detailed experimental program will be conducted to determine these correlations. Second, improved hydraulic fracturing models will be developed which are suitable for CO2 sequestration as opposed to enhanced oil recovery (EOR

  20. Feasibility of CO2 storage in geothermal reservoirs example of the Paris Basin - France. Final report

    International Nuclear Information System (INIS)

    Barbier, J.; Robelin, C.; Kervevan, C.; Thiery, D.; Menjoz, A.; Matray, J.M.; Cotiche, C.; Herbrich, B.

    2003-01-01

    This study is realized in the framework of GESCO project, which aims to provide the first documentation that, for emission sources within selected key areas, sufficient geological storage capacity is available. Then the BRGM/ANTEA/CFG took care to provide: an inventory of the CO 2 emitters in France, an inventory of the main deep aquifers present in the Paris basin, an evaluation of the storage capacities of CO 2 in one of the four principal case-study, technical solutions for CO 2 injection in geothermal aquifers and an evaluation of the cost of CO 2 storage in such an aquifer. (A.L.B.)

  1. Geological rock property and production problems of the underground gas storage reservoir of Ketzin

    Energy Technology Data Exchange (ETDEWEB)

    Lange, W

    1966-01-01

    The purpose of the program of operation for an industrial injection of gas is briefly reviewed. It is emphasized that the works constitute the final stage of exploration. The decisive economic and extractive aspects are given. Final remarks deal with the methods of floor consolidation and tightness control. In the interest of the perspective exploration of the reservoir it is concluded and must be realized as an operating principle that the main problem, after determining the probable reservoir structure, consists in determining step-by-step (by combined theoretical, technical and economic parameters) the surface equipment needed from the geological and rock property factors, which were determined by suitable methods (hydro-exploration, gas injection). The technique and time-table of the geological exploration, and the design and construction of the installations will depend on the solution of the main problem. At the beginning, partial capacities will be sufficient for the surface installation. (12 refs.)

  2. Geologic storage of carbon dioxide and enhanced oil recovery. I. Uncertainty quantification employing a streamline based proxy for reservoir flow simulation

    International Nuclear Information System (INIS)

    Kovscek, A.R.; Wang, Y.

    2005-01-01

    Carbon dioxide (CO 2 ) is already injected into a limited class of reservoirs for oil recovery purposes; however, the engineering design question for simultaneous oil recovery and storage of anthropogenic CO 2 is significantly different from that of oil recovery alone. Currently, the volumes of CO 2 injected solely for oil recovery are minimized due to the purchase cost of CO 2 . If and when CO 2 emissions to the atmosphere are managed, it will be necessary to maximize simultaneously both economic oil recovery and the volumes of CO 2 emplaced in oil reservoirs. This process is coined 'cooptimization'. This paper proposes a work flow for cooptimization of oil recovery and geologic CO 2 storage. An important component of the work flow is the assessment of uncertainty in predictions of performance. Typical methods for quantifying uncertainty employ exhaustive flow simulation of multiple stochastic realizations of the geologic architecture of a reservoir. Such approaches are computationally intensive and thereby time consuming. An analytic streamline based proxy for full reservoir simulation is proposed and tested. Streamline trajectories represent the three-dimensional velocity field during multiphase flow in porous media and so are useful for quantifying the similarity and differences among various reservoir models. The proxy allows rational selection of a representative subset of equi-probable reservoir models that encompass uncertainty with respect to true reservoir geology. The streamline approach is demonstrated to be thorough and rapid

  3. Factors affecting storage of compressed air in porous-rock reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Doherty, T.J.; Erikson, R.L.; Wiles, L.E.

    1983-05-01

    This report documents a review and evaluation of the geotechnical aspects of porous medium (aquifer) storage. These aspects include geologic, petrologic, geophysical, hydrologic, and geochemical characteristics of porous rock masses and their interactions with compressed air energy storage (CAES) operations. The primary objective is to present criteria categories for the design and stability of CAES in porous media (aquifers). The document will also describe analytical, laboratory, and field-scale investigations that have been conducted.

  4. Geomechanical behavior of the reservoir and caprock system at the In Salah CO2 storage project.

    Science.gov (United States)

    White, Joshua A; Chiaramonte, Laura; Ezzedine, Souheil; Foxall, William; Hao, Yue; Ramirez, Abelardo; McNab, Walt

    2014-06-17

    Almost 4 million metric tons of CO2 were injected at the In Salah CO2 storage site between 2004 and 2011. Storage integrity at the site is provided by a 950-m-thick caprock that sits above the injection interval. This caprock consists of a number of low-permeability units that work together to limit vertical fluid migration. These are grouped into main caprock units, providing the primary seal, and lower caprock units, providing an additional buffer and some secondary storage capacity. Monitoring observations at the site indirectly suggest that pressure, and probably CO2, have migrated upward into the lower portion of the caprock. Although there are no indications that the overall storage integrity has been compromised, these observations raise interesting questions about the geomechanical behavior of the system. Several hypotheses have been put forward to explain the measured pressure, seismic, and surface deformation behavior. These include fault leakage, flow through preexisting fractures, and the possibility that injection pressures induced hydraulic fractures. This work evaluates these hypotheses in light of the available data. We suggest that the simplest and most likely explanation for the observations is that a portion of the lower caprock was hydrofractured, although interaction with preexisting fractures may have played a significant role. There are no indications, however, that the overall storage complex has been compromised, and several independent data sets demonstrate that CO2 is contained in the confinement zone.

  5. [Response of Algae to Nitrogen and Phosphorus Concentration and Quantity of Pumping Water in Pumped Storage Reservoir].

    Science.gov (United States)

    Wan, You-peng; Yin, Kui-hao; Peng, Sheng-hua

    2015-06-01

    Taking a pumped storage reservoir located in southern China as the research object, the paper established a three-dimensional hydrodynamic and eutrophication model of the reservoir employing EFDC (environmental fluid dynamics code) model, calibrated and verified the model using long-term hydraulic and water quality data. Based on the model results, the effects of nitrogen and phosphorus concentrations on the algae growth were analyzed, and the response of algae to nitrogen and phosphorus concentration and quantity of pumping water was also calculated. The results showed that the nitrogen and phosphorus concentrations had little limit on algae growth rate in the reservoir. In the nutrients reduction scenarios, reducing phosphorus would gain greater algae biomass reduction than reducing nitrogen. When reducing 60 percent of nitrogen, the algae biomass did not decrease, while 12.4 percent of algae biomass reduction could be gained with the same reduction ratio of phosphorus. When the reduction ratio went to 90 percent, the algae biomass decreased by 17.9 percent and 35.1 percent for nitrogen and phosphorus reduction, respectively. In the pumping water quantity regulation scenarios, the algae biomass decreased with the increasing pumping water quantity when the pumping water quantity was greater than 20 percent of the current value; when it was less than 20 percent, the algae biomass increased with the increasing pumping water quantity. The algae biomass decreased by 25.7 percent when the pumping water quantity was doubled, and increased by 38.8 percent when it decreased to 20 percent. The study could play an important role in supporting eutrophication controlling in water source area.

  6. Use of ground-water reservoirs for storage of surface water in the San Joaquin Valley, California

    Science.gov (United States)

    Davis, G.H.; Lofgren, B.E.; Mack, Seymour

    1964-01-01

    The San Joaquin Valley includes roughly the southern two-thirds of the Central Valley of California, extending 250 miles from Stockton on the north to Grapevine at the foot of the Tehachapi Mountains. The valley floor ranges in width from 25 miles near Bakersfield to about 55 miles near Visalia; it has a surface area of about 10,000 square miles. More than one-quarter of all the ground water pumped for irrigation in the United States is used in this highly productive valley. Withdrawal of ground water from storage by heavy pumping not only provides a needed irrigation water supply, but it also lowers the ground-water level and makes storage space available in which to conserve excess water during periods of heavy runoff. A storage capacity estimated to be 93 million acre-feet to a depth of 200 feet is available in this ground-water reservoir. This is about nine times the combined capacity of the existing and proposed surface-water reservoirs in the San Joaquin Valley under the California Water Plan. The landforms of the San Joaquin Valley include dissected uplands, low plains and fans, river flood plains and channels, and overflow lands and lake bottoms. Below the land surface, unconsolidated sediments derived from the surrounding mountain highlands extend downward for hundreds of feet. These unconsolidated deposits, consisting chiefly of alluvial deposits, but including some widespread lacustrine sediments, are the principal source of ground water in the valley. Ground water occurs under confined and unconfined conditions in the San Joaquin Valley. In much of the western, central, and southeastern parts of the valley, three distinct ground-water reservoirs are present. In downward succession these are 1) a body of unconfined and semiconfined fresh water in alluvial deposits of Recent, Pleistocene, and possibly later Pliocene age, overlying the Corcoran clay member of the Tulare formation; 2) a body of fresh water confined beneath the Corcoran clay member, which

  7. Well Integrity for Natural Gas Storage in Depleted Reservoirs and Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Freifeld, Barry [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oldenburg, Curtis [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jordan, Preston [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pan, Lehua [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Perfect, Scott [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morris, Joseph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, Joshua [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bauer, Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Blankenship, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bromhal, Grant [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Glosser, Deborah [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Wyatt, Douglas [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Rose, Kelly [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2016-09-01

    The 2015-2016 Aliso Canyon/Porter Ranch natural gas well blowout emitted approximately 100,000 tonnes of natural gas (mostly methane, CH4) over four months. The blowout impacted thousands of nearby residents, who were displaced from their homes. The high visibility of the event has led to increased scrutiny of the safety of natural gas storage at the Aliso Canyon facility, as well as broader concern for natural gas storage integrity throughout the country. This report presents the findings of the DOE National Laboratories Well Integrity Work Group efforts in the four tasks. In addition to documenting the work of the Work Group, this report presents high priority recommendations to improve well integrity and reduce the likelihood and consequences of subsurface natural gas leaks.

  8. Comment on "Rapid cooling and cold storage in a silicic magma reservoir recorded in individual crystals".

    Science.gov (United States)

    Wilson, Colin J N; Morgan, Daniel J; Charlier, Bruce L A; Barker, Simon J

    2017-12-22

    Rubin et al (Reports, 16 June 2017, p. 1154) proposed that gradients in lithium abundance in zircons from a rhyolitic eruption in New Zealand reflected short-lived residence at magmatic temperatures interleaved with long-term "cold" (<650°C) storage. Important issues arise with the interpretation of these lithium gradients and consequent crystal thermal histories that raise concerns about the validity of this conclusion. Copyright © 2017, American Association for the Advancement of Science.

  9. Well Integrity for Natural Gas Storage in Depleted Reservoirs and Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Freifeld, Barry M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Oldenburg, Curtis M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jordan, Preston [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pan, Lehua [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Perfect, Scott [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Morris, Joseph [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, Joshua [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bauer, Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Blankenship, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Barry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bromhal, Grant [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Glosser, Deborah [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Wyatt, Douglas [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Rose, Kelly [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2016-09-02

    Introduction Motivation The 2015-2016 Aliso Canyon/Porter Ranch natural gas well blowout emitted approximately 100,000 tonnes of natural gas (mostly methane, CH4) over four months. The blowout impacted thousands of nearby residents, who were displaced from their homes. The high visibility of the event has led to increased scrutiny of the safety of natural gas storage at the Aliso Canyon facility, as well as broader concern for natural gas storage integrity throughout the country. Federal Review of Well Integrity In April of 2016, the U.S. Department of Energy (DOE), in conjunction with the U.S. Department of Transportation (DOT) through the Pipeline and Hazardous Materials Safety Administration (PHMSA), announced the formation of a new Interagency Task Force on Natural Gas Storage Safety. The Task Force enlisted a group of scientists and engineers at the DOE National Laboratories to review the state of well integrity in natural gas storage in the U.S. The overarching objective of the review is to gather, analyze, catalogue, and disseminate information and findings that can lead to improved natural gas storage safety and security and thus reduce the risk of future events. The “Protecting our Infrastructure of Pipelines and Enhancing Safety Act of 2016’’ or the ‘‘PIPES Act of 2016,’’which was signed into law on June 22, 2016, created an Aliso Canyon Natural Gas Leak Task Force led by the Secretary of Energy and consisting of representatives from the DOT, Environmental Protection Agency (EPA), Department of Health and Human Services, Federal Energy Regulatory Commission (FERC), Department of Commerce and the Department of Interior. The Task Force was asked to perform an analysis of the Aliso Canyon event and make recommendations on preventing similar incidents in the future. The PIPES Act also required that DOT/PHMSA promulgate minimum safety standards for underground storage that would take effect within two years. Background on the DOE

  10. Kinetics of carbonate mineral dissolution in CO2-acidified brines at storage reservoir conditions.

    Science.gov (United States)

    Peng, Cheng; Anabaraonye, Benaiah U; Crawshaw, John P; Maitland, Geoffrey C; Trusler, J P Martin

    2016-10-20

    We report experimental measurements of the dissolution rate of several carbonate minerals in CO 2 -saturated water or brine at temperatures between 323 K and 373 K and at pressures up to 15 MPa. The dissolution kinetics of pure calcite were studied in CO 2 -saturated NaCl brines with molalities of up to 5 mol kg -1 . The results of these experiments were found to depend only weakly on the brine molality and to conform reasonably well with a kinetic model involving two parallel first-order reactions: one involving reactions with protons and the other involving reaction with carbonic acid. The dissolution rates of dolomite and magnesite were studied in both aqueous HCl solution and in CO 2 -saturated water. For these minerals, the dissolution rates could be explained by a simpler kinetic model involving only direct reaction between protons and the mineral surface. Finally, the rates of dissolution of two carbonate-reservoir analogue minerals (Ketton limestone and North-Sea chalk) in CO 2 -saturated water were found to follow the same kinetics as found for pure calcite. Vertical scanning interferometry was used to study the surface morphology of unreacted and reacted samples. The results of the present study may find application in reactive-flow simulations of CO 2 -injection into carbonate-mineral saline aquifers.

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

    Science.gov (United States)

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

    2010-05-01

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

  12. Element mobilization and immobilization from carbonate rocks between CO 2 storage reservoirs and the overlying aquifers during a potential CO 2 leakage

    Energy Technology Data Exchange (ETDEWEB)

    Lawter, Amanda R.; Qafoku, Nikolla P.; Asmussen, R. Matthew; Kukkadapu, Ravi K.; Qafoku, Odeta; Bacon, Diana H.; Brown, Christopher F.

    2018-04-01

    Despite the numerous studies on changes within the reservoir following CO2 injection and the effects of CO2 release into overlying aquifers, little or no literature is available on the effect of CO2 release on rock between the storage reservoirs and subsurface. To address this knowledge gap, relevant rock materials, temperatures and pressures were used to study mineralogical and elemental changes in this intermediate zone. After rocks reacted with CO2, liquid analysis showed an increase of major elements (e.g., Ca, and Mg) and variable concentrations of potential contaminants (e.g., Sr and Ba); lower concentrations were observed in N2 controls. In experiments with As/Cd and/or organic spikes, representing potential contaminants in the CO2 plume originating in the storage reservoir, most or all of these contaminants were removed from the aqueous phase. SEM and Mössbauer spectroscopy results showed the formation of new minerals and Fe oxides in some CO2-reacted samples, indicating potential for contaminant removal through mineral incorporation or adsorption onto Fe oxides. These experiments show the interactions between the CO2-laden plume and the rock between storage reservoirs and overlying aquifers have the potential to affect the level of risk to overlying groundwater, and should be considered during site selection and risk evaluation.

  13. Predicting Formation Damage in Aquifer Thermal Energy Storage Systems Utilizing a Coupled Hydraulic-Thermal-Chemical Reservoir Model

    Science.gov (United States)

    Müller, Daniel; Regenspurg, Simona; Milsch, Harald; Blöcher, Guido; Kranz, Stefan; Saadat, Ali

    2014-05-01

    In aquifer thermal energy storage (ATES) systems, large amounts of energy can be stored by injecting hot water into deep or intermediate aquifers. In a seasonal production-injection cycle, water is circulated through a system comprising the porous aquifer, a production well, a heat exchanger and an injection well. This process involves large temperature and pressure differences, which shift chemical equilibria and introduce or amplify mechanical processes. Rock-fluid interaction such as dissolution and precipitation or migration and deposition of fine particles will affect the hydraulic properties of the porous medium and may lead to irreversible formation damage. In consequence, these processes determine the long-term performance of the ATES system and need to be predicted to ensure the reliability of the system. However, high temperature and pressure gradients and dynamic feedback cycles pose challenges on predicting the influence of the relevant processes. Within this study, a reservoir model comprising a coupled hydraulic-thermal-chemical simulation was developed based on an ATES demonstration project located in the city of Berlin, Germany. The structural model was created with Petrel, based on data available from seismic cross-sections and wellbores. The reservoir simulation was realized by combining the capabilities of multiple simulation tools. For the reactive transport model, COMSOL Multiphysics (hydraulic-thermal) and PHREEQC (chemical) were combined using the novel interface COMSOL_PHREEQC, developed by Wissmeier & Barry (2011). It provides a MATLAB-based coupling interface between both programs. Compared to using COMSOL's built-in reactive transport simulator, PHREEQC additionally calculates adsorption and reaction kinetics and allows the selection of different activity coefficient models in the database. The presented simulation tool will be able to predict the most important aspects of hydraulic, thermal and chemical transport processes relevant to

  14. Two-phase flow visualization under reservoir conditions for highly heterogeneous conglomerate rock: A core-scale study for geologic carbon storage.

    Science.gov (United States)

    Kim, Kue-Young; Oh, Junho; Han, Weon Shik; Park, Kwon Gyu; Shinn, Young Jae; Park, Eungyu

    2018-03-20

    Geologic storage of carbon dioxide (CO 2 ) is considered a viable strategy for significantly reducing anthropogenic CO 2 emissions into the atmosphere; however, understanding the flow mechanisms in various geological formations is essential for safe storage using this technique. This study presents, for the first time, a two-phase (CO 2 and brine) flow visualization under reservoir conditions (10 MPa, 50 °C) for a highly heterogeneous conglomerate core obtained from a real CO 2 storage site. Rock heterogeneity and the porosity variation characteristics were evaluated using X-ray computed tomography (CT). Multiphase flow tests with an in-situ imaging technology revealed three distinct CO 2 saturation distributions (from homogeneous to non-uniform) dependent on compositional complexity. Dense discontinuity networks within clasts provided well-connected pathways for CO 2 flow, potentially helping to reduce overpressure. Two flow tests, one under capillary-dominated conditions and the other in a transition regime between the capillary and viscous limits, indicated that greater injection rates (potential causes of reservoir overpressure) could be significantly reduced without substantially altering the total stored CO 2 mass. Finally, the capillary storage capacity of the reservoir was calculated. Capacity ranged between 0.5 and 4.5%, depending on the initial CO 2 saturation.

  15. Production of inert gas for substitution of a part of the cushion gas trapped in an aquifer underground storage reservoir

    International Nuclear Information System (INIS)

    Berger, L.; Arnoult, J.P.

    1990-01-01

    In a natural gas storage reservoir operating over the different seasons, a varying fraction of the injected gas, the cushion gas, remains permanently trapped. This cushion gas may represent more than half the total gas volume, and more than 50% of the initial investment costs for the storage facility. Studies conducted by Gaz de France, backed up by experience acquired over the years, have shown that at least 20% of the cushion gas could be replaced by a less expensive inert gas. Nitrogen, carbon dioxide, or a mixture of the two, satisfy the specifications required for this inert gas. Two main production methods exist: recovery of natural gas combustion products (mixture of 88% N 2 and 12% Co 2 ) and physical separation of air components (more or less pure N 2 , depending on industrial conditions). For the specific needs of Gaz de France, the means of production must be suited to its programme of partial cushion gas substitution. The equipment must satisfy requirements of autonomy, operating flexibility and mobility. Gaz de France has tested two units for recovery of natural gas combustion products. In the first unit, the inert gas is produced in a combustion chamber, treated in a catalytic reactor to reduce nitrogen oxide content and then compressed by gas engine driven compressors. In the second unit, the exhaust gases of the compressor gas engines are collected, treated to eliminate nitrogen oxides and then compressed. The energy balance is improved. A PSA method nitrogen production unit by selective absorption of nitrogen in the air, will be put into service in 1989. The specific features of these two methods and the reasons for choosing them will be reviewed. (author). 1 fig

  16. Assessment of the impact of the Kruonis hydro pumped storage on the ichtyocenosis of the Kaunas water reservoir

    International Nuclear Information System (INIS)

    Valushiene, V.; Gerulaitis, A.; Repechka, R.

    1996-01-01

    During the exploitation period (1992-1993) of one hydroagregate unit of the Kruonis Hydro Pumped Storage (HPS) the lower basin of the Kaunas Water Reservoir (Kauno Marios) fish species, their dimensions and age were found to change insignificantly as compared with the background data of the previous years (1989-1991). These changes can be associated with the peculiarities of natural conditions. At the current velocity 9-10 cm/s the penetration of young fish and their larvae into the hydroagregates of HPS was observed. At the end of summer, the abundance of fish larvae in the reverse canal before the unit started operating made up 41.3, during the pumping period - 51.3, at discharge time - 30.5 spec./100 m 3 . The greater part of the 'pumped in' fish accumulated in the upper basin. The rest ones, having passed through aggregates, penetrated into the reverse canal and came back into the lower basin. When operating one unit at the regime of 'pump', the injuries of young fish do not exceed 3-5%. The larger the fish the more often the injuries. The main injuries were mechanical or associated with fluctuations of pressure. 12 refs., 4 figs

  17. Numerical analysis of temperature and flow effects in a dry, two-dimensional, porous-media reservoir used for compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, L.E.

    1979-10-01

    The purpose of the work is to define the hydrodynamic and thermodynamic response of a CAES dry porous media reservoir subjected to simulated air mass cycling. The knowledge gained will provide, or will assist in providing, design guidelines for the efficient and stable operation of the air storage reservoir. The analysis and results obtained by two-dimensional modeling of dry reservoirs are presented. While the fluid/thermal response of the underground system is dependent on many parameters, the two-dimensional model was applied only to those parameters that entered the analysis by virtue of inclusion of the vertical dimension. In particular, the parameters or responses that were quantified or characterized include wellbore heat transfer, heat losses to the vertical boundaries of the porous zone, gravitationally induced flows, producing length of the wellbore, and the effects of nonuniform permeability. The analysis of the wellbore heat transfer included consideration of insulation, preheating (bubble development with heated air), and air mass flow rate.

  18. Quantifying the uncertainties of climate change effects on the storage-yield and performance characteristics of the Pong multi-purpose reservoir, India

    Directory of Open Access Journals (Sweden)

    B. Soundharajan

    2015-06-01

    Full Text Available Climate change is predicted to affect water resources infrastructure due to its effect on rainfall, temperature and evapotranspiration. However, there are huge uncertainties on both the magnitude and direction of these effects. The Pong reservoir on the Beas River in northern India serves irrigation and hydropower needs. The hydrology of the catchment is highly influenced by Himalayan seasonal snow and glaciers, and Monsoon rainfall; the changing pattern of the latter and the predicted disappearance of the former will have profound effects on the performance of the reservoir. This study employed a Monte-Carlo simulation approach to characterise the uncertainties in the future storage requirements and performance of the reservoir. Using a calibrated rainfall-runoff (R-R model, the baseline runoff scenario was first simulated. The R-R inputs (rainfall and temperature were then perturbed using plausible delta-changes to produce simulated climate change runoff scenarios. Stochastic models of the runoff were developed and used to generate ensembles of both the current and climate-change perturbed future scenarios. The resulting runoff ensembles were used to simulate the behaviour of the reservoir and determine "populations" of reservoir storage capacity and performance characteristics. Comparing these parameters between the current and the perturbed provided the population of climate change effects which was then analysed to determine the uncertainties. The results show that contrary to the usual practice of using single records, there is wide variability in the assessed impacts. This variability or uncertainty will, no doubt, complicate the development of climate change adaptation measures; however, knowledge of its sheer magnitude as demonstrated in this study will help in the formulation of appropriate policy and technical interventions for sustaining and possibly enhancing water security for irrigation and other uses served by Pong reservoir.

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    Macedo Faria, Breno; Franco Barbosa, Paulo Sergio [Universidad Estatal de Campinas (Brazil)

    2002-09-01

    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.

  20. The use of contained nuclear explosions to create underground reservoirs, and experience of operating these for gas condensate storage

    International Nuclear Information System (INIS)

    Kedrovskij, O.L.; Myasnikov, K.V.; Leonov, E.A.; Romadin, N.M.; Dorodnov, V.F.; Nikiforov, G.A.

    1975-01-01

    Investigations on the creation of underground reservoirs by means of nuclear explosions have been going on in the Soviet Union for many years. In this paper the authors consider three main kinds of sites or formations that can be used for constructing reservoirs by this method, namely, low-permeable rocks, worked-out mines and rock salt formations. Formulae are given for predicting the mechanical effect of an explosion in rocks, taking their strength characteristics into account. Engineering procedures are described for sealing and restoring the emplacement holes, so that they can be used for operating the underground reservoir. Experience with the contruction and operation of a 50 000 m 3 gas-condensate reservoir in a rock salt formation is described. In the appendix to the paper a method is presented for calculating the stability of spherical cavities created by nuclear explosions in rock salt, allowing for the development of elasto-plastic deformations and creep

  1. [Algal community structure and water quality assessment on drawdown area of Kaixian waters in Three Gorges Reservoir during winter storage period].

    Science.gov (United States)

    Guo, Jing-Song; Xie, Dan; Li, Zhe; Chen, Yuan; Sun, Zhi-Yu; Chen, Yong-Bo; Long, Man

    2012-04-01

    The old town area of Kaixian county was flooded and showed reservoir characteristics after the water level of Three Gorges Reservoir got 172. 8 m in December 2008. The aquatic ecology and nutritional status of Kaixian drawdown area after water storage are still rarely reported. To understand the current water environment and changes in algal community structure of Kaixian drawdown area after 172.8 m water level, the algal composition, abundance, biomass distribution and changes of its sampling spots including Hanfeng Lake were observed twice during winter storage period in January and December 2009. The trends in phytoplankton community structure were analyzed and the water quality assessment of nutritional status was carried out. The results indicated that 6 phylums, 37 genera, 69 species of phytoplankton in total were identified in the two sampling, and the dominant species were Dinophyta and Cryptophyta. The cell density and biomass in December 2009 were lower than those in January 2009. The evaluation results of algal population structure and pollution indicators showed that the nutrition level of Kaixian drawdown area during the winter storage period was mesotrophic to eutrophic type, while diversity analysis result indicated moderate pollution.

  2. Evolution of the Petrophysical and Mineralogical Properties of Two Reservoir Rocks Under Thermodynamic Conditions Relevant for CO2 Geological Storage at 3 km Depth

    International Nuclear Information System (INIS)

    Rimmel, G.; Barlet-Gouedard, V.; Renard, F.

    2010-01-01

    Injection of carbon dioxide (CO 2 ) underground, for long-term geological storage purposes, is considered as an economically viable option to reduce greenhouse gas emissions in the atmosphere. The chemical interactions between supercritical CO 2 and the potential reservoir rock need to be thoroughly investigated under thermodynamic conditions relevant for geological storage. In the present study, 40 samples of Lavoux limestone and Adamswiller sandstone, both collected from reservoir rocks in the Paris basin, were experimentally exposed to CO 2 in laboratory autoclaves specially built to simulate CO 2 -storage-reservoir conditions. The two types of rock were exposed to wet supercritical CO 2 and CO 2 -saturated water for one month, at 28 MPa and 90 C, corresponding to conditions for a burial depth approximating 3 km. The changes in mineralogy and micro-texture of the samples were measured using X-ray diffraction analyses, Raman spectroscopy, scanning-electron microscopy, and energy-dispersion spectroscopy microanalysis. The petrophysical properties were monitored by measuring the weight, density, mechanical properties, permeability, global porosity, and local porosity gradients through the samples. Both rocks maintained their mechanical and mineralogical properties after CO 2 exposure despite an increase of porosity and permeability. Microscopic zones of calcite dissolution observed in the limestone are more likely to be responsible for such increase. In the sandstone, an alteration of the petro-fabric is assumed to have occurred due to clay minerals reacting with CO 2 . All samples of Lavoux limestone and Adamswiller sandstone showed a measurable alteration when immersed either in wet supercritical CO 2 or in CO 2 -saturated water. These batch experiments were performed using distilled water and thus simulate more severe conditions than using formation water (brine). (authors)

  3. Gravity Recovery and Climate Experiment (GRACE) detection of water storage changes in the Three Gorges Reservoir of China and comparison with in situ measurements

    Science.gov (United States)

    Wang, Xianwei; de Linage, Caroline; Famiglietti, James; Zender, Charles S.

    2011-12-01

    Water impoundment in the Three Gorges Reservoir (TGR) of China caused a large mass redistribution from the oceans to a concentrated land area in a short time period. We show that this mass shift is captured by the Gravity Recovery and Climate Experiment (GRACE) unconstrained global solutions at a 400 km spatial resolution after removing correlated errors. The WaterGAP Global Hydrology Model (WGHM) is selected to isolate the TGR contribution from regional water storage changes. For the first time, this study compares the GRACE (minus WGHM) estimated TGR volume changes with in situ measurements from April 2002 to May 2010 at a monthly time scale. During the 8 year study period, GRACE-WGHM estimated TGR volume changes show an increasing trend consistent with the TGR in situ measurements and lead to similar estimates of impounded water volume. GRACE-WGHM estimated total volume increase agrees to within 14% (3.2 km3) of the in situ measurements. This indicates that GRACE can retrieve the true amplitudes of large surface water storage changes in a concentrated area that is much smaller than the spatial resolution of its global harmonic solutions. The GRACE-WGHM estimated TGR monthly volume changes explain 76% (r2 = 0.76) of in situ measurement monthly variability and have an uncertainty of 4.62 km3. Our results also indicate reservoir leakage and groundwater recharge due to TGR filling and contamination from neighboring lakes are nonnegligible in the GRACE total water storage changes. Moreover, GRACE observations could provide a relatively accurate estimate of global water volume withheld by newly constructed large reservoirs and their impacts on global sea level rise since 2002.

  4. Area of Interest 1, CO2 at the Interface. Nature and Dynamics of the Reservoir/Caprock Contact and Implications for Carbon Storage Performance

    Energy Technology Data Exchange (ETDEWEB)

    Mozley, Peter [New Mexico Institute Of Mining And Technology, Socorro, NM (United States); Evans, James [New Mexico Institute Of Mining And Technology, Socorro, NM (United States); Dewers, Thomas [New Mexico Institute Of Mining And Technology, Socorro, NM (United States)

    2014-10-31

    Formation reservoir/caprock interface in order to extend our work to a reservoir/caprock pair this is currently being assessed for long-term carbon storage. These analyses indicate that interface features similar to those observed at the Utah sites 3 were not observed. Although not directly related to our main study topic, one byproduct of our investigation is documentation of exceptionally high degrees of heterogeneity in the pore-size distribution of the Mount Simon Sandstone. This suggests that the unit has a greater-than-normal potential for residual trapping of supercritical CO2.

  5. South Louisiana Enhanced Oil Recovery/Sequestration R&D Project Small Scale Field Tests of Geologic Reservoir Classes for Geologic Storage

    Energy Technology Data Exchange (ETDEWEB)

    Hite, Roger [Blackhorse Energy LLC, Houston, TX (United States)

    2016-10-01

    The project site is located in Livingston Parish, Louisiana, approximately 26 miles due east of Baton Rouge. This project proposed to evaluate an early Eocene-aged Wilcox oil reservoir for permanent storage of CO2. Blackhorse Energy, LLC planned to conduct a parallel CO2 oil recovery project in the First Wilcox Sand. The primary focus of this project was to examine and prove the suitability of South Louisiana geologic formations for large-scale geologic sequestration of CO2 in association with enhanced oil recovery applications. This was to be accomplished through the focused demonstration of small-scale, permanent storage of CO2 in the First Wilcox Sand. The project was terminated at the request of Blackhorse Energy LLC on October 22, 2014.

  6. Estimating reservoir permeability from gravity current modeling of CO2 flow at Sleipner storage project, North Sea

    Science.gov (United States)

    Cowton, L. R.; Neufeld, J. A.; Bickle, M.; White, N.; White, J.; Chadwick, A.

    2017-12-01

    Vertically-integrated gravity current models enable computationally efficient simulations of CO2 flow in sub-surface reservoirs. These simulations can be used to investigate the properties of reservoirs by minimizing differences between observed and modeled CO2 distributions. At the Sleipner project, about 1 Mt yr-1 of supercritical CO2 is injected at a depth of 1 km into a pristine saline aquifer with a thick shale caprock. Analysis of time-lapse seismic reflection surveys shows that CO2 is distributed within 9 discrete layers. The trapping mechanism comprises a stacked series of 1 m thick, impermeable shale horizons that are spaced at 30 m intervals through the reservoir. Within the stratigraphically highest reservoir layer, Layer 9, a submarine channel deposit has been mapped on the pre-injection seismic survey. Detailed measurements of the three-dimensional CO2 distribution within Layer 9 have been made using seven time-lapse surveys, providing a useful benchmark against which numerical flow simulations can be tested. Previous simulations have, in general, been largely unsuccessful in matching the migration rate of CO2 in this layer. Here, CO2 flow within Layer 9 is modeled as a vertically-integrated gravity current that spreads beneath a structurally complex caprock using a two-dimensional grid, considerably increasing computational efficiency compared to conventional three-dimensional simulators. This flow model is inverted to find the optimal reservoir permeability in Layer 9 by minimizing the difference between observed and predicted distributions of CO2 as a function of space and time. A three parameter inverse model, comprising reservoir permeability, channel permeability and channel width, is investigated by grid search. The best-fitting reservoir permeability is 3 Darcys, which is consistent with measurements made on core material from the reservoir. Best-fitting channel permeability is 26 Darcys. Finally, the ability of this simplified numerical model

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-09-30

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

  8. Peak Discharge, Flood Profile, Flood Inundation, and Debris Movement Accompanying the Failure of the Upper Reservoir at the Taum Sauk Pump Storage Facility near Lesterville, Missouri

    Science.gov (United States)

    Rydlund, Jr., Paul H.

    2006-01-01

    The Taum Sauk pump-storage hydroelectric power plant located in Reynolds County, Missouri, uses turbines that operate as pumps and hydraulic head generated by discharging water from an upper to a lower reservoir to produce electricity. A 55-acre upper reservoir with a 1.5- billion gallon capacity was built on top of Proffit Mountain, approximately 760 feet above the floodplain of the East Fork Black River. At approximately 5:16 am on December 14, 2005, a 680-foot wide section of the upper reservoir embankment failed suddenly, sending water rushing down the western side of Proffit Mountain and emptying into the floodplain of East Fork Black River. Flood waters from the upper reservoir flowed downstream through Johnson's Shut-Ins State Park and into the lower reservoir of the East Fork Black River. Floods such as this present unique challenges and opportunities to analyze and document peak-flow characteristics, flood profiles, inundation extents, and debris movement. On December 16, 2005, Light Detection and Ranging (LiDAR) data were collected and used to support hydraulic analyses, forensic failure analyses, damage extent, and mitigation of future disasters. To evaluate the impact of sedimentation in the lower reservoir, a bathymetric survey conducted on December 22 and 23, 2005, was compared to a previous bathymetric survey conducted in April, 2005. Survey results indicated the maximum reservoir capacity difference of 147 acre-feet existed at a pool elevation of 730 feet. Peak discharge estimates of 289,000 cubic feet per second along Proffit Mountain and 95,000 cubic feet per second along the East Fork Black River were determined through indirect measurement techniques. The magnitude of the embankment failure flood along the East Fork Black River was approximately 4 times greater than the 100-year flood frequency estimate of 21,900 cubic feet per second, and approximately 3 times greater than the 500-year flood frequency estimate of 30,500 cubic feet per second

  9. Well-based stable carbon isotope leakage monitoring of an aquifer overlying the CO2 storage reservoir at the Ketzin pilot site, Germany

    Science.gov (United States)

    Nowak, Martin; Myrttinen, Anssi; Zimmer, Martin; van Geldern, Robert; Barth, Johannes A. C.

    2014-05-01

    At the pilot site for CO2 storage in Ketzin, a new well-based leakage-monitoring concept was established, comprising geochemical and hydraulic observations of the aquifer directly above the CO2 reservoir (Wiese et al., 2013, Nowak et al. 2013). Its purpose was to allow early detection of un-trapped CO2. Within this monitoring concept, we established a stable carbon isotope monitoring of dissolved inorganic carbon (DIC). If baseline isotope values of aquifer DIC (δ13CDIC) and reservoir CO2 (δ13CCO2) are known and distinct from each other, the δ13CDIC has the potential to serve as an an early indicator for an impact of leaked CO2 on the aquifer brine. The observation well of the overlying aquifer was equipped with an U-tube sampling system that allowed sampling of unaltered brine. The high alkaline drilling mud that was used during well drilling masked δ13CDIC values at the beginning of the monitoring campaign. However, subsequent monitoring allowed observing on-going re-equilibration of the brine, indicated by changing δ13CDIC and other geochemical values, until values ranging around -23 ‰ were reached. The latter were close to baseline values before drilling. Baselineδ13CDIC and δ13CCO2 values were used to derive a geochemical and isotope model that predicts evolution of δ13CDIC, if CO2 from the reservoir would leak into the aquifer. The model shows that equilibrium isotope fractionation would have to be considered if CO2 dissolves in the brine. The model suggests that stable carbon isotope monitoring is a suitable tool to assess the impact of injected CO2 in overlying groundwater aquifers. However, more data are required to close gaps of knowledge about fractionation behaviour within the CO2(g) - DIC system under elevated pressures and temperatures. Nowak, M., Myrttinen, A., Zimmer, M., Wiese, B., van Geldern, R., Barth, J.A.C., 2013. Well-based, Geochemical Leakage Monitoring of an Aquifer Immediately Above a CO2 Storage Reservoir by Stable Carbon

  10. Mineralogical controls on porosity and water chemistry during O_2-SO_2-CO_2 reaction of CO_2 storage reservoir and cap-rock core

    International Nuclear Information System (INIS)

    Pearce, Julie K.; Golab, Alexandra; Dawson, Grant K.W.; Knuefing, Lydia; Goodwin, Carley; Golding, Suzanne D.

    2016-01-01

    Reservoir and cap-rock core samples with variable lithology's representative of siliciclastic reservoirs used for CO_2 storage have been characterized and reacted at reservoir conditions with an impure CO_2 stream and low salinity brine. Cores from a target CO_2 storage site in Queensland, Australia were tested. Mineralogical controls on the resulting changes to porosity and water chemistry have been identified. The tested siliciclastic reservoir core samples can be grouped generally into three responses to impure CO_2-brine reaction, dependent on mineralogy. The mineralogically clean quartzose reservoir cores had high porosities, with negligible change after reaction, in resolvable porosity or mineralogy, calculated using X-ray micro computed tomography and QEMSCAN. However, strong brine acidification and a high concentration of dissolved sulphate were generated in experiments owing to minimal mineral buffering. Also, the movement of kaolin has the potential to block pore throats and reduce permeability. The reaction of the impure CO_2-brine with calcite-cemented cap-rock core samples caused the largest porosity changes after reaction through calcite dissolution; to the extent that one sample developed a connection of open pores that extended into the core sub-plug. This has the potential to both favor injectivity but also affect CO_2 migration. The dissolution of calcite caused the buffering of acidity resulting in no significant observable silicate dissolution. Clay-rich cap-rock core samples with minor amounts of carbonate minerals had only small changes after reaction. Created porosity appeared mainly disconnected. Changes were instead associated with decreases in density from Fe-leaching of chlorite or dissolution of minor amounts of carbonates and plagioclase. The interbedded sandstone and shale core also developed increased porosity parallel to bedding through dissolution of carbonates and reactive silicates in the sandy layers. Tight interbedded cap

  11. Self-consistent signal-to-noise analysis of the statistical behavior of analog neural networks and enhancement of the storage capacity

    Science.gov (United States)

    Shiino, Masatoshi; Fukai, Tomoki

    1993-08-01

    Based on the self-consistent signal-to-noise analysis (SCSNA) capable of dealing with analog neural networks with a wide class of transfer functions, enhancement of the storage capacity of associative memory and the related statistical properties of neural networks are studied for random memory patterns. Two types of transfer functions with the threshold parameter θ are considered, which are derived from the sigmoidal one to represent the output of three-state neurons. Neural networks having a monotonically increasing transfer function FM, FM(u)=sgnu (||u||>θ), FM(u)=0 (||u||memory patterns), implying the reduction of the number of spurious states. The behavior of the storage capacity with changing θ is qualitatively the same as that of the Ising spin neural networks with varying temperature. On the other hand, the nonmonotonic transfer function FNM, FNM(u)=sgnu (||u||=θ) gives rise to remarkable features in several respects. First, it yields a large enhancement of the storage capacity compared with the Amit-Gutfreund-Sompolinsky (AGS) value: with decreasing θ from θ=∞, the storage capacity αc of such a network is increased from the AGS value (~=0.14) to attain its maximum value of ~=0.42 at θ~=0.7 and afterwards is decreased to vanish at θ=0. Whereas for θ>~1 the storage capacity αc coincides with the value αc~ determined by the SCSNA as the upper bound of α ensuring the existence of retrieval solutions, for θr≠0 (i.e., finite width of the local field distribution), which is implied by the order-parameter equations of the SCSNA, disappears at a certain critical loading rate α0, and for αr=0+). As a consequence, memory retrieval without errors becomes possible even in the saturation limit α≠0. Results of the computer simulations on the statistical properties of the novel phase with αstorage capacity is also analyzed for the two types of networks. It is conspicuous for the networks with FNM, where the self-couplings increase the stability of

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

    Science.gov (United States)

    Roberts-Ashby, Tina; Brandon N. Ashby,

    2016-01-01

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

  13. The Effect of Model Grid Resolution on the Distributed Hydrologic Simulations for Forecasting Stream Flows and Reservoir Storage

    Science.gov (United States)

    Turnbull, S. J.

    2017-12-01

    Within the US Army Corps of Engineers (USACE), reservoirs are typically operated according to a rule curve that specifies target water levels based on the time of year. The rule curve is intended to maximize flood protection by specifying releases of water before the dominant rainfall period for a region. While some operating allowances are permissible, generally the rule curve elevations must be maintained. While this operational approach provides for the required flood control purpose, it may not result in optimal reservoir operations for multi-use impoundments. In the Russian River Valley of California a multi-agency research effort called Forecast-Informed Reservoir Operations (FIRO) is assessing the application of forecast weather and streamflow predictions to potentially enhance the operation of reservoirs in the watershed. The focus of the study has been on Lake Mendocino, a USACE project important for flood control, water supply, power generation and ecological flows. As part of this effort the Engineer Research and Development Center is assessing the ability of utilizing the physics based, distributed watershed model Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model to simulate stream flows, reservoir stages, and discharges while being driven by weather forecast products. A key question in this application is the effect of watershed model resolution on forecasted stream flows. To help resolve this question, GSSHA models of multiple grid resolutions, 30, 50, and 270m, were developed for the upper Russian River, which includes Lake Mendocino. The models were derived from common inputs: DEM, soils, land use, stream network, reservoir characteristics, and specified inflows and discharges. All the models were calibrated in both event and continuous simulation mode using measured precipitation gages and then driven with the West-WRF atmospheric model in prediction mode to assess the ability of the model to function in short term, less than one week

  14. Numerical modeling of self-limiting and self-enhancing caprock alteration induced by CO2 storage in a depleted gas reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tianfu; Gherardi, Fabrizio; Xu, Tianfu; Pruess, Karsten

    2007-09-07

    }-dominated phase migrates into the caprock through fractures, or through zones with high initial porosity possibly acting as preferential flow paths for reservoir fluids, low pH values are predicted, accompanied by significant calcite dissolution and porosity enhancement. In contrast, when fluid-rock interactions occur under fully liquid-saturated conditions and a diffusion-controlled regime, pH will be buffered at higher values, and some calcite precipitation is predicted which leads to further sealing of the storage reservoir.

  15. Reservoir Characterization and CO2 Plume Migration Modeling Based on Bottom-hole Pressure Data: An Example from the AEP Mountaineer Geological Storage Project

    Science.gov (United States)

    Mishra, Srikanta; Kelley, Mark; Oruganti, YagnaDeepika; Bhattacharya, Indra; Spitznogle, Gary

    2014-05-01

    We present an integrated approach for formation permeability estimation, front tracking, reservoir model calibration, and plume migration modeling based on injection rate and down-hole pressure data from CO2 geologic sequestration projects. The data are taken from the 20 MW CO2 capture and storage project at American Electric Power's Mountaineer Plant in West Virginia, USA. The Mountaineer CO2 injection system consists of two injection wells - one in the Copper Ridge Dolomite formation and one in the Rose Run sandstone formation, and three deep observation wells that were operational between October 2009 and May 2011. Approximately 27000 MT and 10000 MT were injected into the Copper Ridge dolomite formation and Rose Run sandstone formation, respectively. A wealth of pressure and rate data from injection and observation wells is available covering a series of injection and pressure falloff events. The methodology developed and applied for interpreting and integrating the data during reservoir analysis and modeling from the Rose Run formation is the subject of this paper. For the analysis of transient pressure data at the injection and observation wells, the CO2 storage reservoir is conceptualized as a radial composite system, where the inner (invaded) zone consists of both supercritical CO2 and brine, and the outer (uninvaded) zone consists of undisturbed brine. Using established analytical solutions for analyzing fluid injection problems in the petroleum reservoir engineering literature, we show how the late-time pressure derivative response from both injection and observation wells will be identical - reflecting the permeability-thickness product of the undisturbed brine-filled formation. We also show how the expanding CO2 plume affects the "effective" compressibility that can be estimated by history matching injection-falloff data and how this can be used to develop a relationship between the plume radius and "effective" compressibility. This provides a novel non

  16. Field demonstration of an active reservoir pressure management through fluid injection and displaced fluid extractions at the Rock Springs Uplift, a priority geologic CO2 storage site for Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Jiao, Zunsheng [Univ. of Wyoming, Laramie, WY (United States)

    2017-04-05

    This report provides the results from the project entitled Field Demonstration of Reservoir Pressure Management through Fluid Injection and Displaced Fluid Extraction at the Rock Springs Uplift, a Priority Geologic CO2 Storage Site for Wyoming (DE-FE0026159 for both original performance period (September 1, 2015 to August 31, 2016) and no-cost extension (September 1, 2016 to January 6, 2017)).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-29

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

  18. Response to Comment on "Rapid cooling and cold storage in a silicic magma reservoir recorded in individual crystals".

    Science.gov (United States)

    Cooper, Kari M; Till, Christy B; Kent, Adam J R; Costa, Fidel; Rubin, Allison E; Gravley, Darren; Deering, Chad; Cole, Jim; Bose, Maitrayee

    2017-12-22

    In a recent paper, we used Li concentration profiles and U-Th ages to constrain the thermal conditions of magma storage. Wilson and co-authors argue that the data instead reflect control of Li behavior by charge balance during partitioning and not by experimentally determined diffusion rates. Their arguments are based on (i) a coupled diffusion mechanism for Li, which has been postulated but has not been documented to occur, and (ii) poorly constrained zircon growth rates combined with the assumption of continuous zircon crystallization. Copyright © 2017, American Association for the Advancement of Science.

  19. Water chemistry, seepage investigation, streamflow, reservoir storage, and annual availability of water for the San Juan-Chama Project, northern New Mexico, 1942-2010

    Science.gov (United States)

    McKean, Sarah E.; Anderholm, Scott K.

    2014-01-01

    at Azotea Tunnel Outlet occurred from May through June, with a median duration of slightly longer than a month. Years with higher maximum daily streamflow generally are associated with higher annual streamflow than years with lower maximum daily streamflow. The amount of water that can be diverted for the SJCP is controlled by the availability of streamflow and is limited by several factors including legal limits for diversion, limits from the SJCP infrastructure including the size of the diversion dams and tunnels, the capacity of Heron Reservoir, and operational constraints that limit when water can be diverted. The average annual streamflow at Azotea Tunnel Outlet was 94,710 acre-feet, and the annual streamflow at Azotea Tunnel Outlet was approximately 75 percent of the annual streamflow available for the SJCP. The average annual percentage of available streamflow not diverted for the SJCP was 14 percent because of structural limitations of the capacity of infrastructure, 1 percent because of limitations of the reservoir storage capacity, and 29 percent because of the limitations from operations. For most years, the annual available streamflow not diverted for unknown reasons exceeded the sum of the water not diverted because of structural, capacity, and operational limitations.

  20. On the use of flow-storage repartitions derived from artificial tracer tests for geothermal reservoir characterization in the Malm-Molasse basin: a theoretical study

    Science.gov (United States)

    Dewi, Dina Silvia; Osaigbovo Enomayo, Augustine; Mohsin, Rizwan; Karmakar, Shyamal; Ghergut, Julia; Sauter, Martin

    2016-04-01

    Flow-storage repartition (FSR) analysis (Shook 2003) is a versatile tool for characterizing subsurface flow and transport systems. FSR can be derived from measured signals of inter-well tracer tests, if certain requirements are met - basically, the same as required for equivalence between fluid residence time distribution (RTD) and a measured inter-well tracer signal (pre-processed and de-convolved if necessary). Nominally, a FSR is derived from a RTD as a trajectory in normalized {1st, 0th}-order statistical moment space; more intuitively, as a parametric plot of 0th-order against 1st-order statistical moments of RTD truncated at time t, with t as a parameter running from the first tracer input to the latest available tracer sampling; 0th-order moments being normalized by the total tracer recovery, and 1st-order moments by the mean RT. Fracture-dominated systems plot in the upper left (high F , low S) region of FSR diagrams; a homogeneous single-continuum with no dispersion (infinite Peclet number) displays a straight line from {F ,S}={0,0} to {F ,S}={1,1}. This analysis tool appears particularly attractive for characterizing markedly-heterogeneous, porous-fissured-fractured (partly karstified) formations like those targeted by geothermal exploration in the Malm-Molasse basin in Southern Germany, and especially for quantifying flow and transport contributions from contrasting facies types ('reef' versus 'bedded'). However, tracer tests conducted in such systems with inter-well distances of some hundreds of metres (as required by economic considerations on geothermal reservoir sizing) face the problem of very long residence times - and thus the need to deal with incomplete (truncated) signals. For the geothermal well triplet at the Sauerlach site near Munich, tracer peak arrival times exceeding 2 years have been predicted, and signal tails decreasing by less than 50% over >10 years, which puts great uncertainty on the (extrapolation-based) normalizing factors

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

    Directory of Open Access Journals (Sweden)

    Stef Iulian Ioan

    2013-05-01

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

  2. Sediment management for reservoir

    International Nuclear Information System (INIS)

    Rahman, A.

    2005-01-01

    All natural lakes and reservoirs whether on rivers, tributaries or off channel storages are doomed to be sited up. Pakistan has two major reservoirs of Tarbela and Managla and shallow lake created by Chashma Barrage. Tarbela and Mangla Lakes are losing their capacities ever since first impounding, Tarbela since 1974 and Mangla since 1967. Tarbela Reservoir receives average annual flow of about 62 MAF and sediment deposits of 0.11 MAF whereas Mangla gets about 23 MAF of average annual flows and is losing its storage at the rate of average 34,000 MAF annually. The loss of storage is a great concern and studies for Tarbela were carried out by TAMS and Wallingford to sustain its capacity whereas no study has been done for Mangla as yet except as part of study for Raised Mangla, which is only desk work. Delta of Tarbala reservoir has advanced to about 6.59 miles (Pivot Point) from power intakes. In case of liquefaction of delta by tremor as low as 0.12g peak ground acceleration the power tunnels I, 2 and 3 will be blocked. Minimum Pool of reservoir is being raised so as to check the advance of delta. Mangla delta will follow the trend of Tarbela. Tarbela has vast amount of data as reservoir is surveyed every year, whereas Mangla Reservoir survey was done at five-year interval, which has now been proposed .to be reduced to three-year interval. In addition suspended sediment sampling of inflow streams is being done by Surface Water Hydrology Project of WAPDA as also some bed load sampling. The problem of Chasma Reservoir has also been highlighted, as it is being indiscriminately being filled up and drawdown several times a year without regard to its reaction to this treatment. The Sediment Management of these reservoirs is essential and the paper discusses pros and cons of various alternatives. (author)

  3. Impact of CO2 leakage from sub-seabed carbon dioxide capture and storage (CCS) reservoirs on benthic virus-prokaryote interactions and functions.

    Science.gov (United States)

    Rastelli, Eugenio; Corinaldesi, Cinzia; Dell'Anno, Antonio; Amaro, Teresa; Queirós, Ana M; Widdicombe, Stephen; Danovaro, Roberto

    2015-01-01

    Atmospheric CO2 emissions are a global concern due to their predicted impact on biodiversity, ecosystems functioning, and human life. Among the proposed mitigation strategies, CO2 capture and storage, primarily the injection of CO2 into marine deep geological formations has been suggested as a technically practical option for reducing emissions. However, concerns have been raised that possible leakage from such storage sites, and the associated elevated levels of pCO2 could locally impact the biodiversity and biogeochemical processes in the sediments above these reservoirs. Whilst a number of impact assessment studies have been conducted, no information is available on the specific responses of viruses and virus-host interactions. In the present study, we tested the impact of a simulated CO2 leakage on the benthic microbial assemblages, with specific focus on microbial activity and virus-induced prokaryotic mortality (VIPM). We found that exposure to levels of CO2 in the overlying seawater from 1,000 to 20,000 ppm for a period up to 140 days, resulted in a marked decrease in heterotrophic carbon production and organic matter degradation rates in the sediments, associated with lower rates of VIPM, and a progressive accumulation of sedimentary organic matter with increasing CO2 concentrations. These results suggest that the increase in seawater pCO2 levels that may result from CO2 leakage, can severely reduce the rates of microbial-mediated recycling of the sedimentary organic matter and viral infections, with major consequences on C cycling and nutrient regeneration, and hence on the functioning of benthic ecosystems.

  4. Use of imitation mathematical model of phosphorus system for analysis of rates of production-destruction processes in reservoir of the Zagorsk pumped-storage plant

    International Nuclear Information System (INIS)

    Leonov, A.V.; Margolina, G.L.; Sokolov, A.G.

    1993-01-01

    The rates of production-destruction processes in water media are traditionally measured for investigation of the conditions of operation of water-ecology systems and to study the role of microorganisms in the transformation of substances of different origins. One possibility for investigation of the production-destruction process is the use of numerical analytic methods and, in particular, of imitation mathematical modeling. The task of this investigation consisted of evaluation, from observations carried out in 1989, of the rates of production-destruction processes in the water of the reservoir of the Zagorsk pumped-storage plant by means of an imitation mathematical model of a phosphorus system. The model was based on a study of the characteristics of transformation of phosphorus in the water media, as well as by comparison of evaluations of the rates of the above-mentioned processes by two methods -- an experimental one (a modification of the oxygen flask method) and an analytical one (an imitation model of a phosphorus system). 7 refs., 6 figs., 4 tabs

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

    Science.gov (United States)

    Wójcicki, Adam; Jarosiński, Marek

    2017-04-01

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

  6. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  7. Experimental simulation of the geological storage of CO2: particular study of the interfaces between well cement, cap-rock and reservoir rock

    International Nuclear Information System (INIS)

    Jobard, Emmanuel

    2013-01-01

    The geological storage of the CO 2 is envisaged to mitigate the anthropogenic greenhouse gas emissions in the short term. CO 2 is trapped from big emitters and is directly injected into a reservoir rock (mainly in deep salty aquifers, depleted hydrocarbon oil fields or unexploited charcoal lodes) located at more than 800 m deep. In the framework of the CO 2 storage, it is crucial to ensure the integrity of the solicited materials in order to guarantee the permanent confinement of the sequestrated fluids. Using experimental simulation the purpose of this work is to study the mechanisms which could be responsible for the system destabilization and could lead CO 2 leakage from the injection well. The experimental simulations are performed under pressure and temperature conditions of the geological storage (100 bar and from 80 to 100 deg. C). The first experimental model, called COTAGES (for 'Colonne Thermoregulee A Grains pour Gaz a Effet de Serre') allows studying the effects of the thermal destabilisation caused by the injection of a fluid at 25 deg. C in a hotter reservoir (submitted to the geothermal gradient). This device composed of an aqueous saline solution (4 g.L -1 of NaCl), crushed rock (Lavoux limestone or Callovo-Oxfordian argillite) and gas (N 2 or CO 2 ) allows demonstrating an important matter transfer from the cold area (30 deg. C) toward the hot area (100 deg. C). The observed dissolution/precipitation phenomena leading to changes of the petro-physical rocks properties occur in presence of N 2 or CO 2 but are significantly amplified by the presence of CO 2 . Concerning the experiments carried out with Lavoux limestone, the dissolution in the cold zone causes a raise of porosity of about 2% (initial porosity of 8%) due to the formation of about 500 pores/mm 2 with a size ranging between 10 and 100 μm 2 . The precipitation in the hot zone forms a micro-calcite fringe on the external part of the grains and fills the intergrain porosity

  8. Petrophysical examination of CO₂-brine-rock interactions-results of the first stage of long-term experiments in the potential Zaosie Anticline reservoir (central Poland) for CO₂ storage.

    Science.gov (United States)

    Tarkowski, Radosław; Wdowin, Magdalena; Manecki, Maciej

    2015-01-01

    The objective of the study was determination of experiment-induced alterations and changes in the properties of reservoir rocks and sealing rocks sampled from potential reservoir for CO₂. In the experiment, rocks submerged in brine in specially constructed reactors were subjected to CO₂ pressure of 6 MPa for 20 months at room temperature. Samples of Lower Jurassic reservoir rocks and sealing rocks (sandstones, claystones, and mudstones) from the Zaosie Anticline (central Poland) were analysed for their petrophysical properties (specific surface area, porosity, pore size and distribution) before and after the experiment. Comparison of the ionic composition the brines before and after the experiment demonstrated an increase in total dissolved solids as well as the concentration of sulphates and calcium ions. This indicates partial dissolution of the rock matrix and the cements. As a result of the reaction, the properties of reservoir rocks did not changed significantly and should not affect the process of CO₂ storage. In the case of the sealing rocks, however, the porosity, the framework density, as well as the average capillary and threshold diameter increased. Also, the pore distribution in the pore space changed in favour of larger pores. The reasons for these changes could not be explained by petrographic characteristics and should be thoroughly investigated.

  9. Reservoir management

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  10. Reservoir management

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  11. Experimental and modeling results on geochemical impacts of leaking CO2 from subsurface storage reservoirs to an unconfined oxidizing carbonate aquifer

    Science.gov (United States)

    Qafoku, N. P.; Bacon, D. H.; Shao, H.; Lawter, A.; Wang, G.; Brown, C. F.

    2013-12-01

    Deep subsurface storage and sequestration of CO2 has been identified as a potential mitigation technique for rising atmospheric CO2 concentrations. Sequestered CO2 represents a potential risk to overlying aquifers if the CO2 leaks from the deep storage reservoir. Experimental and modeling work is required to evaluate risks to groundwater quality and develop a systematic understanding on how CO2 leakage may cause important changes in aquifer chemistry and mineralogy by promoting dissolution/precipitation, adsorption/desorption, and redox reactions. Solid materials (rocks and slightly weathered rocks) from an unconfined aquifer, i.e., the Edwards Aquifer in Texas, were used in this investigation. The experimental part consisted of: 1) wet chemical acid extractions (8M HNO3 solution at 90 0C); 2) batch experiments conducted at low solid to solution ratios to study time-dependent releases of major, minor and trace elements during periodic or continuous exposure to CO2 gas; 3) hydraulically saturated column experiments conducted under continuous and stop-flow conditions using a CO2 gas saturated synthetic groundwater; 4) pre- and post-treatment solid phase characterization studies. Major variables tested included reaction time (0-336 hours), CO2 flow rate (50 to 350 ml/min), brine concentration (0.1 and 1 M NaCl), rock type and particle size fraction. We are currently investigating the solution composition effects (i.e., presence of contaminants in the initial solution) on the fate and behavior of potential contaminants (As, Pb and Cd) in these systems. Results from the solid phase characterization studies showed that the mineralogy of the Edwards aquifer materials was dominated by calcite. Quartz and montmorillonite were also present in some samples. Acid extractions confirmed that the solid phase had appreciable amounts of potential contaminants (As, Cd, Cr, Cu, Pb and Zn). However, the results from the batch and column experiments demonstrated that these contaminants

  12. Analog earthquakes

    International Nuclear Information System (INIS)

    Hofmann, R.B.

    1995-01-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository

  13. Stable large-scale CO2 storage in defiance of an energy system based on renewable energy - Modelling the impact of varying CO2 injection rates on reservoir behavior

    Science.gov (United States)

    Bannach, Andreas; Hauer, Rene; Martin, Streibel; Stienstra, Gerard; Kühn, Michael

    2015-04-01

    The IPCC Report 2014 strengthens the need for CO2 storage as part of CCS or BECCS to reach ambitious climate goals despite growing energy demand in the future. The further expansion of renewable energy sources is a second major pillar. As it is today in Germany the weather becomes the controlling factor for electricity production by fossil fuelled power plants which lead to significant fluctuations of CO2-emissions which can be traced in injection rates if the CO2 were captured and stored. To analyse the impact of such changing injection rates on a CO2 storage reservoir. two reservoir simulation models are applied: a. An (smaller) reservoir model approved by gas storage activities for decades, to investigate the dynamic effects in the early stage of storage filling (initial aquifer displacement). b. An anticline structure big enough to accommodate a total amount of ≥ 100 Mega tons CO2 to investigate the dynamic effects for the entire operational life time of the storage under particular consideration of very high filling levels (highest aquifer compression). Therefore a reservoir model was generated. The defined yearly injection rate schedule is based on a study performed on behalf of IZ Klima (DNV GL, 2014). According to this study the exclusive consideration of a pool of coal-fired power plants causes the most intensive dynamically changing CO2 emissions and hence accounts for variations of a system which includes industry driven CO2 production. Besides short-term changes (daily & weekly cycles) seasonal influences are also taken into account. Simulation runs cover a variation of injection points (well locations at the top vs. locations at the flank of the structure) and some other largely unknown reservoir parameters as aquifer size and aquifer mobility. Simulation of a 20 year storage operation is followed by a post-operational shut-in phase which covers approximately 500 years to assess possible effects of changing injection rates on the long-term reservoir

  14. Natural CO2 Analogs for Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Scott H. Stevens; B. Scott Tye

    2005-07-31

    The report summarizes research conducted at three naturally occurring geologic CO{sub 2} fields in the US. The fields are natural analogs useful for the design of engineered long-term storage of anthropogenic CO{sub 2} in geologic formations. Geologic, engineering, and operational databases were developed for McElmo Dome in Colorado; St. Johns Dome in Arizona and New Mexico; and Jackson Dome in Mississippi. The three study sites stored a total of 2.4 billion t (46 Tcf) of CO{sub 2} equivalent to 1.5 years of power plant emissions in the US and comparable in size with the largest proposed sequestration projects. The three CO{sub 2} fields offer a scientifically useful range of contrasting geologic settings (carbonate vs. sandstone reservoir; supercritical vs. free gas state; normally pressured vs. overpressured), as well as different stages of commercial development (mostly undeveloped to mature). The current study relied mainly on existing data provided by the CO{sub 2} field operator partners, augmented with new geochemical data. Additional study at these unique natural CO{sub 2} accumulations could further help guide the development of safe and cost-effective design and operation methods for engineered CO{sub 2} storage sites.

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

    Directory of Open Access Journals (Sweden)

    Sri Legowo

    2009-11-01

    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.

  16. Archaeological analogous and industrials for deep storage: study of the archaeological metallic piece; Analogos arqueologicos e industriales para almacenamientos profundos: estudio de piezas arqueologicas metalicas

    Energy Technology Data Exchange (ETDEWEB)

    Criado Portal, A J; Martinez Garcia, J A; Calabres Molina, R; Garcia abajo, A; Penco Valenzuela, F; Lecanda Esteban, J A; Garcia Bartual, M; Jimenez Gonzalez, J M; Bravo Munoz, E; Rodriguez Lobo, L M; Fernandez Cascos, T; Fernandes Cordero, O; Montero Ruiz, I

    2000-07-01

    The aim of present research is to obtain information about archaeological analogous of iron and steel, useful for the model of deep geological repository (AGP). The analogous examined have remained buried between 1400 and 2400 years, in very assorted geochemical environments. The extraction of the archaeological pieces has been accomplished according to normalised protocols, trying to carry to the laboratory so the piece as its burial environment, avoiding all possible pollution. Trying to the archaeological analogous could provide valuable information to the AGP model, the study has been directed to related the physical-chemical characteristics of the terrain respect to the deterioration of the archaeological metallic piece. The geology of the surrounding terrain to the archaeological deposit, the geomorphological study of the terrain and data from the analysis of ground: pH, wetness, porosity, organic matter contents, bacteria presence, sulphates, carbonates, chlorides, etc., have allowed to explain the physical-chemical phenomena suffered by the archaeological iron and steel pieces. Also, an exhaustive study of the archaeological piece has been accomplished, concerning the microstructure of the corrosion layer and of the not deteriorated metallic rest. Obtained information concerns different items, such as corrosion velocity and formations of oxide layers, diffusion of chemical elements from the corrosion layer to the metal and viceversa, and structural changes in oxide layers and in the metallic remains by structural ageing. Obtained data have allowed to develop a mathematical model for calculation of corrosion velocity in buried iron and steels, based on physical-chemical variables of grounds, chemical composition and thermomechanical treatment given to the metal during its manufacture. (Author)

  17. Prototyping and Testing a New Volumetric Curvature Tool for Modeling Reservoir Compartments and Leakage Pathways in the Arbuckle Saline Aquifer: Reducing Uncertainty in CO2 Storage and Permanence

    Energy Technology Data Exchange (ETDEWEB)

    Rush, Jason [Univ. of Kansas and Kansas Geological Survey, Lawrence, KS (United States); Holubnyak, Yevhen [Univ. of Kansas and Kansas Geological Survey, Lawrence, KS (United States); Watney, Willard [Univ. of Kansas and Kansas Geological Survey, Lawrence, KS (United States)

    2016-12-09

    This DOE-funded project evaluates the utility of seismic volumetric curvature (VC) for predicting stratal and structural architecture diagnostic of paleokarst reservoirs. Of special interest are applications geared toward carbon capture, utilization, and storage (CCUS). VC has been championed for identifying faults (offset <¼ λ) that cannot be imaged by conventional 3-D seismic attributes such as coherence. The objective of this research was to evaluate VC-techniques for reducing uncertainties in reservoir compartmentalization studies and seal risk assessments especially for saline aquifers. A 2000-ft horizontal lateral was purposefully drilled across VC-imaged lineaments—interpreted to record a fractured and a fault-bounded doline—to physically confirm their presence. The 15-mi² study area is located in southeastern Bemis-Shutts Field, which is situated along the crest of the Central Kansas Uplift (CKU) in Ellis County, Kansas. The uppermost Arbuckle (200+ ft) has extensive paleokarst including collapsed paleocaverns and dolines related to exceedingly prolonged pre-Simpson (Sauk–Tippecanoe) and/or pre-Pennsylvanian subaerial exposure. A lateral borehole was successfully drilled across the full extent (~1100 ft) of a VC-inferred paleokarst doline. Triple combo (GR-neutron/density-resistivity), full-wave sonic, and borehole micro-imager logs were successfully run to TD on drill-pipe. Results from the formation evaluation reveal breccias (e.g., crackle, mosaic, chaotic), fractures, faults, vugs (1-6"), and unaffected host strata consistent with the pre-spud interpretation. Well-rounded pebbles were also observed on the image log. VC-inferred lineaments coincide with 20–80-ft wide intervals of high GR values (100+ API), matrix-rich breccias, and faults. To further demonstrate their utility, VC attributes are integrated into a geocellular modeling workflow: 1) to constrain the structural model; 2) to generate facies probability grids, and; 3) to collocate

  18. Geoscience/engineering characterization of the interwell environment in carbonate reservoirs based on outcrop analogs, Permian Basin, West Texas and New Mexico-stratigraphic hierarchy and cycle stacking facies distribution, and interwell-scale heterogeneity: Grayburg Formation, New Mexico. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barnaby, R.J.; Ward, W.B.; Jennings, J.W. Jr.

    1997-06-01

    The Grayburg Formation (middle Guadalupian) is a major producing interval in the Permian Basin and has yielded more than 2.5 billion barrels of oil in West Texas. Grayburg reservoirs have produced, on average, less than 30 percent of their original oil in place and are undergoing secondary and tertiary recovery. Efficient design of such enhanced recovery programs dictates improved geological models to better understand and predict reservoir heterogeneity imposed by depositional and diagenetic controls. The Grayburg records mixed carbonate-siliciclastic sedimentation on shallow-water platforms that rimmed the Delaware and Midland Basins. Grayburg outcrops in the Guadalupe and Brokeoff Mountains region on the northwest margin of the Delaware Basin present an opportunity to construct a detailed, three-dimensional image of the stratigraphic and facies architecture. This model can be applied towards improved description and characterization of heterogeneity in analogous Grayburg reservoirs. Four orders of stratigraphic hierarchy are recognized in the Grayburg Formation. The Grayburg represents a long-term composite sequence composed of four high-frequency sequences (HFS 1-4). Each HFS contains several composite cycles comprising two or more cycles that define intermediate-scale transgressive-regressive successions. Cycles are the smallest scale upward-shoaling vertical facies successions that can be recognized and correlated across various facies tracts. Cycles thus form the basis for establishing the detailed chronostratigraphic correlations needed to delineate facies heterogeneity.

  19. Integrated assessment of variable density-viscosity groundwater flow for a high temperature mono-well aquifer thermal energy storage (HT-ATES) system in a geothermal reservoir

    NARCIS (Netherlands)

    Zeghici, Răzvan Mihai; Oude Essink, Gualbert H.P.; Hartog, Niels; Sommer, Wijb

    2015-01-01

    The use of groundwater systems for heat storage increasingly gains interest among water managers, policy makers and researchers as a way to increase the efficiency of energy production and to allow the re-use of waste heat. Typically, mono-well storage systems are thought to require the use of

  20. Resistive RAMs as analog trimming elements

    Science.gov (United States)

    Aziza, H.; Perez, A.; Portal, J. M.

    2018-04-01

    This work investigates the use of Resistive Random Access Memory (RRAM) as an analog trimming device. The analog storage feature of the RRAM cell is evaluated and the ability of the RRAM to hold several resistance states is exploited to propose analog trim elements. To modulate the memory cell resistance, a series of short programming pulses are applied across the RRAM cell allowing a fine calibration of the RRAM resistance. The RRAM non volatility feature makes the analog device powers up already calibrated for the system in which the analog trimmed structure is embedded. To validate the concept, a test structure consisting of a voltage reference is evaluated.

  1. COSTING MODELS FOR WATER SUPPLY DISTRIBUTION: PART III- PUMPS, TANKS, AND RESERVOIRS

    Science.gov (United States)

    Distribution systems are generally designed to ensure hydraulic reliability. Storage tanks, reservoirs and pumps are critical in maintaining this reliability. Although storage tanks, reservoirs and pumps are necessary for maintaining adequate pressure, they may also have a negati...

  2. Remaining gaps for "safe" CO2 storage: the INGV CO2GAPS vision of "learning by doing" monitoring geogas leakage, reservoirs contamination/mixing and induced/triggered seismicity

    Science.gov (United States)

    Quattrocchi, F.; Vinciguerra, S.; Chiarabba, C.; Boschi, E.; Anselmi, M.; Burrato, P.; Buttinelli, M.; Cantucci, B.; Cinti, D.; Galli, G.; Improta, L.; Nazzari, M.; Pischiutta, M.; Pizzino, L.; Procesi, M.; Rovelli, A.; Sciarra, A.; Voltattorni, N.

    2012-12-01

    The CO2GAPS project proposed by INGV is intended to build up an European Proposal for a new kind of research strategy in the field of the geogas storage. Aim of the project would be to fill such key GAPS concerning the main risks associated to CO2 storage and their implications on the entire Carbon Capture and Storage (CCS) process, which are: i) the geogas leakage both in soils and shallow aquifers, up to indoor seepage; ii) the reservoirs contamination/mixing by hydrocarbons and heavy metals; iii) induced or triggered seismicity and microseismicity, especially for seismogenic blind faults. In order to consider such risks and make the CCS public acceptance easier, a new kind of research approach should be performed by: i) a better multi-disciplinary and "site specific" risk assessment; ii) the development of more reliable multi-disciplinary monitoring protocols. In this view robust pre-injection base-lines (seismicity and degassing) as well as identification and discrimination criteria for potential anomalies are mandatory. CO2 injection dynamic modelling presently not consider reservoirs geomechanical properties during reactive mass-transport large scale simulations. Complex simulations of the contemporaneous physic-chemical processes involving CO2-rich plumes which move, react and help to crack the reservoir rocks are not totally performed. These activities should not be accomplished only by the oil-gas/electric companies, since the experienced know-how should be shared among the CCS industrial operators and research institutions, with the governments support and overview, also flanked by a transparent and "peer reviewed" scientific popularization process. In this context, a preliminary and reliable 3D modelling of the entire "storage complex" as defined by the European Directive 31/2009 is strictly necessary, taking into account the above mentioned geological, geochemical and geophysical risks. New scientific results could also highlighting such opportunities

  3. An environmental data base for all Hydro-Quebec reservoirs

    International Nuclear Information System (INIS)

    Demers, C.

    1988-01-01

    Hydro-Quebec has created two management positions specifically for reservoirs, namely Reservoir Ecology Advisor and Reservoir Management Advisor. To assist management decisions, a means was required of bringing together all existing environmental information for each reservoir operated by Hydro-Quebec, including storage reservoirs, auxiliary reservoirs and forebays. A relational database using Reflex software was developed on a network of Macintosh computers. The database contains five blocks of information: general information, and physical, physiochemical, biologic and socioeconomic characteristics for each reservoir. Data will be collected on over 100 sites, and the tool will form the basis for developing a medium-range study program on reservoir ecology. The program must take into account the physical, biological and socioeconomic aspects of the environment, as well as the concerns of management personnel operating the reservoirs, the local population, reservoir users, and various government departments. 2 figs

  4. Maqalika Reservoir: utilisation and sustainability of Maqalika Reservoir as a source of potable water supply for Maseru in Lesotho

    CSIR Research Space (South Africa)

    Letsie, M

    2008-07-01

    Full Text Available The storage of water in the Maqalika reservoir is gradually decreasing as sediment, carried by the natural catchment run-off, accumulates in the reservoir. Moreover, water pumped into the reservoir from the Caledon River (which is heavily sedimented...

  5. Apport de la géostatistique à la description des stockages de gaz en aquifère Contribution of Geostatistics to Describing Aquifer Gas-Storage Reservoirs

    Directory of Open Access Journals (Sweden)

    Delhomme J. P.

    2006-11-01

    Full Text Available L'étude du comportement d'un réservoir de gaz en nappe aquifère réclame une connaissance aussi précise que possible des caractéristiques géométriques et pétrophysiques des couches réservoirs. Les moyens d'investigation sont de deux natures : - forages permettant une connaissance locale des roches réservoirs ; - mesures sismiques conduisant à une estimation approximative des cotes de certains repères stratigraphiques, en des points situés le long de profils. Les données recueillies sont donc, par nature, fragmentaires et discrètes : là où elles sont absentes, il y a lieu d'estimer les grandeurs étudiées en tenant compte au mieux de notre connaissance de leur variabilité spatiale. Ce problème d'interpolation optimale a donné lieu, depuis une vingtaine d'années, à l'élaboration et la mise en pratique d'un outil théorique particulièrement bien adapté aux besoins exprimés par les techniciens des sciences de la terre : la théorie des variables régionalisées due à G. Matheron. Des programmes informatiques mettant en oeuvre cette théorie sont actuellement opérationnels. Des exemples d'application en sont donnés : - tracé automatique de cartes structurales à partir des données de forages et des mesures sismiques ; - estimation des incertitudes de prévision sur les profondeurs ; - tracé de plusieurs variantes de carte compatibles avec les données ; - établissement d'éléments statistiques relatifs à une grandeur caractéristique d'un stockage : volume stockable par exemple ; - génération automatique des données nécessaires à la mise en oeuvre d'un modèle maillé de réservoir. Predicting and monitoring the behavior of an aquifer gas-storage reservoir requires as precise a knowledge as possible of the geometric and petrophysical properties of the reservoir layer. Two ways of obtaining this information can be given: (a Boreholes which provide local knowledge of the reservoir, and (b Seismic measurements

  6. Data Compression of Hydrocarbon Reservoir Simulation Grids

    KAUST Repository

    Chavez, Gustavo Ivan

    2015-05-28

    A dense volumetric grid coming from an oil/gas reservoir simulation output is translated into a compact representation that supports desired features such as interactive visualization, geometric continuity, color mapping and quad representation. A set of four control curves per layer results from processing the grid data, and a complete set of these 3-dimensional surfaces represents the complete volume data and can map reservoir properties of interest to analysts. The processing results yield a representation of reservoir simulation results which has reduced data storage requirements and permits quick performance interaction between reservoir analysts and the simulation data. The degree of reservoir grid compression can be selected according to the quality required, by adjusting for different thresholds, such as approximation error and level of detail. The processions results are of potential benefit in applications such as interactive rendering, data compression, and in-situ visualization of large-scale oil/gas reservoir simulations.

  7. State of the art of reservoir sedimentation management in Spain

    OpenAIRE

    Avendaño Salas, Cándido; Sanz Montero, Esther; Cobo Rayán, Rafael

    2000-01-01

    Part of the total reservoir storage capacity in Spain (56 km3) is lost due to sedimentation processes taking place. Surveys carried out in 121 reservoirs indicate that 6% of them have undergone a capacity reduction of over 50%. However, most of them (81%) are characterised by a reservoir capacity loss below 20%. The most frequent methods used to control reservoir sedimentation in Spain fall into one of the following groups: reduction of sediment yield through basin management and removal of t...

  8. Performance report for Stanford/SLAC Microstore Analog Memory Unit

    International Nuclear Information System (INIS)

    Freytag, D.R.; Walker, J.T.

    1984-09-01

    Tests of a newly developed Analog Memory Unit (AMU) are described. The device contains 256 analog storage cells consisting of pass transistors, a storage capacitor and a differential read out buffer. By addressing the storage cells sequentially, the shape of the signal present at the input can be recorded in time. Fast response and good amplitude resolution were the design goals for the development. Measurements on individual devices will be presented and the status of hybridized subsystems containing eight AMUs discussed

  9. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-08-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

  10. Modeling the Transport and Fate of Fecal Pollution and Nutrients of Miyun Reservoir

    Science.gov (United States)

    Liu, L.; Fu, X.; Wang, G.

    2009-12-01

    Miyun Reservoir, a mountain valley reservoir, is located 100 km northeast of Beijing City. Besides the functions of flood control, irrigation and fishery for Beijing area, Miyun Reservoir is the main drinking water storage for Beijing city. The water quality is therefore of great importance. Recently, the concentration of fecal pollution and nutrients in the reservoir are constantly rising to arrest the attention of Beijing municipality. Fecal pollution from sewage is a significant public health concern due to the known presence of human viruses and parasites in these discharges. To investigate the transport and fate of the fecal pollution and nutrients at Miyun reservoir and the health risks associated with drinking and fishery, the reservoir and two tributaries, Chaohe river and Baihe river discharging into it are being examined for bacterial, nutrients and other routine pollution. To understand the relative importance of different processes influencing pollution transport and inactivation, a finite-element model of surf-zone hydrodynamics (coupled with models for temperature, fecal pollution, nutrients and other routine contaminants) is used. The developed models are being verified by the observed water quality data including water temperature, conductivities and dissolved oxygen from the reservoir and its tributaries. Different factors impacting the inactivation of fecal pollution and the transport of nutrients such as water temperature, sedimentation, sunlight insolation are evaluated for Miyun reservoir by a sensitivity analysis analogized from the previous research of Lake Michigan (figure 1, indicating that solar insolation dominates the inactivation of E. Coli, an indicator of fecal pollution, Liu et al. 2006). The calibrated modeling system can be used to temporally and spatially simulate and predict the variation of the concentration of fecal pollution and nutrients of Miyun reservoir. Therefore this research can provide a forecasting tool for the

  11. Smoothing-based compressed state Kalman filter for joint state-parameter estimation: Applications in reservoir characterization and CO2 storage monitoring

    Science.gov (United States)

    Li, Y. J.; Kokkinaki, Amalia; Darve, Eric F.; Kitanidis, Peter K.

    2017-08-01

    The operation of most engineered hydrogeological systems relies on simulating physical processes using numerical models with uncertain parameters and initial conditions. Predictions by such uncertain models can be greatly improved by Kalman-filter techniques that sequentially assimilate monitoring data. Each assimilation constitutes a nonlinear optimization, which is solved by linearizing an objective function about the model prediction and applying a linear correction to this prediction. However, if model parameters and initial conditions are uncertain, the optimization problem becomes strongly nonlinear and a linear correction may yield unphysical results. In this paper, we investigate the utility of one-step ahead smoothing, a variant of the traditional filtering process, to eliminate nonphysical results and reduce estimation artifacts caused by nonlinearities. We present the smoothing-based compressed state Kalman filter (sCSKF), an algorithm that combines one step ahead smoothing, in which current observations are used to correct the state and parameters one step back in time, with a nonensemble covariance compression scheme, that reduces the computational cost by efficiently exploring the high-dimensional state and parameter space. Numerical experiments show that when model parameters are uncertain and the states exhibit hyperbolic behavior with sharp fronts, as in CO2 storage applications, one-step ahead smoothing reduces overshooting errors and, by design, gives physically consistent state and parameter estimates. We compared sCSKF with commonly used data assimilation methods and showed that for the same computational cost, combining one step ahead smoothing and nonensemble compression is advantageous for real-time characterization and monitoring of large-scale hydrogeological systems with sharp moving fronts.

  12. Multiobjective Optimization Modeling Approach for Multipurpose Single Reservoir Operation

    Directory of Open Access Journals (Sweden)

    Iosvany Recio Villa

    2018-04-01

    Full Text Available The water resources planning and management discipline recognizes the importance of a reservoir’s carryover storage. However, mathematical models for reservoir operation that include carryover storage are scarce. This paper presents a novel multiobjective optimization modeling framework that uses the constraint-ε method and genetic algorithms as optimization techniques for the operation of multipurpose simple reservoirs, including carryover storage. The carryover storage was conceived by modifying Kritsky and Menkel’s method for reservoir design at the operational stage. The main objective function minimizes the cost of the total annual water shortage for irrigation areas connected to a reservoir, while the secondary one maximizes its energy production. The model includes operational constraints for the reservoir, Kritsky and Menkel’s method, irrigation areas, and the hydropower plant. The study is applied to Carlos Manuel de Céspedes reservoir, establishing a 12-month planning horizon and an annual reliability of 75%. The results highly demonstrate the applicability of the model, obtaining monthly releases from the reservoir that include the carryover storage, degree of reservoir inflow regulation, water shortages in irrigation areas, and the energy generated by the hydroelectric plant. The main product is an operational graph that includes zones as well as rule and guide curves, which are used as triggers for long-term reservoir operation.

  13. Reservoir Operating Rule Optimization for California's Sacramento Valley

    Directory of Open Access Journals (Sweden)

    Timothy Nelson

    2016-03-01

    Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss1art6Reservoir operating rules for water resource systems are typically developed by combining intuition, professional discussion, and simulation modeling. This paper describes a joint optimization–simulation approach to develop preliminary economically-based operating rules for major reservoirs in California’s Sacramento Valley, based on optimized results from CALVIN, a hydro-economic optimization model. We infer strategic operating rules from the optimization model results, including storage allocation rules to balance storage among multiple reservoirs, and reservoir release rules to determine monthly release for individual reservoirs. Results show the potential utility of considering previous year type on water availability and various system and sub-system storage conditions, in addition to normal consideration of local reservoir storage, season, and current inflows. We create a simple simulation to further refine and test the derived operating rules. Optimization model results show particular insights for balancing the allocation of water storage among Shasta, Trinity, and Oroville reservoirs over drawdown and refill seasons, as well as some insights for release rules at major reservoirs in the Sacramento Valley. We also discuss the applicability and limitations of developing reservoir operation rules from optimization model results.

  14. Optimal Operation of Hydropower Reservoirs under Climate Change: The Case of Tekeze Reservoir, Eastern Nile

    Directory of Open Access Journals (Sweden)

    Fikru Fentaw Abera

    2018-03-01

    Full Text Available Optimal operation of reservoirs is very essential for water resource planning and management, but it is very challenging and complicated when dealing with climate change impacts. The objective of this paper was to assess existing and future hydropower operation at the Tekeze reservoir in the face of climate change. In this study, a calibrated and validated Soil and Water Assessment Tool (SWAT was used to model runoff inflow into the Tekeze hydropower reservoir under present and future climate scenarios. Inflow to the reservoir was simulated using hydro-climatic data from an ensemble of downscaled climate data based on the Coordinated Regional climate Downscaling Experiment over African domain (CORDEX-Africa with Coupled Intercomparison Project Phase 5 (CMIP5 simulations under Representative Concentration Pathway (RCP4.5 and RCP8.5 climate scenarios. Observed and projected inflows to Tekeze hydropower reservoir were used as input to the US Army Corps of Engineer’s Reservoir Evaluation System Perspective Reservoir Model (HEC-ResPRM, a reservoir operation model, to optimize hydropower reservoir release, storage and pool level. Results indicated that climate change has a clear impact on reservoir inflow and showed increase in annual and monthly inflow into the reservoir except in dry months from May to June under RCP4.5 and RCP8.5 climate scenarios. HEC-ResPRM optimal operation results showed an increase in Tekeze reservoir power storage potential up to 25% and 30% under RCP4.5 and RCP8.5 climate scenarios, respectively. This implies that Tekeze hydropower production will be affected by climate change. This analysis can be used by water resources planners and mangers to develop reservoir operation techniques considering climate change impact to increase power production.

  15. Modelling of Reservoir Operations using Fuzzy Logic and ANNs

    Science.gov (United States)

    Van De Giesen, N.; Coerver, B.; Rutten, M.

    2015-12-01

    Today, almost 40.000 large reservoirs, containing approximately 6.000 km3 of water and inundating an area of almost 400.000 km2, can be found on earth. Since these reservoirs have a storage capacity of almost one-sixth of the global annual river discharge they have a large impact on the timing, volume and peaks of river discharges. Global Hydrological Models (GHM) are thus significantly influenced by these anthropogenic changes in river flows. We developed a parametrically parsimonious method to extract operational rules based on historical reservoir storage and inflow time-series. Managing a reservoir is an imprecise and vague undertaking. Operators always face uncertainties about inflows, evaporation, seepage losses and various water demands to be met. They often base their decisions on experience and on available information, like reservoir storage and the previous periods inflow. We modeled this decision-making process through a combination of fuzzy logic and artificial neural networks in an Adaptive-Network-based Fuzzy Inference System (ANFIS). In a sensitivity analysis, we compared results for reservoirs in Vietnam, Central Asia and the USA. ANFIS can indeed capture reservoirs operations adequately when fed with a historical monthly time-series of inflows and storage. It was shown that using ANFIS, operational rules of existing reservoirs can be derived without much prior knowledge about the reservoirs. Their validity was tested by comparing actual and simulated releases with each other. For the eleven reservoirs modelled, the normalised outflow, , was predicted with a MSE of 0.002 to 0.044. The rules can be incorporated into GHMs. After a network for a specific reservoir has been trained, the inflow calculated by the hydrological model can be combined with the release and initial storage to calculate the storage for the next time-step using a mass balance. Subsequently, the release can be predicted one time-step ahead using the inflow and storage.

  16. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  17. Rhetoric and analogies

    OpenAIRE

    Aragonès, Enriqueta; Gilboa, Itzhak; Postlewaite, Andrew; Schmeidler, David; Universitat Autònoma de Barcelona. Unitat de Fonaments de l'Anàlisi Econòmica; Universitat Autònoma de Barcelona. Institut d'Anàlisi Econòmica

    2013-01-01

    The art of rhetoric may be defined as changing other people's minds (opinions, beliefs) without providing them new information. One tech- nique heavily used by rhetoric employs analogies. Using analogies, one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain reg- ularities. In this paper we offer two models of analogies, discuss their theoretical equivalence, and show that finding good analogies is a com- p...

  18. Fast storage of nuclear quadrupole resonance signals

    International Nuclear Information System (INIS)

    Anferov, V.P.; Molchanov, S.V.; Levchun, O.D.

    1988-01-01

    Fast multichannel storage of nuclear quadrupole resonance (NQR) signals is described. Analog-to-digital converter, arithmetic-logical unit, internal memory device (IMD) selection-storage unit and control unit are the storage main units. The storage is based on 43 microcircuits and provides for record and storage of NQR-signals at the contributed operation with Mera-60 microcomputer. Time of analog-to-digital conversion and signal recording into IMD is ∼ 1 mks. Capacity of analog-to-digital converter constitutes 8-10 bits. IMD capacity is 4 K bitsx16. Number of storage channels is 4

  19. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  20. Structured Analog CMOS Design

    CERN Document Server

    Stefanovic, Danica

    2008-01-01

    Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

  1. Detecting analogies unconsciously

    Directory of Open Access Journals (Sweden)

    Thomas Peter Reber

    2014-01-01

    Full Text Available Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible and a past subliminal (invisible situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (‘analog’ or not (‘broken analog’. Words in analogs versus broken analogs were judged closer semantically, which reflects unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

  2. Compressed air energy storage system

    Science.gov (United States)

    Ahrens, Frederick W.; Kartsounes, George T.

    1981-01-01

    An internal combustion reciprocating engine is operable as a compressor during slack demand periods utilizing excess power from a power grid to charge air into an air storage reservoir and as an expander during peak demand periods to feed power into the power grid utilizing air obtained from the air storage reservoir together with combustible fuel. Preferably the internal combustion reciprocating engine is operated at high pressure and a low pressure turbine and compressor are also employed for air compression and power generation.

  3. Modelling of sedimentation processes inside Roseires Reservoir (Sudan) (abstract)

    NARCIS (Netherlands)

    Ali, Y.S.A.; Omer, A.Y.A.; Crosato, A.

    2013-01-01

    Roseires Reservoir is located on the Blue Nile River, in Sudan (figure 1). It is the first trap to the sediments coming from the upper catchment in Ethiopia, which suffers from high erosion and desertification problems. The reservoir lost already more than one third of its storage capacity due to

  4. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  5. Analog synthetic biology.

    Science.gov (United States)

    Sarpeshkar, R

    2014-03-28

    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations.

  6. Bathymetry and capacity of Shawnee Reservoir, Oklahoma, 2016

    Science.gov (United States)

    Ashworth, Chad E.; Smith, S. Jerrod; Smith, Kevin A.

    2017-02-13

    Shawnee Reservoir (locally known as Shawnee Twin Lakes) is a man-made reservoir on South Deer Creek with a drainage area of 32.7 square miles in Pottawatomie County, Oklahoma. The reservoir consists of two lakes connected by an equilibrium channel. The southern lake (Shawnee City Lake Number 1) was impounded in 1935, and the northern lake (Shawnee City Lake Number 2) was impounded in 1960. Shawnee Reservoir serves as a municipal water supply, and water is transferred about 9 miles by gravity to a water treatment plant in Shawnee, Oklahoma. Secondary uses of the reservoir are for recreation, fish and wildlife habitat, and flood control. Shawnee Reservoir has a normal-pool elevation of 1,069.0 feet (ft) above North American Vertical Datum of 1988 (NAVD 88). The auxiliary spillway, which defines the flood-pool elevation, is at an elevation of 1,075.0 ft.The U.S. Geological Survey (USGS), in cooperation with the City of Shawnee, has operated a real-time stage (water-surface elevation) gage (USGS station 07241600) at Shawnee Reservoir since 2006. For the period of record ending in 2016, this gage recorded a maximum stage of 1,078.1 ft on May 24, 2015, and a minimum stage of 1,059.1 ft on April 10–11, 2007. This gage did not report reservoir storage prior to this report (2016) because a sufficiently detailed and thoroughly documented bathymetric (reservoir-bottom elevation) survey and corresponding stage-storage relation had not been published. A 2011 bathymetric survey with contours delineated at 5-foot intervals was published in Oklahoma Water Resources Board (2016), but that publication did not include a stage-storage relation table. The USGS, in cooperation with the City of Shawnee, performed a bathymetric survey of Shawnee Reservoir in 2016 and released the bathymetric-survey data in 2017. The purposes of the bathymetric survey were to (1) develop a detailed bathymetric map of the reservoir and (2) determine the relations between stage and reservoir storage

  7. Mathematical and field analysis of longitudinal reservoir infill

    Science.gov (United States)

    Ke, W. T.; Capart, H.

    2016-12-01

    In reservoirs, severe problems are caused by infilled sediment deposits. In long term, the sediment accumulation reduces the capacity of reservoir storage and flood control benefits. In the short term, the sediment deposits influence the intakes of water-supply and hydroelectricity generation. For the management of reservoir, it is important to understand the deposition process and then to predict the sedimentation in reservoir. To investigate the behaviors of sediment deposits, we propose a one-dimensional simplified theory derived by the Exner equation to predict the longitudinal sedimentation distribution in idealized reservoirs. The theory models the reservoir infill geomorphic actions for three scenarios: delta progradation, near-dam bottom deposition, and final infill. These yield three kinds of self-similar analytical solutions for the reservoir bed profiles, under different boundary conditions. Three analytical solutions are composed by error function, complementary error function, and imaginary error function, respectively. The theory is also computed by finite volume method to test the analytical solutions. The theoretical and numerical predictions are in good agreement with one-dimensional small-scale laboratory experiment. As the theory is simple to apply with analytical solutions and numerical computation, we propose some applications to simulate the long-profile evolution of field reservoirs and focus on the infill sediment deposit volume resulting the uplift of near-dam bottom elevation. These field reservoirs introduced here are Wushe Reservoir, Tsengwen Reservoir, Mudan Reservoir in Taiwan, Lago Dos Bocas in Puerto Rico, and Sakuma Dam in Japan.

  8. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  9. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

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

  10. Climate variability and sedimentation of a hydropower reservoir

    International Nuclear Information System (INIS)

    Riedel, M.

    2008-01-01

    As part of the relicensing of a large Hydroelectric Project in the central Appalachians, large scale watershed and reservoir sedimentation models were developed to forecast potential sedimentation scenarios. The GIS based watershed model was spatially explicit and calibrated to long term observed data. Potential socio/economic development scenarios were used to construct future watershed land cover scenarios. Climatic variability and potential change analysis were used to identify future climate regimes and shifts in precipitation and temperature patterns. Permutations of these development and climate changes were forecasted over 50 years and used to develop sediment yield regimes to the project reservoir. Extensive field work and reservoir survey, including current and wave instrumentation, were used to characterize the project watershed, rivers and reservoir hydrodynamics. A fully 3 dimensional hydrodynamic reservoir sedimentation model was developed for the project and calibrated to observed data. Hydrologic and sedimentation results from watershed forecasting provided boundary conditions for reservoir inputs. The calibrated reservoir model was then used to forecast changes in reservoir sedimentation and storage capacity under different future climate scenarios. Results indicated unique zones of advancing sediment deltas and temporary storage areas. Forecasted changes in reservoir bathymetry and sedimentation patterns were also developed for the various climate change scenarios. The warmer and wetter scenario produced sedimentation impacts similar to extensive development under no climate change. The results of these analyses are being used to develop collaborative watershed and soil conservation partnerships to reduce future soil losses and reservoir sedimentation from projected development. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Thomas C. Chidsey, Jr.

    2002-11-01

    exhibits a characteristic set of reservoir properties obtained from outcrop analogs, cores, and geophysical logs. The Anasazi and Runway fields were selected for geostatistical modeling and reservoir compositional simulations. Models and simulations incorporated variations in carbonate lithotypes, porosity, and permeability to accurately predict reservoir responses. History matches tied previous production and reservoir pressure histories so that future reservoir performances could be confidently predicted. The simulation studies showed that despite most of the production being from the mound-core intervals, there were no corresponding decreases in the oil in place in these intervals. This behavior indicates gravity drainage of oil from the supra-mound intervals into the lower mound-core intervals from which the producing wells' major share of production arises. The key to increasing ultimate recovery from these fields (and similar fields in the basin) is to design either waterflood or CO{sub 2}-miscible flood projects capable of forcing oil from high-storage-capacity but low-recovery supra-mound units into the high-recovery mound-core units. Simulation of Anasazi field shows that a CO{sub 2} flood is technically superior to a waterflood and economically feasible. For Anasazi field, an optimized CO{sub 2} flood is predicted to recover a total 4.21 million barrels (0.67 million m3) of oil representing in excess of 89 percent of the original oil in place. For Runway field, the best CO{sub 2} flood is predicted to recover a total of 2.4 million barrels (0.38 million m3) of oil representing 71 percent of the original oil in place. If the CO{sub 2} flood performed as predicted, it is a financially robust process for increasing the reserves in the many small fields in the Paradox Basin. The results can be applied to other fields in the Rocky Mountain region, the Michigan and Illinois Basins, and the Midcontinent.

  12. A reservoir trap for antiprotons

    CERN Document Server

    Smorra, Christian; Franke, Kurt; Nagahama, Hiroki; Schneider, Georg; Higuchi, Takashi; Van Gorp, Simon; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Yamazaki, Yasunori; Ulmer, Stefan

    2015-01-01

    We have developed techniques to extract arbitrary fractions of antiprotons from an accumulated reservoir, and to inject them into a Penning-trap system for high-precision measurements. In our trap-system antiproton storage times > 1.08 years are estimated. The device is fail-safe against power-cuts of up to 10 hours. This makes our planned comparisons of the fundamental properties of protons and antiprotons independent from accelerator cycles, and will enable us to perform experiments during long accelerator shutdown periods when background magnetic noise is low. The demonstrated scheme has the potential to be applied in many other precision Penning trap experiments dealing with exotic particles.

  13. Annual Report: Carbon Storage

    Energy Technology Data Exchange (ETDEWEB)

    Strazisar, Brian [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Guthrie, George [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2012-09-30

    Activities include laboratory experimentation, field work, and numerical modeling. The work is divided into five theme areas (or first level tasks) that each address a key research need: Flow Properties of Reservoirs and Seals, Fundamental Processes and Properties, Estimates of Storage Potential, Verifying Storage Performance, and Geospatial Data Resources. The project also includes a project management effort which coordinates the activities of all the research teams.

  14. Challenges in Using Analogies

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same…

  15. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  16. Optical analogy. Synthesis report

    International Nuclear Information System (INIS)

    1965-01-01

    The authors report the study of conditions under which light attenuation (reflection, diffusion, absorption) and the attenuation of some radiations (notably thermal neutrons) can be described with analogical calculations. The analogy between light physical properties and neutron properties is not searched for, but the analogy between their attenuation characteristics. After having discussed this possible analogy, they propose a mathematical formulation of neutron and optical phenomena which could theoretically justify the optical analogy. The second part reports a more practical study of optics problems such as the study of simple optics materials and illumination measurements, or more precisely the study of angular distributions of optical reflections, a determination of such angular distributions, and an experimental determination of the albedo

  17. Outcropping analogs and multiscale fracture patterns in the Jandaíra formation

    NARCIS (Netherlands)

    Bertotti, G.; Bezerra, F.H.; Bisdom, K.; Cazarin, C.; Reijmer, J.

    2013-01-01

    Outcropping analogs can provide key information on the 3D organization of fracture networks affecting carbonate reservoirs. Such information, however, needs to be integrated in a consistent work flow which includes i) 3D geometric model of the reservoir architecture, ii) mechanic modeling to

  18. Natural CO{sub 2} migrations in the South-Eastern Basin of France: implications for the CO{sub 2} storage in sedimentary formations; Contribution a la connaissance des migrations de CO{sub 2} naturel dans le Bassin du Sud-Est de la France: enseignements pour le stockage geologique du CO{sub 2} dans les reservoirs sedimentaires

    Energy Technology Data Exchange (ETDEWEB)

    Rubert, Y.

    2009-03-15

    Study of natural CO{sub 2} analogues brings key informations on the factors governing the long term stability/instability of future anthropogenic CO{sub 2} storages. The main objective of this work, through the study of cores from V.Mo.2 well crosscutting the Montmiral natural reservoir (Valence Basin, France), is to trace the deep CO{sub 2} migrations in fractures. Petrographic, geochemical and micro-thermometric studies of the V.Mo.2 cores were thus performed in order: 1) to describe the reservoir filling conditions and 2) to detect possible CO{sub 2}-leakage through the sediments overlying the reservoir. Fluid inclusions from the Paleozoic crystalline basement record the progressive unmixing of a hot homogeneous aquo-carbonic fluid. The Montmiral reservoir was therefore probably fed by a CO{sub 2}-enriched gas component at the Late Cretaceous-Paleogene. The study of the sedimentary column in V.Mo.2 well, demonstrates that the CO{sub 2} did not migrate towards the surface through the thick marly unit (Domerian-Middle Oxfordian). These marls have acted as an impermeable barrier that prevented the upward migration of fluids. Two main stages of fluid circulation have been recognized: 1) an ante- Callovian one related to the Tethysian extension 2) a tertiary stage during which the upper units underwent a karstification, with CO{sub 2} leakage related but which remained confined into the deeper parts of the Valence Basin. Since the Paleogene, the Montmiral reservoir has apparently remained stable, despite the Pyrenean and alpine orogeneses. This is mainly due to the efficient seal formed by the thick marly levels and also to the local structuration in faulted blocks which apparently acted as efficient lateral barriers. (author)

  19. Characterization of oil and gas reservoir heterogeneity

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, N.; Barton, M.D.; Bebout, D.G.; Fisher, R.S.; Grigsby, J.D.; Guevara, E.; Holtz, M.; Kerans, C.; Nance, H.S.; Levey, R.A.

    1992-10-01

    Research described In this report addresses the internal architecture of two specific reservoir types: restricted-platform carbonates and fluvial-deltaic sandstones. Together, these two reservoir types contain more than two-thirds of the unrecovered mobile oil remaining ill Texas. The approach followed in this study was to develop a strong understanding of the styles of heterogeneity of these reservoir types based on a detailed outcrop description and a translation of these findings into optimized recovery strategies in select subsurface analogs. Research targeted Grayburg Formation restricted-platform carbonate outcrops along the Algerita Escarpment and In Stone Canyon In southeastern New Mexico and Ferron deltaic sandstones in central Utah as analogs for the North Foster (Grayburg) and Lake Creek (Wilcox) units, respectively. In both settings, sequence-stratigraphic style profoundly influenced between-well architectural fabric and permeability structure. It is concluded that reservoirs of different depositional origins can therefore be categorized Into a heterogeneity matrix'' based on varying intensity of vertical and lateral heterogeneity. The utility of the matrix is that it allows prediction of the nature and location of remaining mobile oil. Highly stratified reservoirs such as the Grayburg, for example, will contain a large proportion of vertically bypassed oil; thus, an appropriate recovery strategy will be waterflood optimization and profile modification. Laterally heterogeneous reservoirs such as deltaic distributary systems would benefit from targeted infill drilling (possibly with horizontal wells) and improved areal sweep efficiency. Potential for advanced recovery of remaining mobile oil through heterogeneity-based advanced secondary recovery strategies In Texas is projected to be an Incremental 16 Bbbl. In the Lower 48 States this target may be as much as 45 Bbbl at low to moderate oil prices over the near- to mid-term.

  20. Improved water management with the development of Snake Lake Reservoir

    International Nuclear Information System (INIS)

    Kemp, P.; Miller, D.; Webber, J.

    1998-01-01

    The $10.3 million Snake Lake Reservoir which is located south of the TransCanada Highway between Bassano and Brooks, in Alberta, was completed in 1997. It provides 19.1 million cubic meters of storage to improve the water supply for the irrigation of 29,000 hectares of agricultural land in the Eastern Irrigation District. One of challenges that engineers faced during the construction of the reservoir was the extremely soft dam foundation conditions. The resolution of this and other challenges are discussed. In addition to water storage, the reservoir also provides wildlife, recreation and aquaculture opportunities. 8 refs., 5 figs

  1. Electricity storage using a thermal storage scheme

    Energy Technology Data Exchange (ETDEWEB)

    White, Alexander, E-mail: ajw36@cam.ac.uk [Hopkinson Laboratory, Cambridge University Engineering Department, Trumpington Street, Cambridge. CB2 1PZ (United Kingdom)

    2015-01-22

    The increasing use of renewable energy technologies for electricity generation, many of which have an unpredictably intermittent nature, will inevitably lead to a greater demand for large-scale electricity storage schemes. For example, the expanding fraction of electricity produced by wind turbines will require either backup or storage capacity to cover extended periods of wind lull. This paper describes a recently proposed storage scheme, referred to here as Pumped Thermal Storage (PTS), and which is based on “sensible heat” storage in large thermal reservoirs. During the charging phase, the system effectively operates as a high temperature-ratio heat pump, extracting heat from a cold reservoir and delivering heat to a hot one. In the discharge phase the processes are reversed and it operates as a heat engine. The round-trip efficiency is limited only by process irreversibilities (as opposed to Second Law limitations on the coefficient of performance and the thermal efficiency of the heat pump and heat engine respectively). PTS is currently being developed in both France and England. In both cases, the schemes operate on the Joule-Brayton (gas turbine) cycle, using argon as the working fluid. However, the French scheme proposes the use of turbomachinery for compression and expansion, whereas for that being developed in England reciprocating devices are proposed. The current paper focuses on the impact of the various process irreversibilities on the thermodynamic round-trip efficiency of the scheme. Consideration is given to compression and expansion losses and pressure losses (in pipe-work, valves and thermal reservoirs); heat transfer related irreversibility in the thermal reservoirs is discussed but not included in the analysis. Results are presented demonstrating how the various loss parameters and operating conditions influence the overall performance.

  2. Meat analog: a review.

    Science.gov (United States)

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

    2015-01-01

    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers.

  3. FEASIBILITY STUDY OF SEDIMENT FLUSHING FROM MOSUL RESERVOIR, IRAQ

    Directory of Open Access Journals (Sweden)

    Thair Mahmood Al-Taiee

    2015-02-01

    Full Text Available The Feasibility of sediment flushing  from Mosul reservoir located northern iraq was conducted. Many up to date world criteria and indices for checking the efficiency of sediment flushing from reservoir which have been got through analyzing large amount of  data from many flushed reservoirs  in the world which were depended tested and applied in the present case study (Mosul Reservoir. These criteria and indices depend mainly on the hydrological , hydraulic and  topographical properties of the reservoirs in-addition to the operation plan of the reservoirs. They gave a good indication for checking the efficiency of the sediment flushing  process in the reservoirs. It was concluded that approximately the main criteria for the successful flushing sediment was  verified  in  Mosul  reservoir  such as  Sediment Balance Ratio   (SBR and the Long Term Capacity Ratio (LTCR,the shape factor  of reservoir (W/L and the hydraulic condition such as the percentage of (Qf/Qin and (Vf/Vin. This gave an indication that the processes of flushing sediment in Mosul reservoir is probably feasible and may be applied  in the future to maintain the water storage in the reservoir.

  4. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  5. Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

    Science.gov (United States)

    Tugurlan, Maria; Tuffner, Francis K; Chassin, David P.

    2016-09-13

    Thermal energy storage devices, systems, and thermal energy storage device monitoring methods are described. According to one aspect, a thermal energy storage device includes a reservoir configured to hold a thermal energy storage medium, a temperature control system configured to adjust a temperature of the thermal energy storage medium, and a state observation system configured to provide information regarding an energy state of the thermal energy storage device at a plurality of different moments in time.

  6. All-optical reservoir computer based on saturation of absorption.

    Science.gov (United States)

    Dejonckheere, Antoine; Duport, François; Smerieri, Anteo; Fang, Li; Oudar, Jean-Louis; Haelterman, Marc; Massar, Serge

    2014-05-05

    Reservoir computing is a new bio-inspired computation paradigm. It exploits a dynamical system driven by a time-dependent input to carry out computation. For efficient information processing, only a few parameters of the reservoir needs to be tuned, which makes it a promising framework for hardware implementation. Recently, electronic, opto-electronic and all-optical experimental reservoir computers were reported. In those implementations, the nonlinear response of the reservoir is provided by active devices such as optoelectronic modulators or optical amplifiers. By contrast, we propose here the first reservoir computer based on a fully passive nonlinearity, namely the saturable absorption of a semiconductor mirror. Our experimental setup constitutes an important step towards the development of ultrafast low-consumption analog computers.

  7. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  8. FGF growth factor analogs

    Science.gov (United States)

    Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  9. Surface analogue outcrops of deep fractured basement reservoirs in extensional geological settings. Examples within active rift system (Uganda) and proximal passive margin (Morocco).

    Science.gov (United States)

    Walter, Bastien; Géraud, Yves; Diraison, Marc

    2014-05-01

    The important role of extensive brittle faults and related structures in the development of reservoirs has already been demonstrated, notably in initially low-porosity rocks such as basement rocks. Large varieties of deep-seated resources (e.g. water, hydrocarbons, geothermal energy) are recognized in fractured basement reservoirs. Brittle faults and fracture networks can develop sufficient volumes to allow storage and transfer of large amounts of fluids. Development of hydraulic model with dual-porosity implies the structural and petrophysical characterization of the basement. Drain porosity is located within the larger fault zones, which are the main fluid transfer channels. The storage porosity corresponds both to the matrix porosity and to the volume produced by the different fractures networks (e.g. tectonic, primary), which affect the whole reservoir rocks. Multi-scale genetic and geometric relationships between these deformation features support different orders of structural domains in a reservoir, from several tens of kilometers to few tens of meters. In subsurface, 3D seismic data in basement can be sufficient to characterize the largest first order of structural domains and bounding fault zones (thickness, main orientation, internal architecture, …). However, lower order structural blocks and fracture networks are harder to define. The only available data are 1D borehole electric imaging and are used to characterize the lowest order. Analog outcrop studies of basement rocks fill up this resolution gap and help the understanding of brittle deformation, definition of reservoir geometries and acquirement of reservoir properties. These geological outcrop studies give information about structural blocks of second and third order, getting close to the field scale. This allows to understand relationships between brittle structures geometry and factors controlling their development, such as the structural inheritance or the lithology (e.g. schistosity, primary

  10. Fortescue reservoir development and reservoir studies

    Energy Technology Data Exchange (ETDEWEB)

    Henzell, S.T.; Hicks, G.J.; Horden, M.J.; Irrgang, H.R.; Janssen, E.J.; Kable, C.W.; Mitchell, R.A.H.; Morrell, N.W.; Palmer, I.D.; Seage, N.W.

    1985-03-01

    The Fortescue field in the Gippsland Basin, offshore southeastern Australia is being developed from two platforms (Fortescue A and Cobia A) by Esso Australia Ltd. (operator) and BHP Petroleum. The Fortescue reservoir is a stratigraphic trap at the top of the Latrobe Group of sediments. It overlies the western flank of the Halibut and Cobia fields and is separated from them by a non-net sequence of shales and coals which form a hydraulic barrier between the two systems. Development drilling into the Fortescue reservoir commenced in April 1983 with production coming onstream in May 1983. Fortescue, with booked reserves of 44 stock tank gigalitres (280 million stock tank barrels) of 43/sup 0/ API oil, is the seventh major oil reservoir to be developed in the offshore Gippsland Basin by Esso/BHP. In mid-1984, after drilling a total of 20 exploration and development wells, and after approximately one year of production, a detailed three-dimensional, two-phase reservoir simulation study was performed to examine the recovery efficiency, drainage patterns, pressure performance and production rate potential of the reservoir. The model was validated by history matching an extensive suite of Repeat Formation Test (RFT) pressure data. The results confirmed the reserves basis, and demonstrated that the ultimate oil recovery from the reservoir is not sensitive to production rate. This result is consistent with studies on other high quality Latrobe Group reservoirs in the Gippsland Basin which contain undersaturated crudes and receive very strong water drive from the Basin-wide aquifer system. With the development of the simulation model during the development phase, it has been possible to more accurately define the optimal well pattern for the remainder of the development.

  11. The reservoir properties of the upper Cretaceous productive deposits at the Pravoberezhnoe field. Kollektornyye svoystva verkhnemelovykh produktivnykh otlozheniy mestorozhdeniya Pravobeiezhnoye

    Energy Technology Data Exchange (ETDEWEB)

    Merkulov, A.V.; Yengibarov, V.N.

    1984-01-01

    Based on a set of various studies, an evaluation of the type of upper Cretaceous reservoir in the Pravoberezhnoe field is given. Compared to other fields in the Chechen Ingush Autonomous Soviet Socialist Republic, the upper Cretaceous productive deposits at this field are characterized by poorer reservoir properties. The set of all data indicates that the upper Cretaceous reservoir is analogous to reservoirs of equal age in existing fields in this republic and are cavernous fissured type.

  12. Analog Integrated Circuit Design for Spike Time Dependent Encoder and Reservoir in Reservoir Computing Processors

    Science.gov (United States)

    2018-01-01

    HAS BEEN REVIEWED AND IS APPROVED FOR PUBLICATION IN ACCORDANCE WITH ASSIGNED DISTRIBUTION STATEMENT. FOR THE CHIEF ENGINEER : / S / / S...bridged high-performance computing, nanotechnology , and integrated circuits & systems. 15. SUBJECT TERMS neuromorphic computing, neuron design, spike...multidisciplinary effort encompassed high-performance computing, nanotechnology , integrated circuits, and integrated systems. The project’s architecture was

  13. Transport of reservoir fines

    DEFF Research Database (Denmark)

    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....

  14. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  15. Hydrogen storage by adsorption on activated carbon: investigation of the thermal effects during the charging process; Stockage de l'hydrogene par adsorption sur charbon actif: etude des effets thermiques lors de la charge dynamique d'un reservoir a lit fixe adsorbant

    Energy Technology Data Exchange (ETDEWEB)

    Hermosilla-Lara, G

    2007-02-15

    This work presents an experimental and numerical investigation of the thermal effects occurring during the charge of adsorbent fixed bed tank. The influence of these thermal effects, which result from the exothermal character of the adsorption process and the pressure forces work, on the storage capacity is specially analysed. An experimental setup allowing the dynamic measurements of the temperature and pressure profiles has been used. Then the numerical protocol with the Fluent software, has been validated by comparison of the simulated pressure, flow rate and temperature fields in the tank with the results obtained from an experimental investigation carried out the dynamic storage. Several predictive simulations have been carried out in order to study the effect of the boundary conditions, as the wall temperature or effective thermal conductivity of the porous bed, on the storage capacity of the reservoir. We searched the optimal geometry of an interbed thermal dissipator for a given industrial tank. To do this we made vary the H/L ratio, which represents the ratio of the height of an elementary stage and the total length of the tank. We could determine an optimal geometry which corresponds to the value 1/3 of the ratio H/L. From this optimum we studied the effect of five additional cooling tubes on the tank storage capacity. The stored mass is 15 % higher than that obtained without these tubes. (author)

  16. Energy storage

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role that energy storage may have on the energy future of the US. The topics discussed in the chapter include historical aspects of energy storage, thermal energy storage including sensible heat storage, latent heat storage, thermochemical heat storage, and seasonal heat storage, electricity storage including batteries, pumped hydroelectric storage, compressed air energy storage, and superconducting magnetic energy storage, and production and combustion of hydrogen as an energy storage option

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

    Science.gov (United States)

    Bonnema, M.; Hossain, F.

    2017-12-01

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

  18. Fuzzy rule-based model for hydropower reservoirs operation

    Energy Technology Data Exchange (ETDEWEB)

    Moeini, R.; Afshar, A.; Afshar, M.H. [School of Civil Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of)

    2011-02-15

    Real-time hydropower reservoir operation is a continuous decision-making process of determining the water level of a reservoir or the volume of water released from it. The hydropower operation is usually based on operating policies and rules defined and decided upon in strategic planning. This paper presents a fuzzy rule-based model for the operation of hydropower reservoirs. The proposed fuzzy rule-based model presents a set of suitable operating rules for release from the reservoir based on ideal or target storage levels. The model operates on an 'if-then' principle, in which the 'if' is a vector of fuzzy premises and the 'then' is a vector of fuzzy consequences. In this paper, reservoir storage, inflow, and period are used as premises and the release as the consequence. The steps involved in the development of the model include, construction of membership functions for the inflow, storage and the release, formulation of fuzzy rules, implication, aggregation and defuzzification. The required knowledge bases for the formulation of the fuzzy rules is obtained form a stochastic dynamic programming (SDP) model with a steady state policy. The proposed model is applied to the hydropower operation of ''Dez'' reservoir in Iran and the results are presented and compared with those of the SDP model. The results indicate the ability of the method to solve hydropower reservoir operation problems. (author)

  19. Reservoir Sedimentation: Impact, Extent, and Mitigation

    Science.gov (United States)

    Hadley, Richard F.

    Storage reservoirs play an important role in water resources development throughout the world. The one problem with reservoirs that is universal is the continual reduction in usable capacity caused by siltation. This book reviews the world picture of erosion and sediment yield, the large variations that exist, and the physical phenomena related to reservoir siltation. The book is in the Technical Paper series of The World Bank (Technical Paper 71) and is not a formal publication. Rather, it is intended to be circulated to encourage discussion and comment and to communicate results quickly. The book is reproduced from typescript, but this does not detract from the value of the contents as a useful text for hydrologrsts, engineers, and soil conservationists in developing countries.

  20. Frameworks for amending reservoir water management

    Science.gov (United States)

    Mower, Ethan; Miranda, Leandro E.

    2013-01-01

    Managing water storage and withdrawals in many reservoirs requires establishing seasonal targets for water levels (i.e., rule curves) that are influenced by regional precipitation and diverse water demands. Rule curves are established as an attempt to balance various water needs such as flood control, irrigation, and environmental benefits such as fish and wildlife management. The processes and challenges associated with amending rule curves to balance multiuse needs are complicated and mostly unfamiliar to non-US Army Corps of Engineers (USACE) natural resource managers and to the public. To inform natural resource managers and the public we describe the policies and process involved in amending rule curves in USACE reservoirs, including 3 frameworks: a general investigation, a continuing authority program, and the water control plan. Our review suggests that water management in reservoirs can be amended, but generally a multitude of constraints and competing demands must be addressed before such a change can be realized.

  1. Toward a 62.5 MHz analog virtual pipeline integrated data acquisition system

    International Nuclear Information System (INIS)

    Kleinfelder, S.A.; Levi, M.; Milgrome, O.

    1991-01-01

    Requirements of analog pipeline memories at the SSC are reviewed and the concept of virtual pipelines is introduced. Design details and test results of several new custom analog and digital integrated circuits implementing sections of the virtual multiple pipeline (VMP) scheme are provied. These include serial, random access and simultaneous read and write random access analog storage and retrieval circuits, a 100 MHz systolic variable depth digital pipeline, and a prototye 32 μs, 12 bit serial analog to digital converter. (orig.)

  2. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    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.

  3. CMOS analog circuit design

    CERN Document Server

    Allen, Phillip E

    1987-01-01

    This text presents the principles and techniques for designing analog circuits to be implemented in a CMOS technology. The level is appropriate for seniors and graduate students familiar with basic electronics, including biasing, modeling, circuit analysis, and some familiarity with frequency response. Students learn the methodology of analog integrated circuit design through a hierarchically-oriented approach to the subject that provides thorough background and practical guidance for designing CMOS analog circuits, including modeling, simulation, and testing. The authors' vast industrial experience and knowledge is reflected in the circuits, techniques, and principles presented. They even identify the many common pitfalls that lie in the path of the beginning designer--expert advice from veteran designers. The text mixes the academic and practical viewpoints in a treatment that is neither superficial nor overly detailed, providing the perfect balance.

  4. Analogical Reasoning in Geometry Education

    Science.gov (United States)

    Magdas, Ioana

    2015-01-01

    The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

  5. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  6. Analogs for transuranic elements

    International Nuclear Information System (INIS)

    Weimer, W.C.; Laul, J.C.; Kutt, J.C.

    1981-01-01

    A combined theoretical and experimental approach is being used to estimate the long-term environmental and biogeochemical behaviors of selected transuranic elements. The objective of this research is to estimate the effect that long-term (hundreds of years) environmental weathering has on the behavior of the transuranic elements americium and curium. This is achieved by investigating the actual behavior of naturally occurring rare earth elements, especially neodymium, that serve as transuranic analogs. Determination of the analog element behavior provides data that can be used to estimate the ultimate availability to man of transuranic materials released into the environment

  7. Nonlinear Filtering Effects of Reservoirs on Flood Frequency Curves at the Regional Scale: RESERVOIRS FILTER FLOOD FREQUENCY CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Li, Hong-Yi; Leung, Lai-Yung; Yigzaw, Wondmagegn Y.; Zhao, Jianshi; Lu, Hui; Deng, Zhiqun; Demissie, Yonas; Bloschl, Gunter

    2017-10-01

    Anthropogenic activities, e.g., reservoir operation, may alter the characteristics of Flood Frequency Curve (FFC) and challenge the basic assumption of stationarity used in flood frequency analysis. This paper presents a combined data-modeling analysis of the nonlinear filtering effects of reservoirs on the FFCs over the contiguous United States. A dimensionless Reservoir Impact Index (RII), defined as the total upstream reservoir storage capacity normalized by the annual streamflow volume, is used to quantify reservoir regulation effects. Analyses are performed for 388 river stations with an average record length of 50 years. The first two moments of the FFC, mean annual maximum flood (MAF) and coefficient of variations (CV), are calculated for the pre- and post-dam periods and compared to elucidate the reservoir regulation effects as a function of RII. It is found that MAF generally decreases with increasing RII but stabilizes when RII exceeds a threshold value, and CV increases with RII until a threshold value beyond which CV decreases with RII. The processes underlying the nonlinear threshold behavior of MAF and CV are investigated using three reservoir models with different levels of complexity. All models capture the non-linear relationships of MAF and CV with RII, suggesting that the basic flood control function of reservoirs is key to the non-linear relationships. The relative roles of reservoir storage capacity, operation objectives, available storage prior to a flood event, and reservoir inflow pattern are systematically investigated. Our findings may help improve flood-risk assessment and mitigation in regulated river systems at the regional scale.

  8. Air ejector augmented compressed air energy storage system

    Science.gov (United States)

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  9. Terrestrial Analogs to Mars

    Science.gov (United States)

    Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.

    2002-08-01

    It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

  10. Reasoning through Instructional Analogies

    Science.gov (United States)

    Kapon, Shulamit; diSessa, Andrea A.

    2012-01-01

    This article aims to account for students' assessments of the plausibility and applicability of analogical explanations, and individual differences in these assessments, by analyzing properties of students' underlying knowledge systems. We developed a model of explanation and change in explanation focusing on knowledge elements that provide a…

  11. The Paradox of Analogy

    Directory of Open Access Journals (Sweden)

    David Botting

    2012-03-01

    Full Text Available I will show that there is a type of analogical reasoning that instantiates a pattern of reasoning in confirmation theory that is considered at best paradoxical and at worst fatal to the entire syntactical approach to confirmation and explanation. However, I hope to elaborate conditions under which this is a sound (although not necessarily strong method of reasoning.

  12. Analogy, explanation, and proof

    Science.gov (United States)

    Hummel, John E.; Licato, John; Bringsjord, Selmer

    2014-01-01

    People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic) whose truth was not even known prior to the existence of the explanation (proof). What do the cognitive operations underlying the inference that the milk is sour have in common with the proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This seemingly small difference poses a challenge to the task of marshaling our understanding of analogical reasoning to understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence. PMID:25414655

  13. How Analogy Drives Physics

    International Nuclear Information System (INIS)

    Hofstadter, Doug

    2004-01-01

    Many new ideas in theoretical physics come from analogies to older ideas in physics. For instance, the abstract notion of 'isospin' (or isotopic spin) originated in the prior concept of 'spin' (quantized angular momentum); likewise, the concept of 'phonon' (quantum of sound, or quantized collective excitation of a crystal) was based on the prior concept of 'photon' (quantum of light, or quantized element of the electromagnetic field). But these two examples, far from being exceptions, in fact represent the bread and butter of inventive thinking in physics. In a nutshell, intraphysics analogy-making -- borrowing by analogy with something already known in another area of physics -- is central to the progress of physics. The aim of this talk is to reveal the pervasiveness -- indeed, the indispensability -- of this kind of semi-irrational, wholly intuitive type of thinking (as opposed to more deductive mathematical inference) in the mental activity known as 'doing physics'. Speculations as to why wild analogical leaps are so crucial to the act of discovery in physics (as opposed to other disciplines) will be offered.

  14. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  15. Sediment transport-storage relations for degrading, gravel bed channels

    Science.gov (United States)

    Thomas E. Lisle; Michael Church

    2002-01-01

    In a drainage network,sediment is transferred through a series of channel/valley segments (natural sediment storage reservoirs) that are distinguished from their neighbors by their particular capacity to store and transport sediment. We propose that the sediment transport capacity of each reservoir is a unique positive function of storage volume, which influences...

  16. Physical Model-Based Investigation of Reservoir Sedimentation Processes

    Directory of Open Access Journals (Sweden)

    Cheng-Chia Huang

    2018-03-01

    Full Text Available Sedimentation is a serious problem in the operations of reservoirs. In Taiwan, the situation became worse after the Chi-Chi Earthquake recorded on 21 September 1999. The sediment trap efficiency in several regional reservoirs has been sharply increased, adversely affecting the operations on water supplies. According to the field record, the average annual sediment deposition observed in several regional reservoirs in Taiwan has been increased. For instance, the typhoon event recorded in 2008 at the Wushe Reservoir, Taiwan, produced a 3 m sediment deposit upstream of the dam. The remaining storage capacity in the Wushe Reservoir was reduced to 35.9% or a volume of 53.79 million m3 for flood water detention in 2010. It is urgent that research should be conducted to understand the sediment movement in the Wushe Reservoir. In this study, a scale physical model was built to reproduce the flood flow through the reservoir, investigate the long-term depositional pattern, and evaluate sediment trap efficiency. This allows us to estimate the residual life of the reservoir by proposing a modification of Brune’s method. It can be presented to predict the lifespan of Taiwan reservoirs due to higher applicability in both the physical model and the observed data.

  17. Optimising reservoir operation

    DEFF Research Database (Denmark)

    Ngo, Long le

    Anvendelse af optimeringsteknik til drift af reservoirer er blevet et væsentligt element i vandressource-planlægning og -forvaltning. Traditionelt har reservoirer været styret af heuristiske procedurer for udtag af vand, suppleret i en vis udstrækning af subjektive beslutninger. Udnyttelse af...... reservoirer involverer en lang række interessenter med meget forskellige formål (f.eks. kunstig vanding, vandkraft, vandforsyning mv.), og optimeringsteknik kan langt bedre lede frem til afbalancerede løsninger af de ofte modstridende interesser. Afhandlingen foreslår en række tiltag, hvormed traditionelle...

  18. Small Reservoir Impact on Simulated Watershed-Scale Nutrient Yield

    Directory of Open Access Journals (Sweden)

    Shane J. Prochnow

    2007-01-01

    Full Text Available The soil and water assessment tool (SWAT is used to assess the influence of small upland reservoirs (PL566 on watershed nutrient yield. SWAT simulates the impact of collectively increasing and decreasing PL566 magnitudes (size parameters on the watershed. Totally removing PL566 reservoirs results in a 100% increase in total phosphorus and an 82% increase in total nitrogen, while a total maximum daily load (TMDL calling for a 50% reduction in total phosphorus can be achieved with a 500% increase in the magnitude of PL566s in the watershed. PL566 reservoirs capture agriculture pollution in surface flow, providing long-term storage of these constituents when they settle to the reservoir beds. A potential strategy to reduce future downstream nutrient loading is to enhance or construct new PL566 reservoirs in the upper basin to better capture agricultural runoff.

  19. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, M.

    1995-02-01

    This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

  20. SSERVI Analog Regolith Simulant Testbed Facility

    Science.gov (United States)

    Minafra, J.; Schmidt, G. K.

    2016-12-01

    SSERVI's goals include supporting planetary researchers within NASA, other government agencies; private sector and hardware developers; competitors in focused prize design competitions; and academic sector researchers. The SSERVI Analog Regolith Simulant Testbed provides opportunities for research scientists and engineers to study the effects of regolith analog testbed research in the planetary exploration field. This capability is essential to help to understand the basic effects of continued long-term exposure to a simulated analog test environment. The current facility houses approximately eight tons of JSC-1A lunar regolith simulant in a test bin consisting of a 4 meter by 4 meter area. SSERVI provides a bridge between several groups, joining together researchers from: 1) scientific and exploration communities, 2) multiple disciplines across a wide range of planetary sciences, and 3) domestic and international communities and partnerships. This testbed provides a means of consolidating the tasks of acquisition, storage and safety mitigation in handling large quantities of regolith simulant Facility hardware and environment testing scenarios include, but are not limited to the following; Lunar surface mobility, Dust exposure and mitigation, Regolith handling and excavation, Solar-like illumination, Lunar surface compaction profile, Lofted dust, Mechanical properties of lunar regolith, and Surface features (i.e. grades and rocks) Numerous benefits vary from easy access to a controlled analog regolith simulant testbed, and planetary exploration activities at NASA Research Park, to academia and expanded commercial opportunities in California's Silicon Valley, as well as public outreach and education opportunities.

  1. Energy Storage.

    Science.gov (United States)

    Eaton, William W.

    Described are technological considerations affecting storage of energy, particularly electrical energy. The background and present status of energy storage by batteries, water storage, compressed air storage, flywheels, magnetic storage, hydrogen storage, and thermal storage are discussed followed by a review of development trends. Included are…

  2. Terrestrial Spaceflight Analogs: Antarctica

    Science.gov (United States)

    Crucian, Brian

    2013-01-01

    Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

  3. Analogy, Explanation, and Proof

    Directory of Open Access Journals (Sweden)

    John eHummel

    2014-11-01

    Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  4. Efficient Reservoir Simulation with Cubic Plus Association and Cross-Association Equation of State for Multicomponent Three-Phase Compressible Flow with Applications in CO2 Storage and Methane Leakage

    Science.gov (United States)

    Moortgat, J.

    2017-12-01

    We present novel simulation tools to model multiphase multicomponent flow and transport in porous media for mixtures that contain non-polar hydrocarbons, self-associating polar water, and cross-associating molecules like methane, ethane, unsaturated hydrocarbons, CO2 and H2S. Such mixtures often occur when CO2 is injected and stored in saline aquifers, or when methane is leaking into groundwater. To accurately predict the species transfer between aqueous, gaseous and oleic phases, and the subsequent change in phase properties, the self- and cross-associating behavior of molecules needs to be taken into account, particularly at the typical temperatures and pressures in deep formations. The Cubic-Plus-Association equation-of-state (EOS) has been demonstrated to be highly accurate for such problems but its excessive computational cost has prevented widespread use in reservoir simulators. We discuss the thermodynamical framework and develop sophisticated numerical algorithms that allow reservoir simulations with efficiencies comparable to a simple cubic EOS. This approach improves our predictive powers for highly nonlinear fluid behavior related to geological carbon sequestration, such as density driven flow and natural convection (solubility trapping), evaporation of water into the CO2-rich gas phase, and competitive dissolution-evaporation when CO2 is injected in, e.g., methane saturated aquifers. Several examples demonstrate the accuracy and robustness of this EOS framework for complex applications.

  5. Component Processes in Analogical Reasoning

    Science.gov (United States)

    Sternberg, Robert J.

    1977-01-01

    Describes alternative theoretical positions regarding (a) the component information processes used in analogical reasoning and (b) strategies for combining these processes. Also presents results from three experiments on analogical reasoning. (Author/RK)

  6. Advancing the capabilities of reservoir remote sensing by leveraging multi-source satellite data

    Science.gov (United States)

    Gao, H.; Zhang, S.; Zhao, G.; Li, Y.

    2017-12-01

    With a total global capacity of more than 6000 km3, reservoirs play a key role in the hydrological cycle and in water resources management. However, essential reservoir data (e.g., elevation, storage, and evaporation loss) are usually not shared at a large scale. While satellite remote sensing offers a unique opportunity for monitoring large reservoirs from space, the commonly used radar altimeters can only detect storage variations of about 15% of global lakes at a repeat period of 10 days or longer. To advance the capabilities of reservoir sensing, we developed a series of algorithms geared towards generating long term reservoir records at improved spatial coverage, and at improved temporal resolution. To this goal, observations are leveraged from multiple satellite sensors, which include radar/laser altimeters, imagers, and passive microwave radiometers. In South Asia, we demonstrate that reservoir storage can be estimated under all-weather conditions at a 4 day time step, with the total capacity of monitored reservoirs increased to 45%. Within the Continuous United States, a first Landsat based evaporation loss dataset was developed (containing 204 reservoirs) from 1984 to 2011. The evaporation trends of these reservoirs are identified and the causes are analyzed. All of these algorithms and products were validated with gauge observations. Future satellite missions, which will make significant contributions to monitoring global reservoirs, are also discussed.

  7. Optimization In Searching Daily Rule Curve At Mosul Regulating Reservoir, North Iraq Using Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Thair M. Al-Taiee

    2013-05-01

    Full Text Available To obtain optimal operating rules for storage reservoirs, large numbers of simulation and optimization models have been developed over the past several decades, which vary significantly in their mechanisms and applications. Rule curves are guidelines for long term reservoir operation. An efficient technique is required to find the optimal rule curves that can mitigate water shortage in long term operation. The investigation of developed Genetic Algorithm (GA technique, which is an optimization approach base on the mechanics of natural selection, derived from the theory of natural evolution, was carried out to through the application to predict the daily rule curve of  Mosul regulating reservoir in Iraq.  Record daily inflows, outflow, water level in the reservoir for 19 year (1986-1990 and (1994-2007 were used in the developed model for assessing the optimal reservoir operation. The objective function is set to minimize the annual sum of squared deviation from the desired downstream release and desired storage volume in the reservoir. The decision variables are releases, storage volume, water level and outlet (demand from the reservoir. The results of the GA model gave a good agreement during the comparison with the actual rule curve and the designed rating curve of the reservoir. The simulated result shows that GA-derived policies are promising and competitive and can be effectively used for daily reservoir operation in addition to the rational monthly operation and predicting also rating curve of reservoirs.

  8. Inductive, Analogical, and Communicative Generalization

    Directory of Open Access Journals (Sweden)

    Adri Smaling

    2003-03-01

    Full Text Available Three forms of inductive generalization - statistical generalization, variation-based generalization and theory-carried generalization - are insufficient concerning case-to-case generalization, which is a form of analogical generalization. The quality of case-to-case generalization needs to be reinforced by setting up explicit analogical argumentation. To evaluate analogical argumentation six criteria are discussed. Good analogical reasoning is an indispensable support to forms of communicative generalization - receptive and responsive (participative generalization — as well as exemplary generalization.

  9. Analogical Reasoning and Computer Programming.

    Science.gov (United States)

    Clement, Catherine A.; And Others

    1986-01-01

    A study of correlations between analogical reasoning and Logo programming mastery among female high school students related the results of pretests of analogical reasoning to posttests of programming mastery. A significant correlation was found between analogical reasoning and the ability to write subprocedures for use in several different…

  10. Naturally fractured reservoirs-yet an unsolved mystery

    International Nuclear Information System (INIS)

    Zahoor, M.K.

    2013-01-01

    Some of the world's most profitable reservoirs are assumed to be naturally fractured reservoirs (NFR). Effective evaluation, prediction and planning of these reservoirs require an early recognition of the role of natural fractures and then a comprehensive study of factors which affect the flowing performance through these fractures is necessary. As NFRs are the combination of matrix and fractures mediums so their analysis varies from non-fractured reservoirs. Matrix acts as a storage medium while mostly fluid flow takes place from fracture network. Many authors adopted different approaches to understand the flow behavior in such reservoirs. In this paper a broad review about the previous work done in naturally fractured reservoirs area is outlined and a different idea is initiated for the NFR simulation studies. The role of capillary pressure in natural fractures is always been a key factor for accurate recovery estimations. Also recovery through these reservoirs is dependent upon grid block shape while doing NFR simulation. Some authors studied above mentioned factors in combination with other rock properties to understand the flow behavior in such reservoirs but less emphasis was given for checking the effects on recovery estimations by the variations of only fracture capillary pressures and grid block shapes. So there is need to analyze the behavior of NFR for the mentioned conditions. (author)

  11. Analogical scaffolding: Making meaning in physics through representation and analogy

    Science.gov (United States)

    Podolefsky, Noah Solomon

    This work reviews the literature on analogy, introduces a new model of analogy, and presents a series of experiments that test and confirm the utility of this model to describe and predict student learning in physics with analogy. Pilot studies demonstrate that representations (e.g., diagrams) can play a key role in students' use of analogy. A new model of analogy, Analogical Scaffolding, is developed to explain these initial empirical results. This model will be described in detail, and then applied to describe and predict the outcomes of further experiments. Two large-scale (N>100) studies will demonstrate that: (1) students taught with analogies, according to the Analogical Scaffolding model, outperform students taught without analogies on pre-post assessments focused on electromagnetic waves; (2) the representational forms used to teach with analogy can play a significant role in student learning, with students in one treatment group outperforming students in other treatment groups by factors of two or three. It will be demonstrated that Analogical Scaffolding can be used to predict these results, as well as finer-grained results such as the types of distracters students choose in different treatment groups, and to describe and analyze student reasoning in interviews. Abstraction in physics is reconsidered using Analogical Scaffolding. An operational definition of abstraction is developed within the Analogical Scaffolding framework and employed to explain (a) why physicists consider some ideas more abstract than others in physics, and (b) how students conceptions of these ideas can be modeled. This new approach to abstraction suggests novel approaches to curriculum design in physics using Analogical Scaffolding.

  12. Analysis of Sedimentation in Wonogiri Reservoir

    Directory of Open Access Journals (Sweden)

    Tri Joko Inti Budi Santosa

    2016-01-01

    Full Text Available The Wonogiri reservoir which has 730 million cubic meters of total storage, 90 square kilometers of water area, and 1260 square kilometers of catchment area, is located in the Wonogiri Regency, Central Java Province. It was first established in 1981 and began its operation in 1982 with the expectation that it would last for about 100 years. Today (2002 the reservoir has got a serious problem of sedimentation. The sedimentation is so large that it would decrease the capacity storage of the reservoir and would shorten the length of operation. Therefore, it is necessary to predict the sediment that comes into the reservoir. This research would be based on the total sediment calculation of the sedimentation, through some methods, such as echo sounding measured data, land erosion (USLE, the calculation of the sediment in rivers. This research calculates the sediment capacities based on the water flow data and the sediment rating curves in rivers of Keduang, Tirtomoyo, Temon, upstream reach of Bengawan Solo, Alang, and Wuryantoro. The suspended load was calculated based on the sediment rating curves, whereas the bed load was computed as the percentage of the suspended load. The sum of both calculation results would be the total sediment. The calculation result showed that the total sediment which has come into the reservoir is 6.68 million cubic meters per year. As a comparison, the writer noted that the former researcher using echo sounding method done by the Faculty of Geography of the Universitas Gadjah Mada in 1985, it found that the total sediment capacity which came into the reservoir was 6.60 million cubic meters per year or 5.40 mm per year of sheet erosion. The other research using echo sounding method done by JICA in 2000 found that the total sediment which had come into the reservoir was 4.50 million cubic meters per year or 3.50 mm per year of sheet erosion. By knowing the results of calculation of the total sediment, we can learn that

  13. Representing Reservoir Stratification in Land Surface and Earth System Models

    Science.gov (United States)

    Yigzaw, W.; Li, H. Y.; Leung, L. R.; Hejazi, M. I.; Voisin, N.; Payn, R. A.; Demissie, Y.

    2017-12-01

    A one-dimensional reservoir stratification modeling has been developed as part of Model for Scale Adaptive River Transport (MOSART), which is the river transport model used in the Accelerated Climate Modeling for Energy (ACME) and Community Earth System Model (CESM). Reservoirs play an important role in modulating the dynamic water, energy and biogeochemical cycles in the riverine system through nutrient sequestration and stratification. However, most earth system models include lake models that assume a simplified geometry featuring a constant depth and a constant surface area. As reservoir geometry has important effects on thermal stratification, we developed a new algorithm for deriving generic, stratified area-elevation-storage relationships that are applicable at regional and global scales using data from Global Reservoir and Dam database (GRanD). This new reservoir geometry dataset is then used to support the development of a reservoir stratification module within MOSART. The mixing of layers (energy and mass) in the reservoir is driven by eddy diffusion, vertical advection, and reservoir inflow and outflow. Upstream inflow into a reservoir is treated as an additional source/sink of energy, while downstream outflow represented a sink. Hourly atmospheric forcing from North American Land Assimilation System (NLDAS) Phase II and simulated daily runoff by ACME land component are used as inputs for the model over the contiguous United States for simulations between 2001-2010. The model is validated using selected observed temperature profile data in a number of reservoirs that are subject to various levels of regulation. The reservoir stratification module completes the representation of riverine mass and heat transfer in earth system models, which is a major step towards quantitative understanding of human influences on the terrestrial hydrological, ecological and biogeochemical cycles.

  14. Will building new reservoirs always help increase the water supply reliability? - insight from a modeling-based global study

    Science.gov (United States)

    Zhuang, Y.; Tian, F.; Yigzaw, W.; Hejazi, M. I.; Li, H. Y.; Turner, S. W. D.; Vernon, C. R.

    2017-12-01

    More and more reservoirs are being build or planned in order to help meet the increasing water demand all over the world. However, is building new reservoirs always helpful to water supply? To address this question, the river routing module of Global Change Assessment Model (GCAM) has been extended with a simple yet physical-based reservoir scheme accounting for irrigation, flood control and hydropower operations at each individual reservoir. The new GCAM river routing model has been applied over the global domain with the runoff inputs from the Variable Infiltration Capacity Model. The simulated streamflow is validated at 150 global river basins where the observed streamflow data are available. The model performance has been significantly improved at 77 basins and worsened at 35 basins. To facilitate the analysis of additional reservoir storage impacts at the basin level, a lumped version of GCAM reservoir model has been developed, representing a single lumped reservoir at each river basin which has the regulation capacity of all reservoir combined. A Sequent Peak Analysis is used to estimate how much additional reservoir storage is required to satisfy the current water demand. For basins with water deficit, the water supply reliability can be improved with additional storage. However, there is a threshold storage value at each basin beyond which the reliability stops increasing, suggesting that building new reservoirs will not help better relieve the water stress. Findings in the research can be helpful to the future planning and management of new reservoirs.

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

    Science.gov (United States)

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

    2015-12-01

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

  16. Using analogs to generate production forecasts in Faja

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Lugo, Rolando A. [Repsol (Canada)

    2011-07-01

    In the Carabobol Block, extra heavy oil will be produced by cold production from Miocene Morical Member sands. Many parameters such as pressure, temperature, solution gas oil ratio and viscosity variation significantly impact well productivity; unfortunately little information is available on the Carabobol Block. The aim of this paper is to provide a new methodology for using analog data to develop fluid properties correlations and a future production profile. Data from the analog neighbour field in the Orinoco oil belt was used. A methodology using scatter data was successfully applied for the Carabobol Block and fluid composition, a complete PVT and an analytical forecast were found and confirmed with actual laboratory data and a gross numerical model. This study showed that analog data can be used as a first approach to assess initial reservoir conditions and fluid properties and to generate production forecasts.

  17. Archaeological analogs and corrosion

    International Nuclear Information System (INIS)

    David, D.

    2008-01-01

    In the framework of the high level and long life radioactive wastes disposal deep underground, the ANDRA built a research program on the material corrosion. In particular they aim to design containers for a very long time storage. Laboratory experiments are in progress and can be completed by the analysis of metallic archaeological objects and their corrosion after hundred years. (A.L.B.)

  18. Discrete Calculus by Analogy

    CERN Document Server

    Izadi, F A; Bagirov, G

    2009-01-01

    With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati

  19. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  20. Geochemical Influence on Microbial Communities at CO2-Leakage Analog Sites.

    Science.gov (United States)

    Ham, Baknoon; Choi, Byoung-Young; Chae, Gi-Tak; Kirk, Matthew F; Kwon, Man Jae

    2017-01-01

    Microorganisms influence the chemical and physical properties of subsurface environments and thus represent an important control on the fate and environmental impact of CO 2 that leaks into aquifers from deep storage reservoirs. How leakage will influence microbial populations over long time scales is largely unknown. This study uses natural analog sites to investigate the long-term impact of CO 2 leakage from underground storage sites on subsurface biogeochemistry. We considered two sites with elevated CO 2 levels (sample groups I and II) and one control site with low CO 2 content (group III). Samples from sites with elevated CO 2 had pH ranging from 6.2 to 4.5 and samples from the low-CO 2 control group had pH ranging from 7.3 to 6.2. Solute concentrations were relatively low for samples from the control group and group I but high for samples from group II, reflecting varying degrees of water-rock interaction. Microbial communities were analyzed through clone library and MiSeq sequencing. Each 16S rRNA analysis identified various bacteria, methane-producing archaea, and ammonia-oxidizing archaea. Both bacterial and archaeal diversities were low in groundwater with high CO 2 content and community compositions between the groups were also clearly different. In group II samples, sequences classified in groups capable of methanogenesis, metal reduction, and nitrate reduction had higher relative abundance in samples with relative high methane, iron, and manganese concentrations and low nitrate levels. Sequences close to Comamonadaceae were abundant in group I, while the taxa related to methanogens, Nitrospirae , and Anaerolineaceae were predominant in group II. Our findings provide insight into subsurface biogeochemical reactions that influence the carbon budget of the system including carbon fixation, carbon trapping, and CO 2 conversion to methane. The results also suggest that monitoring groundwater microbial community can be a potential tool for tracking CO 2

  1. Geochemical Influence on Microbial Communities at CO2-Leakage Analog Sites

    Directory of Open Access Journals (Sweden)

    Baknoon Ham

    2017-11-01

    Full Text Available Microorganisms influence the chemical and physical properties of subsurface environments and thus represent an important control on the fate and environmental impact of CO2 that leaks into aquifers from deep storage reservoirs. How leakage will influence microbial populations over long time scales is largely unknown. This study uses natural analog sites to investigate the long-term impact of CO2 leakage from underground storage sites on subsurface biogeochemistry. We considered two sites with elevated CO2 levels (sample groups I and II and one control site with low CO2 content (group III. Samples from sites with elevated CO2 had pH ranging from 6.2 to 4.5 and samples from the low-CO2 control group had pH ranging from 7.3 to 6.2. Solute concentrations were relatively low for samples from the control group and group I but high for samples from group II, reflecting varying degrees of water-rock interaction. Microbial communities were analyzed through clone library and MiSeq sequencing. Each 16S rRNA analysis identified various bacteria, methane-producing archaea, and ammonia-oxidizing archaea. Both bacterial and archaeal diversities were low in groundwater with high CO2 content and community compositions between the groups were also clearly different. In group II samples, sequences classified in groups capable of methanogenesis, metal reduction, and nitrate reduction had higher relative abundance in samples with relative high methane, iron, and manganese concentrations and low nitrate levels. Sequences close to Comamonadaceae were abundant in group I, while the taxa related to methanogens, Nitrospirae, and Anaerolineaceae were predominant in group II. Our findings provide insight into subsurface biogeochemical reactions that influence the carbon budget of the system including carbon fixation, carbon trapping, and CO2 conversion to methane. The results also suggest that monitoring groundwater microbial community can be a potential tool for tracking

  2. Albert Einstein, Analogizer Extraordinaire

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    Where does deep insight in physics come from? It is tempting to think that it comes from the purest and most precise of reasoning, following ironclad laws of thought that compel the clear mind completely rigidly. And yet the truth is quite otherwise. One finds, when one looks closely at any major discovery, that the greatest of physicists are, in some sense, the most crazily daring and irrational of all physicists. Albert Einstein exemplifies this thesis in spades. In this talk I will describe the key role, throughout Albert Einstein's fabulously creative life, played by wild guesses made by analogy lacking any basis whatsoever in pure reasoning. In particular, in this year of 2007, the centenary of 1907, I will describe how over the course of two years (1905 through 1907) of pondering, Einstein slowly came, via analogy, to understand the full, radical consequences of the equation that he had first discovered and published in 1905, arguably the most famous equation of all time: E = mc2.

  3. An Effective Reservoir Parameter for Seismic Characterization of Organic Shale Reservoir

    Science.gov (United States)

    Zhao, Luanxiao; Qin, Xuan; Zhang, Jinqiang; Liu, Xiwu; Han, De-hua; Geng, Jianhua; Xiong, Yineng

    2017-12-01

    Sweet spots identification for unconventional shale reservoirs involves detection of organic-rich zones with abundant porosity. However, commonly used elastic attributes, such as P- and S-impedances, often show poor correlations with porosity and organic matter content separately and thus make the seismic characterization of sweet spots challenging. Based on an extensive analysis of worldwide laboratory database of core measurements, we find that P- and S-impedances exhibit much improved linear correlations with the sum of volume fraction of organic matter and porosity than the single parameter of organic matter volume fraction or porosity. Importantly, from the geological perspective, porosity in conjunction with organic matter content is also directly indicative of the total hydrocarbon content of shale resources plays. Consequently, we propose an effective reservoir parameter (ERP), the sum of volume fraction of organic matter and porosity, to bridge the gap between hydrocarbon accumulation and seismic measurements in organic shale reservoirs. ERP acts as the first-order factor in controlling the elastic properties as well as characterizing the hydrocarbon storage capacity of organic shale reservoirs. We also use rock physics modeling to demonstrate why there exists an improved linear correlation between elastic impedances and ERP. A case study in a shale gas reservoir illustrates that seismic-derived ERP can be effectively used to characterize the total gas content in place, which is also confirmed by the production well.

  4. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  5. Reservoir simulation with MUFITS code: Extension for double porosity reservoirs and flows in horizontal wells

    Science.gov (United States)

    Afanasyev, Andrey

    2017-04-01

    Numerical modelling of multiphase flows in porous medium is necessary in many applications concerning subsurface utilization. An incomplete list of those applications includes oil and gas fields exploration, underground carbon dioxide storage and geothermal energy production. The numerical simulations are conducted using complicated computer programs called reservoir simulators. A robust simulator should include a wide range of modelling options covering various exploration techniques, rock and fluid properties, and geological settings. In this work we present a recent development of new options in MUFITS code [1]. The first option concerns modelling of multiphase flows in double-porosity double-permeability reservoirs. We describe internal representation of reservoir models in MUFITS, which are constructed as a 3D graph of grid blocks, pipe segments, interfaces, etc. In case of double porosity reservoir, two linked nodes of the graph correspond to a grid cell. We simulate the 6th SPE comparative problem [2] and a five-spot geothermal production problem to validate the option. The second option concerns modelling of flows in porous medium coupled with flows in horizontal wells that are represented in the 3D graph as a sequence of pipe segments linked with pipe junctions. The well completions link the pipe segments with reservoir. The hydraulics in the wellbore, i.e. the frictional pressure drop, is calculated in accordance with Haaland's formula. We validate the option against the 7th SPE comparative problem [3]. We acknowledge financial support by the Russian Foundation for Basic Research (project No RFBR-15-31-20585). References [1] Afanasyev, A. MUFITS Reservoir Simulation Software (www.mufits.imec.msu.ru). [2] Firoozabadi A. et al. Sixth SPE Comparative Solution Project: Dual-Porosity Simulators // J. Petrol. Tech. 1990. V.42. N.6. P.710-715. [3] Nghiem L., et al. Seventh SPE Comparative Solution Project: Modelling of Horizontal Wells in Reservoir Simulation

  6. Nagylengyel: an interesting reservoir. [Yugoslovia

    Energy Technology Data Exchange (ETDEWEB)

    Dedinszky, J

    1971-04-01

    The Nagylengyel oil field, discovered in 1951, has oil-producing formations mostly in the Upper-Triassic dolomites, in the Norian-Ractian transition formations, in the Upper-Cretaceous limestones and shales, and in the Miocene. The formation of the reservoir space occurred in many stages. A porous, cavernous fractured reservoir is developed in the Norian principal dolomite. A cavernous fractured reservoir exists in the Cretaceous limestone and in the Cretaceous shale and porous fractured reservoir is developed in the Miocene. The derivation of the model of the reservoir, and the conservative evaluation of the volume of the reservoir made it possible to use secondary recovery.

  7. Overspill avalanching in a dense reservoir network

    Science.gov (United States)

    Mamede, George L.; Araújo, Nuno A. M.; Schneider, Christian M.; de Araújo, José Carlos; Herrmann, Hans J.

    2012-01-01

    Sustainability of communities, agriculture, and industry is strongly dependent on an effective storage and supply of water resources. In some regions the economic growth has led to a level of water demand that can only be accomplished through efficient reservoir networks. Such infrastructures are not always planned at larger scale but rather made by farmers according to their local needs of irrigation during droughts. Based on extensive data from the upper Jaguaribe basin, one of the world’s largest system of reservoirs, located in the Brazilian semiarid northeast, we reveal that surprisingly it self-organizes into a scale-free network exhibiting also a power-law in the distribution of the lakes and avalanches of discharges. With a new self-organized-criticality-type model we manage to explain the novel critical exponents. Implementing a flow model we are able to reproduce the measured overspill evolution providing a tool for catastrophe mitigation and future planning. PMID:22529343

  8. Proposition d'explication de la formation d'hydrogène sulfuré dans les stockages souterrains de gaz naturel par réduction des sulfures minéraux de la roche magasin Proposed Explanation of Hydrogen-Sulfide Formation in Underground Natural-Gas Storage Structures by Reduction of Mineral Sulfides in the Reservoir Rock.

    Directory of Open Access Journals (Sweden)

    Bourgeois J. P.

    2006-11-01

    Full Text Available La formation d'hydrogène sulfuré dans les structures de stockage peu expliquer autrement que par l'action de bactéries sulfato-réductrices. La contenue dans la roche magasin constitue une source de sulfures capable d'alimenter en H2S le gaz naturel. La réduction de la pyrite en sulfures du type Fe 1-x S et l'équilibre de dissolution précipitation, lié principalement à la pression de CO2, dans les structures stockages, constituent un processus de formation d'H2S capable d'expliquer tativement et quantitativement les phénomènes observés sur le terrain. Un modèle simplifié de stockage reprend ce schéma et teste la sensibililté de la teneur en H2S à la valeur des paramètres physiques et chimiques définissant le stockage. Cette étude permet de proposer un certain nombre d'actions susceptibles de limiter la formation d'H2S et d'orienter les choix futurs du couple gaz naturel - structures de stockage. The formation of hydrogen sulfide in storage structures can be explained otherwise thon by the action of sulfate-reducing bacteria. The pyrite contained in the reservoir rock makes up a source of sulfides capable of supplying the natural gas with H2S.Reduction of pyrite ta sulfides of the Fe,-,S type and the dissolution precipitation equilibrium, linked mainly ta C02 pressure in storage structures, make up an H2S for-mation process capable of qualitatively and quantitatively explained phenomena observed in the field.A simplified storage model reflects this scheme and can be used ta test the sensi-tivity of the H2S content ta the value of the physical and chemical parameters defining the storage structure.This investigation can be used to propose various means of action (sable ta "mit H2S formation and ta guide future choices of natural gas/storage-structure pairs.

  9. Modeling Reservoir-River Networks in Support of Optimizing Seasonal-Scale Reservoir Operations

    Science.gov (United States)

    Villa, D. L.; Lowry, T. S.; Bier, A.; Barco, J.; Sun, A.

    2011-12-01

    each timestep and minimize computational overhead. Power generation for each reservoir is estimated using a 2-dimensional regression that accounts for both the available head and turbine efficiency. The object-oriented architecture makes run configuration easy to update. The dynamic model inputs include inflow and meteorological forecasts while static inputs include bathymetry data, reservoir and power generation characteristics, and topological descriptors. Ensemble forecasts of hydrological and meteorological conditions are supplied in real-time by Pacific Northwest National Laboratory and are used as a proxy for uncertainty, which is carried through the simulation and optimization process to produce output that describes the probability that different operational scenario's will be optimal. The full toolset, which includes HydroSCOPE, is currently being tested on the Feather River system in Northern California and the Upper Colorado Storage Project.

  10. Associative memory in an analog iterated-map neural network

    Science.gov (United States)

    Marcus, C. M.; Waugh, F. R.; Westervelt, R. M.

    1990-03-01

    The behavior of an analog neural network with parallel dynamics is studied analytically and numerically for two associative-memory learning algorithms, the Hebb rule and the pseudoinverse rule. Phase diagrams in the parameter space of analog gain β and storage ratio α are presented. For both learning rules, the networks have large ``recall'' phases in which retrieval states exist and convergence to a fixed point is guaranteed by a global stability criterion. We also demonstrate numerically that using a reduced analog gain increases the probability of recall starting from a random initial state. This phenomenon is comparable to thermal annealing used to escape local minima but has the advantage of being deterministic, and therefore easily implemented in electronic hardware. Similarities and differences between analog neural networks and networks with two-state neurons at finite temperature are also discussed.

  11. Comparison of static and dynamic resilience for a multipurpose reservoir operation

    Science.gov (United States)

    Simonovic, Slobodan P.; Arunkumar, R.

    2016-11-01

    Reliability, resilience, and vulnerability are the traditional risk measures used to assess the performance of a reservoir system. Among these measures, resilience is used to assess the ability of a reservoir system to recover from a failure event. However, the time-independent static resilience does not consider the system characteristics, interaction of various individual components and does not provide much insight into reservoir performance from the beginning of the failure event until the full performance recovery. Knowledge of dynamic reservoir behavior under the disturbance offers opportunities for proactive and/or reactive adaptive response that can be selected to maximize reservoir resilience. A novel measure is required to provide insight into the dynamics of reservoir performance based on the reservoir system characteristics and its adaptive capacity. The reservoir system characteristics include, among others, reservoir storage curve, reservoir inflow, reservoir outflow capacity, and reservoir operating rules. The reservoir adaptive capacity can be expressed using various impacts of reservoir performance under the disturbance (like reservoir release for meeting a particular demand, socioeconomic consequences of reservoir performance, or resulting environmental state of the river upstream and downstream from the reservoir). Another way of expressing reservoir adaptive capacity to a disturbing event may include aggregated measures like reservoir robustness, redundancy, resourcefulness, and rapidity. A novel measure that combines reservoir performance and its adaptive capacity is proposed in this paper and named "dynamic resilience." The paper also proposes a generic simulation methodology for quantifying reservoir resilience as a function of time. The proposed resilience measure is applied to a single multipurpose reservoir operation and tested for a set of failure scenarios. The dynamic behavior of reservoir resilience is captured using the system

  12. Water Storage: Quo Vadis?

    Science.gov (United States)

    Smakhtin, V.

    2017-12-01

    Humans stored water - in various forms - for ages, coping with water resources variability, and its extremes - floods and droughts. Storage per capita, and other storage-related indicators, have essentially become one way of reflecting the progress of economic development. Massive investments went into large surface water reservoirs that have become the characteristic feature of the earth's landscapes, bringing both benefits and controversy. As water variability progressively increases with changing climate, globally, on one hand, and the idea of sustainable development receives strong traction, on another - it may be worth the while to comprehensively examine current trends and future prospects for water storage development. The task is surely big, to say the least. The presentation will aim to initiate a structured discussion on this multi-facet issue and identify which aspects and trends of water storage development may be most important in the context of Sustainable Development Goals, Sendai Framework for Disaster Risk Reduction, Paris Agreement on Climate Change, and examine how, where and to what extent water storage planning can be improved. It will cover questions like i) aging of large water storage infrastructure, the current extent of this trend in various geographical regions, and possible impacts on water security and security of nations; ii) improved water storage development planning overall in the context of various water development alternatives and storage options themselves and well as their combinations iii) prospects for another "storage revolution" - speed increase in dam numbers, and where, if at all this is most likely iv) recent events in storage development, e.g. is dam decommissioning a trend that picks pace, or whether some developing economies in Asia can do without going through the period of water storage construction, with alternatives, or suggestions for alleviation of negative impacts v) the role of subsurface storage as an

  13. Detecting analogical resemblance without retrieving the source analogy.

    Science.gov (United States)

    Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

    2010-06-01

    We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory.

  14. Parallel reservoir simulator computations

    International Nuclear Information System (INIS)

    Hemanth-Kumar, K.; Young, L.C.

    1995-01-01

    The adaptation of a reservoir simulator for parallel computations is described. The simulator was originally designed for vector processors. It performs approximately 99% of its calculations in vector/parallel mode and relative to scalar calculations it achieves speedups of 65 and 81 for black oil and EOS simulations, respectively on the CRAY C-90

  15. unconventional natural gas reservoirs

    International Nuclear Information System (INIS)

    Correa G, Tomas F; Osorio, Nelson; Restrepo R, Dora P

    2009-01-01

    This work is an exploration about different unconventional gas reservoirs worldwide: coal bed methane, tight gas, shale gas and gas hydrate? describing aspects such as definition, reserves, production methods, environmental issues and economics. The overview also mentioned preliminary studies about these sources in Colombia.

  16. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  17. A Tool for Assessing Future Capacity Loss Due to Sedimentation in the United States' Reservoirs

    Science.gov (United States)

    Pinson, A. O.; Baker, B.; White, K. D.

    2017-12-01

    Federal reservoirs are critical components of the United States' water supply, flood risk management, hydropower and navigation infrastructure. These reservoirs included capacity for storage loss due to the deposition of sediment by inflowing streams in their original design. However, the actual rate of capacity loss experienced is controlled in part by climate, topography, soils, and land use/land cover, and may vary from the design. To assess the current and future vulnerability of its reservoirs to sedimentation. USACE has developed an online planning tool to identify USACE reservoirs where sedimentation is currently a problem (e.g., sedimentation rate exceeds design sedimentation rate, or zone losses disproportionately affect authorized purposes), and reservoirs where rates are expected to increase significantly in the future. The goal is to be able to prioritize operation and maintenance actions to minimize the effects of reservoir capacity loss on authorized purposes and help maximize reservoir use life.

  18. Design and modeling of reservoir operation strategies for sediment management

    NARCIS (Netherlands)

    Sloff, C.J.; Omer, A.Y.A.; Heynert, K.V.; Mohamed, Y.A.

    2015-01-01

    Appropriate operation strategies that allow for sediment flushing and sluicing (sediment routing) can reduce rapid storage losses of (hydropower and water-supply) reservoirs. In this study we have shown, using field observations and computational models, that the efficiency of these operations

  19. Reservoir system optimisation using a penalty approach and a multi ...

    African Journals Online (AJOL)

    ... IV obtained several high-performance solutions of varied sizes and supply capabilities. This analysis revealed specific limitations of supply reliability and the expected storage states of one of the reservoirs. The analysis also obtained the ranges within which the optimal monthly operating rules for the system are expected.

  20. Communication: Relaxation-limited electronic currents in extended reservoir simulations

    Science.gov (United States)

    Gruss, Daniel; Smolyanitsky, Alex; Zwolak, Michael

    2017-10-01

    Open-system approaches are gaining traction in the simulation of charge transport in nanoscale and molecular electronic devices. In particular, "extended reservoir" simulations, where explicit reservoir degrees of freedom are present, allow for the computation of both real-time and steady-state properties but require relaxation of the extended reservoirs. The strength of this relaxation, γ, influences the conductance, giving rise to a "turnover" behavior analogous to Kramers turnover in chemical reaction rates. We derive explicit, general expressions for the weak and strong relaxation limits. For weak relaxation, the conductance increases linearly with γ and every electronic state of the total explicit system contributes to the electronic current according to its "reduced" weight in the two extended reservoir regions. Essentially, this represents two conductors in series—one at each interface with the implicit reservoirs that provide the relaxation. For strong relaxation, a "dual" expression-one with the same functional form-results, except now proportional to 1/γ and dependent on the system of interest's electronic states, reflecting that the strong relaxation is localizing electrons in the extended reservoirs. Higher order behavior (e.g., γ2 or 1/γ2) can occur when there is a gap in the frequency spectrum. Moreover, inhomogeneity in the frequency spacing can give rise to a pseudo-plateau regime. These findings yield a physically motivated approach to diagnosing numerical simulations and understanding the influence of relaxation, and we examine their occurrence in both simple models and a realistic, fluctuating graphene nanoribbon.

  1. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  2. Geological model of supercritical geothermal reservoir related to subduction system

    Science.gov (United States)

    Tsuchiya, Noriyoshi

    2017-04-01

    Following the Great East Japan Earthquake and the accident at the Fukushima Daiichi Nuclear power station on 3.11 (11th March) 2011, geothermal energy came to be considered one of the most promising sources of renewable energy for the future in Japan. The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. Supercritical geothermal resources could be evaluated in terms of present volcanic activities, thermal structure, dimension of hydrothermal circulation, properties of fracture system, depth of heat source, depth of brittle factures zone, dimension of geothermal reservoir. On the basis of the GIS, potential of supercritical geothermal resources could be characterized into the following four categories. 1. Promising: surface manifestation d shallow high temperature, 2 Probability: high geothermal gradient, 3 Possibility: Aseismic zone which indicates an existence of melt, 4 Potential : low velocity zone which indicates magma input. Base on geophysical data for geothermal reservoirs, we have propose adequate tectonic model of development of the supercritical geothermal reservoirs. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550

  3. A dimension reduction method for flood compensation operation of multi-reservoir system

    Science.gov (United States)

    Jia, B.; Wu, S.; Fan, Z.

    2017-12-01

    Multiple reservoirs cooperation compensation operations coping with uncontrolled flood play vital role in real-time flood mitigation. This paper come up with a reservoir flood compensation operation index (ResFCOI), which formed by elements of flood control storage, flood inflow volume, flood transmission time and cooperation operations period, then establish a flood cooperation compensation operations model of multi-reservoir system, according to the ResFCOI to determine a computational order of each reservoir, and lastly the differential evolution algorithm is implemented for computing single reservoir flood compensation optimization in turn, so that a dimension reduction method is formed to reduce computational complexity. Shiguan River Basin with two large reservoirs and an extensive uncontrolled flood area, is used as a case study, results show that (a) reservoirs' flood discharges and the uncontrolled flood are superimposed at Jiangjiaji Station, while the formed flood peak flow is as small as possible; (b) cooperation compensation operations slightly increase in usage of flood storage capacity in reservoirs, when comparing to rule-based operations; (c) it takes 50 seconds in average when computing a cooperation compensation operations scheme. The dimension reduction method to guide flood compensation operations of multi-reservoir system, can make each reservoir adjust its flood discharge strategy dynamically according to the uncontrolled flood magnitude and pattern, so as to mitigate the downstream flood disaster.

  4. Energy Storage Systems

    Science.gov (United States)

    Elliott, David

    2017-07-01

    As renewable energy use expands there will be a need to develop ways to balance its variability. Storage is one of the options. Presently the main emphasis is for systems storing electrical power in advanced batteries (many of them derivatives of parallel developments in the electric vehicle field), as well as via liquid air storage, compressed air storage, super-capacitors and flywheels, and, the leader so far, pumped hydro reservoirs. In addition, new systems are emerging for hydrogen generation and storage, feeding fuel cell power production. Heat (and cold) is also a storage medium and some systems exploit thermal effects as part of wider energy management activity. Some of the more exotic ones even try to use gravity on a large scale. This short book looks at all the options, their potentials and their limits. There are no clear winners, with some being suited to short-term balancing and others to longer-term storage. The eventual mix adopted will be shaped by the pattern of development of other balancing measures, including smart-grid demand management and super-grid imports and exports.

  5. APPLICATION OF INTEGRATED RESERVOIR MANAGEMENT AND RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jack Bergeron; Tom Blasingame; Louis Doublet; Mohan Kelkar; George Freeman; Jeff Callard; David Moore; David Davies; Richard Vessell; Brian Pregger; Bill Dixon; Bryce Bezant

    2000-03-01

    Reservoir performance and characterization are vital parameters during the development phase of a project. Infill drilling of wells on a uniform spacing, without regard to characterization does not optimize development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, especially carbonate reservoirs. These reservoirs are typically characterized by: (1) large, discontinuous pay intervals; (2) vertical and lateral changes in reservoir properties; (3) low reservoir energy; (4) high residual oil saturation; and (5) low recovery efficiency. The operational problems they encounter in these types of reservoirs include: (1) poor or inadequate completions and stimulations; (2) early water breakthrough; (3) poor reservoir sweep efficiency in contacting oil throughout the reservoir as well as in the nearby well regions; (4) channeling of injected fluids due to preferential fracturing caused by excessive injection rates; and (5) limited data availability and poor data quality. Infill drilling operations only need target areas of the reservoir which will be economically successful. If the most productive areas of a reservoir can be accurately identified by combining the results of geological, petrophysical, reservoir performance, and pressure transient analyses, then this ''integrated'' approach can be used to optimize reservoir performance during secondary and tertiary recovery operations without resorting to ''blanket'' infill drilling methods. New and emerging technologies such as geostatistical modeling, rock typing, and rigorous decline type curve analysis can be used to quantify reservoir quality and the degree of interwell communication. These results can then be used to develop a 3-D simulation model for prediction of infill locations. The application of reservoir surveillance techniques to identify additional reservoir ''pay'' zones

  6. Energy R and D. Geothermal energy and underground reservoirs; R et D energie. Geothermie et reservoirs souterrains

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Geothermal energy appears as a viable economic alternative among the different renewable energy sources. The French bureau of geological and mining researches (BRGM) is involved in several research and development programs in the domain of geothermal energy and underground reservoirs. This document presents the content of 5 programs: the deep hot dry rock system of Soultz-sous-Forets (construction and testing of the scientific pilot, modeling of the reservoir structure), the development of low and high enthalpy geothermal energy in the French West Indies, the comparison of the geothermal development success of Bouillante (Guadeloupe, French West Indies) with the check of the geothermal development of Nyssiros (Greece) and Pantelleria (Italy), the development of the high enthalpy geothermal potentialities of Reunion Island, and the underground storage of CO{sub 2} emissions in geologic formations (deep aquifers, geothermal reservoirs, abandoned mines or oil reservoirs). (J.S.)

  7. Children's Development of Analogical Reasoning: Insights from Scene Analogy Problems

    Science.gov (United States)

    Richland, Lindsey E.; Morrison, Robert G.; Holyoak, Keith J.

    2006-01-01

    We explored how relational complexity and featural distraction, as varied in scene analogy problems, affect children's analogical reasoning performance. Results with 3- and 4-year-olds, 6- and 7-year-olds, 9- to 11-year-olds, and 13- and 14-year-olds indicate that when children can identify the critical structural relations in a scene analogy…

  8. Biomedical sensor design using analog compressed sensing

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.

  9. Device and methods for writing and erasing analog information in small memory units via voltage pulses

    Science.gov (United States)

    El Gabaly Marquez, Farid; Talin, Albert Alec

    2018-04-17

    Devices and methods for non-volatile analog data storage are described herein. In an exemplary embodiment, an analog memory device comprises a potential-carrier source layer, a barrier layer deposited on the source layer, and at least two storage layers deposited on the barrier layer. The memory device can be prepared to write and read data via application of a biasing voltage between the source layer and the storage layers, wherein the biasing voltage causes potential-carriers to migrate into the storage layers. After initialization, data can be written to the memory device by application of a voltage pulse between two storage layers that causes potential-carriers to migrate from one storage layer to another. A difference in concentration of potential carriers caused by migration of potential-carriers between the storage layers results in a voltage that can be measured in order to read the written data.

  10. Characterization of oil and gas reservoir heterogeneity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, N.; Barton, M.D.; Bebout, D.G.; Fisher, R.S.; Grigsby, J.D.; Guevara, E.; Holtz, M.; Kerans, C.; Nance, H.S.; Levey, R.A.

    1992-10-01

    Research described In this report addresses the internal architecture of two specific reservoir types: restricted-platform carbonates and fluvial-deltaic sandstones. Together, these two reservoir types contain more than two-thirds of the unrecovered mobile oil remaining ill Texas. The approach followed in this study was to develop a strong understanding of the styles of heterogeneity of these reservoir types based on a detailed outcrop description and a translation of these findings into optimized recovery strategies in select subsurface analogs. Research targeted Grayburg Formation restricted-platform carbonate outcrops along the Algerita Escarpment and In Stone Canyon In southeastern New Mexico and Ferron deltaic sandstones in central Utah as analogs for the North Foster (Grayburg) and Lake Creek (Wilcox) units, respectively. In both settings, sequence-stratigraphic style profoundly influenced between-well architectural fabric and permeability structure. It is concluded that reservoirs of different depositional origins can therefore be categorized Into a ``heterogeneity matrix`` based on varying intensity of vertical and lateral heterogeneity. The utility of the matrix is that it allows prediction of the nature and location of remaining mobile oil. Highly stratified reservoirs such as the Grayburg, for example, will contain a large proportion of vertically bypassed oil; thus, an appropriate recovery strategy will be waterflood optimization and profile modification. Laterally heterogeneous reservoirs such as deltaic distributary systems would benefit from targeted infill drilling (possibly with horizontal wells) and improved areal sweep efficiency. Potential for advanced recovery of remaining mobile oil through heterogeneity-based advanced secondary recovery strategies In Texas is projected to be an Incremental 16 Bbbl. In the Lower 48 States this target may be as much as 45 Bbbl at low to moderate oil prices over the near- to mid-term.

  11. Chalk as a reservoir

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke

    , and the best reservoir properties are typically found in mudstone intervals. Chalk mudstones vary a lot though. The best mudstones are purely calcitic, well sorted and may have been redeposited by traction currents. Other mudstones are rich in very fine grained silica, which takes up pore space and thus...... basin, so stylolite formation in the chalk is controlled by effective burial stress. The stylolites are zones of calcite dissolution and probably are the source of calcite for porefilling cementation which is typical in water zone chalk and also affect the reservoirs to different extent. The relatively...... have hardly any stylolites and can have porosity above 40% or even 50% and thus also have relatively high permeability. Such intervals have the problem though, that increasing effective stress caused by hydrocarbon production results in mechanical compaction and overall subsidence. Most other chalk...

  12. Optical analog transmission device

    International Nuclear Information System (INIS)

    Ikawa, Shinji.

    1994-01-01

    The present invention concerns a device such as electro-optical conversion elements, optoelectric-electric elements and optical transmission channel, not undergoing deleterious effects on the efficiency of conversion and transmission due to temperature, and aging change. That is, a sine wave superposing means superposes, on a detector signal to be transmitted, a sine-wave signal having a predetermined amplitude and at a frequency lower than that of the detector signal. An optoelectric conversion means converts the electric signal as the signal of the sine-wave signal superposing means into an optical signal and outputs the same to an optical transmitting channel. The optoelectric conversion means converts the transmitted signal to an electric signal. A discriminating means discriminates the electric signal into a detector signal and a sine-wave signal. A calculating means calculates an optical transmitting efficiency of the transmitting channel based on the amplitude of the discriminated sine-wave signal. A processing means compensates an amplitude value of the detector signals discriminated by the discriminating means based on the optical transmission efficiency. As a result, an optical analog transmission device can be attained, which conducts optical transmission at a high accuracy without undergoing the defective effects of the optical transmission efficiency. (I.S.)

  13. Modular reservoir concept for MEMS-based transdermal drug delivery systems

    International Nuclear Information System (INIS)

    Cantwell, Cara T; Wei, Pinghung; Ziaie, Babak; Rao, Masaru P

    2014-01-01

    While MEMS-based transdermal drug delivery device development efforts have typically focused on tightly-integrated solutions, we propose an alternate conception based upon a novel, modular drug reservoir approach. By decoupling the drug storage functionality from the rest of the delivery system, this approach seeks to minimize cold chain storage volume, enhance compatibility with conventional pharmaceutical practices, and allow independent optimization of reservoir device design, materials, and fabrication. Herein, we report the design, fabrication, and preliminary characterization of modular reservoirs that demonstrate the virtue of this approach within the application context of transdermal insulin administration for diabetes management. (technical note)

  14. Modular reservoir concept for MEMS-based transdermal drug delivery systems

    Science.gov (United States)

    Cantwell, Cara T.; Wei, Pinghung; Ziaie, Babak; Rao, Masaru P.

    2014-11-01

    While MEMS-based transdermal drug delivery device development efforts have typically focused on tightly-integrated solutions, we propose an alternate conception based upon a novel, modular drug reservoir approach. By decoupling the drug storage functionality from the rest of the delivery system, this approach seeks to minimize cold chain storage volume, enhance compatibility with conventional pharmaceutical practices, and allow independent optimization of reservoir device design, materials, and fabrication. Herein, we report the design, fabrication, and preliminary characterization of modular reservoirs that demonstrate the virtue of this approach within the application context of transdermal insulin administration for diabetes management.

  15. Work reservoirs in thermodynamics

    International Nuclear Information System (INIS)

    Anacleto, Joaquim

    2010-01-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  16. Work reservoirs in thermodynamics

    Science.gov (United States)

    Anacleto, Joaquim

    2010-05-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  17. Conjecturing via Reconceived Classical Analogy

    Science.gov (United States)

    Lee, Kyeong-Hwa; Sriraman, Bharath

    2011-01-01

    Analogical reasoning is believed to be an efficient means of problem solving and construction of knowledge during the search for and the analysis of new mathematical objects. However, there is growing concern that despite everyday usage, learners are unable to transfer analogical reasoning to learning situations. This study aims at facilitating…

  18. Musik som analogi og metafor

    DEFF Research Database (Denmark)

    Bonde, Lars Ole

    2014-01-01

    Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser......Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser...

  19. Drawing Analogies in Environmental Education

    Science.gov (United States)

    Affifi, Ramsey

    2014-01-01

    Reconsidering the origin, process, and outcomes of analogy-making suggests practices for environmental educators who strive to disengage humans from the isolating illusions of dichotomizing frameworks. We can view analogies as outcomes of developmental processes within which human subjectivity is but an element, threading our sense of self back…

  20. A Statistical Graphical Model of the California Reservoir System

    Science.gov (United States)

    Taeb, A.; Reager, J. T.; Turmon, M.; Chandrasekaran, V.

    2017-11-01

    The recent California drought has highlighted the potential vulnerability of the state's water management infrastructure to multiyear dry intervals. Due to the high complexity of the network, dynamic storage changes in California reservoirs on a state-wide scale have previously been difficult to model using either traditional statistical or physical approaches. Indeed, although there is a significant line of research on exploring models for single (or a small number of) reservoirs, these approaches are not amenable to a system-wide modeling of the California reservoir network due to the spatial and hydrological heterogeneities of the system. In this work, we develop a state-wide statistical graphical model to characterize the dependencies among a collection of 55 major California reservoirs across the state; this model is defined with respect to a graph in which the nodes index reservoirs and the edges specify the relationships or dependencies between reservoirs. We obtain and validate this model in a data-driven manner based on reservoir volumes over the period 2003-2016. A key feature of our framework is a quantification of the effects of external phenomena that influence the entire reservoir network. We further characterize the degree to which physical factors (e.g., state-wide Palmer Drought Severity Index (PDSI), average temperature, snow pack) and economic factors (e.g., consumer price index, number of agricultural workers) explain these external influences. As a consequence of this analysis, we obtain a system-wide health diagnosis of the reservoir network as a function of PDSI.

  1. Advantageous Reservoir Characterization Technology in Extra Low Permeability Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yutian Luo

    2017-01-01

    Full Text Available This paper took extra low permeability reservoirs in Dagang Liujianfang Oilfield as an example and analyzed different types of microscopic pore structures by SEM, casting thin sections fluorescence microscope, and so on. With adoption of rate-controlled mercury penetration, NMR, and some other advanced techniques, based on evaluation parameters, namely, throat radius, volume percentage of mobile fluid, start-up pressure gradient, and clay content, the classification and assessment method of extra low permeability reservoirs was improved and the parameter boundaries of the advantageous reservoirs were established. The physical properties of reservoirs with different depth are different. Clay mineral variation range is 7.0%, and throat radius variation range is 1.81 μm, and start pressure gradient range is 0.23 MPa/m, and movable fluid percentage change range is 17.4%. The class IV reservoirs account for 9.56%, class II reservoirs account for 12.16%, and class III reservoirs account for 78.29%. According to the comparison of different development methods, class II reservoir is most suitable for waterflooding development, and class IV reservoir is most suitable for gas injection development. Taking into account the gas injection in the upper section of the reservoir, the next section of water injection development will achieve the best results.

  2. Electricity Storage. Technology Brief

    Energy Technology Data Exchange (ETDEWEB)

    Simbolotti, G. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development ENEA, Rome (Italy); Kempener, R. [International Renewable Energy Agency IRENA, Bonn (Germany)

    2012-04-15

    Electricity storage is a key technology for electricity systems with a high share of renewables as it allows electricity to be generated when renewable sources (i.e. wind, sunlight) are available and to be consumed on demand. It is expected that the increasing price of fossil fuels and peak-load electricity and the growing share of renewables will result in electricity storage to grow rapidly and become more cost effective. However, electricity storage is technically challenging because electricity can only be stored after conversion into other forms of energy, and this involves expensive equipment and energy losses. At present, the only commercial storage option is pumped hydro power where surplus electricity (e.g. electricity produced overnight by base-load coal or nuclear power) is used to pump water from a lower to an upper reservoir. The stored energy is then used to produce hydropower during daily high-demand periods. Pumped hydro plants are large-scale storage systems with a typical efficiency between 70% and 80%, which means that a quarter of the energy is lost in the process. Other storage technologies with different characteristics (i.e. storage process and capacity, conversion back to electricity and response to power demand, energy losses and costs) are currently in demonstration or pre-commercial stages and discussed in this brief report: Compressed air energy storage (CAES) systems, Flywheels; Electrical batteries; Supercapacitors; Superconducting magnetic storage; and Thermal energy storage. No single electricity storage technology scores high in all dimensions. The technology of choice often depends on the size of the system, the specific service, the electricity sources and the marginal cost of peak electricity. Pumped hydro currently accounts for 95% of the global storage capacity and still offers a considerable expansion potential but does not suit residential or small-size applications. CAES expansion is limited due to the lack of suitable

  3. Fast event recorder utilizing a CCD analog shift register

    International Nuclear Information System (INIS)

    Ducar, R.J.; McIntyre, P.M.

    1978-01-01

    A system of electronics has been developed to allow the capture and recording of relatively fast, low-amplitude analog events. The heart of the system is a dual 455-cell analog shift register charge-coupled device, Fairchild CCD321ADC-3. The CCD is operated in a dual clock mode. The input is sampled at a selectable clock rate of .25-20 MHz. The stored analog data is then clocked out at a slower rate, typically about .25 MHz. The time base expansion of the analog data allows for analog-to-digital conversion and memory storage using conventional medium-speed devices. The digital data is sequentially loaded into a static RAM and may then be block transferred to a computer. The analog electronics are housed in a single-width NIM module, and the RAM memory in a single-width CAMAC module. Each pair of modules provides six parallel channels. Cost is about $200.00 per channel. Applications are described for ionization imaging (TPC, IRC) and long-drift calorimetry in liquid argon

  4. Electrokinetic and Poroelastic Characterization of Porous Media : Application to CO2 storage monitoring

    NARCIS (Netherlands)

    Kirichek, O.J.

    2018-01-01

    Monitoring the properties of a CO2 storage reservoir is important for two main reasons: firstly, to verify that the injected CO2 is safely contained in the reservoir rock as planned, and secondly, to provide data which can be used to update the existing reservoir models and support eventual

  5. Tritium storage

    International Nuclear Information System (INIS)

    Hircq, B.

    1990-01-01

    This document represents a synthesis relative to tritium storage. After indicating the main storage particularities as regards tritium, storages under gaseous and solid form are after examined before establishing choices as a function of the main criteria. Finally, tritium storage is discussed regarding tritium devices associated to Fusion Reactors and regarding smaller devices [fr

  6. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  7. Analog fourier transform channelizer and OFDM receiver

    OpenAIRE

    2007-01-01

    An OFDM receiver having an analog multiplier based I-Q channelizing filter, samples and holds consecutive analog I-Q samples of an I-Q baseband, the I-Q basebands having OFDM sub-channels. A lattice of analog I-Q multipliers and analog I-Q summers concurrently receives the held analog I-Q samples, performs analog I-Q multiplications and analog I-Q additions to concurrently generate a plurality of analog I-Q output signals, representing an N-point discrete Fourier transform of the held analog ...

  8. Molecular modeling of fentanyl analogs

    Directory of Open Access Journals (Sweden)

    LJILJANA DOSEN-MICOVIC

    2004-11-01

    Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

  9. Gemini analogs of vitamin D.

    Science.gov (United States)

    Pazos, Gonzalo; Rivadulla, Marcos L; Pérez-García, Xenxo; Gandara, Zoila; Pérez, Manuel

    2014-01-01

    The Gemini analogs are the last significant contribution to the family of vitamin D derivatives in medicine, for the treatment of cancer. The first Gemini analog was characterized by two symmetric side chains at C-20. Following numerous modifications, the most active analog bears a C-23-triple bond, C-26, 27- hexafluoro substituents on one side chain and a terminal trideuteromethylhydroxy group on the other side chain. This progression was possible due to improvements in the synthetic methods for the preparation of these derivatives, which allowed for increasing molecular complexity and complete diastereoselective control at C-20 and the substituted sidechains.

  10. Three-dimensional multiphase effects in aquifer gas storage

    Energy Technology Data Exchange (ETDEWEB)

    Witherspoon, P.A.; Fuller, P.; Finsterle, S. [Lawrence Berkeley Laboratory, Berkeley, CA (United States)

    1995-03-01

    The underground storage of natural gas in the United States is one of the most widespread methods of storing energy in the United States. There are two main kinds of storage: (a) dry gas fields, and (b) aquifer storage fields. The storage of gas in dry gas fields involves the conversion of petroleum bearing reservoirs, usually after they have been depleted of any economic production, into a storage operation. An appropriate number of injection-withdrawal (I-W) wells are either drilled or converted from existing exploitation wells, and the storage operations begin by injecting gas to build up to some desired volume of gas in storage.

  11. Advances in photonic reservoir computing

    Science.gov (United States)

    Van der Sande, Guy; Brunner, Daniel; Soriano, Miguel C.

    2017-05-01

    We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir's complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  12. Encapsulated microsensors for reservoir interrogation

    Science.gov (United States)

    Scott, Eddie Elmer; Aines, Roger D.; Spadaccini, Christopher M.

    2016-03-08

    In one general embodiment, a system includes at least one microsensor configured to detect one or more conditions of a fluidic medium of a reservoir; and a receptacle, wherein the receptacle encapsulates the at least one microsensor. In another general embodiment, a method include injecting the encapsulated at least one microsensor as recited above into a fluidic medium of a reservoir; and detecting one or more conditions of the fluidic medium of the reservoir.

  13. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  14. Analog elements for transuranic chemistries

    International Nuclear Information System (INIS)

    Weimer, W.C.

    1982-01-01

    The analytical technique for measuring trace concentrations of the analog rare earth elements has been refined for optimal detection. The technique has been used to determine the rare earth concentrations in a series of geological and biological materials, including samples harvested from controlled lysimeter investigations. These studies have demonstrated that any of the trivalent rare earth elements may be used as analog elements for the trivalent transuranics, americium and curium

  15. CMOS Analog IC Design: Fundamentals

    OpenAIRE

    Bruun, Erik

    2018-01-01

    This book is intended for use as the main textbook for an introductory course in CMOS analog integrated circuit design. It is aimed at electronics engineering students who have followed basic courses in mathematics, physics, circuit theory, electronics and signal processing. It takes the students directly from a basic level to a level where they can start working on simple analog IC design projects or continue their studies using more advanced textbooks in the field. A distinct feature of thi...

  16. All-optical reservoir computing.

    Science.gov (United States)

    Duport, François; Schneider, Bendix; Smerieri, Anteo; Haelterman, Marc; Massar, Serge

    2012-09-24

    Reservoir Computing is a novel computing paradigm that uses a nonlinear recurrent dynamical system to carry out information processing. Recent electronic and optoelectronic Reservoir Computers based on an architecture with a single nonlinear node and a delay loop have shown performance on standardized tasks comparable to state-of-the-art digital implementations. Here we report an all-optical implementation of a Reservoir Computer, made of off-the-shelf components for optical telecommunications. It uses the saturation of a semiconductor optical amplifier as nonlinearity. The present work shows that, within the Reservoir Computing paradigm, all-optical computing with state-of-the-art performance is possible.

  17. Analogical proportions: another logical view

    Science.gov (United States)

    Prade, Henri; Richard, Gilles

    This paper investigates the logical formalization of a restricted form of analogical reasoning based on analogical proportions, i.e. statements of the form a is to b as c is to d. Starting from a naive set theoretic interpretation, we highlight the existence of two noticeable companion proportions: one states that a is to b the converse of what c is to d (reverse analogy), while the other called paralogical proportion expresses that what a and b have in common, c and d have it also. We identify the characteristic postulates of the three types of proportions and examine their consequences from an abstract viewpoint. We further study the properties of the set theoretic interpretation and of the Boolean logic interpretation, and we provide another light on the understanding of the role of permutations in the modeling of the three types of proportions. Finally, we address the use of these proportions as a basis for inference in a propositional setting, and relate it to more general schemes of analogical reasoning. The differences between analogy, reverse-analogy, and paralogy is still emphasized in a three-valued setting, which is also briefly presented.

  18. Geologic CO2 Sequestration: Predicting and Confirming Performance in Oil Reservoirs and Saline Aquifers

    Science.gov (United States)

    Johnson, J. W.; Nitao, J. J.; Newmark, R. L.; Kirkendall, B. A.; Nimz, G. J.; Knauss, K. G.; Ziagos, J. P.

    2002-05-01

    Reducing anthropogenic CO2 emissions ranks high among the grand scientific challenges of this century. In the near-term, significant reductions can only be achieved through innovative sequestration strategies that prevent atmospheric release of large-scale CO2 waste streams. Among such strategies, injection into confined geologic formations represents arguably the most promising alternative; and among potential geologic storage sites, oil reservoirs and saline aquifers represent the most attractive targets. Oil reservoirs offer a unique "win-win" approach because CO2 flooding is an effective technique of enhanced oil recovery (EOR), while saline aquifers offer immense storage capacity and widespread distribution. Although CO2-flood EOR has been widely used in the Permian Basin and elsewhere since the 1980s, the oil industry has just recently become concerned with the significant fraction of injected CO2 that eludes recycling and is therefore sequestered. This "lost" CO2 now has potential economic value in the growing emissions credit market; hence, the industry's emerging interest in recasting CO2 floods as co-optimized EOR/sequestration projects. The world's first saline aquifer storage project was also catalyzed in part by economics: Norway's newly imposed atmospheric emissions tax, which spurred development of Statoil's unique North Sea Sleipner facility in 1996. Successful implementation of geologic sequestration projects hinges on development of advanced predictive models and a diverse set of remote sensing, in situ sampling, and experimental techniques. The models are needed to design and forecast long-term sequestration performance; the monitoring techniques are required to confirm and refine model predictions and to ensure compliance with environmental regulations. We have developed a unique reactive transport modeling capability for predicting sequestration performance in saline aquifers, and used it to simulate CO2 injection at Sleipner; we are now

  19. Understanding satellite-based monthly-to-seasonal reservoir outflow estimation as a function of hydrologic controls

    Science.gov (United States)

    Bonnema, Matthew; Sikder, Safat; Miao, Yabin; Chen, Xiaodong; Hossain, Faisal; Ara Pervin, Ismat; Mahbubur Rahman, S. M.; Lee, Hyongki

    2016-05-01

    Growing population and increased demand for water is causing an increase in dam and reservoir construction in developing nations. When rivers cross international boundaries, the downstream stakeholders often have little knowledge of upstream reservoir operation practices. Satellite remote sensing in the form of radar altimetry and multisensor precipitation products can be used as a practical way to provide downstream stakeholders with the fundamentally elusive upstream information on reservoir outflow needed to make important and proactive water management decisions. This study uses a mass balance approach of three hydrologic controls to estimate reservoir outflow from satellite data at monthly and annual time scales: precipitation-induced inflow, evaporation, and reservoir storage change. Furthermore, this study explores the importance of each of these hydrologic controls to the accuracy of outflow estimation. The hydrologic controls found to be unimportant could potentially be neglected from similar future studies. Two reservoirs were examined in contrasting regions of the world, the Hungry Horse Reservoir in a mountainous region in northwest U.S. and the Kaptai Reservoir in a low-lying, forested region of Bangladesh. It was found that this mass balance method estimated the annual outflow of both reservoirs with reasonable skill. The estimation of monthly outflow from both reservoirs was however less accurate. The Kaptai basin exhibited a shift in basin behavior resulting in variable accuracy across the 9 year study period. Monthly outflow estimation from Hungry Horse Reservoir was compounded by snow accumulation and melt processes, reflected by relatively low accuracy in summer and fall, when snow processes control runoff. Furthermore, it was found that the important hydrologic controls for reservoir outflow estimation at the monthly time scale differs between the two reservoirs, with precipitation-induced inflow being the most important control for the Kaptai

  20. Cesium reservoir and interconnective components

    International Nuclear Information System (INIS)

    1994-03-01

    The program objective is to demonstrate the technology readiness of a TFE (thermionic fuel element) suitable for use as the basic element in a thermionic reactor with electric power output in the 0.5 to 5.0 MW range. A thermionic converter must be supplied with cesium vapor for two reasons. Cesium atoms adsorbed on the surface of the emitter cause a reduction of the emitter work function to permit high current densities without excessive heating of the emitter. The second purpose of the cesium vapor is to provide space-charge neutralization in the emitter-collector gap so that the high current densities may flow across the gap unattenuated. The function of the cesium reservoir is to provide a source of cesium atoms, and to provide a reserve in the event that cesium is lost from the plasma by any mechanism. This can be done with a liquid cesium metal reservoir in which case it is heated to the desired temperature with auxiliary heaters. In a TFE, however, it is desirable to have the reservoir passively heated by the nuclear fuel. In this case, the reservoir must operate at a temperature intermediate between the emitter and the collector, ruling out the use of liquid reservoirs. Integral reservoirs contained within the TFE will produce cesium vapor pressures in the desired range at typical electrode temperatures. The reservoir material that appears to be the best able to meet requirements is graphite. Cesium intercalates easily into graphite, and the cesium pressure is insensitive to loading for a given intercalation stage. The goals of the cesium reservoir test program were to verify the performance of Cs-graphite reservoirs in the temperature-pressure range of interest to TFE operation, and to test the operation of these reservoirs after exposure to a fast neutron fluence corresponding to seven year mission lifetime. In addition, other materials were evaluated for possible use in the integral reservoir

  1. Williston Reservoir: Site preparation and post-flood cleanup

    International Nuclear Information System (INIS)

    Loose, J.A.

    1990-01-01

    Williston Reservoir is the second largest in Canada and ranks ninth on the world scale. It was formed by the construction of the W.A.C. Bennet Dam and is the most important hydroelectric storage reservoir and largest body of fresh water in British Columbia. Site preparation for the reservoir began in 1962, with pre-flood clearing involving salvage of merchantable timber, handfalling, machine downing, burning of slash and burial. Post-flood cleanup included timber salvage, bailing and burning debris, tractor piling and burning, crane piling in shallows, underwater cutting, and hand cutting during low drawdown. Various types of floating debris have presented problems for recreational use, log booming and transport, waterways and aviation. Protection of the spillway is accomplished with a floating boom upstream of the channel. Administration, funding, forest clearance, salvage methods, clearing standards, wood volumes, project costs, environmental concerns, and future priorities are discussed. 5 figs., 2 tabs

  2. Energy storage

    Science.gov (United States)

    Kaier, U.

    1981-04-01

    Developments in the area of energy storage are characterized, with respect to theory and laboratory, by an emergence of novel concepts and technologies for storing electric energy and heat. However, there are no new commercial devices on the market. New storage batteries as basis for a wider introduction of electric cars, and latent heat storage devices, as an aid for solar technology applications, with satisfactory performance standards are not yet commercially available. Devices for the intermediate storage of electric energy for solar electric-energy systems, and for satisfying peak-load current demands in the case of public utility companies are considered. In spite of many promising novel developments, there is yet no practical alternative to the lead-acid storage battery. Attention is given to central heat storage for systems transporting heat energy, small-scale heat storage installations, and large-scale technical energy-storage systems.

  3. Producing and Recognizing Analogical Relations

    Science.gov (United States)

    Lipkens, Regina; Hayes, Steven C

    2009-01-01

    Analogical reasoning is an important component of intelligent behavior, and a key test of any approach to human language and cognition. Only a limited amount of empirical work has been conducted from a behavior analytic point of view, most of that within Relational Frame Theory (RFT), which views analogy as a matter of deriving relations among relations. The present series of four studies expands previous work by exploring the applicability of this model of analogy to topography-based rather than merely selection-based responses and by extending the work into additional relations, including nonsymmetrical ones. In each of the four studies participants pretrained in contextual control over nonarbitrary stimulus relations of sameness and opposition, or of sameness, smaller than, and larger than, learned arbitrary stimulus relations in the presence of these relational cues and derived analogies involving directly trained relations and derived relations of mutual and combinatorial entailment, measured using a variety of productive and selection-based measures. In Experiment 1 participants successfully recognized analogies among stimulus networks containing same and opposite relations; in Experiment 2 analogy was successfully used to extend derived relations to pairs of novel stimuli; in Experiment 3 the procedure used in Experiment 1 was extended to nonsymmetrical comparative relations; in Experiment 4 the procedure used in Experiment 2 was extended to nonsymmetrical comparative relations. Although not every participant showed the effects predicted, overall the procedures occasioned relational responses consistent with an RFT account that have not yet been demonstrated in a behavior-analytic laboratory setting, including productive responding on the basis of analogies. PMID:19230515

  4. Reservoir engineering and hydrogeology

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Summaries are included which show advances in the following areas: fractured porous media, flow in single fractures or networks of fractures, hydrothermal flow, hydromechanical effects, hydrochemical processes, unsaturated-saturated systems, and multiphase multicomponent flows. The main thrust of these efforts is to understand the movement of mass and energy through rocks. This has involved treating fracture rock masses in which the flow phenomena within both the fractures and the matrix must be investigated. Studies also address the complex coupling between aspects of thermal, hydraulic, and mechanical processes associated with a nuclear waste repository in a fractured rock medium. In all these projects, both numerical modeling and simulation, as well as field studies, were employed. In the theoretical area, a basic understanding of multiphase flow, nonisothermal unsaturated behavior, and new numerical methods have been developed. The field work has involved reservoir testing, data analysis, and case histories at a number of geothermal projects

  5. FRACTURED PETROLEUM RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    1999-06-11

    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

  6. Reservoir sedimentation; a literature survey

    NARCIS (Netherlands)

    Sloff, C.J.

    1991-01-01

    A survey of literature is made on reservoir sedimentation, one of the most threatening processes for world-wide reservoir performance. The sedimentation processes, their impacts, and their controlling factors are assessed from a hydraulic engineering point of view with special emphasis on

  7. Advances in photonic reservoir computing

    Directory of Open Access Journals (Sweden)

    Van der Sande Guy

    2017-05-01

    Full Text Available We review a novel paradigm that has emerged in analogue neuromorphic optical computing. The goal is to implement a reservoir computer in optics, where information is encoded in the intensity and phase of the optical field. Reservoir computing is a bio-inspired approach especially suited for processing time-dependent information. The reservoir’s complex and high-dimensional transient response to the input signal is capable of universal computation. The reservoir does not need to be trained, which makes it very well suited for optics. As such, much of the promise of photonic reservoirs lies in their minimal hardware requirements, a tremendous advantage over other hardware-intensive neural network models. We review the two main approaches to optical reservoir computing: networks implemented with multiple discrete optical nodes and the continuous system of a single nonlinear device coupled to delayed feedback.

  8. Flood moderation by large reservoirs in the humid tropics of Western ghat region of Kerala, India

    Energy Technology Data Exchange (ETDEWEB)

    Abe, George [Centre for Water Resources Development and Management, Sub Centre, Kottayam South P.O, Kottayam-686 039, Kerala (India); James, E.J. [Water Institute and Dean (Research), Karunya University, Coimbatore-641 114, Tamil Nadu (India)

    2013-07-01

    Kerala State located in the humid tropics receives an average rainfall of 2810 mm. On an average 85% of this rainfall is received during the two monsoons spread from June to November. Midland and lowland regions of several of the river basins of Kerala experience severe flood events during the monsoons. Idamalayar hydro-electric project (1987) in Periyar River basin envisages flood control apart from power generation. This paper analyzes the flood moderation by Idamalayar reservoir considering the storage regime (inflow and outflow) which is subjected to a strong inter annual variability. The role of Idamalayar reservoir in controlling the monsoon floods is analyzed using daily data (1987-2010). The results of analysis show that the flood moderation by the reservoir is 92% when water storage is less than 50%. The reduction is 87% when reservoir storage is between 50 to 90% and moderation reduces to 62% when the reservoir storage is above 90%. Non-parametric trend analysis of fifty years of hydrologic data shows a reducing trend in inflow and storage during south-west monsoon which reduced spill and subsequent flood events during north-east monsoon.

  9. Fishery management problems and possibilities on large southeastern reservoirs

    Science.gov (United States)

    Parsons, John W.

    1958-01-01

    Principal problems concerning the fisheries of large reservoirs in the Southeast are: inefficient and highly selective exploitation of fish stocks, and protection and reclamation of damaged or threatened fisheries in tailwaters and tributary streams. Seven mainstream reservoirs on which data are available support an average angling pressure of 4.9 trips per acre per year and an average catch of 16 pounds of sport fish and 6 pounds of food fish. Commercial take is 7 pounds per acre. The rate of catch of sport fish, based upon tag returns, is only 3 percent. Sixteen storage reservoirs support an average angling pressure of 5.0 trips per acre per year and an average catch of 13 pounds of sport fish and 1 pound of food fish. Commercial catch is of no significance. Average rate of catch of sport fish is 17 percent of the catchable population. Fish population studies indicate that there are twice as many sport fish and four times as many food fish in mainstream than there are in storage reservoirs.

  10. A global water supply reservoir yield model with uncertainty analysis

    International Nuclear Information System (INIS)

    Kuria, Faith W; Vogel, Richard M

    2014-01-01

    Understanding the reliability and uncertainty associated with water supply yields derived from surface water reservoirs is central for planning purposes. Using a global dataset of monthly river discharge, we introduce a generalized model for estimating the mean and variance of water supply yield, Y, expected from a reservoir for a prespecified reliability, R, and storage capacity, S assuming a flow record of length n. The generalized storage–reliability–yield (SRY) relationships reported here have numerous water resource applications ranging from preliminary water supply investigations, to economic and climate change impact assessments. An example indicates how our generalized SRY relationship can be combined with a hydroclimatic model to determine the impact of climate change on surface reservoir water supply yields. We also document that the variability of estimates of water supply yield are invariant to characteristics of the reservoir system, including its storage capacity and reliability. Standardized metrics of the variability of water supply yields are shown to depend only on the sample size of the inflows and the statistical characteristics of the inflow series. (paper)

  11. Energy storage: a review of recent literature

    International Nuclear Information System (INIS)

    Tatone, O.S.

    1981-12-01

    Recent literature on the technological and economic status of reversible energy storage has been reviewed. A broad range of research and development activities have been pursued between 1975 and the present. Most of this work has concentrated on improving technical and economic performance of previously known storage technologies. Hydraulic pumped storage with both reservoirs above ground and compressed air storage (1 plant) are the only methods that have been adopted by electric utilities. The need for electrical energy storage in Canada has not been acute because of the large proportion of hydraulic generation which incorporates some storge and, in most cases, can readily be used for load-following. Residential heat storage in ceramic room heaters has been used in Europe for several years. For Canadian climatic and market conditions larger, central heating units would be required. Residential heat storage depends upon utilities offering time-of-use rates and none in Canada do so at present. Most seasonal storage concepts depend upon storage of low-grade heat for district heating. The cost of energy storage is highly dependent upon annual energy throughput and hence favours smaller capacity systems operating on frequent charge/discharge cycles over long-term storage. Capital costs of energy storage methods from the literature, expressed in constant dollars, are compared graphically and tentative investment costs are presented for several storage methods

  12. Modeling of Turbidity Variation in Two Reservoirs Connected by a Water Transfer Tunnel in South Korea

    Directory of Open Access Journals (Sweden)

    Jae Chung Park

    2017-06-01

    Full Text Available The Andong and Imha reservoirs in South Korea are connected by a water transfer tunnel. The turbidity of the Imha reservoir is much higher than that of the Andong reservoir. Thus, it is necessary to examine the movement of turbidity between the two reservoirs via the water transfer tunnel. The aim of this study was to investigate the effect of the water transfer tunnel on the turbidity behavior of the two connecting reservoirs and to further understand the effect of reservoir turbidity distribution as a function of the selective withdrawal depth. This study applied the CE-QUAL-W2, a water quality and 2-dimensional hydrodynamic model, for simulating the hydrodynamic processes of the two reservoirs. Results indicate that, in the Andong reservoir, the turbidity of the released water with the water transfer tunnel was similar to that without the tunnel. However, in the Imha reservoir, the turbidity of the released water with the water transfer tunnel was lower than that without the tunnel. This can be attributed to the higher capacity of the Andong reservoir, which has double the storage of the Imha reservoir. Withdrawal turbidity in the Imha reservoir was investigated using the water transfer tunnel. This study applied three withdrawal selections as elevation (EL. 141.0 m, 146.5 m, and 152.0 m. The highest withdrawal turbidity resulted in EL. 141.0 m, which indicates that the high turbidity current is located at a vertical depth of about 20–30 m because of the density difference. These results will be helpful for understanding the release and selective withdrawal turbidity behaviors for a water transfer tunnel between two reservoirs.

  13. Energy storage

    International Nuclear Information System (INIS)

    2012-01-01

    After having outlined the importance of energy storage in the present context, this document outlines that it is an answer to economic, environmental and technological issues. It proposes a brief overview of the various techniques of energy storage: under the form of chemical energy (hydrocarbons, biomass, hydrogen production), thermal energy (sensitive or latent heat storage), mechanical energy (potential energy by hydraulic or compressed air storage, kinetic energy with flywheels), electrochemical energy (in batteries), electric energy (super-capacitors, superconductor magnetic energy storage). Perspectives are briefly evoked

  14. Discussion of the feasibility of air injection for enhanced oil recovery in shale oil reservoirs

    Directory of Open Access Journals (Sweden)

    Hu Jia

    2017-06-01

    Full Text Available Air injection in light oil reservoirs has received considerable attention as an effective, improved oil recovery process, based primarily on the success of several projects within the Williston Basin in the United States. The main mechanism of air injection is the oxidation behavior between oxygen and crude oil in the reservoir. Air injection is a good option because of its wide availability and low cost. Whether air injection can be applied to shale is an interesting topic from both economic and technical perspectives. This paper initiates a comprehensive discussion on the feasibility and potential of air injection in shale oil reservoirs based on state-of-the-art literature review. Favorable and unfavorable effects of using air injection are discussed in an analogy analysis on geology, reservoir features, temperature, pressure, and petrophysical, mineral and crude oil properties of shale oil reservoirs. The available data comparison of the historically successful air injection projects with typical shale oil reservoirs in the U.S. is summarized in this paper. Some operation methods to improve air injection performance are recommended. This paper provides an avenue for us to make use of many of the favorable conditions of shale oil reservoirs for implementing air injection, or air huff ‘n’ puff injection, and the low cost of air has the potential to improve oil recovery in shale oil reservoirs. This analysis may stimulate further investigation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-01

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

  16. Analog electronics for radiation detection

    CERN Document Server

    2016-01-01

    Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

  17. Natural analogs for Yucca Mountain

    International Nuclear Information System (INIS)

    Murphy, W.M.

    1995-01-01

    High-level radioactive waste in the US, spent fuels from commercial reactors and nuclear materials generated by defense activities, will remain potentially hazardous for thousands of years. Demonstrable long-term stability of certain geologic and geochemical systems motivates and sustains the concept that high-level waste can be safely isolated in geologic repositories for requisite periods of time. Each geologic repository is unique in its properties and performance with reguard to isolation of nuclear wastes. Studies of processes analogous to waste-form alteration and radioelement transport in environments analogous to Yucca Mountain are being conducted at two sites, described in this article to illustrate uses of natural analog data: the Nopal I uranium deposit in the Sierra Pena Blanca, Mexico, and the Akrotiri archaeological site on the island of Santorini, Greece

  18. GAS STORAGE TECHNOLOGY CONSORTIUM

    Energy Technology Data Exchange (ETDEWEB)

    Robert W. Watson

    2004-10-18

    Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services, and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet (TCF) over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is critical in meeting the needs of these new markets. In order to address the gas storage needs of the natural gas industry, an industry-driven consortium was created--the Gas Storage Technology Consortium (GSTC). The objective of the GSTC is to provide a means to accomplish industry-driven research and development designed to enhance operational flexibility and deliverability of the Nation's gas storage system, and provide a cost effective, safe, and reliable supply of natural gas to meet domestic demand. To accomplish this objective, the project is divided into three phases that are managed and directed by the GSTC Coordinator. The first phase, Phase 1A, was initiated on September 30, 2003, and was completed on March 31, 2004. Phase 1A of the project included the creation of the GSTC structure, development and refinement of a technical approach (work plan) for deliverability enhancement and reservoir management. This report deals with Phase 1B and encompasses the period July 1, 2004, through September 30, 2004. During this time period there were three main activities. First was the

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

    2006-11-01

    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

  20. Effect of reservoir zones and hedging factor dynamism on reservoir adaptive capacity for climate change impacts

    Science.gov (United States)

    Adeloye, Adebayo J.; Soundharajan, Bankaru-Swamy

    2018-06-01

    When based on the zones of available water in storage, hedging has traditionally used a single hedged zone and a constant rationing ratio for constraining supply during droughts. Given the usual seasonality of reservoir inflows, it is also possible that hedging could feature multiple hedged zones and temporally varying rationing ratios but very few studies addressing this have been reported especially in relation to adaptation to projected climate change. This study developed and tested Genetic Algorithms (GA) optimised zone-based operating policies of various configurations using data for the Pong reservoir, Himachal Pradesh, India. The results show that hedging does lessen vulnerability, which dropped from ≥ 60 % without hedging to below 25 % with the single stage hedging. More complex hedging policies, e.g. two stage and/or temporally varying rationing ratios only produced marginal improvements in performance. All this shows that water hedging policies do not have to be overly complex to effectively offset reservoir vulnerability caused by water shortage resulting from e.g. projected climate change.

  1. Synthetic Analogs of Phospholipid Metabolites as Antimalarials.

    Science.gov (United States)

    1979-07-01

    phosphatidic acid analogs containing ether and phosphonate groups; completely non- hydrolyzable lecithin analogs containing phosphinate and ether groups...substance is a completely non- hydrolyzable analog of lecithin containing ether and phosphonate moieties instead of the normally labile carboxylic and...and also ant-i-phospholipase C (clostridial enzyme) activity. This substance Is a completely non- hydrolyzable analog of lecithin containing ether

  2. Rigorous Screening Technology for Identifying Suitable CO2 Storage Sites II

    Energy Technology Data Exchange (ETDEWEB)

    George J. Koperna Jr.; Vello A. Kuuskraa; David E. Riestenberg; Aiysha Sultana; Tyler Van Leeuwen

    2009-06-01

    This report serves as the final technical report and users manual for the 'Rigorous Screening Technology for Identifying Suitable CO2 Storage Sites II SBIR project. Advanced Resources International has developed a screening tool by which users can technically screen, assess the storage capacity and quantify the costs of CO2 storage in four types of CO2 storage reservoirs. These include CO2-enhanced oil recovery reservoirs, depleted oil and gas fields (non-enhanced oil recovery candidates), deep coal seems that are amenable to CO2-enhanced methane recovery, and saline reservoirs. The screening function assessed whether the reservoir could likely serve as a safe, long-term CO2 storage reservoir. The storage capacity assessment uses rigorous reservoir simulation models to determine the timing, ultimate storage capacity, and potential for enhanced hydrocarbon recovery. Finally, the economic assessment function determines both the field-level and pipeline (transportation) costs for CO2 sequestration in a given reservoir. The screening tool has been peer reviewed at an Electrical Power Research Institute (EPRI) technical meeting in March 2009. A number of useful observations and recommendations emerged from the Workshop on the costs of CO2 transport and storage that could be readily incorporated into a commercial version of the Screening Tool in a Phase III SBIR.

  3. Remotely Sensed Monitoring of Small Reservoir Dynamics: A Bayesian Approach

    Directory of Open Access Journals (Sweden)

    Dirk Eilander

    2014-01-01

    Full Text Available Multipurpose small reservoirs are important for livelihoods in rural semi-arid regions. To manage and plan these reservoirs and to assess their hydrological impact at a river basin scale, it is important to monitor their water storage dynamics. This paper introduces a Bayesian approach for monitoring small reservoirs with radar satellite images. The newly developed growing Bayesian classifier has a high degree of automation, can readily be extended with auxiliary information and reduces the confusion error to the land-water boundary pixels. A case study has been performed in the Upper East Region of Ghana, based on Radarsat-2 data from November 2012 until April 2013. Results show that the growing Bayesian classifier can deal with the spatial and temporal variability in synthetic aperture radar (SAR backscatter intensities from small reservoirs. Due to its ability to incorporate auxiliary information, the algorithm is able to delineate open water from SAR imagery with a low land-water contrast in the case of wind-induced Bragg scattering or limited vegetation on the land surrounding a small reservoir.

  4. Inflow forecasting using Artificial Neural Networks for reservoir operation

    Directory of Open Access Journals (Sweden)

    C. Chiamsathit

    2016-05-01

    Full Text Available In this study, multi-layer perceptron (MLP artificial neural networks have been applied to forecast one-month-ahead inflow for the Ubonratana reservoir, Thailand. To assess how well the forecast inflows have performed in the operation of the reservoir, simulations were carried out guided by the systems rule curves. As basis of comparison, four inflow situations were considered: (1 inflow known and assumed to be the historic (Type A; (2 inflow known and assumed to be the forecast (Type F; (3 inflow known and assumed to be the historic mean for month (Type M; and (4 inflow is unknown with release decision only conditioned on the starting reservoir storage (Type N. Reservoir performance was summarised in terms of reliability, resilience, vulnerability and sustainability. It was found that Type F inflow situation produced the best performance while Type N was the worst performing. This clearly demonstrates the importance of good inflow information for effective reservoir operation.

  5. Hydrodynamic modeling of petroleum reservoirs using simulator MUFITS

    Science.gov (United States)

    Afanasyev, Andrey

    2015-04-01

    MUFITS is new noncommercial software for numerical modeling of subsurface processes in various applications (www.mufits.imec.msu.ru). To this point, the simulator was used for modeling nonisothermal flows in geothermal reservoirs and for modeling underground carbon dioxide storage. In this work, we present recent extension of the code to petroleum reservoirs. The simulator can be applied in conventional black oil modeling, but it also utilizes a more complicated models for volatile oil and gas condensate reservoirs as well as for oil rim fields. We give a brief overview of the code by providing the description of internal representation of reservoir models, which are constructed of grid blocks, interfaces, stock tanks as well as of pipe segments and pipe junctions for modeling wells and surface networks. For conventional black oil approach, we present the simulation results for SPE comparative tests. We propose an accelerated compositional modeling method for sub- and supercritical flows subjected to various phase equilibria, particularly to three-phase equilibria of vapour-liquid-liquid type. The method is based on the calculation of the thermodynamic potential of reservoir fluid as a function of pressure, total enthalpy and total composition and storing its values as a spline table, which is used in hydrodynamic simulation for accelerated PVT properties prediction. We provide the description of both the spline calculation procedure and the flashing algorithm. We evaluate the thermodynamic potential for a mixture of two pseudo-components modeling the heavy and light hydrocarbon fractions. We develop a technique for converting black oil PVT tables to the potential, which can be used for in-situ hydrocarbons multiphase equilibria prediction under sub- and supercritical conditions, particularly, in gas condensate and volatile oil reservoirs. We simulate recovery from a reservoir subject to near-critical initial conditions for hydrocarbon mixture. We acknowledge

  6. Practical considerations of reservoir heterogeneities on SAGD projects

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.; Fong, C.; Li, T. [Epic Consulting Services Ltd., Calgary, AB (Canada); Bowes, C.; Toews, M. [Calgary Univ., AB (Canada)

    2008-10-15

    Significant emphasis has been placed on developing cost-effective strategies for the production of large heavy oil and bitumen reserves located in western Canada and around the world. An effective method that has been proven to be effective in this regard is steam-assisted gravity drainage (SAGD). However, determining the optimum and cost-effective strategy is a challenge to any SAGD reservoir. Average rock quality and reservoir heterogeneities have a significant impact on steam chamber development and the overall volumetric sweep. As well, the approach to SAGD simulation varies as heterogeneity changes. This paper examined two well pairs with different degrees of heterogeneity in the Surmont pilot project. The paper also addressed potential geological risk through analogy and the amount of heterogeneity that must be accounted for when developing a representative simulation. The paper provided background information on the Surmont pilot project, which consists of three horizontal SAGD well pairs in the Athabasca oil sands of northeast Alberta. The reservoir simulation model was then described. Results and conclusions were offered. It was concluded that careful production controls and strategy must be applied particular to the reservoir to ensure that the SAGD well pairs were capable of draining the mobilized oil. 5 refs., 1 tab., 25 figs.

  7. The mechanics of shallow magma reservoir outgassing

    Science.gov (United States)

    Parmigiani, A.; Degruyter, W.; Leclaire, S.; Huber, C.; Bachmann, O.

    2017-08-01

    Magma degassing fundamentally controls the Earth's volatile cycles. The large amount of gas expelled into the atmosphere during volcanic eruptions (i.e., volcanic outgassing) is the most obvious display of magmatic volatile release. However, owing to the large intrusive:extrusive ratio, and considering the paucity of volatiles left in intrusive rocks after final solidification, volcanic outgassing likely constitutes only a small fraction of the overall mass of magmatic volatiles released to the Earth's surface. Therefore, as most magmas stall on their way to the surface, outgassing of uneruptible, crystal-rich magma storage regions will play a dominant role in closing the balance of volatile element cycling between the mantle and the surface. We use a numerical approach to study the migration of a magmatic volatile phase (MVP) in crystal-rich magma bodies ("mush zones") at the pore scale. Our results suggest that buoyancy-driven outgassing is efficient over crystal volume fractions between 0.4 and 0.7 (for mm-sized crystals). We parameterize our pore-scale results for MVP migration in a thermomechanical magma reservoir model to study outgassing under dynamical conditions where cooling controls the evolution of the proportion of crystal, gas, and melt phases and to investigate the role of the reservoir size and the temperature-dependent viscoelastic response of the crust on outgassing efficiency. We find that buoyancy-driven outgassing allows for a maximum of 40-50% volatiles to leave the reservoir over the 0.4-0.7 crystal volume fractions, implying that a significant amount of outgassing must occur at high crystal content (>0.7) through veining and/or capillary fracturing.

  8. High Density Digital Data Storage System

    Science.gov (United States)

    Wright, Kenneth D., II; Gray, David L.; Rowland, Wayne D.

    1991-01-01

    The High Density Digital Data Storage System was designed to provide a cost effective means for storing real-time data from the field-deployable digital acoustic measurement system. However, the high density data storage system is a standalone system that could provide a storage solution for many other real time data acquisition applications. The storage system has inputs for up to 20 channels of 16-bit digital data. The high density tape recorders presently being used in the storage system are capable of storing over 5 gigabytes of data at overall transfer rates of 500 kilobytes per second. However, through the use of data compression techniques the system storage capacity and transfer rate can be doubled. Two tape recorders have been incorporated into the storage system to produce a backup tape of data in real-time. An analog output is provided for each data channel as a means of monitoring the data as it is being recorded.

  9. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf; Saad, Bilal; Negara, Ardiansyah; Sun, Shuyu

    2017-01-01

    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

  10. Identification and assessment of potential water quality impact factors for drinking-water reservoirs.

    Science.gov (United States)

    Gu, Qing; Deng, Jinsong; Wang, Ke; Lin, Yi; Li, Jun; Gan, Muye; Ma, Ligang; Hong, Yang

    2014-06-10

    Various reservoirs have been serving as the most important drinking water sources in Zhejiang Province, China, due to the uneven distribution of precipitation and severe river pollution. Unfortunately, rapid urbanization and industrialization have been continuously challenging the water quality of the drinking-water reservoirs. The identification and assessment of potential impacts is indispensable in water resource management and protection. This study investigates the drinking water reservoirs in Zhejiang Province to better understand the potential impact on water quality. Altogether seventy-three typical drinking reservoirs in Zhejiang Province encompassing various water storage levels were selected and evaluated. Using fifty-two reservoirs as training samples, the classification and regression tree (CART) method and sixteen comprehensive variables, including six sub-sets (land use, population, socio-economy, geographical features, inherent characteristics, and climate), were adopted to establish a decision-making model for identifying and assessing their potential impacts on drinking-water quality. The water quality class of the remaining twenty-one reservoirs was then predicted and tested based on the decision-making model, resulting in a water quality class attribution accuracy of 81.0%. Based on the decision rules and quantitative importance of the independent variables, industrial emissions was identified as the most important factor influencing the water quality of reservoirs; land use and human habitation also had a substantial impact on water quality. The results of this study provide insights into the factors impacting the water quality of reservoirs as well as basic information for protecting reservoir water resources.

  11. How well will the Surface Water and Ocean Topography (SWOT) mission observe global reservoirs?

    Science.gov (United States)

    Solander, Kurt C.; Reager, John T.; Famiglietti, James S.

    2016-03-01

    Accurate observations of global reservoir storage are critical to understand the availability of managed water resources. By enabling estimates of surface water area and height for reservoir sizes exceeding 250 m2 at a maximum repeat orbit of up to 21 days, the NASA Surface Water and Ocean Topography (SWOT) satellite mission (anticipated launch date 2020) is expected to greatly improve upon existing reservoir monitoring capabilities. It is thus essential that spatial and temporal measurement uncertainty for water bodies is known a priori to maximize the utility of SWOT observations as the data are acquired. In this study, we evaluate SWOT reservoir observations using a three-pronged approach that assesses temporal aliasing, errors due to specific reservoir spatial properties, and SWOT performance over actual reservoirs using a combination of in situ and simulated reservoir observations from the SWOTsim instrument simulator. Results indicate temporal errors to be less than 5% for the smallest reservoir sizes (100 km2). Surface area and height errors were found to be minimal (area SWOT, this study will be have important implications for future applications of SWOT reservoir measurements in global monitoring systems and models.

  12. Opportunities in independent gas storage

    International Nuclear Information System (INIS)

    Daniel, R.

    1999-01-01

    The range of business opportunities currently available for the midstream oil and gas business were discussed with particular focus on storage opportunities. Alberta Energy Co. (AEC) Ltd.'s two midstream business units include AEC Pipelines and Gas Processing, and AEC Storage and Hub Services. These two businesses provide the company with good investment returns, stable cash flow, and some significant strategic synergies with their exploration and production businesses. In 1988, the AECO C Hub in southeastern Alberta was created as an outgrowth of AEC's gas production operations on the Suffield block, where they had depleted gas reservoirs with high rock quality suitable for high deliverability storage. With the AECO C Hub, AEC was able to offer firm storage contracts of from 1 to 20 years, and to introduce short term interruptible parking and lending services, title exchange, a spot price index for greater price discovery, and an electronic nomination system. AEC is currently completing construction of their second commercial storage facility, the Wild Goose project, in northern California. D ebottlenecking' the Western Canada supply basin should provide additional opportunities for further expansion not only for AEC but also for other midstream service providers. Opportunities are especially available in the areas of new storage facilities to serve location-specific needs, replacement of declining storage capacity, replacement of retiring facilities, technological optimization of existing facilities, more flexible, higher deliverability facilities and commercial optimization of existing facilities. A map of the hubs and market centres of North America are included. 5 figs

  13. The Role of Rainfall Variability in Reservoir Storage Management at ...

    African Journals Online (AJOL)

    Bheema

    Climate can be defined as average weather over long period of time; say 30-35 years. ... also decreases from the South of the Kaduna basin northwards except where .... stream flow pattern of most rivers and streams in the Guinea Savannah.

  14. The analog processing system for the Liquid Argon Calorimeter for SLD at SLAC

    International Nuclear Information System (INIS)

    Haller, G.M.; Nelson, D.; Freytag, D.R.

    1986-09-01

    The analog processing system for the Liquid Argon Calorimeter for the SLD project at SLAC is described. Amplification, storage of the analog information, and multiplexing is realized on specially developed hybrids, which will be mounted directly on the detector. This leads to a substantial reduction of the cable plant. Test results for the amplifier and for the sampling and multiplexing hybrid (CDU hybrid) are presented. The latter hybird contains a custom monolithic device, the Calorimeter Data Unit

  15. Multichannel analog temperature sensing system

    International Nuclear Information System (INIS)

    Gribble, R.

    1985-08-01

    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer

  16. 49205 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1997-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course 49205 Analog and Digital Filters...

  17. Drawing Analogies to Deepen Learning

    Science.gov (United States)

    Fava, Michelle

    2017-01-01

    This article offers examples of how drawing can facilitate thinking skills that promote analogical reasoning to enable deeper learning. The instructional design applies cognitive principles, briefly described here. The workshops were developed iteratively, through feedback from student and teacher participants. Elements of the UK National…

  18. 4D Joint Stratigraphic Inversion of Prestack Seismic Data: Application to the CO2 Storage Reservoir (Utsira Sand Formation at Sleipner Site Inversion stratigraphique jointe 4D de données sismiques avant sommation : application au réservoir de stockage de CO2 (Formation Utsira du site de Sleipner

    Directory of Open Access Journals (Sweden)

    Labat K.

    2012-04-01

    Full Text Available Seismic monitoring is commonly used in the oil industry to follow the evolution of reservoir properties during production. We present a methodology of time-lapse (or 4D stratigraphic inversion, which is able to provide an estimation of P- and S-wave impedance variations in the reservoir by inverting prestack time-lapse seismic data. The 4D inversion is implemented in the time domain and requires a time scaling law for each repeated seismic dataset in order to adjust the arrival times of homologous events observed in the so-called reference and monitor datasets. This operation is often referred to as the warping problem. The 4D inversion is a 3-step methodology. The first step consists in inverting each seismic vintage independently, thus providing as many P- and S-wave impedance distributions as datasets considered. The second step uses the available P-wave impedance information to solve the warping problem which is crucial to the third and final step: the joint inversion of all available seismic vintages. This 4D inversion sequence was applied to seismic datasets recorded on the Norwegian CO2 storage reservoir of Sleipner field located in the North Sea. The latter is becoming a reference industrial site for the long-term storage of carbon dioxide (CO2 in a saline aquifer, the Utsira sand formation. We focused our 4D inversion study on the 1994 and 2006 vintages acquired two years before and ten years after the beginning of CO2 injection, respectively. The warping correction resulted in a time-scaling law with a maximum pushdown effect of about 45 ms at the base of the Utsira aquifer. The joint 4D inversion results show more consistency than the single 3D inversion results: the 4D inversion notably provides P-wave impedances for the CO2 -saturated sandstones which are close to the values derived from rock physics studies. Le monitoring sismique est couramment utilisé dans l'industrie pétrolière pour suivre l'évolution des propriétés des r

  19. Simulation and optimisation modelling approach for operation of the Hoa Binh Reservoir, Vietnam

    DEFF Research Database (Denmark)

    Ngo, Long le; Madsen, Henrik; Rosbjerg, Dan

    2007-01-01

    Hoa Binh, the largest reservoir in Vietnam, plays an important role in flood control for the Red River delta and hydropower generation. Due to its multi-purpose character, conflicts and disputes in operating the reservoir have been ongoing since its construction, particularly in the flood season....... This paper proposes to optimise the control strategies for the Hoa Binh reservoir operation by applying a combination of simulation and optimisation models. The control strategies are set up in the MIKE 11 simulation model to guide the releases of the reservoir system according to the current storage level......, the hydro-meteorological conditions, and the time of the year. A heuristic global optimisation tool, the shuffled complex evolution (SCE) algorithm, is adopted for optimising the reservoir operation. The optimisation puts focus on the trade-off between flood control and hydropower generation for the Hoa...

  20. Bayesian analogy with relational transformations.

    Science.gov (United States)

    Lu, Hongjing; Chen, Dawn; Holyoak, Keith J

    2012-07-01

    How can humans acquire relational representations that enable analogical inference and other forms of high-level reasoning? Using comparative relations as a model domain, we explore the possibility that bottom-up learning mechanisms applied to objects coded as feature vectors can yield representations of relations sufficient to solve analogy problems. We introduce Bayesian analogy with relational transformations (BART) and apply the model to the task of learning first-order comparative relations (e.g., larger, smaller, fiercer, meeker) from a set of animal pairs. Inputs are coded by vectors of continuous-valued features, based either on human magnitude ratings, normed feature ratings (De Deyne et al., 2008), or outputs of the topics model (Griffiths, Steyvers, & Tenenbaum, 2007). Bootstrapping from empirical priors, the model is able to induce first-order relations represented as probabilistic weight distributions, even when given positive examples only. These learned representations allow classification of novel instantiations of the relations and yield a symbolic distance effect of the sort obtained with both humans and other primates. BART then transforms its learned weight distributions by importance-guided mapping, thereby placing distinct dimensions into correspondence. These transformed representations allow BART to reliably solve 4-term analogies (e.g., larger:smaller::fiercer:meeker), a type of reasoning that is arguably specific to humans. Our results provide a proof-of-concept that structured analogies can be solved with representations induced from unstructured feature vectors by mechanisms that operate in a largely bottom-up fashion. We discuss potential implications for algorithmic and neural models of relational thinking, as well as for the evolution of abstract thought. Copyright 2012 APA, all rights reserved.

  1. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Development and linearization of generalized material balance equation for coal bed methane reservoirs

    International Nuclear Information System (INIS)

    Penuela, G; Ordonez R, A; Bejarano, A

    1998-01-01

    A generalized material balance equation was presented at the Escuela de Petroleos de la Universidad Industrial de Santander for coal seam gas reservoirs based on Walsh's method, who worked in an analogous approach for oil and gas conventional reservoirs (Walsh, 1995). Our equation was based on twelve similar assumptions itemized by Walsh for his generalized expression for conventional reservoirs it was started from the same volume balance consideration and was finally reorganized like Walsh (1994) did. Because it is not expressed in terms of traditional (P/Z) plots, as proposed by King (1990), it allows to perform a lot of quantitative and qualitative analyses. It was also demonstrated that the existent equations are only particular cases of the generalized expression evaluated under certain restrictions. This equation is applicable to coal seam gas reservoirs in saturated, equilibrium and under saturated conditions, and to any type of coal beds without restriction on especial values of the constant diffusion

  3. Neutron storage

    International Nuclear Information System (INIS)

    Strelkov, A.V.

    2004-01-01

    The report is devoted to neutron storage (NS) and describes the history of experiments on the NS development. Great attention is paid to ultracold neutron (UCN) storage. The experiments on the UCN generation, transport, spectroscopy, storage and detection are described. Experiments on searching the UCN electric-dipole moment and electric charge are continued. Possible using of UCN for studying the nanoparticles is discussed [ru

  4. Energy storage

    International Nuclear Information System (INIS)

    Odru, P.

    2010-01-01

    This book proposes a broad overview of the technologies developed in the domains of on-board electricity storage (batteries, super-capacitors, flywheels), stationary storage (hydraulic dams, compressed air, batteries and hydrogen), and heat storage (sensible, latent and sorption) together with their relative efficiency, their expected developments and what advantages they can offer. Eminent specialists of this domain have participated to the redaction of this book, all being members of the Tuck's Foundation 'IDees' think tank. (J.S.)

  5. Energy storage

    CERN Document Server

    Brunet, Yves

    2013-01-01

    Energy storage examines different applications such as electric power generation, transmission and distribution systems, pulsed systems, transportation, buildings and mobile applications. For each of these applications, proper energy storage technologies are foreseen, with their advantages, disadvantages and limits. As electricity cannot be stored cheaply in large quantities, energy has to be stored in another form (chemical, thermal, electromagnetic, mechanical) and then converted back into electric power and/or energy using conversion systems. Most of the storage technologies are examined: b

  6. Tritium storage

    International Nuclear Information System (INIS)

    Hircq, B.

    1989-01-01

    A general synthesis about tritium storage is achieved in this paper and a particular attention is given to practical application in the Fusion Technology Program. Tritium, storage under gaseous form and solid form are discussed (characteristics, advantages, disadvantages and equipments). The way of tritium storage is then discussed and a choice established as a function of a logic which takes into account the main working parameters

  7. The dynamic capacity calculation method and the flood control ability of the Three Gorges Reservoir

    Science.gov (United States)

    Zhang, Shanghong; Jing, Zhu; Yi, Yujun; Wu, Yu; Zhao, Yong

    2017-12-01

    To evaluate the flood control ability of a river-type reservoir, an accurate simulation method for the flood storage, discharge process, and dynamic capacity of the reservoir is important. As the world's largest reservoir, the storage capacity and flood control capacity of the Three Gorges Reservoir (TGR) has attracted widespread interest and academic debate for nearly 20 years. In this study, a model for calculating the dynamic capacity of a river-type reservoir is established based on data from 394 river cross sections and 2.5-m resolution digital elevation model (DEM) data of the TGR area. The storage capacity and flood control capacity of the TGR were analysed based on the scheduling procedures of a normal impoundment period. The results show that the static capacity of the TGR is 43.43 billion m3, the dynamic flood control capacity is 22.45 billion m3, and the maximum floodwater flow regulated by the dynamic capacity at Zhicheng is no more than 67,700 m3/s. This study supply new simulation method and up-to-date high-precision data to discuss the 20 years debate, and the results reveal the TGR design is conservative for flood control according to the Preliminary Design Report of the Three Gorges Project. The dynamic capacity calculation method used here can provide a reference for flood regulation of large river-type reservoirs.

  8. A simulation method for the rapid screening of potential depleted oil reservoirs for CO2 sequestration

    International Nuclear Information System (INIS)

    Bossie-Codreanu, D.; Le Gallo, Y.

    2004-01-01

    The reduction of greenhouse gases emission is a growing concern of many industries. The oil and gas industry has a long commercial practice of gas injection, enhanced oil recovery (EOR) and gas storage. Using a depleted oil or gas reservoir for CO 2 storage has several interesting advantages. The long-term risk analysis of the CO 2 behavior and its impact on the environment is a major concern. That is why the selection of an appropriate reservoir is crucial to the success of a sequestration operation. Our modeling study, based on a synthetic reservoir, quantifies uncertainties due to reservoir parameters in order to establish a set of guidelines to select the most appropriate depleted reservoirs. Several production and sequestration scenarios are investigated in order to quantify key parameter for CO 2 storage. The influence of parameters such as API gravity, heterogeneity (Dykstra-Parson coefficient), pressure support (water injection) and cap rock integrity are analyzed. Estimation of sequestration capacity is proposed through a sequestration factor (SF) estimated for different reservoir production drives. Multiple regression relationships were developed, allowing SF estimation. CO 2 sequestration optimization highlights the best clean oil recovery strategy (CO 2 injection and/or oil production)

  9. Design Techniques and Reservoir Simulation

    Directory of Open Access Journals (Sweden)

    Ahad Fereidooni

    2012-11-01

    Full Text Available Enhanced oil recovery using nitrogen injection is a commonly applied method for pressure maintenance in conventional reservoirs. Numerical simulations can be practiced for the prediction of a reservoir performance in the course of injection process; however, a detailed simulation might take up enormous computer processing time. In such cases, a simple statistical model may be a good approach to the preliminary prediction of the process without any application of numerical simulation. In the current work, seven rock/fluid reservoir properties are considered as screening parameters and those parameters having the most considerable effect on the process are determined using the combination of experimental design techniques and reservoir simulations. Therefore, the statistical significance of the main effects and interactions of screening parameters are analyzed utilizing statistical inference approaches. Finally, the influential parameters are employed to create a simple statistical model which allows the preliminary prediction of nitrogen injection in terms of a recovery factor without resorting to numerical simulations.

  10. The Characteristics of Spanish Reservoirs

    National Research Council Canada - National Science Library

    Armengol, J; Merce, R

    2003-01-01

    Sau Reservoir was first filled in 1963 in a middle stretch of the Ter River, as part of a multi-use scheme, including hydroelectric power, agricultural irrigation, domestic and industrial water supply...

  11. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf

    2017-06-06

    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

  12. A remote sensing method for estimating regional reservoir area and evaporative loss

    Science.gov (United States)

    Zhang, Hua; Gorelick, Steven M.; Zimba, Paul V.; Zhang, Xiaodong

    2017-12-01

    Evaporation from the water surface of a reservoir can significantly affect its function of ensuring the availability and temporal stability of water supply. Current estimations of reservoir evaporative loss are dependent on water area derived from a reservoir storage-area curve. Such curves are unavailable if the reservoir is located in a data-sparse region or questionable if long-term sedimentation has changed the original elevation-area relationship. We propose a remote sensing framework to estimate reservoir evaporative loss at the regional scale. This framework uses a multispectral water index to extract reservoir area from Landsat imagery and estimate monthly evaporation volume based on pan-derived evaporative rates. The optimal index threshold is determined based on local observations and extended to unobserved locations and periods. Built on the cloud computing capacity of the Google Earth Engine, this framework can efficiently analyze satellite images at large spatiotemporal scales, where such analysis is infeasible with a single computer. Our study involves 200 major reservoirs in Texas, captured in 17,811 Landsat images over a 32-year period. The results show that these reservoirs contribute to an annual evaporative loss of 8.0 billion cubic meters, equivalent to 20% of their total active storage or 53% of total annual water use in Texas. At five coastal basins, reservoir evaporative losses exceed the minimum freshwater inflows required to sustain ecosystem health and fishery productivity of the receiving estuaries. Reservoir evaporative loss can be significant enough to counterbalance the positive effects of impounding water and to offset the contribution of water conservation and reuse practices. Our results also reveal the spatially variable performance of the multispectral water index and indicate the limitation of using scene-level cloud cover to screen satellite images. This study demonstrates the advantage of combining satellite remote sensing and

  13. ECONOMIC EVALUATION OF CO2 STORAGE AND SINK ENHANCEMENT OPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Bert Bock; Richard Rhudy; Howard Herzog; Michael Klett; John Davison; Danial G. De La Torre Ugarte; Dale Simbeck

    2003-02-01

    This project developed life-cycle costs for the major technologies and practices under development for CO{sub 2} storage and sink enhancement. The technologies evaluated included options for storing captured CO{sub 2} in active oil reservoirs, depleted oil and gas reservoirs, deep aquifers, coal beds, and oceans, as well as the enhancement of carbon sequestration in forests and croplands. The capture costs for a nominal 500 MW{sub e} integrated gasification combined cycle plant from an earlier study were combined with the storage costs from this study to allow comparison among capture and storage approaches as well as sink enhancements.

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

    Science.gov (United States)

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

    2017-12-01

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

  15. Chickamauga reservoir embayment study - 1990

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-12-01

    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.

  16. Performance of a system of reservoirs on futuristic front

    Science.gov (United States)

    Saha, Satabdi; Roy, Debasri; Mazumdar, Asis

    2017-10-01

    Application of simulation model HEC-5 to analyze the performance of the DVC Reservoir System (a multipurpose system with a network of five reservoirs and one barrage) on the river Damodar in Eastern India in meeting projected future demand as well as controlling flood for synthetically generated future scenario is addressed here with a view to develop an appropriate strategy for its operation. Thomas-Fiering model (based on Markov autoregressive model) has been adopted for generation of synthetic scenario (monthly streamflow series) and subsequently downscaling of modeled monthly streamflow to daily values was carried out. The performance of the system (analysed on seasonal basis) in terms of `Performance Indices' (viz., both quantity based reliability and time based reliability, mean daily deficit, average failure period, resilience and maximum vulnerability indices) for the projected scenario with enhanced demand turned out to be poor compared to that for historical scenario. However, judicious adoption of resource enhancement (marginal reallocation of reservoir storage capacity) and demand management strategy (curtailment of projected high water requirements and trading off between demands) was found to be a viable option for improvement of the performance of the reservoir system appreciably [improvement being (1-51 %), (2-35 %), (16-96 %), (25-50 %), (8-36 %) and (12-30 %) for the indices viz., quantity based reliability, time based reliability, mean daily deficit, average failure period, resilience and maximum vulnerability, respectively] compared to that with normal storage and projected demand. Again, 100 % reliability for flood control for current as well as future synthetically generated scenarios was noted. The results from the study would assist concerned authority in successful operation of reservoirs in the context of growing demand and dwindling resource.

  17. A rationale for reservoir management economics

    International Nuclear Information System (INIS)

    Hickman, T.S.

    1995-01-01

    Significant economic benefits can be derived from the application f reservoir management. The key elements in economical reservoir management are the efficient use of available resources and optimization of reservoir exploitation through a multidisciplined approach. This paper describes various aspects of and approaches to reservoir management and provides case histories that support the findings

  18. Analog circuit design art, science and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

  19. A method for the assessment of long-term changes in carbon stock by construction of a hydropower reservoir.

    Science.gov (United States)

    Bernardo, Julio Werner Yoshioka; Mannich, Michael; Hilgert, Stephan; Fernandes, Cristovão Vicente Scapulatempo; Bleninger, Tobias

    2017-09-01

    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.

  20. Probe Storage

    NARCIS (Netherlands)

    Gemelli, Marcellino; Abelmann, Leon; Engelen, Johannes Bernardus Charles; Khatib, M.G.; Koelmans, W.W.; Zaboronski, Olog; Campardo, Giovanni; Tiziani, Federico; Laculo, Massimo

    2011-01-01

    This chapter gives an overview of probe-based data storage research over the last three decades, encompassing all aspects of a probe recording system. Following the division found in all mechanically addressed storage systems, the different subsystems (media, read/write heads, positioning, data

  1. Flow characteristic of Hijiori HDR reservoir from circulation test in 1991; Koon tantai Hijiori jikkenjo ni okeru senbu choryuso shiken (1991 nendo) kekka to ryudo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Shiga, T; Hyodo, M; Shinohara, N; Takasugi, S [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1996-05-01

    This paper reports one example of flow analyses on a circulation test carried out in fiscal 1991 at the Hijiori hot dry rock experimental field (Yamagata Prefecture). A fluid circulation model was proposed to simulate an HDR circulation system for a shallow reservoir (at a depth of about 1800 m) demonstrated in the circulation test by using an electric circuit network (which expresses continuity impedance in resistance and fluid storage in capacitance). Storage capacity of the reservoir was estimated by deriving time constant of the system from data of time-based change in reservoir pressure associated with transition phenomena during the circulation test. The storage capacity was estimated separately by dividing change of storage in the reservoir by change in the reservoir pressure. To derive the storage in the reservoir, a method to calculate non-recovered flows in the circulation test was utilized. The results of evaluating the reservoir capacity in the shallow reservoir using the above two independent methods were found substantially consistent. 3 refs., 6 figs., 1 tab.

  2. Mercury bioaccumulation in the food web of Three Gorges Reservoir (China): Tempo-spatial patterns and effect of reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Zhou, Qiong, E-mail: hainan@mail.hzau.edu.cn [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Yuan, Gailing; He, Xugang [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan 430070 (China); Xie, Ping [College of Fisheries, Huazhong Agricultural University, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan 430070 (China); Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)

    2015-09-15

    Tempo-spatial patterns of mercury bioaccumulation and tropho-dynamics, and the potential for a reservoir effect were evaluated in the Three Gorges Reservoir (TGR, China) from 2011 to 2012, using total mercury concentrations (THg) and stable isotopes (δ{sup 13}C and δ{sup 15}N) of food web components (seston, aquatic invertebrates and fish). Hg concentrations in aquatic invertebrates and fish indicated a significant temporal trend associated with regular seasonal water-level manipulation. This includes water level lowering to allow for storage of water during the wet season (summer); a decrease of water levels from September to June providing a setting for flood storage. Hg concentrations in organisms were the highest after flooding. Higher Hg concentrations in fish were observed at the location farthest from the dam. Hg concentrations in water and sediment were correlated. Compared with the reservoirs of United States and Canada, TGR had lower trophic magnification factors (0.046–0.066), that are explained primarily by organic carbon concentrations in sediment, and the effect of “growth dilution”. Based on comparison before and after the impoundment of TGR, THg concentration in biota did not display an obvious long-term reservoir effect due to (i) short time since inundation, (ii) regular water discharge associated with water-level regulation, and/or (iii) low organic matter content in the sediment. - Highlights: • Hg concentrations were measured in biota of the main stem of 3 Gorges Reservoir. • Fish Hg concentration post-flood period > pre-flood period > flood period. • Fish Hg concentrations were the highest farthest from the dam. • THg in fish 2 years after inundation were the same as before impoundment. • Low biomagnification was ascribed to low DOC content in the sediment.

  3. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel

    2017-01-01

    This textbook is appropriate for use in graduate-level curricula in analog-to-digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters. It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation. This book presents an overview of the state of the art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, third edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 22-nm technology and the need for a more statistical approach to accuracy. Pedagogical enhancements to this edition include additional, new exercises, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate. Considerable background information and practical tips, from designing a PCB, to lay-o...

  4. Analogies between antiferromagnets and antiferroelectrics

    International Nuclear Information System (INIS)

    Enz, C.P.; Matthias, B.T.

    1980-01-01

    Ferro- and antiferromagnetism in the Laves phase TiBesub(2-x) Cusub(x) occurs for 0.1 4 H 2 PO 4 and its solid solutions with TlH 2 PO 4 and with the ferroelectric KH 2 PO 4 are discussed as function of deuteration and of pressure. Another analogy as function of pressure is established with the antiferroelectric perovskite PbZrO 3 . (author)

  5. Novel phosphanucleoside analogs of dideoxynucleosides

    Czech Academy of Sciences Publication Activity Database

    Páv, Ondřej; Buděšínský, Miloš; Rosenberg, Ivan

    2017-01-01

    Roč. 73, č. 34 (2017), s. 5220-5228 ISSN 0040-4020 R&D Projects: GA ČR(CZ) GA17-12703S; GA ČR GA13-26526S; GA MZd NV15-31604A Institutional support: RVO:61388963 Keywords : phosphanucleoside * nucleoside analog * ring-closing metathesis * stereoselective hydroboration * chiral resolution Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 2.651, year: 2016

  6. Correlation functions and susceptibilities of photonics band gap reservoirs

    International Nuclear Information System (INIS)

    Konopka, M.

    1998-01-01

    We investigate quantum statistical properties of photonic band gap reservoirs in terms of correlation functions and susceptibilities in time and spectral domains. Typical features are oscillations of the time-dependent correlation functions and susceptibilities. This is because photonic bad gap reservoirs are intrinsically non-Markovian reservoirs. The results help us to understand better how intrinsic quantum-statistical properties of a reservoir influence dynamics of an atom interacting with this reservoir. Boundary conditions influence time and spectral properties of the electromagnetic field. This well-known fact has a great importance in optics and generally in electromagnetism. Specific examples are resonators used in laser technique and cavity electrodynamics. In quantum optics high-Q micro cavities are used for single-atom experiments when an atom can interact in a coherent way with an electromagnetic field which has its mode structure totally different from those in free space. In particular, interaction of an (effectively) two-level atom with a single-mode cavity field was observed in the region of microwaves (with the wavelength about 1 cm). In 1987 Yablonovitch and John independently proposed that certain periodic dielectric structures can present forbidden frequency gaps (or pseudo gaps in partially disordered structures) for transverse modes. Such periodic structures were named 'photonic band structures' or 'photonic crystals', in analogy with electronic crystals which also have a (forbidden) gap for electronic energy. For true photonic crystals the basic property of blocking electromagnetic wave propagation must be fulfilled for all waves within some frequency range, i.e. for all wavevector and polarization directions

  7. Geological storage of CO2

    International Nuclear Information System (INIS)

    Czernichowski-Lauriol, I.

    2005-01-01

    The industrial storage of CO 2 is comprised of three steps: - capture of CO 2 where it is produced (power plants, cement plants, etc.); - transport (pipe lines or boats); - storage, mainly underground, called geological sequestration... Three types of reservoirs are considered: - salted deep aquifers - they offer the biggest storage capacity; - exhausted oil and gas fields; - non-exploited deep coal mine streams. The two latter storage types may allow the recovery of sellable products, which partially or totally offsets the storage costs. This process is largely used in the petroleum industry to improve the productivity of an oil field, and is called FOR (Enhanced Oil Recovery). A similar process is applied in the coal mining industry to recover the imprisoned gas, and is called ECBM (Enhanced Coal Bed methane). Two storage operations have been initiated in Norway and in Canada, as well as research programmes in Europe, North America, Australia and Japan. International organisations to stimulate this technology have been created such as the 'Carbon Sequestration Leadership Forum' and 'the Intergovernmental Group for Climate Change'. This technology will be taken into account in the instruments provided by the Tokyo Protocol. (author)

  8. Electrostatic analogy for symmetron gravity

    Science.gov (United States)

    Ogden, Lillie; Brown, Katherine; Mathur, Harsh; Rovelli, Kevin

    2017-12-01

    The symmetron model is a scalar-tensor theory of gravity with a screening mechanism that suppresses the effect of the symmetron field at high densities characteristic of the Solar System and laboratory scales but allows it to act with gravitational strength at low density on the cosmological scale. We elucidate the screening mechanism by showing that in the quasistatic Newtonian limit there are precise analogies between symmetron gravity and electrostatics for both strong and weak screening. For strong screening we find that large dense bodies behave in a manner analogous to perfect conductors in electrostatics. Based on this analogy we find that the symmetron field exhibits a lightning rod effect wherein the field gradients are enhanced near the ends of pointed or elongated objects. An ellipsoid placed in a uniform symmetron gradient is shown to experience a torque. By symmetry there is no gravitational torque in this case. Hence this effect unmasks the symmetron and might serve as the basis for future laboratory experiments. The symmetron force between a point mass and a large dense body includes a component corresponding to the interaction of the point mass with its image in the larger body. None of these effects have counterparts in the Newtonian limit of Einstein gravity. We discuss the similarities between symmetron gravity and the chameleon model as well as the differences between the two.

  9. Centralized versus distributed reservoirs: an investigation of their implications on environmental flows and sustainable water resources management

    Directory of Open Access Journals (Sweden)

    N. Eriyagama

    2018-06-01

    Full Text Available Storage of surface water is widely regarded as a form of insurance against rainfall variability. However, creation of surface storage often endanger the functions of natural ecosystems, and, in turn, ecosystem services that benefit humans. The issues of optimal size, placement and the number of reservoirs in a river basin – which maximizes sustainable benefits from storage – remain subjects for debate. This study examines the above issues through the analysis of a range of reservoir configurations in the Malwatu Oya river basin in the dry zone of Sri Lanka. The study produced multiple surface storage development pathways for the basin under different scenarios of environmental flow (EF releases and reservoir network configurations. The EF scenarios ranged from zero to very healthy releases. It is shown that if the middle ground between the two extreme EF scenarios is considered, the theoretical maximum safe yield from surface storage is about 65–70 % of the mean annual runoff (MAR of the basin. It is also identified that although distribution of reservoirs in the river network reduces the cumulative yield from the basin, this cumulative yield is maximized if the ratio among the storage capacities placed in each sub drainage basin is equivalent to the ratio among their MAR. The study suggests a framework to identify drainage regions having higher surface storage potential, to plan for the right distribution of storage capacity within a river basin, as well as to plan for EF allocations.

  10. Centralized versus distributed reservoirs: an investigation of their implications on environmental flows and sustainable water resources management

    Science.gov (United States)

    Eriyagama, Nishadi; Smakhtin, Vladimir; Udamulla, Lakshika

    2018-06-01

    Storage of surface water is widely regarded as a form of insurance against rainfall variability. However, creation of surface storage often endanger the functions of natural ecosystems, and, in turn, ecosystem services that benefit humans. The issues of optimal size, placement and the number of reservoirs in a river basin - which maximizes sustainable benefits from storage - remain subjects for debate. This study examines the above issues through the analysis of a range of reservoir configurations in the Malwatu Oya river basin in the dry zone of Sri Lanka. The study produced multiple surface storage development pathways for the basin under different scenarios of environmental flow (EF) releases and reservoir network configurations. The EF scenarios ranged from zero to very healthy releases. It is shown that if the middle ground between the two extreme EF scenarios is considered, the theoretical maximum safe yield from surface storage is about 65-70 % of the mean annual runoff (MAR) of the basin. It is also identified that although distribution of reservoirs in the river network reduces the cumulative yield from the basin, this cumulative yield is maximized if the ratio among the storage capacities placed in each sub drainage basin is equivalent to the ratio among their MAR. The study suggests a framework to identify drainage regions having higher surface storage potential, to plan for the right distribution of storage capacity within a river basin, as well as to plan for EF allocations.

  11. Detecting the leakage source of a reservoir using isotopes.

    Science.gov (United States)

    Yi, Peng; Yang, Jing; Wang, Yongdong; Mugwanezal, Vincent de Paul; Chen, Li; Aldahan, Ala

    2018-07-01

    A good monitoring method is vital for understanding the sources of a water reservoir leakage and planning for effective restoring. Here we present a combination of several tracers ( 222 Rn, oxygen and hydrogen isotopes, anions and temperature) for identification of water leakage sources in the Pushihe pumped storage power station which is in the Liaoning province, China. The results show an average 222 Rn activity of 6843 Bq/m 3 in the leakage water, 3034 Bq/m 3 in the reservoir water, and 41,759 Bq/m 3 in the groundwater. Considering that 222 Rn activity in surface water is typically less than 5000 Bq/m 3 , the low level average 222 Rn activity in the leakage water suggests the reservoir water as the main source of water. Results of the oxygen and hydrogen isotopes show comparable ranges and values in the reservoir and the leakage water samples. However, important contribution of the groundwater (up to 36%) was present in some samples from the bottom and upper parts of the underground powerhouse, while the leakage water from some other parts indicate the reservoir water as the dominant source. The isotopic finding suggests that the reservoir water is the main source of the leakage water which is confirmed by the analysis of anions (nitrate, sulfate, and chloride) in the water samples. The combination of these tracer methods for studying dam water leakage improves the accuracy of identifying the source of leaks and provide a scientific reference for engineering solutions to ensure the dam safety. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. The RHIC general purpose multiplexed analog to digital converter system

    International Nuclear Information System (INIS)

    Michnoff, R.

    1995-01-01

    A general purpose multiplexed analog to digital converter system is currently under development to support acquisition of analog signals for the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. The system consists of a custom intelligent VME based controller module (V113) and a 14-bit 64 channel multiplexed A/D converter module (V114). The design features two independent scan groups, where one scan group is capable of acquiring 64 channels at 60 Hz, concurrently with the second scan group acquiring data at an aggregate rate of up to 80 k samples/second. An interface to the RHIC serially encoded event line is used to synchronize acquisition. Data is stored in a circular static RAM buffer on the controller module, then transferred to a commercial VMEbus CPU board and higher level workstations for plotting, report Generation, analysis and storage

  13. Bathymetric maps and water-quality profiles of Table Rock and North Saluda Reservoirs, Greenville County, South Carolina

    Science.gov (United States)

    Clark, Jimmy M.; Journey, Celeste A.; Nagle, Doug D.; Lanier, Timothy H.

    2014-01-01

    Lakes and reservoirs are the water-supply source for many communities. As such, water-resource managers that oversee these water supplies require monitoring of the quantity and quality of the resource. Monitoring information can be used to assess the basic conditions within the reservoir and to establish a reliable estimate of storage capacity. In April and May 2013, a global navigation satellite system receiver and fathometer were used to collect bathymetric data, and an autonomous underwater vehicle was used to collect water-quality and bathymetric data at Table Rock Reservoir and North Saluda Reservoir in Greenville County, South Carolina. These bathymetric data were used to create a bathymetric contour map and stage-area and stage-volume relation tables for each reservoir. Additionally, statistical summaries of the water-quality data were used to provide a general description of water-quality conditions in the reservoirs.

  14. The Development of Analogical Reasoning Processes.

    Science.gov (United States)

    Sternberg, Robert J.; Rifkin, Bathsheva

    1979-01-01

    Two experiments were conducted to test the generalizability to children of a theory of analogical reasoning processes, originally proposed for adults, and to examine the development of analogical reasoning processes in terms of five proposed sources of cognitive development. (MP)

  15. 16-channel analog store and multiplexer unit

    Energy Technology Data Exchange (ETDEWEB)

    Brossard, M; Kulka, Z [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire

    1979-03-15

    A 16-channel analog store and multiplexer unit is described. The unit enables storing and selection of analog information which is then digitally encoded by single ADC. This solution becomes economically attractive particularly in multidetector pulse height analysis systems.

  16. Underground storage of natural gas in Italy

    International Nuclear Information System (INIS)

    Henking, E.

    1992-01-01

    After first relating the importance of natural gas storage to the viability of Italian industrial activities, this paper discusses the geo-physical nature of different types of underground cavities which can be used for natural gas storage. These include depleted petroleum and natural gas reservoirs, aquifers and abandoned mines. Attention is given to the geologic characteristics and physical characteristics such as porosity, permeability and pressure that determine the suitability of any given storage area, and to the techniques used to resolve problems relative to partially depleted reservoirs, e.g., the presence of oil, water and salt. A review is made of Italy's main storage facilities. This review identifies the various types of storage techniques, major equipment, operating and maintenance practices. A look is then given at Italy's plans for the development of new facilities to meet rising demand expected to reach 80 billion cubic meters/year by the turn of the century. The operating activities of the two leading participants, SNAM and AGIP, in Italy's natural gas industry are highlighted. Specific problems which contribute to the high operating costs of natural gas storage are identified and a review is made of national normatives governing gas storage. The report comes complete with a glossary of the relative terminology and units of measure

  17. Possibilities of rationalizing gas storage in hydrocarbon deposits

    International Nuclear Information System (INIS)

    Stricker; Gilch; Kretzschmar

    1990-01-01

    A number of criteria on the utilization of gas fields for storage and major methods for rationalizing such storage reservoirs (such as pressure optimization and increase of well performance) are indicated. The pressure reduction/ pressure increase conducted in phases and the investigations involved are discussed in detail. In particular, experiences and results for fixing the maximum allowable storage pressures are analyzed critically. Problems of gas blending in case of different compositions of residual gas and storage gas are dealt with. Finally, some recommendations are given for the necessary investigations to increase efficiency in the conversion of depleted hydrocarbon deposits to gas storage. 3 figs

  18. Atheism and Analogy: Aquinas Against the Atheists

    OpenAIRE

    Linford, Daniel J.

    2014-01-01

    In the 13th century, Thomas Aquinas developed two models for how humans may speak of God - either by the analogy of proportion or by the analogy of proportionality. Aquinas's doctrines initiated a theological debate concerning analogy that spanned several centuries. In the 18th century, there appeared two closely related arguments for atheism which both utilized analogy for their own purposes. In this thesis, I show that one argument, articulated by the French materialist Paul-Henri Thiry Bar...

  19. Enhancing programming logic thinking using analogy mapping

    Science.gov (United States)

    Sukamto, R. A.; Megasari, R.

    2018-05-01

    Programming logic thinking is the most important competence for computer science students. However, programming is one of the difficult subject in computer science program. This paper reports our work about enhancing students' programming logic thinking using Analogy Mapping for basic programming subject. Analogy Mapping is a computer application which converts source code into analogies images. This research used time series evaluation and the result showed that Analogy Mapping can enhance students' programming logic thinking.

  20. Mechanistic Processes Controlling Gas Sorption in Shale Reservoirs

    Science.gov (United States)

    Schaef, T.; Loring, J.; Ilton, E. S.; Davidson, C. L.; Owen, T.; Hoyt, D.; Glezakou, V. A.; McGrail, B. P.; Thompson, C.

    2014-12-01

    Utilization of CO2 to stimulate natural gas production in previously fractured shale-dominated reservoirs where CO2 remains in place for long-term storage may be an attractive new strategy for reducing the cost of managing anthropogenic CO2. A preliminary analysis of capacities and potential revenues in US shale plays suggests nearly 390 tcf in additional gas recovery may be possible via CO2 driven enhanced gas recovery. However, reservoir transmissivity properties, optimum gas recovery rates, and ultimate fate of CO2 vary among reservoirs, potentially increasing operational costs and environmental risks. In this paper, we identify key mechanisms controlling the sorption of CH4 and CO2 onto phyllosilicates and processes occurring in mixed gas systems that have the potential of impacting fluid transfer and CO2 storage in shale dominated formations. Through a unique set of in situ experimental techniques coupled with molecular-level simulations, we identify structural transformations occurring to clay minerals, optimal CO2/CH4 gas exchange conditions, and distinguish between adsorbed and intercalated gases in a mixed gas system. For example, based on in situ measurements with magic angle spinning NMR, intercalation of CO2 within the montmorillonite structure occurs in CH4/CO2 gas mixtures containing low concentrations (hydrocarbon recovery processes.

  1. Energy storage

    Energy Technology Data Exchange (ETDEWEB)

    1962-07-01

    The papers on energy storage problems, given to the United Nations Conference on New Sources of Energy, Rome, 1961, are reviewed. Many aspects of the subject are discussed: comparisons between the costs of storing energy in batteries and in fuel cells; the use, efficiency and expected improvement of fuel cells; the principles involved in the chemical conversion of solar energy to chemical energy; the use of metal hydride fuel cells; the chemical conversion and storage of concentrated solar energy for which the solar furnace is used for photochemical reactions. Finally, the general costs of storing energy in any form and delivering it are analyzed with particular reference to storage batteries and fuel cells.

  2. Analogies and the 5E Model

    Science.gov (United States)

    Orgill, Mary Kay; Thomas, Megan

    2007-01-01

    Science classes are full of abstract or challenging concepts that are easier to understand if an analogy is used to illustrate the points. Effective analogies motivate students, clarify students' thinking, help students overcome misconceptions, and give students ways to visualize abstract concepts. When they are used appropriately, analogies can…

  3. Science Teachers' Analogical Reasoning

    Science.gov (United States)

    Mozzer, Nilmara Braga; Justi, Rosária

    2013-01-01

    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to…

  4. The Micro-Category Account of Analogy

    Science.gov (United States)

    Green, Adam E.; Fugelsang, Jonathan A.; Kraemer, David J. M.; Dunbar, Kevin N.

    2008-01-01

    Here, we investigate how activation of mental representations of categories during analogical reasoning influences subsequent cognitive processing. Specifically, we present and test the central predictions of the "Micro-Category" account of analogy. This account emphasizes the role of categories in aligning terms for analogical mapping. In a…

  5. Cold reservoir integrated into a brine circuit of energy roofing, coupled to a heat pump

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, M.

    1983-12-01

    Model studies are presented in which the economic effects of a cold reservoir integrated in a heat pump system were established. Cold reservoirs have the following advantages: 1. The absolute annual savings increase with the storage volume. Storage volumes of 1 to 10 m/sup 3/ are economical, depending on the mode of operation. 2. If the storage volume is sufficiently large, the heat pump (operated in a bivalent, parallel system) can supply a considerable amount of the required even below the design temperature. 3. With a sufficiently large storage volume, the heat pump may be operated in more or less monovalent mode even if the heat pump has not been designed for a minimum ambient temperature.

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

    Science.gov (United States)

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

    2013-12-01

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

  7. Cloud computing and Reservoir project

    International Nuclear Information System (INIS)

    Beco, S.; Maraschini, A.; Pacini, F.; Biran, O.

    2009-01-01

    The support for complex services delivery is becoming a key point in current internet technology. Current trends in internet applications are characterized by on demand delivery of ever growing amounts of content. The future internet of services will have to deliver content intensive applications to users with quality of service and security guarantees. This paper describes the Reservoir project and the challenge of a reliable and effective delivery of services as utilities in a commercial scenario. It starts by analyzing the needs of a future infrastructure provider and introducing the key concept of a service oriented architecture that combines virtualisation-aware grid with grid-aware virtualisation, while being driven by business service management. This article will then focus on the benefits and the innovations derived from the Reservoir approach. Eventually, a high level view of Reservoir general architecture is illustrated.

  8. Multilevel techniques for Reservoir Simulation

    DEFF Research Database (Denmark)

    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...... is extended to include a hybrid strategy, where FAS is combined with Newton’s method to construct a multilevel nonlinear preconditioner. This method demonstrates high efficiency and robustness. Second, an improved IMPES formulated reservoir simulator is implemented using a novel variational upscaling approach...

  9. Carbon Sequestration in Unconventional Reservoirs: Geophysical, Geochemical and Geomechanical Considerations

    Science.gov (United States)

    Zakharova, Natalia V.

    In the face of the environmental challenges presented by the acceleration of global warming, carbon capture and storage, also called carbon sequestration, may provide a vital option to reduce anthropogenic carbon dioxide emissions, while meeting the world's energy demands. To operate on a global scale, carbon sequestration would require thousands of geologic repositories that could accommodate billions of tons of carbon dioxide per year. In order to reach such capacity, various types of geologic reservoirs should be considered, including unconventional reservoirs such as volcanic rocks, fractured formations, and moderate-permeability aquifers. Unconventional reservoirs, however, are characterized by complex pore structure, high heterogeneity, and intricate feedbacks between physical, chemical and mechanical processes, and their capacity to securely store carbon emissions needs to be confirmed. In this dissertation, I present my contribution toward the understanding of geophysical, geochemical, hydraulic, and geomechanical properties of continental basalts and fractured sedimentary formations in the context of their carbon storage capacity. The data come from two characterization projects, in the Columbia River Flood Basalt in Washington and the Newark Rift Basin in New York, funded by the U.S. Department of Energy through Big Sky Carbon Sequestration Partnerships and TriCarb Consortium for Carbon Sequestration. My work focuses on in situ analysis using borehole geophysical measurements that allow for detailed characterization of formation properties on the reservoir scale and under nearly unaltered subsurface conditions. The immobilization of injected CO2 by mineralization in basaltic rocks offers a critical advantage over sedimentary reservoirs for long-term CO2 storage. Continental flood basalts, such as the Columbia River Basalt Group, possess a suitable structure for CO2 storage, with extensive reservoirs in the interflow zones separated by massive impermeable

  10. Digitizing high frequency signals using serial analog memories

    International Nuclear Information System (INIS)

    Coonrod, J.W.

    1975-10-01

    An online computer system has been developed as a replacement for oscilloscopes and cameras on the Tormac project. Up to 32 simultaneous waveforms are recorded at up to 2 MHz in analog shift registers, then digitized sequentially after the event into a small PDP-11 computer. Data and functions of data may be displayed or plotted locally, and then forwarded for storage at a larger, remote computer via a network arrangement. Advantages over scopes have been lower incremental cost (approximately $200/channel), less noise pickup, better resolution (less than 1%), and immediate presentation of data

  11. A CO2-storage supply curve for North America and its implications for the deployment of carbon dioxide capture and storage systems

    International Nuclear Information System (INIS)

    Dooley, J.J.; Bachu, S.; Gupta, N.; Gale, J.

    2005-01-01

    This paper presented a highly disaggregated estimate of carbon dioxide (CO 2 )-storage capacity of more than 330 onshore geological reservoirs across the United States and Canada. The demand placed upon these reservoirs by thousands of existing large anthropogenic CO 2 point sources was also reviewed based on a newly developed methodology for estimating the effective storage capacities of deep saline formations, depleted oil and gas reservoirs, and deep unmineable coal seams. This analysis was based on matching the identified point sources with candidate storage reservoirs. By incorporating the updated source and reservoir data into the Battelle CO 2 -GIS, a series of pairwise costs for transporting CO 2 from sites of anthropogenic CO 2 sources was calculated along with the net cost of storing it in each of the candidate reservoirs within a specified distance of the point source. Results indicate a large and variably distributed North American storage capacity of at least 3,800 gigatonnes of CO 2 , with deep saline formations accounting for most of this capacity. A geospatial and techno-economic database of 2,082 anthropogenic CO 2 point sources in North America, each with annual emissions greater than 100,000 tonnes of CO 2 , was also refined. Sensitivities examined for the CO 2 -storage cost curve focused on high/low oil and gas prices; the maximum allowed distance between source and reservoir; and, the infrastructure costs associated with CO 2 -driven hydrocarbon recovery. 20 refs., 5 figs

  12. Reservoir effects in radiocarbon dating

    International Nuclear Information System (INIS)

    Head, M.J.

    1997-01-01

    Full text: The radiocarbon dating technique depends essentially on the assumption that atmospheric carbon dioxide containing the cosmogenic radioisotope 14 C enters into a state of equilibrium with all living material (plants and animals) as part of the terrestrial carbon cycle. Terrestrial reservoir effects occur when the atmospheric 14 C signal is diluted by local effects where systems depleted in 14 C mix with systems that are in equilibrium with the atmosphere. Naturally, this can occur with plant material growing close to an active volcano adding very old CO 2 to the atmosphere (the original 14 C has completely decayed). It can also occur in highly industrialised areas where fossil fuel derived CO 2 dilutes the atmospheric signal. A terrestrial reservoir effect can occur in the case of fresh water shells living in rivers or lakes where there is an input of ground water from springs or a raising of the water table. Soluble bicarbonate derived from the dissolution of very old limestone produces a 14 C dilution effect. Land snail shells and stream carbonate depositions (tufas and travertines) can be affected by a similar mechanism. Alternatively, in specific cases, these reservoir effects may not occur. This means that general interpretations assuming quantitative values for these terrestrial effects are not possible. Each microenvironment associated with samples being analysed needs to be evaluated independently. Similarly, the marine environment produces reservoir effects. With respect to marine shells and corals, the water depth at which carbonate growth occurs can significantly affect quantitative 14 C dilution, especially in areas where very old water is uplifted, mixing with top layers of water that undergo significant exchange with atmospheric CO 2 . Hence, generalisations with respect to the marine reservoir effect also pose problems. These can be exacerbated by the mixing of sea water with either terrestrial water in estuaries, or ground water where

  13. Geological Model of Supercritical Geothermal Reservoir on the Top of the Magma Chamber

    Science.gov (United States)

    Tsuchiya, N.

    2017-12-01

    We are conducting supercritical geothermal project, and deep drilling project named as "JBBP: Japan Beyond Brittle Project" The temperatures of geothermal fields operating in Japan range from 200 to 300 °C (average 250 °C), and the depths range from 1000 to 2000 m (average 1500 m). In conventional geothermal reservoirs, the mechanical behavior of the rocks is presumed to be brittle, and convection of the hydrothermal fluid through existing network is the main method of circulation in the reservoir. In order to minimize induced seismicity, a rock mass that is "beyond brittle" is one possible candidate, because the rock mechanics of "beyond brittle" material is one of plastic deformation rather than brittle failure. To understand the geological model of a supercritical geothermal reservoir, granite-porphyry system, which had been formed in subduction zone, was investigated as a natural analog of the supercritical geothermal energy system. Quartz veins, hydrothermal breccia veins, and glassy veins are observed in a granitic body. The glassy veins formed at 500-550 °C under lithostatic pressures, and then pressures dropped drastically. The solubility of silica also dropped, resulting in formation of quartz veins under a hydrostatic pressure regime. Connections between the lithostatic and hydrostatic pressure regimes were key to the formation of the hydrothermal breccia veins, and the granite-porphyry system provides useful information for creation of fracture clouds in supercritical geothermal reservoirs. A granite-porphyry system, associated with hydrothermal activity and mineralization, provides a suitable natural analog for studying a deep-seated geothermal reservoir where stockwork fracture systems are created in the presence of supercritical geothermal fluids. I describe fracture networks and their formation mechanisms using petrology and fluid inclusion studies in order to understand this "beyond brittle" supercritical geothermal reservoir, and a geological

  14. Are all analogies created equal? Prefrontal cortical functioning may predict types of analogical reasoning.

    Science.gov (United States)

    Chrysikou, Evangelia G; Thompson-Schill, Sharon L

    2010-06-01

    Abstract The proposed theory can account for analogies based on learned relationships between elements in the source and target domains. However, its explanatory power regarding the discovery of new relationships during analogical reasoning is limited. We offer an alternative perspective for the role of PFC in analogical thought that may better address different types of analogical mappings.

  15. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    Energy Technology Data Exchange (ETDEWEB)

    P. K. Pande

    1998-10-29

    Initial 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 reservoirs, and carbonate reservoirs in particular. These reservoirs are typically characterized by: o Large, discontinuous pay intervals o Vertical and lateral changes in reservoir properties o Low reservoir energy o High residual oil saturation o Low recovery efficiency

  16. Sedimentological and Geomorphological Effects of Reservoir Flushing: The Cachi Reservoir, Costa Rica, 1996

    DEFF Research Database (Denmark)

    Brandt, Anders; Swenning, Joar

    1999-01-01

    Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs......Physical geography, hydrology, geomorphology, sediment transport, erosion, sedimentation, dams, reservoirs...

  17. Practical analog electronics for technicians

    CERN Document Server

    Kimber, W A

    2013-01-01

    'Practical Analog Electronics for Technicians' not only provides an accessible introduction to electronics, but also supplies all the problems and practical activities needed to gain hands-on knowledge and experience. This emphasis on practice is surprisingly unusual in electronics texts, and has already gained Will Kimber popularity through the companion volume, 'Practical Digital Electronics for Technicians'. Written to cover the Advanced GNVQ optional unit in electronics, this book is also ideal for BTEC National, A-level electronics and City & Guilds courses. Together with 'Practical Digit

  18. Analog and mixed-signal electronics

    CERN Document Server

    Stephan, Karl

    2015-01-01

    A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

  19. Analog circuit design art, science, and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

  20. PREDICTION OF RESERVOIR FLOW RATE OF DEZ DAM BY THE PROBABILITY MATRIX METHOD

    Directory of Open Access Journals (Sweden)

    Mohammad Hashem Kanani

    2012-12-01

    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.

  1. Rapid heterogeneous assembly of multiple magma reservoirs prior to Yellowstone supereruptions.

    Science.gov (United States)

    Wotzlaw, Jörn-Frederik; Bindeman, Ilya N; Stern, Richard A; D'Abzac, Francois-Xavier; Schaltegger, Urs

    2015-09-10

    Large-volume caldera-forming eruptions of silicic magmas are an important feature of continental volcanism. The timescales and mechanisms of assembly of the magma reservoirs that feed such eruptions as well as the durations and physical conditions of upper-crustal storage remain highly debated topics in volcanology. Here we explore a comprehensive data set of isotopic (O, Hf) and chemical proxies in precisely U-Pb dated zircon crystals from all caldera-forming eruptions of Yellowstone supervolcano. Analysed zircons record rapid assembly of multiple magma reservoirs by repeated injections of isotopically heterogeneous magma batches and short pre-eruption storage times of 10(3) to 10(4) years. Decoupled oxygen-hafnium isotope systematics suggest a complex source for these magmas involving variable amounts of differentiated mantle-derived melt, Archean crust and hydrothermally altered shallow-crustal rocks. These data demonstrate that complex magma reservoirs with multiple sub-chambers are a common feature of rift- and hotspot related supervolcanoes. The short duration of reservoir assembly documents rapid crustal remelting and two to three orders of magnitude higher magma production rates beneath Yellowstone compared to continental arc volcanoes. The short pre-eruption storage times further suggest that the detection of voluminous reservoirs of eruptible magma beneath active supervolcanoes may only be possible prior to an impending eruption.

  2. Erosion index formulation with respect to reservoir life in the upper Citarum watershed

    Directory of Open Access Journals (Sweden)

    Bakhtiar

    2018-01-01

    Full Text Available This study aimed to formulate erosion index in the upper Citarum watershed with respect to the Saguling reservoir life. Soil and Water Assessment Tool model was incorporated to simulate hydrological processes in the catchment. From the calibration and validation results, the model is considerably of good performance. The simulated sediment inflow at Nanjung outlet was then extrapolated to determine the sediment inflow into the reservoir. The study revealed that the average value of sediment inflow into the reservoir is 29.24 tonnes/ha/year just below the tolerable erosion limit of 30 tonnes/ha/year assumed by Hammer (1981. It was also found that the relationship between sediment yield and sediment inflow is non linear. Erosion index is formulated as the ratio between the mean annual sediment yield generated in the watershed and the mean annual sediment yield that leads dead storage to be full in the designated life of the reservoir. Erosion index equals to 1.0 indicates that the dead storage will be full in the designated life of the reservoir. A classification of erosion index can be subsequently be made based on erosion index and reservoir life relationship.

  3. Spillways Scheduling for Flood Control of Three Gorges Reservoir Using Mixed Integer Linear Programming Model

    Directory of Open Access Journals (Sweden)

    Maoyuan Feng

    2014-01-01

    Full Text Available This study proposes a mixed integer linear programming (MILP model to optimize the spillways scheduling for reservoir flood control. Unlike the conventional reservoir operation model, the proposed MILP model specifies the spillways status (including the number of spillways to be open and the degree of the spillway opened instead of reservoir release, since the release is actually controlled by using the spillway. The piecewise linear approximation is used to formulate the relationship between the reservoir storage and water release for a spillway, which should be open/closed with a status depicted by a binary variable. The control order and symmetry rules of spillways are described and incorporated into the constraints for meeting the practical demand. Thus, a MILP model is set up to minimize the maximum reservoir storage. The General Algebraic Modeling System (GAMS and IBM ILOG CPLEX Optimization Studio (CPLEX software are used to find the optimal solution for the proposed MILP model. The China’s Three Gorges Reservoir, whose spillways are of five types with the total number of 80, is selected as the case study. It is shown that the proposed model decreases the flood risk compared with the conventional operation and makes the operation more practical by specifying the spillways status directly.

  4. Future reservoir management under climate change for the Mississippi River

    International Nuclear Information System (INIS)

    Asnaashari, Ahmad; Gharabaghi, Bahram; McBean, Edward A.; Kunjikutty, Sobhalatha; Lehman, Paul; Wade, Winston

    2010-01-01

    This paper is part of an ongoing research project designed to evaluate the effect of climate change on reservoir operation policies in the Mississippi Valley Conservation Authority. The study used the results from a first paper, including projected daily temperature and precipitation, for future streamflow calculation. This paper presented the development, calibration and validation of a rainfall-runoff NAM model for the Mississippi River watershed. The calibrated Mike11/NAM model was fed with predicted climatic data to generate long term future streamflow in the basin. Forecast flows were run in a Mike 11/HD model to estimate the corresponding lake levels. The storages and flows at Shabomeka Lake, Mazinaw Lake and Marble Lake were simulated. The results showed that climate change is likely to have implications for reservoir operations in the Mississippi River watershed, which will include changed water level regimes due to modifications in the projected future streamflow hydrograph to meet desired lake levels.

  5. Screening reservoir systems by considering the efficient trade-offs—informing infrastructure investment decisions on the Blue Nile

    Science.gov (United States)

    Geressu, Robel T.; Harou, Julien J.

    2015-12-01

    Multi-reservoir system planners should consider how new dams impact downstream reservoirs and the potential contribution of each component to coordinated management. We propose an optimized multi-criteria screening approach to identify best performing designs, i.e., the selection, size and operating rules of new reservoirs within multi-reservoir systems. Reservoir release operating rules and storage sizes are optimized concurrently for each separate infrastructure design under consideration. Outputs reveal system trade-offs using multi-dimensional scatter plots where each point represents an approximately Pareto-optimal design. The method is applied to proposed Blue Nile River reservoirs in Ethiopia, where trade-offs between total and firm energy output, aggregate storage and downstream irrigation and energy provision for the best performing designs are evaluated. This proof-of concept study shows that recommended Blue Nile system designs would depend on whether monthly firm energy or annual energy is prioritized. 39 TWh/yr of energy potential is available from the proposed Blue Nile reservoirs. The results show that depending on the amount of energy deemed sufficient, the current maximum capacities of the planned reservoirs could be larger than they need to be. The method can also be used to inform which of the proposed reservoir type and their storage sizes would allow for the highest downstream benefits to Sudan in different objectives of upstream operating objectives (i.e., operated to maximize either average annual energy or firm energy). The proposed approach identifies the most promising system designs, reveals how they imply different trade-offs between metrics of system performance, and helps system planners asses the sensitivity of overall performance to the design parameters of component reservoirs.

  6. Analogical reasoning in schizophrenic delusions.

    Science.gov (United States)

    Simpson, Jane; Done, D John

    2004-09-01

    Reasoning ability has often been argued to be impaired in people with schizophrenic delusions, although evidence for this is far from convincing. This experiment examined the analogical reasoning abilities of several groups of patients, including non-deluded and deluded schizophrenics, to test the hypothesis that performance by the deluded schizophrenic group would be impaired. Eleven deluded schizophrenics, 10 depressed subjects, seven non-deluded schizophrenics and 16 matched non-psychiatric controls, who were matched on a number of key variables, were asked to solve an analogical reasoning task. Performance by the deluded schizophrenic group was certainly impaired when compared with the depressed and non-psychiatric control groups though less convincingly so when compared with the non-deluded schizophrenic group. The impairment shown by the deluded schizophrenic group seemed to occur at the initial stage of the reasoning task. The particular type of impairment shown by the deluded subjects was assessed in relation to other cognitive problems already researched and the implications of these problems on reasoning tasks and theories of delusions was discussed.

  7. Reliability of analog quantum simulation

    Energy Technology Data Exchange (ETDEWEB)

    Sarovar, Mohan [Sandia National Laboratories, Digital and Quantum Information Systems, Livermore, CA (United States); Zhang, Jun; Zeng, Lishan [Shanghai Jiao Tong University, Joint Institute of UMich-SJTU, Key Laboratory of System Control and Information Processing (MOE), Shanghai (China)

    2017-12-15

    Analog quantum simulators (AQS) will likely be the first nontrivial application of quantum technology for predictive simulation. However, there remain questions regarding the degree of confidence that can be placed in the results of AQS since they do not naturally incorporate error correction. Specifically, how do we know whether an analog simulation of a quantum model will produce predictions that agree with the ideal model in the presence of inevitable imperfections? At the same time there is a widely held expectation that certain quantum simulation questions will be robust to errors and perturbations in the underlying hardware. Resolving these two points of view is a critical step in making the most of this promising technology. In this work we formalize the notion of AQS reliability by determining sensitivity of AQS outputs to underlying parameters, and formulate conditions for robust simulation. Our approach naturally reveals the importance of model symmetries in dictating the robust properties. To demonstrate the approach, we characterize the robust features of a variety of quantum many-body models. (orig.)

  8. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J. M

    2013-01-01

    This textbook is appropriate for use in graduate-level curricula in analog to digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters.  It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation.  This book presents an overview of the state-of-the-art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, second edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 45-nm technology and the need for a more statistical approach to accuracy.  Pedagogical enhancements to this edition include more than twice the exercises available in the first edition, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate.  Considerable background information and pr...

  9. Developing Novel Reservoir Rule Curves Using Seasonal Inflow Projections

    Science.gov (United States)

    Tseng, Hsin-yi; Tung, Ching-pin

    2015-04-01

    Due to significant seasonal rainfall variations, reservoirs and their flexible operational rules are indispensable to Taiwan. Furthermore, with the intensifying impacts of climate change on extreme climate, the frequency of droughts in Taiwan has been increasing in recent years. Drought is a creeping phenomenon, the slow onset character of drought makes it difficult to detect at an early stage, and causes delays on making the best decision of allocating water. For these reasons, novel reservoir rule curves using projected seasonal streamflow are proposed in this study, which can potentially reduce the adverse effects of drought. This study dedicated establishing new rule curves which consider both current available storage and anticipated monthly inflows with leading time of two months to reduce the risk of water shortage. The monthly inflows are projected based on the seasonal climate forecasts from Central Weather Bureau (CWB), which a weather generation model is used to produce daily weather data for the hydrological component of the GWLF. To incorporate future monthly inflow projections into rule curves, this study designs a decision flow index which is a linear combination of current available storage and inflow projections with leading time of 2 months. By optimizing linear relationship coefficients of decision flow index, the shape of rule curves and the percent of water supply in each zone, the best rule curves to decrease water shortage risk and impacts can be developed. The Shimen Reservoir in the northern Taiwan is used as a case study to demonstrate the proposed method. Existing rule curves (M5 curves) of Shimen Reservoir are compared with two cases of new rule curves, including hindcast simulations and historic seasonal forecasts. The results show new rule curves can decrease the total water shortage ratio, and in addition, it can also allocate shortage amount to preceding months to avoid extreme shortage events. Even though some uncertainties in

  10. Offshore Storage Resource Assessment - FINAL SCIENTIFIC/TECHNICAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Savage, Bill [NITEC LLC; Ozgen, Chet [NITEC LLC

    2017-12-13

    The DOE developed volumetric equation for estimating Prospective Resources (CO2 storage) in oil and gas reservoirs was utilized on each depleted field in the Federal GOM. This required assessment of the in-situ hydrocarbon fluid volumes for the fields under evaluation in order to apply the DOE equation. This project utilized public data from the U.S. Department of the Interior, Bureau of Ocean Energy Management (BOEM) Reserves database and from a well reputed, large database (250,000+ wells) of GOM well and production data marketed by IHS, Inc. IHS interpreted structure map files were also accessed for a limited number of fields. The databases were used along with geological and petrophysical software to identify depleted oil and gas fields in the Federal GOM region. BOEM arranged for access by the project team to proprietary reservoir level maps under an NDA. Review of the BOEM’s Reserves database as of December 31, 2013 indicated that 675 fields in the region were depleted. NITEC identified and rank these 675 fields containing 3,514 individual reservoirs based on BOEM’s estimated OOIP or OGIP values available in the Reserves database. The estimated BOEM OOIP or OGIP values for five fields were validated by an independent evaluation using available petrophysical, geologic and engineering data in the databases. Once this validation was successfully completed, the BOEM ranked list was used to calculate the estimated CO2 storage volume for each field/reservoir using the DOE CO2 Resource Estimate Equation. This calculation assumed a range for the CO2 efficiency factor in the equation, as it was not known at that point in time. NITEC then utilize reservoir simulation to further enhance and refine the DOE equation estimated range of CO2 storage volumes. NITEC used a purpose built, publically available, 4-component, compositional reservoir simulator developed under funding from DOE (DE-FE0006015) to assess CO2-EOR and CO2 storage in 73 fields/461 reservoirs. This

  11. Optimal reservoir operation policies using novel nested algorithms

    Science.gov (United States)

    Delipetrev, Blagoj; Jonoski, Andreja; Solomatine, Dimitri

    2015-04-01

    Historically, the two most widely practiced methods for optimal reservoir operation have been dynamic programming (DP) and stochastic dynamic programming (SDP). These two methods suffer from the so called "dual curse" which prevents them to be used in reasonably complex water systems. The first one is the "curse of dimensionality" that denotes an exponential growth of the computational complexity with the state - decision space dimension. The second one is the "curse of modelling" that requires an explicit model of each component of the water system to anticipate the effect of each system's transition. We address the problem of optimal reservoir operation concerning multiple objectives that are related to 1) reservoir releases to satisfy several downstream users competing for water with dynamically varying demands, 2) deviations from the target minimum and maximum reservoir water levels and 3) hydropower production that is a combination of the reservoir water level and the reservoir releases. Addressing such a problem with classical methods (DP and SDP) requires a reasonably high level of discretization of the reservoir storage volume, which in combination with the required releases discretization for meeting the demands of downstream users leads to computationally expensive formulations and causes the curse of dimensionality. We present a novel approach, named "nested" that is implemented in DP, SDP and reinforcement learning (RL) and correspondingly three new algorithms are developed named nested DP (nDP), nested SDP (nSDP) and nested RL (nRL). The nested algorithms are composed from two algorithms: 1) DP, SDP or RL and 2) nested optimization algorithm. Depending on the way we formulate the objective function related to deficits in the allocation problem in the nested optimization, two methods are implemented: 1) Simplex for linear allocation problems, and 2) quadratic Knapsack method in the case of nonlinear problems. The novel idea is to include the nested

  12. The NAP-M proton storage

    International Nuclear Information System (INIS)

    Bolvanov, Yu.A.; Kononov, V.I.; Kuper, Eh.A.

    1976-01-01

    A system is considered controlling the proton storage unit of NAP-M. The control system operates on line with ODRA-1325 computer. This enables one to process the data directly in the course of the experiment and to control the operating regime of the storage unit. The authors give a detailed description of the principal units of the control system: digital-to-analog converters, equipment for data conveying, and analog-to-digital converters. They describe the control program, which coordinates interaction of the computer with the control system. The control program provides for the possibility of editing the working programs, which realize the elementary operation in the storage unit control cycle

  13. Prevention of Reservoir Interior Discoloration

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, K.F.

    2001-04-03

    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.

  14. Nonlinear Multigrid for Reservoir Simulation

    DEFF Research Database (Denmark)

    Christensen, Max la Cour; Eskildsen, Klaus Langgren; Engsig-Karup, Allan Peter

    2016-01-01

    efficiency for a black-oil model. Furthermore, the use of the FAS method enables a significant reduction in memory usage compared with conventional techniques, which suggests new possibilities for improved large-scale reservoir simulation and numerical efficiency. Last, nonlinear multilevel preconditioning...

  15. The potential of GRACE gravimetry to detect the heavy rainfall-induced impoundment of a small reservoir in the upper Yellow River

    OpenAIRE

    Yi, Shuang; Song, Chunqiao; Wang, Qiuyu; Wang, Linsong; Heki, Kosuke; Sun, Wenke

    2017-01-01

    Artificial reservoirs are important indicators of anthropogenic impacts on environments, and their cumulative influences on the local water storage will change the gravity signal. However, because of their small signal size, such gravity changes are seldom studied using satellite gravimetry from the Gravity Recovery and Climate Experiment (GRACE). Here we investigate the ability of GRACE to detect water storage changes in the Longyangxia Reservoir (LR), which is situated in the uppe...

  16. A pragmatic method for estimating seepage losses for small reservoirs with application in rural India

    Science.gov (United States)

    Oblinger, Jennifer A.; Moysey, Stephen M. J.; Ravindrinath, Rangoori; Guha, Chiranjit

    2010-05-01

    SummaryThe informal construction of small dams to capture runoff and artificially recharge ground water is a widespread strategy for dealing with water scarcity. A lack of technical capacity for the formal characterization of these systems, however, is often an impediment to the implementation of effective watershed management practices. Monitoring changes in reservoir storage provides a conceptually simple approach to quantify seepage, but does not account for the losses occurring when seepage is balanced by inflows to the reservoir and the stage remains approximately constant. To overcome this problem we evaluate whether a physically-based volume balance model that explicitly represents watershed processes, including reservoir inflows, can be constrained by a limited set of data readily collected by non-experts, specifically records of reservoir stage, rainfall, and evaporation. To assess the impact of parameter non-uniqueness associated with the calibration of the non-linear model, we perform a Monte Carlo analysis to quantify uncertainty in the total volume of water contributed to the subsurface by the 2007 monsoon for a dam located in the Deccan basalts near the village of Salri in Madhya Pradesh, India. The Monte Carlo analysis demonstrated that subsurface losses from the reservoir could be constrained with the available data, but additional measurements are required to constrain reservoir inflows. Our estimate of seepage from the reservoir (7.0 ± 0.6 × 10 4 m 3) is 3.5 times greater than the recharge volume estimated by considering reservoir volume changes alone. This result suggests that artificial recharge could be significantly underestimated when reservoir inflows are not explicitly included in models. Our seepage estimate also accounts for about 11% of rainfall occurring upstream of the dam and is comparable in magnitude to natural ground water recharge, thereby indicating that the reservoir plays a significant role in the hydrology of this small

  17. 49 CFR 236.792 - Reservoir, equalizing.

    Science.gov (United States)

    2010-10-01

    ... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of the equalizing piston chamber of the automatic brake valve, to provide uniform service reductions in brake pipe...

  18. RECENT ADVANCES IN NATURALLY FRACTURED RESERVOIR MODELING

    OpenAIRE

    ORDOÑEZ, A; PEÑUELA, G; IDROBO, E. A; MEDINA, C. E

    2001-01-01

    Large amounts of oil reserves are contained in naturally fractured reservoirs. Most of these hydrocarbon volumes have been left behind because of the poor knowledge and/or description methodology of those reservoirs. This lack of knowledge has lead to the nonexistence of good quantitative models for this complicated type of reservoirs. The complexity of naturally fractured reservoirs causes the need for integration of all existing information at all scales (drilling, well logging, seismic, we...

  19. Reservoir resistivity characterization incorporating flow dynamics

    KAUST Repository

    Arango, Santiago; Sun, Shuyu; Hoteit, Ibrahim; Katterbauer, Klemens

    2016-01-01

    Systems and methods for reservoir resistivity characterization are provided, in various aspects, an integrated framework for the estimation of Archie's parameters for a strongly heterogeneous reservoir utilizing the dynamics of the reservoir are provided. The framework can encompass a Bayesian estimation/inversion method for estimating the reservoir parameters, integrating production and time lapse formation conductivity data to achieve a better understanding of the subsurface rock conductivity properties and hence improve water saturation imaging.

  20. Reservoir resistivity characterization incorporating flow dynamics

    KAUST Repository

    Arango, Santiago

    2016-04-07

    Systems and methods for reservoir resistivity characterization are provided, in various aspects, an integrated framework for the estimation of Archie\\'s parameters for a strongly heterogeneous reservoir utilizing the dynamics of the reservoir are provided. The framework can encompass a Bayesian estimation/inversion method for estimating the reservoir parameters, integrating production and time lapse formation conductivity data to achieve a better understanding of the subsurface rock conductivity properties and hence improve water saturation imaging.

  1. Automatic activation of categorical and abstract analogical relations in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N

    2006-10-01

    We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy.

  2. On the suitability of lanthanides as actinide analogs

    International Nuclear Information System (INIS)

    Raymond, Kenneth; Szigethy, Geza

    2008-01-01

    With the current level of actinide materials used in civilian power generation and the need for safe and efficient methods for the chemical separation of these species from their daughter products and for long-term storage requirements, a detailed understanding of actinide chemistry is of great importance. Due to the unique bonding properties of the f-elements, the lanthanides are commonly used as structural and chemical models for the actinides, but differences in the bonding between these 4f and 5f elements has become a question of immediate applicability to separations technology. This brief overview of actinide coordination chemistry in the Raymond group at UC Berkeley/LBNL examines the validity of using lanthanide analogs as structural models for the actinides, with particular attention paid to single crystal X-ray diffraction structures. Although lanthanides are commonly accepted as reasonable analogs for the actinides, these comparisons suggest the careful study of actinide materials independent of their lanthanide analogs to be of utmost importance to present and future efforts in nuclear industries. (authors)

  3. Towards an Improved Represenation of Reservoirs and Water Management in a Land Surface-Hydrology Model

    Science.gov (United States)

    Yassin, F.; Anis, M. R.; Razavi, S.; Wheater, H. S.

    2017-12-01

    Water management through reservoirs, diversions, and irrigation have significantly changed river flow regimes and basin-wide energy and water balance cycles. Failure to represent these effects limits the performance of land surface-hydrology models not only for streamflow prediction but also for the estimation of soil moisture, evapotranspiration, and feedbacks to the atmosphere. Despite recent research to improve the representation of water management in land surface models, there remains a need to develop improved modeling approaches that work in complex and highly regulated basins such as the 406,000 km2 Saskatchewan River Basin (SaskRB). A particular challenge for regional and global application is a lack of local information on reservoir operational management. To this end, we implemented a reservoir operation, water abstraction, and irrigation algorithm in the MESH land surface-hydrology model and tested it over the SaskRB. MESH is Environment Canada's Land Surface-hydrology modeling system that couples Canadian Land Surface Scheme (CLASS) with hydrological routing model. The implemented reservoir algorithm uses an inflow-outflow relationship that accounts for the physical characteristics of reservoirs (e.g., storage-area-elevation relationships) and includes simplified operational characteristics based on local information (e.g., monthly target volume and release under limited, normal, and flood storage zone). The irrigation algorithm uses the difference between actual and potential evapotranspiration to estimate irrigation water demand. This irrigation demand is supplied from the neighboring reservoirs/diversion in the river system. We calibrated the model enabled with the new reservoir and irrigation modules in a multi-objective optimization setting. Results showed that the reservoir and irrigation modules significantly improved the MESH model performance in generating streamflow and evapotranspiration across the SaskRB and that this our approach provides

  4. How Reservoirs Alter DOM Amount and Composition: Sources, Sinks, and Transformations

    Science.gov (United States)

    Kraus, T. E.; Bergamaschi, B. A.; Hernes, P. J.; Doctor, D. H.; Kendall, C.; Losee, R. F.; Downing, B. D.

    2011-12-01

    Reservoirs are critical components of many water supply systems as they allow the storage of water when supply exceeds demand. However, during water storage biogeochemical processes can alter both the amount and composition of dissolved organic matter (DOM), which can in turn affect water quality. While the balance between production and loss determines whether a reservoir is a net sink or source of DOM, changes in chemical composition are also relevant as they affect DOM reactivity (e.g. persistence in the environment, removability during coagulation treatment, and potential to form toxic compounds during drinking water treatment). The composition of the DOM pool also provides information about the DOM sources and processing, which can inform reservoir management. We examined the concentration and composition of DOM in San Luis Reservoir (SLR), a large off-stream impoundment of the California State Water Project. We used an array of DOM chemical tracers including dissolved organic carbon (DOC) concentration, optical properties, isotopic composition, lignin phenol content, and structural groupings determined by 13C NMR. There were periods when the reservoir was i) a net source of DOM due to the predominance of algal production (summer), ii) a net sink due to the predominance of degradation (fall/winter), and iii) balanced between production and consumption (spring). Despite only moderate variation in bulk DOC concentration (3.0-3.6 mg C/L), substantial changes in DOM composition indicated that terrestrial-derived material entering the reservoir was being degraded and replaced by aquatic-derived DOM produced within the reservoir. Results suggest reservoirs have the potential to reduce DOM amount and reactivity via degradative processes, however, these benefits can be decreased or even negated by the production of algal-derived DOM.

  5. Tenth workshop on geothermal reservoir engineering: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-22

    The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

  6. The Young Solar Analogs Project

    Science.gov (United States)

    Gray, Richard O.; Saken, J. M.; Corbally, C. J.; Fuller, V.; Kahvaz, Y.; Lambert, R.; Newsome, I.; Seeds, M.

    2013-01-01

    We are carrying out a long-term project of measuring chromospheric activity and brightness variations in 31 young solar analogs (YSAs) using facilities at the Dark Sky Observatory (DSO - Appalachian State University) and the Vatican Advanced Technology Telescope (VATT). These YSAs are solar-type (spectral types F8 - K2) stars with ages ranging from 0.3 - 1.5 Gyr. The goal of this project is to gain better understanding of the magnetic activity of the early Sun, and especially how that activity may have impacted the development of life on the Earth. This project will also yield insights into the space environments experienced by young Earth analogs. We are currently in the 6th year of spectroscopic measurements of these stars: these data include Ca II H & K chromospheric flux measurements, and narrow-band measurements in the photospheric G-band, both obtained with the G/M spectrograph on the DSO 32-inch telescope. We will present evidence of activity cycles in a number of our stars, as well as periods determined from rotational modulation of the spectroscopic indices. The relationship between the Ca II activity index and the G-band index will be explored. NSF support for our project has provided funds for the construction of a robotic photometric telescope to monitor the program stars in a 5-passband system (Strömgren-v, Johnson-Cousins B, V, and R, and a 3-nm wide Hα filter). The robotic telescope has been functional since April 2012 and observes the program stars on every clear night; combined with the Piggy-back telescope attached to the DSO 32-inch, we now have photometric observations on over 130 nights stretching over nearly 2 years. We will examine the relationships between variations in the Ca II H & K index, the G-band index and the photometric bands. This project is supported by the National Science Foundation, grant AST-1109158.

  7. The Young Solar Analogs Project

    Science.gov (United States)

    Gray, Richard O.; Saken, J. M.; Corbally, C. J.; Seeds, M. F.; Morrison, S. S.

    2012-01-01

    We are carrying out a long-term project of measuring chromospheric activity and brightness variations in 31 young solar analogs (YSAs) using the Dark Sky Observatory (DSO -- Appalachian State University) 32-inch telescope and the G/M spectrograph. These YSAs are solar-type (spectral types F8 - K2) stars with ages ranging from 0.3 - 1.5 Gyr. The goal of this project is to gain better understanding of the magnetic activity of the early Sun, and especially how that activity may have impacted the development of life on the Earth. This project will also yield insights into the space environments experienced by young Earth analogs. We are currently in our 5th year of obtaining Ca II K & H chromospheric flux measurements, and are beginning to see signs of long-term activity cycles in a number of our stars. In addition, rotational modulation of the chromospheric fluxes is detectable in our data, and we have determined rotational periods for many of our stars. Short timescale increases in the K & H fluxes have been observed in a number of our stars; these events may be related to stellar flares. VATTSpec, a new moderate-resolution spectrograph on the 1.8-m Vatican Telescope in Arizona, has recently become involved with the project. This spectrograph will increase our ability to detect short-term changes in stellar activity on timescales of hours to minutes. We have been monitoring the program stars for one year in a multi-band photometric system consisting of Stromgren-v, and Johnson B, V, and R filters. We will soon add a narrow-band H-alpha filter to the system. Photometry is being carried out with a small piggy-back telescope on the 32-inch, but a robotic photometric telescope is currently being installed at DSO for this purpose. This project is supported by the National Science Foundation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nurhandoko, Bagus Endar B., E-mail: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [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: bagusnur@bdg.centrin.net.id, E-mail: bagusnur@rock-fluid.com [Rock Fluid Imaging Lab., Bandung (Indonesia)

    2015-04-16

    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.

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

    International Nuclear Information System (INIS)

    thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" data-affiliation=" (Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" >Nurhandoko, Bagus Endar B.; Susilowati

    2015-01-01

    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

  10. Priming analogical reasoning with false memories.

    Science.gov (United States)

    Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

    2015-08-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.

  11. Neural correlates of creativity in analogical reasoning.

    Science.gov (United States)

    Green, Adam E; Kraemer, David J M; Fugelsang, Jonathan A; Gray, Jeremy R; Dunbar, Kevin N

    2012-03-01

    Brain-based evidence has implicated the frontal pole of the brain as important for analogical mapping. Separately, cognitive research has identified semantic distance as a key determinant of the creativity of analogical mapping (i.e., more distant analogies are generally more creative). Here, we used functional magnetic resonance imaging to assess brain activity during an analogy generation task in which we varied the semantic distance of analogical mapping (as derived quantitatively from a latent semantic analysis). Data indicated that activity within an a priori region of interest in left frontopolar cortex covaried parametrically with increasing semantic distance, even after removing effects of task difficulty. Results implicate increased recruitment of frontopolar cortex as a mechanism for integrating semantically distant information to generate solutions in creative analogical reasoning. 2012 APA, all rights reserved

  12. An emergent approach to analogical inference

    Science.gov (United States)

    Thibodeau, Paul H.; Flusberg, Stephen J.; Glick, Jeremy J.; Sternberg, Daniel A.

    2013-03-01

    In recent years, a growing number of researchers have proposed that analogy is a core component of human cognition. According to the dominant theoretical viewpoint, analogical reasoning requires a specific suite of cognitive machinery, including explicitly coded symbolic representations and a mapping or binding mechanism that operates over these representations. Here we offer an alternative approach: we find that analogical inference can emerge naturally and spontaneously from a relatively simple, error-driven learning mechanism without the need to posit any additional analogy-specific machinery. The results also parallel findings from the developmental literature on analogy, demonstrating a shift from an initial reliance on surface feature similarity to the use of relational similarity later in training. Variants of the model allow us to consider and rule out alternative accounts of its performance. We conclude by discussing how these findings can potentially refine our understanding of the processes that are required to perform analogical inference.

  13. Development of a national, dynamic reservoir-sedimentation database

    Science.gov (United States)

    Gray, J.R.; Bernard, J.M.; Stewart, D.W.; McFaul, E.J.; Laurent, K.W.; Schwarz, G.E.; Stinson, J.T.; Jonas, M.M.; Randle, T.J.; Webb, J.W.

    2010-01-01

    The importance of dependable, long-term water supplies, coupled with the need to quantify rates of capacity loss of the Nation’s re servoirs due to sediment deposition, were the most compelling reasons for developing the REServoir- SEDimentation survey information (RESSED) database and website. Created under the auspices of the Advisory Committee on Water Information’s Subcommittee on Sedimenta ion by the U.S. Geological Survey and the Natural Resources Conservation Service, the RESSED database is the most comprehensive compilation of data from reservoir bathymetric and dry-basin surveys in the United States. As of March 2010, the database, which contains data compiled on the 1950s vintage Soil Conservation Service’s Form SCS-34 data sheets, contained results from 6,616 surveys on 1,823 reservoirs in the United States and two surveys on one reservoir in Puerto Rico. The data span the period 1755–1997, with 95 percent of the surveys performed from 1930–1990. The reservoir surface areas range from sub-hectare-scale farm ponds to 658 km2 Lake Powell. The data in the RESSED database can be useful for a number of purposes, including calculating changes in reservoir-storage characteristics, quantifying sediment budgets, and estimating erosion rates in a reservoir’s watershed. The March 2010 version of the RESSED database has a number of deficiencies, including a cryptic and out-of-date database architecture; some geospatial inaccuracies (although most have been corrected); other data errors; an inability to store all data in a readily retrievable manner; and an inability to store all data types that currently exist. Perhaps most importantly, the March 2010 version of RESSED database provides no publically available means to submit new data and corrections to existing data. To address these and other deficiencies, the Subcommittee on Sedimentation, through the U.S. Geological Survey and the U.S. Army Corps of Engineers, began a collaborative project in

  14. Analog techniques in CEBAF's RF control system

    International Nuclear Information System (INIS)

    Hovater, C.; Fugitt, J.

    1989-01-01

    Recent developments in high-speed analog technology have progressed into the areas of traditional RF technology. Diode related devices are being replaced by analog IC's in the CEBAF RF control system. Complex phase modulators and attenuators have been successfully tested at 70 MHz. They have three advantages over existing technology: lower cost, less temperature sensitivity, and more linearity. RF signal conditioning components and how to implement the new analog IC's will be covered in this paper. 4 refs., 5 figs

  15. Analog techniques in CEBAF'S RF control system

    International Nuclear Information System (INIS)

    Hovater, C.; Fugitt, J.

    1989-01-01

    Recent developments in high-speed analog technology have progressed into the areas of traditional rf technology. Diode-related devices are being replaced by analog IC's in the CEBAF rf control system. Complex phase modulators and attenuators have been successfully tested at 70 MHz. They have three advantages over existing technology: lower cost, less temperature sensitivity, and more linearity. Rf signal conditioning components and how to implement the new analog IC's will be covered in this paper. 4 refs., 5 figs

  16. Design and Analysis of Reconfigurable Analog System

    Science.gov (United States)

    2011-02-01

    34010010" �" �" �" �" �" �" �±" N3 N2 N± P1 P2 P3 * Current sources $RR = 1; *Ramp Rate (slope of the...2008/12/12/31e83bac-500f-4182- acca -4d360295fd9c.pdf, Analog Devices, Analog Dialogue 39-06, June 2005. [15] D. A. Johns, K. Martin "Analog Integrated

  17. Energy Storage

    CSIR Research Space (South Africa)

    Bladergroen, B

    2015-10-01

    Full Text Available In commercial arena, the most recent developments in EES are in electrochemical storage, singling out Li-ion batteries and Vanadium Redox flow batteries, while power-to-gas/-fuels (electrolysis of water into hydrogen and subsequent methanisation...

  18. Liver Storage

    African Journals Online (AJOL)

    1971-10-23

    Oct 23, 1971 ... The need for whole-organ preservation has become in- cre.asingly important ... ideally fulfil the same purpose as the circulation of blood through the body, ... Hepatic hypothermia produced by the introduction of cold electrolyte ... Recently, we reported successful hypothermic immersion storage for up to 8 ...

  19. Dry storage

    International Nuclear Information System (INIS)

    Arnott, Don.

    1985-01-01

    The environmental movement has consistently argued against disposal of nuclear waste. Reasons include its irretrievability in the event of leakage, the implication that reprocessing will continue and the legitimacy attached to an expanding nuclear programme. But there is an alternative. The author here sets out the background and a possible future direction of a campaign based on a call for dry storage. (author)

  20. Depositional sequence analysis and sedimentologic modeling for improved prediction of Pennsylvanian reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W.L.

    1994-12-01

    Reservoirs in the Lansing-Kansas City limestone result from complex interactions among paleotopography (deposition, concurrent structural deformation), sea level, and diagenesis. Analysis of reservoirs and surface and near-surface analogs has led to developing a {open_quotes}strandline grainstone model{close_quotes} in which relative sea-level stabilized during regressions, resulting in accumulation of multiple grainstone buildups along depositional strike. Resulting stratigraphy in these carbonate units are generally predictable correlating to inferred topographic elevation along the shelf. This model is a valuable predictive tool for (1) locating favorable reservoirs for exploration, and (2) anticipating internal properties of the reservoir for field development. Reservoirs in the Lansing-Kansas City limestones are developed in both oolitic and bioclastic grainstones, however, re-analysis of oomoldic reservoirs provides the greatest opportunity for developing bypassed oil. A new technique, the {open_quotes}Super{close_quotes} Pickett crossplot (formation resistivity vs. porosity) and its use in an integrated petrophysical characterization, has been developed to evaluate extractable oil remaining in these reservoirs. The manual method in combination with 3-D visualization and modeling can help to target production limiting heterogeneities in these complex reservoirs and moreover compute critical parameters for the field such as bulk volume water. Application of this technique indicates that from 6-9 million barrels of Lansing-Kansas City oil remain behind pipe in the Victory-Northeast Lemon Fields. Petroleum geologists are challenged to quantify inferred processes to aid in developing rationale geologically consistent models of sedimentation so that acceptable levels of prediction can be obtained.

  1. Fermilab accelerator control system: Analog monitoring facilities

    International Nuclear Information System (INIS)

    Seino, K.; Anderson, L.; Smedinghoff, J.

    1987-10-01

    Thousands of analog signals are monitored in different areas of the Fermilab accelerator complex. For general purposes, analog signals are sent over coaxial or twinaxial cables with varying lengths, collected at fan-in boxes and digitized with 12 bit multiplexed ADCs. For higher resolution requirements, analog signals are digitized at sources and are serially sent to the control system. This paper surveys ADC subsystems that are used with the accelerator control systems and discusses practical problems and solutions, and it describes how analog data are presented on the console system

  2. Relations as transformations: implications for analogical reasoning.

    Science.gov (United States)

    Leech, Robert; Mareschal, Denis; Cooper, Richard P

    2007-07-01

    We present two experiments assessing whether the size of a transformation instantiating a relation between two states of the world (e.g., shrinks) is a performance factor affecting analogical reasoning. The first experiment finds evidence of transformation size as a significant factor in adolescent analogical problem solving while the second experiment finds a similar effect on adult analogical reasoning using a markedly different analogical completion paradigm. The results are interpreted as providing evidence for the more general framework that cognitive representations of relations are best understood as mental transformations.

  3. Epistemology of analogy: Knowledge, society and expression

    Directory of Open Access Journals (Sweden)

    Mauricio Beuchot

    2017-06-01

    Full Text Available In this article we expose the bases of analog epistemology. This theory of knowledge is between an extreme subjectivism and an extreme objectivism. Analog hermeneutics is a realistic hermeneutics. She seeks the truth, but incorporates the meaning and emotion. We have separated the reason from the experience, the praxis theory, the mind or the soul of the body. We have to get them back together, if we do not get lost in the rational (which says little of the human being, or we lose ourselves in the emotional (without logical consistency. The analogical hermeneutic realism is able, thanks to the analogy itself, to mediate in this way of union.

  4. System Dynamics Modeling of Multipurpose Reservoir Operation

    Directory of Open Access Journals (Sweden)

    Ebrahim Momeni

    2006-03-01

    Full Text Available System dynamics, a feedback – based object – oriented simulation approach, not only represents complex dynamic systemic systems in a realistic way but also allows the involvement of end users in model development to increase their confidence in modeling process. The increased speed of model development, the possibility of group model development, the effective communication of model results, and the trust developed in the model due to user participation are the main strengths of this approach. The ease of model modification in response to changes in the system and the ability to perform sensitivity analysis make this approach more attractive compared with systems analysis techniques for modeling water management systems. In this study, a system dynamics model was developed for the Zayandehrud basin in central Iran. This model contains river basin, dam reservoir, plains, irrigation systems, and groundwater. Current operation rule is conjunctive use of ground and surface water. Allocation factor for each irrigation system is computed based on the feedback from groundwater storage in its zone. Deficit water is extracted from groundwater.The results show that applying better rules can not only satisfy all demands such as Gawkhuni swamp environmental demand, but it can also  prevent groundwater level drawdown in future.

  5. 4. International reservoir characterization technical conference

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    This volume contains the Proceedings of the Fourth International Reservoir Characterization Technical Conference held March 2-4, 1997 in Houston, Texas. The theme for the conference was Advances in Reservoir Characterization for Effective Reservoir Management. On March 2, 1997, the DOE Class Workshop kicked off with tutorials by Dr. Steve Begg (BP Exploration) and Dr. Ganesh Thakur (Chevron). Tutorial presentations are not included in these Proceedings but may be available from the authors. The conference consisted of the following topics: data acquisition; reservoir modeling; scaling reservoir properties; and managing uncertainty. Selected papers have been processed separately for inclusion in the Energy Science and Technology database.

  6. Physical Experiment and Numerical Simulation of the Artificial Recharge Effect on Groundwater Reservoir

    Directory of Open Access Journals (Sweden)

    Yang Xu

    2017-11-01

    Full Text Available To improve the efficiency of utilizing water resources in arid areas, the mechanism of artificial recharge effecting on groundwater reservoir was analyzed in this research. Based on a generalized groundwater reservoir in a two-dimensional sand tank model, different scenarios of the infiltration basin location and recharge intensity are designed to study how to improve the efficiency of groundwater reservoir artificial recharge. The effective storage capacity and the effective storage rate are taken as the main parameters to analyze the relation between recharge water volume and storage capacity. By combining with groundwater flow system theory, FEFLOW (Finite Element subsurface FLOW system is adopted to set up the groundwater numerical model. It is used to verify the experiment results and to make deep analysis on the rule of water table fluctuations and groundwater movement in the aquifer. Based on the model, different scenarios are designed to examine the combined effect of recharge intensity and intermittent periods. The research results show that: the distance between infiltration basin and pumping well should be shortened appropriately, but not too close; increasing recharge intensity helps to enlarge the effective storage capacity, but it can also reduce the effective storage rate, which goes against the purpose of effective utilization of water resources; and, the recharge intensity and recharge duration should be given full consideration by the actual requirements when we take the approach of intermittent recharge to make a reasonable choice.

  7. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

    Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams

  8. MIKROMITSETY- MIGRANTS IN MINGECHEVIR RESERVOIR

    Directory of Open Access Journals (Sweden)

    M. A. Salmanov

    2017-01-01

    Full Text Available Aim. It is hardly possible to predict the continued stability of the watercourse ecosystems without the study of biological characteristics and composition of organisms inhabiting them. In the last 35-40 years, environmental conditions of the Mingachevir reservoir are determined by the stationary anthropogenic pressure. It was found that such components of plankton as algae, bacteria and fungi play a leading role in the transformation and migration of pollutants. The role of the three groups of organisms is very important in maintaining the water quality by elimination of pollutants. Among the organisms inhabiting the Mingachevir Reservoir, micromycetes have not yet been studied. Therefore, the study of the species composition and seasonal dynamics, peculiarities of their growth and development in the environment with the presence of some of the pollutants should be considered to date.Methods. In order to determine the role of micromycetes-migrants in the mineralization of organic substrates, as an active participant of self-purification process, we used water samples from the bottom sediments as well as decaying and skeletonized stalks of cane, reeds, algae, macrophytes, exuvia of insects and fish remains submerged in water.Findings. For the first time, we obtained the data on the quality and quantity of microscopic mycelial fungi in freshwater bodies on the example of the Mingachevir water reservoir; we also studied the possibilities for oxygenating the autochthonous organic matter of allochthonous origin with micromycetes-migrants.Conclusions. It was found that the seasonal development of micromycetes-migrants within the Mingachevir reservoir is characterized by an increase in the number of species in the summer and a gradual reduction in species diversity in the fall. 

  9. Mathematical modeling of large floating roof reservoir temperature arena

    Directory of Open Access Journals (Sweden)

    Liu Yang

    2018-03-01

    Full Text Available The current study is a simplification of related components of large floating roof tank and modeling for three dimensional temperature field of large floating roof tank. The heat transfer involves its transfer between the hot fluid in the oil tank, between the hot fluid and the tank wall and between the tank wall and the external environment. The mathematical model of heat transfer and flow of oil in the tank simulates the temperature field of oil in tank. Oil temperature field of large floating roof tank is obtained by numerical simulation, map the curve of central temperature dynamics with time and analyze axial and radial temperature of storage tank. It determines the distribution of low temperature storage tank location based on the thickness of the reservoir temperature. Finally, it compared the calculated results and the field test data; eventually validated the calculated results based on the experimental results.

  10. The storage of greenhouse gases

    International Nuclear Information System (INIS)

    Herzog, H.; Kaarstad, O.; Eliasson, B

    2000-01-01

    Since 1850, that is to say the beginning of the industrial era,the concentration of carbon dioxide in the atmosphere has risen from 280 ppm to 370 ppm, this increase is mainly due to the combustion of fossil fuels. Today fossil fuels represent 85% of all the energy used in the world. Fearing progressive climatic changes, more and more governments become aware of the necessity of reducing the emission of greenhouse gases. A more efficient use of energy and the promoting of renewable energies and of the nuclear energy are the most evident solutions but they appear to be insufficient. A third solution is the storage of carbon dioxide in geological layers. This technique has been put into use since 1996 in Norway. An off-shore natural gas platform injects carbon dioxide in