Science.gov

Sample records for reservoir temperature

  1. Reservoir Temperature Estimator

    SciTech Connect

    Palmer, Carl D.

    2014-12-08

    The Reservoir Temperature Estimator (RTEst) is a program that can be used to estimate deep geothermal reservoir temperature and chemical parameters such as CO2 fugacity based on the water chemistry of shallower, cooler reservoir fluids. This code uses the plugin features provided in The Geochemist’s Workbench (Bethke and Yeakel, 2011) and interfaces with the model-independent parameter estimation code Pest (Doherty, 2005) to provide for optimization of the estimated parameters based on the minimization of the weighted sum of squares of a set of saturation indexes from a user-provided mineral assemblage.

  2. Reservoir Temperature Estimator

    Energy Science and Technology Software Center (ESTSC)

    2014-12-08

    The Reservoir Temperature Estimator (RTEst) is a program that can be used to estimate deep geothermal reservoir temperature and chemical parameters such as CO2 fugacity based on the water chemistry of shallower, cooler reservoir fluids. This code uses the plugin features provided in The Geochemist’s Workbench (Bethke and Yeakel, 2011) and interfaces with the model-independent parameter estimation code Pest (Doherty, 2005) to provide for optimization of the estimated parameters based on the minimization of themore » weighted sum of squares of a set of saturation indexes from a user-provided mineral assemblage.« less

  3. Reservoir Simulations of Low-Temperature Geothermal Reservoirs

    NASA Astrophysics Data System (ADS)

    Bedre, Madhur Ganesh

    The eastern United States generally has lower temperature gradients than the western United States. However, West Virginia, in particular, has higher temperature gradients compared to other eastern states. A recent study at Southern Methodist University by Blackwell et al. has shown the presence of a hot spot in the eastern part of West Virginia with temperatures reaching 150°C at a depth of between 4.5 and 5 km. This thesis work examines similar reservoirs at a depth of around 5 km resembling the geology of West Virginia, USA. The temperature gradients used are in accordance with the SMU study. In order to assess the effects of geothermal reservoir conditions on the lifetime of a low-temperature geothermal system, a sensitivity analysis study was performed on following seven natural and human-controlled parameters within a geothermal reservoir: reservoir temperature, injection fluid temperature, injection flow rate, porosity, rock thermal conductivity, water loss (%) and well spacing. This sensitivity analysis is completed by using ‘One factor at a time method (OFAT)’ and ‘Plackett-Burman design’ methods. The data used for this study was obtained by carrying out the reservoir simulations using TOUGH2 simulator. The second part of this work is to create a database of thermal potential and time-dependant reservoir conditions for low-temperature geothermal reservoirs by studying a number of possible scenarios. Variations in the parameters identified in sensitivity analysis study are used to expand the scope of database. Main results include the thermal potential of reservoir, pressure and temperature profile of the reservoir over its operational life (30 years for this study), the plant capacity and required pumping power. The results of this database will help the supply curves calculations for low-temperature geothermal reservoirs in the United States, which is the long term goal of the work being done by the geothermal research group under Dr. Anderson at

  4. Program predicts reservoir temperature and geothermal gradient

    SciTech Connect

    Kutasov, I.M.

    1992-06-01

    This paper reports that a Fortran computer program has been developed to determine static formation temperatures (SFT) and geothermal gradient (GG). A minimum of input data (only two shut-in temperature logs) is required to obtain the values of SFT and GG. Modeling of primary oil production and designing enhanced oil recovery (EOR) projects requires knowing the undisturbed (static) reservoir temperature. Furthermore, the bottom hole circulating temperature (BHCT) is an important factor affecting a cement's thickening time, rheological properties, compressive strength, development, and set time. To estimate the values of BHCT, the geothermal gradient should be determined with accuracy. Recently we obtained an approximate analytical solution which describes the shut-in temperature behavior.

  5. Geothermal Reservoir Temperatures in Southeastern Idaho using Multicomponent Geothermometry

    SciTech Connect

    Neupane, Ghanashyam; Mattson, Earl D.; McLing, Travis L.; Palmer, Carl D.; Smith, Robert W.; Wood, Thomas R.; Podgorney, Robert K.

    2015-03-01

    Southeastern Idaho exhibits numerous warm springs, warm water from shallow wells, and hot water within oil and gas test wells that indicate a potential for geothermal development in the area. Although the area exhibits several thermal expressions, the measured geothermal gradients vary substantially (19 – 61 ºC/km) within this area, potentially suggesting a redistribution of heat in the overlying ground water from deeper geothermal reservoirs. We have estimated reservoir temperatures from measured water compositions using an inverse modeling technique (Reservoir Temperature Estimator, RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. Compositions of a selected group of thermal waters representing southeastern Idaho hot/warm springs and wells were used for the development of temperature estimates. The temperature estimates in the the region varied from moderately warm (59 ºC) to over 175 ºC. Specifically, hot springs near Preston, Idaho resulted in the highest temperature estimates in the region.

  6. Sudden change of geometric quantum discord in finite temperature reservoirs

    SciTech Connect

    Hu, Ming-Liang Sun, Jian

    2015-03-15

    We investigate sudden change (SC) behaviors of the distance-based measures of geometric quantum discords (GQDs) for two non-interacting qubits subject to the two-sided and the one-sided thermal reservoirs. We found that the GQDs defined by different distances exhibit different SCs, and thus the SCs are the combined result of the chosen discord measure and the property of a state. We also found that the thermal reservoir may generate states having different orderings related to different GQDs. These inherent differences of the GQDs reveal that they are incompatible in characterizing quantum correlations both quantitatively and qualitatively. - Highlights: • Comparable study of different distance-based geometric quantum discords. • Evolution of the geometric quantum discords in finite temperature reservoirs. • Different geometric quantum discords exhibit distinct sudden changes. • Nonunique states ordering imposed by different geometric quantum discords.

  7. Reducing temperature uncertainties by stochastic geothermal reservoir modelling

    NASA Astrophysics Data System (ADS)

    Vogt, C.; Mottaghy, D.; Wolf, A.; Rath, V.; Pechnig, R.; Clauser, C.

    2010-04-01

    Quantifying and minimizing uncertainty is vital for simulating technically and economically successful geothermal reservoirs. To this end, we apply a stochastic modelling sequence, a Monte Carlo study, based on (i) creating an ensemble of possible realizations of a reservoir model, (ii) forward simulation of fluid flow and heat transport, and (iii) constraining post-processing using observed state variables. To generate the ensemble, we use the stochastic algorithm of Sequential Gaussian Simulation and test its potential fitting rock properties, such as thermal conductivity and permeability, of a synthetic reference model and-performing a corresponding forward simulation-state variables such as temperature. The ensemble yields probability distributions of rock properties and state variables at any location inside the reservoir. In addition, we perform a constraining post-processing in order to minimize the uncertainty of the obtained distributions by conditioning the ensemble to observed state variables, in this case temperature. This constraining post-processing works particularly well on systems dominated by fluid flow. The stochastic modelling sequence is applied to a large, steady-state 3-D heat flow model of a reservoir in The Hague, Netherlands. The spatial thermal conductivity distribution is simulated stochastically based on available logging data. Errors of bottom-hole temperatures provide thresholds for the constraining technique performed afterwards. This reduce the temperature uncertainty for the proposed target location significantly from 25 to 12K (full distribution width) in a depth of 2300m. Assuming a Gaussian shape of the temperature distribution, the standard deviation is 1.8K. To allow a more comprehensive approach to quantify uncertainty, we also implement the stochastic simulation of boundary conditions and demonstrate this for the basal specific heat flow in the reservoir of The Hague. As expected, this results in a larger distribution width

  8. Low-to-moderate-temperature hydrothermal reservoir engineering handbook

    SciTech Connect

    Not Available

    1982-06-01

    Guidelines are provided for evaluating reservoir characteristics containing setions on reservoir classification, conceptual modeling, testing during drilling, current theory of testing, test planning and methodology, instrumentation, and a sample computer program. Sections on test planning and methodology, geochemistry, reservoir monitoring, and the appendixes, containing technical detail, are included. Background information needed to monitor the program of reservoir evaluation is provided.

  9. Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs

    SciTech Connect

    Morgan Ames

    2011-06-15

    The feasibility of using nanosensors to measure temperature distribution and predict thermal breakthrough in geothermal reservoirs is addressed in this report. Four candidate sensors were identified: melting tin-bismuth alloy nanoparticles, silica nanoparticles with covalently-attached dye, hollow silica nanoparticles with encapsulated dye and impermeable melting shells, and dye-polymer composite time-temperature indicators. Four main challenges associated with the successful implementation of temperature nanosensors were identified: nanoparticle mobility in porous and fractured media, the collection and detection of nanoparticles at the production well, engineering temperature sensing mechanisms that are both detectable and irreversible, and inferring the spatial geolocation of temperature measurements in order to map temperature distribution. Initial experiments were carried out to investigate each of these challenges. It was demonstrated in a slim-tube injection experiment that it is possible to transport silica nanoparticles over large distances through porous media. The feasibility of magnetic collection of nanoparticles from produced fluid was evaluated experimentally, and it was estimated that 3% of the injected nanoparticles were recovered in a prototype magnetic collection device. An analysis technique was tailored to nanosensors with a dye-release mechanism to estimate temperature measurement geolocation by analyzing the return curve of the released dye. This technique was used in a hypothetical example problem, and good estimates of geolocation were achieved. Tin-bismuth alloy nanoparticles were synthesized using a sonochemical method, and a bench heating experiment was performed using these nanoparticles. Particle growth due to melting was observed, indicating that tin-bismuth nanoparticles have potential as temperature nanosensors

  10. Numerical modeling of temperature and species distributions in hydrocarbon reservoirs

    NASA Astrophysics Data System (ADS)

    Bolton, Edward W.; Firoozabadi, Abbas

    2014-01-01

    We examine bulk fluid motion and diffusion of multicomponent hydrocarbon species in porous media in the context of nonequilibrium thermodynamics, with particular focus on the phenomenology induced by horizontal thermal gradients at the upper and lower horizontal boundaries. The problem is formulated with respect to the barycentric (mass-averaged) frame of reference. Thermally induced convection, with fully time-dependent temperature distributions, can lead to nearly constant hydrocarbon composition, with minor unmixing due to thermal gradients near the horizontal boundaries. Alternately, the composition can be vertically segregated due to gravitational effects. Independent and essentially steady solutions have been found to depend on how the compositions are initialized in space and may have implications for reservoir history. We also examine injection (to represent filling) and extraction (to represent leakage) of hydrocarbons at independent points and find a large distortion of the gas-oil contact for low permeability.

  11. High-temperature logging for basic development of HDR reservoirs

    SciTech Connect

    Mathews, M.; Pettitt, R.A.; Miles, D.J.

    1981-01-01

    The second phase of the Hot Dry Rock (HDR) Geothermal Development Program at Fenton Hill, New Mexico, consists of two boreholes, directionally-drilled in a northeast direction, inclined at an angle of 35/sup 0/, with a vertical separation of 365 m (1200 ft). The two boreholes will be connected by 12 to 15 vertical parallel fractures to make a geothermal reservoir calculated to produce 20 MW(e) for 20 years. Accurate temperature measurements, borehole caliper logs, and directional surveys are required for the successful development and operation of this man-made system. Obtaining these data is extremely difficult because of the bottom hole static temperature of 335/sup 0/C (635/sup 0/F) at a depth of 4660 m (15,289 ft), the 35/sup 0/ deviation, the abrasive formation, and the presence of sticky drilling residue products. The efforts during July, August, and September 1980, to obtain these data are presented as a case history. The temperature logs and borehole directional survey produced realistic results; but the borehole caliper measurements were inconsistent and unreliable, due to the developmental stage of the caliper tools.

  12. A method for temperature estimation in high-temperature geothermal reservoirs by using synthetic fluid inclusions

    NASA Astrophysics Data System (ADS)

    Ruggieri, Giovanni; Orlando, Andrea; Chiarantini, Laura; Borrini, Daniele; Weisenberger, Tobias B.

    2016-04-01

    Super-hot geothermal systems in magmatic areas are a possible target for the future geothermal exploration either for the direct exploitation of fluids or as a potential reservoirs of Enhanced Geothermal Systems. Reservoir temperature measurements are crucial for the assessment of the geothermal resources, however temperature determination in the high-temperature (>380°C) zone of super-hot geothermal systems is difficult or impossible by using either mechanical temperature and pressure gauges (Kuster device) and electronic devices. In the framework of Integrated Methods for Advanced Geothermal Exploration (IMAGE) project, we developed a method to measure high reservoir temperature by the production of synthetic fluid inclusions within an apparatus that will be placed in the high-temperature zone of geothermal wells. First experiments were carried out by placing a gold capsule containing pre-fractured quartz and an aqueous solution (10 wt.% NaCl + 0.4 wt.% NaOH) in an externally heated pressure vessel. Experimental pressure-temperature conditions (i.e. 80-300 bars and 280-400°C) were set close to the liquid/vapour curve of pure H2O or along the H2O critical isochore. The experiments showed that synthetic fluid inclusions form within a relatively short time (even in 48 hours) and that temperatures calculated from homogenization temperatures and isochores of newly formed inclusions are close to experimental temperatures. A second set of laboratory experiments were carried out by using a stainless steel micro-rector in which a gold capsule (containing the pre-fractured quartz and the aqueous solution) was inserted together with an amount of distilled water corresponding to the critical density of water. These experiments were conducted by leaving the new micro-reactor within a furnace at 400°C and were aimed to reproduce the temperature existing in super-hot geothermal wells. Synthetic fluid inclusions formed during the experiments had trapping temperature

  13. Temperature-induced optical bistability with Kerr-nonlinear blackbody reservoir

    NASA Astrophysics Data System (ADS)

    Joshi, Amitabh; Sharaby, Yasser A.; Hassan, Shoukry S.

    2016-01-01

    We investigate both absorptive- and dispersive optical bistability (OB) phenomena for a homogeneously broadened two-level atomic medium interacting with a single mode of the ring cavity in the presence of the Kerr-nonlinear blackbody reservoir. We predict the temperature-induced switching phenomenon with near resonance conditions, as well as lower cooperativity parameter to observe OB due to such reservoir.

  14. Fire flood method for recovering petroleum from oil reservoirs of low permeability and temperature

    DOEpatents

    Kamath, Krishna

    1984-08-14

    The present invention is directed to a method of enhanced oil recovery by fire flooding petroleum reservoirs characterized by a temperature of less than the critical temperature of carbon dioxide, a pore pressure greater than the saturated vapor pressure of carbon dioxide at said temperature (87.7.degree. F. at 1070 psia), and a permeability in the range of about 20 to 100 millidarcies. The in situ combustion of petroleum in the reservoir is provided by injecting into the reservoir a combustion supporting medium consisting essentially of oxygen, ozone, or a combination thereof. The heat of combustion and the products of this combustion which consist essentially of gaseous carbon dioxide and water vapor sufficiently decrease the viscosity of oil adjacent to fire front to form an oil bank which moves through the reservoir towards a recovery well ahead of the fire front. The gaseous carbon dioxide and the water vapor are driven into the reservoir ahead of the fire front by pressure at the injection well. As the gaseous carbon dioxide cools to less than about 88.degree. F. it is converted to liquid which is dissolved in the oil bank for further increasing the mobility thereof. By using essentially pure oxygen, ozone, or a combination thereof as the combustion supporting medium in these reservoirs the permeability requirements of the reservoirs are significantly decreased since the liquid carbon dioxide requires substantially less voidage volume than that required for gaseous combustion products.

  15. A two-stage magnetic refrigerator for astronomical applications with reservoir temperatures above 4 K

    NASA Technical Reports Server (NTRS)

    Hagmann, C.; Richards, P. L.

    1993-01-01

    We propose a novel adiabatic demagnetization refrigerator (ADR) to produce temperatures as low as 100 mK starting from a high temperature reservoir between 4 and 8 K. The high temperature reservoir for the ADR can be provided by a mechanical cooler or an unpumped liquid helium bath. This refrigerator can be used to cool bolometric infrared detectors for low background astronomy from mountain tops, balloons or satellites as well as to cool cryogenic x-ray detectors. The two-stage ADR consists of a single magnet with a paramagnetic chromic-cesium-alum (CCA) salt pill to produce the low temperature and paramagnetic gadolinium-gallium-garnet (GGG) as the first stage to intercept heat from the high temperature reservoir. Thermal contact between the paramagnets and the reservoir during magnetization is made with a mechanical heat switch. The ADR is suspended with Kevlar chords under tension for high mechanical stiffness and low parasitic heat leak. In a single cycle, the ADR maintains a temperature of 100 mK for 10 to 100 hours. This time depends strongly on the magnetic field and reservoir temperature but not on the volume of the paramagnetic material as long as the heat leak is dominated by the suspension.

  16. Thermodynamic modeling and performance analysis of the variable-temperature heat reservoir absorption heat pump cycle

    NASA Astrophysics Data System (ADS)

    Qin, Xiaoyong; Chen, Lingen; Ge, Yanlin; Sun, Fengrui

    2015-10-01

    For practical absorption heat pump (AHP) plants, not all external heat reservoir heat capacities are infinite. External heat reservoir heat capacity should be an effect factor in modeling and performance analysis of AHP cycles. A variable-temperature heat reservoir AHP cycle is modeled, in which internal working substance is working in four temperature levels and all irreversibility factors are considered. The irreversibility includes heat transfer irreversibility, internal dissipation irreversibility and heat leakage irreversibility. The general equations among coefficient of performance (COP), heating load and some key characteristic parameters are obtained. The general and optimal characteristics are obtained by using numerical calculations. Besides, the influences of heat capacities of heat reservoirs, internal dissipation irreversibility, and heat leakage irreversibility on cycle performance are analyzed. The conclusions can offer some guidelines for design and operation of AHP plants.

  17. Loop Heat Pipe Temperature Oscillation Induced by Gravity Assist and Reservoir Heating

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Garrison, Matthew; Patel, Deepak; Robinson, Franklin; Ottenstein, Laura

    2015-01-01

    The Laser Thermal Control System (LCTS) for the Advanced Topographic Laser Altimeter System (ATLAS) to be installed on NASA's Ice, Cloud, and Land Elevation Satellite (ICESat-2) consists of a constant conductance heat pipe and a loop heat pipe (LHP) with an associated radiator. During the recent thermal vacuum testing of the LTCS where the LHP condenser/radiator was placed in a vertical position above the evaporator and reservoir, it was found that the LHP reservoir control heater power requirement was much higher than the analytical model had predicted. Even with the control heater turned on continuously at its full power, the reservoir could not be maintained at its desired set point temperature. An investigation of the LHP behaviors found that the root cause of the problem was fluid flow and reservoir temperature oscillations, which led to persistent alternate forward and reversed flow along the liquid line and an imbalance between the vapor mass flow rate in the vapor line and liquid mass flow rate in the liquid line. The flow and temperature oscillations were caused by an interaction between gravity and reservoir heating, and were exacerbated by the large thermal mass of the instrument simulator which modulated the net heat load to the evaporator, and the vertical radiator/condenser which induced a variable gravitational pressure head. Furthermore, causes and effects of the contributing factors to flow and temperature oscillations intermingled.

  18. Dynamic processes of indigenous microorganisms from a low-temperature petroleum reservoir during nutrient stimulation.

    PubMed

    Gao, Pei-Ke; Li, Guo-Qiang; Zhao, Ling-Xia; Dai, Xue-Cheng; Tian, Hui-Mei; Dai, Liu-Bing; Wang, Hong-Bo; Huang, Hai-Dong; Chen, Yue-Hua; Ma, Ting

    2014-02-01

    Compared to medium-high temperature petroleum reservoirs (30°C-73°C), little is known about microbial regulation by nutrients in low-temperature reservoirs. In this study, we report the performance (oil emulsification and biogas production) and community structure of indigenous microorganisms from a low-temperature (22.6°C) petroleum reservoir during nutrient stimulation. Culture-dependent approaches indicated that the number of hydrocarbon-oxidizing bacteria (HOB), nitrate-reducing bacteria (NRB) and methane-producing bacteria (MPB) increased by between 10- and 1000-fold, while sulfate-reducing bacteria (SRB) were observed at low levels during stimulation. Phylogenetic analysis of the 16S rRNA gene indicated that Pseudomonas, Ochrobactrum, Acinetobacter, Halomonas and Marinobacter, which have the capability to produce surfactants, were selectively enriched. Methanoculleus, Methanosaeta, Methanocorpusculum and Methanocalculus showed the largest increase in relative abundance among archaea. Micro-emulsion formed with an average oil droplet diameter of 14.3 μm (ranging between 4.1 μm and 84.2 μm) during stimulation. Gas chromatographic analysis of gas production (186 mL gas/200 mL medium) showed the levels of CO2 and CH4 increased 8.97% and 6.21%, respectively. Similar to medium-high temperature reservoirs, HOB, NRB, SRB and MPB were ubiquitous in the low-temperature reservoir, and oil emulsification and gas production were the main phenomena observed during stimulation. Oil emulsification required a longer duration of time to occur in the low-temperature reservoir. PMID:23968868

  19. Spatial Correlation of Airborne Magnetic Anomalies with Reservoir Temperatures of Geothermal Fields, Western Anatolia, Turkey

    NASA Astrophysics Data System (ADS)

    Ertekin, Can; Ekinci, Yunus Levent

    2013-04-01

    Geothermal areas in Western Anatolia are remarkably located throughout Büyük Menderes Graben (BMG) and Gediz Graben (GG). These E-W trending grabens have been subjected to N-E stretching since Miocene. Except for these major outcomes of the extensional forces, NE-SW oriented and relatively short grabens take place in Western Anatolia as well. Among them, BMG and GG are remarkable with topographic escarpments that reveal footwall of steeply-dipping active normal faults. They manifest themselves via numerous earthquakes and geothermal activity (fluid discharges from springs and wells). Geothermal discharges are aligned along the rims of E-W trending normal faults trending over detachment faults. Concerning BMG, geothermal manifestations extend along the northern sector of the graben. Geothermal reservoirs inside BMG are the limestone and conglomerate units within Neogene sediments and the marble-quartzite units within The Menderes Massif rocks. The main high and low enthalpy geothermal fields along BMG and their reservoir temperatures are as follows: Kızıldere (242°C), Germencik (232°C), Aydın-Ilıcabası (101°C), Yılmazköy (142°C), Salavatlı (171°C), Söke (26°C), Pamukkale (36°C), Karahayıt (59°C), Gölemezli (101°C) and Yenice (70°C). Through GG, reservoir temperatures decrease from east to west. Geothermal reservoirs inside GG are metamorphics and granodiorite of the Menderes Massif rocks. The Neogene sediments act as cap rock of the geothermal reservoirs. Geothermal fields inside the graben and their reservoir temperatures are as follows: Alaşehir (215°C), Salihli (155°C), Urganlı (85°C), Kurşunlu (135°C), Caferbey (150°C), Sart (100°C). In order to investigate the spatial correlation of magnetic anomalies and the reservoir temperatures of geothermal fields in the region, we analysed airborne magnetic data which were collected by General Directorate of Mineral Research and Exploration (MTA) of Turkey. Airborne magnetic data were taken

  20. DYNAMIC RESPONSE OF STREAM TEMPERATURES TO BOUNDARY AND INFLOW PERTURBATION DUE TO RESERVOIR OPERATIONS

    SciTech Connect

    Khangaonkar, Tarang P.; Yang, Zhaoqing

    2008-05-01

    Dams and reservoir operations modify natural stream behaviour and affect the downstream characteristics such as mean temperatures and diurnal temperature amplitudes. Managing phase effects due to reservoir operation and the associated amplification of daily maximum temperatures in the downstream reaches remains a challenge. An analytical approach derived from a one-dimensional heat advection and dispersion equation with surface heating in the form of equilibrium temperature was developed to examine the potential for restoration of natural stream temperatures. The analytical model was validated with observed temperature data collected in the Clackamas River, Oregon, and was used to highlight key downstream temperature behaviour characteristics. Mean stream temperatures below the dam are relatively stable and upon deviating from natural stream mean temperatures, return asymptotically to their natural state. In contrast, the amplitudes of daily temperature variation are highly sensitive to the phase differences induced by the dam and could nearly double in natural amplitude within the first 24 h. The analysis showed that restoring average stream temperatures to natural levels through structural and operational modifications at the dam may not be sufficient as phase-induced temperatures maximums would continue to persist

  1. Subsurface temperature distribution and structure of the geothermal reservoir at Momotombo, Nicaragua

    SciTech Connect

    Lopez, C.V.; Hoyt, B.R.; Eckstein, Y.

    1980-09-01

    Subsurface distribution of the temperatures in the Momotombo geothermal reservoir indicates that the reservoir is heated by steam emerging from a narrow source-fracture zone, located in the western part of the field. The source fracture zone trends roughly in northern direction. It extends downwards, below the level of -1700 m (m.s.l.). At shallow levels, approximately above the level of -850 m. (m.s.l.), it branches off in the eastern direction, where the hot geothermal fluids form an extensive hot plume, overlying cooler water.

  2. Equation of state density models for hydrocarbons in ultradeep reservoirs at extreme temperature and pressure conditions

    NASA Astrophysics Data System (ADS)

    Wu, Yue; Bamgbade, Babatunde A.; Burgess, Ward A.; Tapriyal, Deepak; Baled, Hseen O.; Enick, Robert M.; McHugh, Mark A.

    2013-10-01

    The necessity of exploring ultradeep reservoirs requires the accurate prediction of hydrocarbon density data at extreme temperatures and pressures. In this study, three equations of state (EoS) models, Peng-Robinson (PR), high-temperature high-pressure volume-translated PR (HTHP VT-PR), and perturbed-chain statistical associating fluid theory (PC-SAFT) EoS are used to predict the density data for hydrocarbons in ultradeep reservoirs at temperatures to 523 K and pressures to 275 MPa. The calculated values are compared with experimental data. The results show that the HTHP VT-PR EoS and PC-SAFT EoS always perform better than the regular PR EoS for all the investigated hydrocarbons.

  3. Loop Heat Pipe Transient Behavior Using Heat Source Temperature for Set Point Control with Thermoelectric Converter on Reservoir

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly done by cold biasing the reservoir and using electrical heaters to provide the required control power. With this method, the loop operating temperature can be controlled within 0.5K or better. However, because the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if the LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP was carried out to investigate the effects on the LHP operation when the control temperature sensor was placed on the heat source instead of the reservoir. In these tests, the LHP reservoir was cold-biased and was heated by a control heater. Test results show that it was feasible to use the heat source temperature for feedback control of the LHP operation. In particular, when a thermoelectric converter was used as the reservoir control heater, the heat source temperature could be maintained within a tight range using a proportional-integral-derivative or on/off control algorithm. Moreover, because the TEC could provide both heating and cooling to the reservoir, temperature oscillations during fast transients such as loop startup could be eliminated or substantially reduced when compared to using an electrical heater as the control heater.

  4. Responsive Stabilization of Nanoparticles for Extreme Salinity and High-Temperature Reservoir Applications.

    PubMed

    Ranka, Mikhil; Brown, Paul; Hatton, T Alan

    2015-09-01

    Colloidal stabilization of nanoparticles under extreme salinity and high temperature conditions is a key challenge in the development of next generation technologies for subsurface reservoir characterization and oil recovery. Polyelectrolytes have been investigated as nanoparticle stabilizers, but typically fail at high ionic strengths and elevated temperatures due to excessive charge screening and dehydration. We report an approach to nanoparticle stabilization that overcomes these limitations, and exploits the antipolyelectrolyte phenomenon, in which screening of intrachain electrostatic interactions causes a polyzwitterion chain to undergo a structural transition from a collapsed globule to a more open coil-like regime with increases in ionic strength and temperature. Small-angle neutron scattering on a model zwitterionic polymer in solution indicated an increase in both radius of gyration and excluded volume parameter of the polymer with increases in ionic strength and temperature. The model zwitterion was subsequently incorporated within a polymeric stabilizer for nanoparticles under harsh reservoir conditions, and used to functionalize hydrophilic (silica) as well as hydrophobic (polystyrene) nanoparticles. Long-term colloidal stability was achieved at salt concentrations up to 120,000 mg/dm3 at 90 °C, approximately twice the stability limit previously reported in the literature. The approach can be broadly generalized to a large class of synthetic polyzwitterions, and can be adapted to a wide variety of other colloidal systems in which demands placed by extreme salinity and temperature conditions must be met. PMID:26278070

  5. Temperature dependence of hydraulic properties of Upper Rhine Graben rocks at conditions modelling deep geothermal reservoirs

    NASA Astrophysics Data System (ADS)

    Hernández Castañeda, Mariela Carolina; Renner, Joerg; Mueller, Thomas

    2016-04-01

    The evolution of reservoir rocks' hydraulic properties critically affects the operation and long term sustainability of geothermal and petroleum reservoirs. Mechanical and chemical effects modify the permeability and the storage capacity of a reservoir, whose time characteristics have remained poorly constrained up to now. The permeability (k) and specific storage capacity (s) of the rocks constituting the geothermal reservoir are important parameters controlling the extent of the space-time characteristics of the pressure drawdown (or buildup at the reinjection site). To study the evolution of permeability and specific storage capacity as a function of pressure, temperature, and time, we performed oscillatory pore pressure tests. Experiments were performed using samples collected at surface outcrops representing the lithological sequence of the Upper Rhine Graben reservoir in southern Germany, i.e. sandstone and limestone, as well as Padang granite, representing a homogeneous, crystalline reservoir rock. Experiments were run at temperatures between 20 and 200 ° C, confining pressures between 20 and 110 MPa, and a fixed fluid pressure of 10 MPa, modeling characteristic conditions of deep geothermal reservoirs. Intact samples of granite, limestone and sandstone yield permeability and specific storage capacity of about 10‑18, 10‑15, and 10‑14 m2, and 10‑10, 10‑11 and 10‑8 Pa‑1, respectively, with modest dependence on temperature and effective pressure. In addition, longitudinally fractured samples were prepared by simple splitting or cutting and grinding. Grinding was performed with sandpaper of different ISO grits designations (P100, P600, and P1200) to systematically vary the surfaces' roughness. Fractures cause an increase in room-temperature permeability up to 3 and 2 orders of magnitudes for samples of granite and limestone, respectively. Their pressure dependence corresponds to a reduction in permeability modulus by about one order of magnitude

  6. A pilot test of polymer flooding in an elevated-temperature reservoir

    SciTech Connect

    Tielong, Chen; Zhengyu, Song; Fan, Y.

    1996-12-31

    A pilot test of polymer flooding has been conducted in Shuanghe reservoir located in southeast Henan oil field, China. The target reservoir has a net thickness of 15.56 meters (50 ft), an average permeability of 420 md, and temperature of 75{degrees}C (167{degrees}F). The polymers used are two types of modified partially hydrolyzed polyacrylamides, named S525 and S625, which have molecular weights of 16,700,000 and 19,670,000 daltons, respectively. The objective of this pilot test is to investigate the feasibility of polymer flooding for improving oil recovery in an elevated-temperature reservoir. The polymer flooding started in February 1994. Up through December 1995, a total of 246 tons (about 0.5 x 106 lb) of dry polymer had been used with an injection concentration of 900-1100 ppm. The pore volume injected reached 0.2164. As a result, oil production increased by 22,000 tons (184,000 bbl) and water production decreased by 153,000 tons (962,000 bbl), which accounts for the incremental oil recovery of 3.8% and water-cut reduction of 5.6% in the test block. It is estimated that by the end of this project, the ultimate increase in oil production will exceed 63,000 tons (528,000 bbl) with the enhanced oil recovery going up to 9.8%. The yield is 0.2 tons more oil produced per kilogram of polymer injected or 0.7 barrel of oil produced per pound of polymer. The success of the pilot test is attributed to a few techniques used during the implementation of the flooding, including prevention of polymer thermal degradation, good reservoir description, and the profile modification carried out before and after the polymer injection. This pilot test illustrates a case where polymers with extra-high molecular weight are successfully injected in an elevated-temperature reservoir to control the mobility ratio and modify the permeability profile.

  7. Stability of waterflood diverting agents at elevated temperatures in reservoir brines

    SciTech Connect

    Nagra, S.S.; Batycky, J.P.; Nieman, R.E.; Bodeux, J.B.

    1986-01-01

    Water channelling is a significant problem in oil producing reservoirs. One way to improve sweep is by diverting water to unswept zones through the placement of polymeric gels as diverting agents. The key to successful application of these materials is the amount of time over which the gels will be effective at reservoir conditions. Gel stabilities of a range of polymer compounds were tested in reservoir brines with salinities up to 10% TDS and at temperatures up to 90/sup 0/C. One characterization of gel stability was the amount of time (half-life) required for a gel to shrink to half its initial volume. Results at 90/sup 0/C with polyacrylamide, cellulosic and xanthan gels showed short half-lives ranging from less than a day (complete syneresis) up to 45 days depending on concentration and polymer type. Intermediate stabilities were observed with scleroglucan while the most stable gels with hlf-lives of more than a year were observed at 90/sup 0/C with lignosulphonate and phenoformaldehyde materials. Based on this screening procedure, phenoformaldehyde gels were tested for permeability reduction in both homogeneous and fractured cores after which the products were field tested. Preliminary results from a number of field tests provide optimism to continue a cautious program to develop placement and evaluation techniques.

  8. Temperature and population density determine reservoir regions of seasonal persistence in highland malaria.

    PubMed

    Siraj, Amir S; Bouma, Menno J; Santos-Vega, Mauricio; Yeshiwondim, Asnakew K; Rothman, Dale S; Yadeta, Damtew; Sutton, Paul C; Pascual, Mercedes

    2015-12-01

    A better understanding of malaria persistence in highly seasonal environments such as highlands and desert fringes requires identifying the factors behind the spatial reservoir of the pathogen in the low season. In these 'unstable' malaria regions, such reservoirs play a critical role by allowing persistence during the low transmission season and therefore, between seasonal outbreaks. In the highlands of East Africa, the most populated epidemic regions in Africa, temperature is expected to be intimately connected to where in space the disease is able to persist because of pronounced altitudinal gradients. Here, we explore other environmental and demographic factors that may contribute to malaria's highland reservoir. We use an extensive spatio-temporal dataset of confirmed monthly Plasmodium falciparum cases from 1995 to 2005 that finely resolves space in an Ethiopian highland. With a Bayesian approach for parameter estimation and a generalized linear mixed model that includes a spatially structured random effect, we demonstrate that population density is important to disease persistence during the low transmission season. This population effect is not accounted for in typical models for the transmission dynamics of the disease, but is consistent in part with a more complex functional form of the force of infection proposed by theory for vector-borne infections, only during the low season as we discuss. As malaria risk usually decreases in more urban environments with increased human densities, the opposite counterintuitive finding identifies novel control targets during the low transmission season in African highlands. PMID:26631558

  9. Molecular Detection of Anaerobic Ammonium-Oxidizing (Anammox) Bacteria in High-Temperature Petroleum Reservoirs

    PubMed Central

    Li, Hui; Chen, Shuo; Mu, Bo-Zhong

    2010-01-01

    Anaerobic ammonium-oxidizing (anammox) process plays an important role in the nitrogen cycle of the worldwide anoxic and mesophilic habitats. Recently, the existence and activity of anammox bacteria have been detected in some thermophilic environments, but their existence in the geothermal subterranean oil reservoirs is still not reported. This study investigated the abundance, distribution and functional diversity of anammox bacteria in nine out of 17 high-temperature oil reservoirs by molecular ecology analysis. High concentration (5.31–39.2 mg l−1) of ammonium was detected in the production water from these oilfields with temperatures between 55°C and 75°C. Both 16S rRNA and hzo molecular biomarkers indicated the occurrence of anammox bacteria in nine out of 17 samples. Most of 16S rRNA gene phylotypes are closely related to the known anammox bacterial genera Candidatus Brocadia, Candidatus Kuenenia, Candidatus Scalindua, and Candidatus Jettenia, while hzo gene phylotypes are closely related to the genera Candidatus Anammoxoglobus, Candidatus Kuenenia, Candidatus Scalindua, and Candidatus Jettenia. The total bacterial and anammox bacterial densities were 6.4 ± 0.5 × 103 to 2.0 ± 0.18 × 106 cells ml−1 and 6.6 ± 0.51 × 102 to 4.9 ± 0.36 × 104 cell ml−1, respectively. The cluster I of 16S rRNA gene sequences showed distant identity (<92%) to the known Candidatus Scalindua species, inferring this cluster of anammox bacteria to be a new species, and a tentative name Candidatus “Scalindua sinooilfield” was proposed. The results extended the existence of anammox bacteria to the high-temperature oil reservoirs. PMID:20740282

  10. Influence of composition and temperature on hydrocarbon migration through Morrow fluvial reservoirs, Las Animas Arch, Colorado

    SciTech Connect

    Bolyard, D.W.

    1995-06-01

    Precipitation of wax in pores may impair permeability and prohibit the flow of oil. Crude oil composition and temperature are the most important controlling factors. Oils are chemically complex, may contain up to 45 wax compounds and may vary significantly even in the same pool. High-wax oils are common in the Morrow of eastern Colorado. Narrow fluvial sandstones provide migration paths toward the Las Animas Arch from adjacent basins. Temperatures range from less than 110{degrees}F. on the top of the arch to 180{degrees}F at a structural position only 1,400 feet lower. A range of 30{degrees}F has been observed in individual pools. Wax has precipitated in the 120-140{degrees}F range, creating relative permeability barriers which cut across the sandstones. Wax barriers are impermeable to oil, but may be permeable to gas and water. They account for certain dry holes with high porosity, permeability and oil saturation (and low water saturation) in both core and electrical log analysis. They explain why some oil wells with impaired permeability are adjacent to structurally lower gas wells with good permeability. A network of wax barriers around the Las Animas Arch accounts for approximately 300 feet of variation in the structural position of a line separating oil from gas fields. Since the low temperature bands may be short and discontinuous, wax barriers are more effective in narrow fluvial reservoirs than in blanket reservoirs.

  11. Predicting cement distribution in geothermal sandstone reservoirs based on estimates of precipitation temperatures

    NASA Astrophysics Data System (ADS)

    Olivarius, Mette; Weibel, Rikke; Whitehouse, Martin; Kristensen, Lars; Hjuler, Morten L.; Mathiesen, Anders; Boyce, Adrian J.; Nielsen, Lars H.

    2016-04-01

    Exploitation of geothermal sandstone reservoirs is challenged by pore-cementing minerals since they reduce the fluid flow through the sandstones. Geothermal exploration aims at finding sandstone bodies located at depths that are adequate for sufficiently warm water to be extracted, but without being too cemented for warm water production. The amount of cement is highly variable in the Danish geothermal reservoirs which mainly comprise the Bunter Sandstone, Skagerrak and Gassum formations. The present study involves bulk and in situ stable isotope analyses of calcite, dolomite, ankerite, siderite and quartz in order to estimate at what depth they were formed and enable prediction of where they can be found. The δ18O values measured in the carbonate minerals and quartz overgrowths are related to depth since they are a result of the temperatures of the pore fluid. Thus the values indicate the precipitation temperatures and they fit the relative diagenetic timing identified by petrographical observations. The sandstones deposited during arid climatic conditions contain calcite and dolomite cement that formed during early diagenesis. These carbonate minerals precipitated as a response to different processes, and precipitation of macro-quartz took over at deeper burial. Siderite was the first carbonate mineral that formed in the sandstones that were deposited in a humid climate. Calcite began precipitating at increased burial depth and ankerite formed during deep burial and replaced some of the other phases. Ankerite and quartz formed in the same temperature interval so constrains on the isotopic composition of the pore fluid can be achieved. Differences in δ13C values exist between the sandstones that were deposited in arid versus humid environments, which suggest that different kinds of processes were active. The estimated precipitation temperatures of the different cement types are used to predict which of them are present in geothermal sandstone reservoirs in

  12. Geothermal Project Den Haag - 3-D models for temperature prediction and reservoir characterization

    NASA Astrophysics Data System (ADS)

    Mottaghy, D.; Pechnig, R.; Willemsen, G.; Simmelink, H. J.; Vandeweijer, V.

    2009-04-01

    In the framework of the "Den Haag Zuidwest" geothermal district heating system a deep geothermal installation is projected. The target horizon of the planned doublet is the "Delft sandstone" which has been extensively explored for oil- and gas reservoirs in the last century. In the target area, this upper Jurassic sandstone layer is found at a depth of about 2300 m with an average thickness of about 50 m. The study presented here focuses on the prediction of reservoir temperatures and production behavior which is crucial for planning a deep geothermal installation. In the first phase, the main objective was to find out whether there is a significant influence of the 3-dimensional structures of anticlines and synclines on the temperature field, which could cause formation temperatures deviating from the predicted extrapolated temperature data from oil and gas exploration wells. To this end a regional model was set up as a basis for steady state numerical simulations. Since representative input parameters are decisive for reliable model results, all available information was compiled: a) the subsurface geometry, depth and thickness of the stratigraphic layers known from seismic data sets 2) borehole geophysical data and c) geological and petrographical information from exploration wells. In addition 50 cuttings samples were taken from two selected key wells in order to provide direct information on thermal properties of the underlying strata. Thermal conductivity and rock matrix density were measured in the laboratory. These data were combined with a petrophysical log analysis (Gamma Ray, Sonic, Density and Resistivity), which resulted in continuous profiles of porosity, effective thermal conductivity and radiogenetic heat production. These profiles allowed to asses in detail the variability of the petrophysical properties with depth and to check for lateral changes between the wells. All this data entered the numerical simulations which were performed by a 3-D

  13. Geothermal low-temperature reservoir assessment in Dona Ana County, New Mexico. Final report

    SciTech Connect

    Icerman, L.; Lohse, R.L.

    1983-04-01

    Sixty-four shallow temperature gradient holes were drilled on the Mesilla Valley East Mesa (east of Interstate Highways 10 and 25), stretching from US Highway 70 north of Las Cruces to NM Highway 404 adjacent to Anthony, New Mexico. Using these data as part of the site selection process, Chaffee Geothermal, Ltd. of Denver, Colorado, drilled two low-temperature geothermal production wells to the immediate north and south of Tortugas Mountain and encountered a significant low-temperature reservoir, with a temperature of about 150{sup 0}F and flow rates of 750 to 1500 gallons per minute at depths from 650 to 1250 feet. These joint exploration activities resulted in the discovery and confirmation of a 30-square-mile low-temperature geothermal anomaly just a few miles to the east of Las Cruces that has been newly named as the Las Cruces east Mesa Geothermal Field. Elevated temperature and heat flow data suggest that the thermal anomaly is fault controlled and extends southward to the Texas border covering a 100-square-mile area. With the exception of some localized perturbations, the anomaly appears to decrease in temperature from the north to the south. Deeper drilling is required in the southern part of the anomaly to confirm the existence of commercially-exploitable geothermal waters.

  14. Ensemble Kalman Filter Assimilation of Temperature Data to Estimate Permeability in Geothermal Reservoirs

    NASA Astrophysics Data System (ADS)

    Vogt, C.; Widera, A.

    2012-04-01

    Reliable information on heterogeneous permeability fields of geothermal reservoirs is of particular interest, even after production started. This information permits the prediction of temperature and pressure variation with time, the optimization of the production rate of the geothermal installation in terms of profit or sustainability, and the detection of optimal locations for additional injection or production wells. Therefore, we study the capability of the data assimilation technique Ensemble Kalman Filter (EnKF) to estimate heterogeneous permeability fields using sparse temperature data from five geothermal wells inside a synthetic reservoir. To simulate the transient temperature variation inside the geothermal system, we use the finite volume software SHEMAT-Suite for solving coupled transient equations for groundwater flow and heat transport in a porous rock matrix. The EnKF is essentially a sequential assimilation procedure which compares observations to predictions by SHEMAT-Suite and adjusts system variables (in this case: permeability, temperature, and hydraulic head) of the numerical simulator according to the error statistics assuming a Gaussian error distribution. For the EnKF, the error statistics are obtained from the mean and variance of a number of realisations. This way, estimated permeability converts in the direction of true permeability assimilation step by assimilation step. We demonstrate that the basic features of the permeability field are reproduced by the EnKF, even when assimilating data from just five wells. In addition, we are able to quantify uncertainty of the permeability estimation. The fit using temperature data is comparable with the fit using tracer concentration data (Vogt et al., 2010). However, different time scales (months respectively years) apply for the two different data types. Optimal fits are obtained when taking into account hydraulic head data in combination with temperature data. We also present the effect of

  15. Effect of temperature on ultrasonic velocities of unconsolidated sandstones reservoirs during the SAGD recovery process

    NASA Astrophysics Data System (ADS)

    Doan, D.-H.; Nauroy, J.-F.; Delage, P.; Mainguy, M.

    2010-06-01

    The steam assisted gravity drainage (SAGD) is a thermal in-situ technology that has been successfully used to enhance the recovery of heavy oil and bitumen in the Western Canada and in the Eastern Venezuela basins. Pressure and temperature variations during SAGD operations induce complex changes in the mechanical and acoustic properties of the reservoir rocks as well as of the caprock. To study these changes, measurements of ultrasonic wave velocities Vp, Vs were performed on both reconstituted samples and natural samples from oil sands reservoir. Reconstituted samples were made of Fontainebleau sands with a slight cementation formed by a silicate solution. They have a high porosity (about 30 % to 40 %) and a high permeability (up to 10 D). Natural oil sands samples are unconsolidated sandstones extracted from the fluvio-estuarine McMurray Formation in Alberta (Canada). The saturating fluids were bitumen and glycerol with a strongly temperature dependent viscosity. The tests were carried out at different temperatures (in the range 40° and +86°C) and at different effective pressures (from 12 bars up to 120 bars). Experimental results firstly showed that the elastic wave propagation velocities measured are strongly dependent on temperature and pore fluid viscosity whereas little effect of effective pressure was observed. Velocities decreased with increasing temperature and increased with increasing effective pressure. These effects are mainly due to the variations of the saturating fluids properties. Finally, the tests were modelled by using Ciz and Shapiro (2007) approach and satisfactory velocities values were obtained with highly viscous fluids, a case that cannot be easily explained by using the poro-elastic theory of Biot-Gassmann.

  16. Efficiency optimization of a closed indirectly fired gas turbine cycle working under two variable-temperature heat reservoirs

    NASA Astrophysics Data System (ADS)

    Ma, Zheshu; Wu, Jieer

    2011-08-01

    Indirectly or externally fired gas turbines (IFGT or EFGT) are interesting technologies under development for small and medium scale combined heat and power (CHP) supplies in combination with micro gas turbine technologies. The emphasis is primarily on the utilization of the waste heat from the turbine in a recuperative process and the possibility of burning biomass even "dirty" fuel by employing a high temperature heat exchanger (HTHE) to avoid the combustion gases passing through the turbine. In this paper, finite time thermodynamics is employed in the performance analysis of a class of irreversible closed IFGT cycles coupled to variable temperature heat reservoirs. Based on the derived analytical formulae for the dimensionless power output and efficiency, the efficiency optimization is performed in two aspects. The first is to search the optimum heat conductance distribution corresponding to the efficiency optimization among the hot- and cold-side of the heat reservoirs and the high temperature heat exchangers for a fixed total heat exchanger inventory. The second is to search the optimum thermal capacitance rate matching corresponding to the maximum efficiency between the working fluid and the high-temperature heat reservoir for a fixed ratio of the thermal capacitance rates of the two heat reservoirs. The influences of some design parameters on the optimum heat conductance distribution, the optimum thermal capacitance rate matching and the maximum power output, which include the inlet temperature ratio of the two heat reservoirs, the efficiencies of the compressor and the gas turbine, and the total pressure recovery coefficient, are provided by numerical examples. The power plant configuration under optimized operation condition leads to a smaller size, including the compressor, turbine, two heat reservoirs and the HTHE.

  17. Bull trout (Salvelinus confluentus) movement in relation to water temperature, season, and habitat features in Arrowrock Reservoir, Idaho, 2012

    USGS Publications Warehouse

    Maret, Terry R.; Schultz, Justin E.

    2013-01-01

    Acoustic telemetry was used to determine spring to summer (April–August) movement and habitat use of bull trout (Salvelinus confluentus) in Arrowrock Reservoir (hereafter “Arrowrock”), a highly regulated reservoir in the Boise River Basin of southwestern Idaho. Water management practices annually use about 86 percent of the reservoir water volume to satisfy downstream water demands. These practices might be limiting bull trout habitat and movement patterns. Bull trout are among the more thermally sensitive coldwater species in North America, and the species is listed as threatened throughout the contiguous United States under the Endangered Species Act. Biweekly water-temperature and dissolved-oxygen profiles were collected by the Bureau of Reclamation at three locations in Arrowrock to characterize habitat conditions for bull trout. Continuous streamflow and water temperature also were measured immediately upstream of the reservoir on the Middle and South Fork Boise Rivers, which influence habitat conditions in the riverine zones of the reservoir. In spring 2012, 18 bull trout ranging in total length from 306 to 630 millimeters were fitted with acoustic transmitters equipped with temperature and depth sensors. Mobile boat tracking and fixed receivers were used to detect released fish. Fish were tagged from March 28 to April 20 and were tracked through most of August. Most bull trout movements were detected in the Middle Fork Boise River arm of the reservoir. Fifteen individual fish were detected at least once after release. Water surface temperature at each fish detection location ranged from 6.0 to 16.2 degrees Celsius (°C) (mean=10.1°C), whereas bull trout body temperatures were colder, ranging from 4.4 to 11.6°C (mean=7.3°C). Bull trout were detected over deep-water habitat, ranging from 8.0 to 42.6 meters (m) (mean=18.1 m). Actual fish depths were shallower than total water depth, ranging from 0.0 to 24.5 m (mean=6.7 m). The last bull trout was

  18. Deep Geothermal Reservoir Temperatures in the Eastern Snake River Plain, Idaho using Multicomponent Geothermometry

    SciTech Connect

    Ghanashyam Neupane; Earl D. Mattson; Travis L. McLing; Carl D. Palmer; Robert W. Smith; Thomas R. Wood

    2014-02-01

    The U.S. Geological survey has estimated that there are up to 4,900 MWe of undiscovered geothermal resources and 92,000 MWe of enhanced geothermal potential within the state of Idaho. Of particular interest are the resources of the Eastern Snake River Plain (ESRP) which was formed by volcanic activity associated with the relative movement of the Yellowstone Hot Spot across the state of Idaho. This region is characterized by a high geothermal gradient and thermal springs occurring along the margins of the ESRP. Masking much of the deep thermal potential of the ESRP is a regionally extensive and productive cold-water aquifer. We have undertaken a study to infer the temperature of the geothermal system hidden beneath the cold-water aquifer of the ESRP. Our approach is to estimate reservoir temperatures from measured water compositions using an inverse modeling technique (RTEst) that calculates the temperature at which multiple minerals are simultaneously at equilibrium while explicitly accounting for the possible loss of volatile constituents (e.g., CO2), boiling and/or water mixing. In the initial stages of this study, we apply the RTEst model to water compositions measured from a limited number of wells and thermal springs to estimate the regionally extensive geothermal system in the ESRP.

  19. Chemical quality and temperature of water in Flaming Gorge Reservoir, Wyoming and Utah, and the effect of the reservoir on the Green River

    USGS Publications Warehouse

    Bolke, E.L.; Waddell, Kidd M.

    1975-01-01

    end of the 1972 water year was 4,500,000 acre-feet (5,550.8 hm3). Of this total, water stored in the reservoir accounted for 3,500,000 acre-feet (4,317.2 hm3), evaporation consumed 700,000 acre-feet (863.4 hm3), and 300,000 acre-feet (370.0 hm3) went into bank storage. The net load of dissolved solids added to the river system during the 1963-72 water years, due to leaching and chemical precipitation, was 1,730,000 tons (1,569,421 t). The leaching rate was 200,000 tons (181,436 t) per year for 1963-68,115,000 tons ( 104,326 t) per year for 1969-70 and 150,000 tons (136,077 t) per year for 1971-72. It appears that the leaching rates should decrease in the future since the reservoir level in 1972 was near maximum pool level. The most significant increase in concentration of the chemical constituents in the water below the reservoir involved the sulfate ion, which increased from about 115 milligrams per litre (42 percent of the anions) in 1957 to about 200 milligrams per litre (54 percent), in 1972. But the highest concentration, about 290 milligrams per litre (58 percent), occurred in 1963, immediately after closure of the dam. Prior to closure of the dam, the average monthly temperature of the Green River below the damsite ranged from 0?C to 19.5?C as compared to 3.5?C to 10.0?C after closure.

  20. Microbial diversity in long-term water-flooded oil reservoirs with different in situ temperatures in China

    PubMed Central

    Zhang, Fan; She, Yue-Hui; Chai, Lu-Jun; Banat, Ibrahim M.; Zhang, Xiao-Tao; Shu, Fu-Chang; Wang, Zheng-Liang; Yu, Long-Jiang; Hou, Du-Jie

    2012-01-01

    Water-flooded oil reservoirs have specific ecological environments due to continual water injection and oil production and water recycling. Using 16S rRNA gene clone library analysis, the microbial communities present in injected waters and produced waters from four typical water-flooded oil reservoirs with different in situ temperatures of 25°C, 40°C, 55°C and 70°C were examined. The results obtained showed that the higher the in situ temperatures of the oil reservoirs is, the less the effects of microorganisms in the injected waters on microbial community compositions in the produced waters is. In addition, microbes inhabiting in the produced waters of the four water-flooded oil reservoirs were varied but all dominated by Proteobacteria. Moreover, most of the detected microbes were not identified as indigenous. The objective of this study was to expand the pictures of the microbial ecosystem of water-flooded oil reservoirs. PMID:23094135

  1. High Temperature and Bacteriophages Can Indirectly Select for Bacterial Pathogenicity in Environmental Reservoirs

    PubMed Central

    Friman, Ville-Petri; Hiltunen, Teppo; Jalasvuori, Matti; Lindstedt, Carita; Laanto, Elina; Örmälä, Anni-Maria; Laakso, Jouni; Mappes, Johanna; Bamford, Jaana K. H.

    2011-01-01

    The coincidental evolution hypothesis predicts that traits connected to bacterial pathogenicity could be indirectly selected outside the host as a correlated response to abiotic environmental conditions or different biotic species interactions. To investigate this, an opportunistic bacterial pathogen, Serratia marcescens, was cultured in the absence and presence of the lytic bacteriophage PPV (Podoviridae) at 25°C and 37°C for four weeks (N = 5). At the end, we measured changes in bacterial phage-resistance and potential virulence traits, and determined the pathogenicity of all bacterial selection lines in the Parasemia plantaginis insect model in vivo. Selection at 37°C increased bacterial motility and pathogenicity but only in the absence of phages. Exposure to phages increased the phage-resistance of bacteria, and this was costly in terms of decreased maximum population size in the absence of phages. However, this small-magnitude growth cost was not greater with bacteria that had evolved in high temperature regime, and no trade-off was found between phage-resistance and growth rate. As a result, phages constrained the evolution of a temperature-mediated increase in bacterial pathogenicity presumably by preferably infecting the highly motile and virulent bacteria. In more general perspective, our results suggest that the traits connected to bacterial pathogenicity could be indirectly selected as a correlated response by abiotic and biotic factors in environmental reservoirs. PMID:21423610

  2. Subsurface monitoring of reservoir pressure, temperature, relative humidity, and water content at the CAES Field Experiment, Pittsfield, Illinois: system design

    SciTech Connect

    Hostetler, D.D.; Childs, S.W.; Phillips, S.J.

    1983-03-01

    This subsurface-instrumentation design has been developed for the first Compressed Air Energy Storage (CAES) field experiment to be performed in porous media. Energy storage will be accomplished by alternating the injection and withdrawal of compressed air in a confined sandstone aquifer near Pittsfield, Illinois. The overall experiment objective is to characterize the reservoir's geochemical and thermohydraulic response to imposed CAES conditions. Specific experiment objectives require monitoring: air-bubble development; thermal development; cyclic pressure response; reservoir dehydration; and water coning. Supporting these objectives, four parameters will be continuously monitored at depth in the reservoir. They are: temperature; pressure; pore-air relative humidity; and pore-water content. Reservoir temperatures and pressures will range to maximum values approaching 200/sup 0/C and 300 psi, respectively. Both pore-air relative humidity and pore-water content will range from approx. 0 to 100%. This report discusses: instrumentation design; sensor and sensor system calibration; field installation and testing; and instrument-system operation. No comprehensive off-the-shelf instrument package exists to adequately monitor CAES reservoir parameters at depth. The best available sensors were selected and adapted for use under expected ranges of reservoir conditions. The instrumentation design criteria required: suitable sensor accuracy; continuous monitoring capability; redundancy; maximum sensor integrity; contingency planning; and minimum cost-information ratio. Three wells will be instrumented: the injection/withdrawal (I/W) well and the two instrument wells. Sensors will be deployed by wireline suspension in both open and backfilled (with sand) wellbores. The sensors deployed in the I/W well will be retrievable; the instrument-well sensors will not.

  3. Microbial abundance and community composition influence production performance in a low-temperature petroleum reservoir.

    PubMed

    Li, Guoqiang; Gao, Peike; Wu, Yunqiang; Tian, Huimei; Dai, Xuecheng; Wang, Yansen; Cui, Qingfeng; Zhang, Hongzuo; Pan, Xiaoxuan; Dong, Hanping; Ma, Ting

    2014-05-01

    Enhanced oil recovery using indigenous microorganisms has been successfully applied in the petroleum industry, but the role of microorganisms remains poorly understood. Here, we investigated the relationship between microbial population dynamics and oil production performance during a water flooding process coupled with nutrient injection in a low-temperature petroleum reservoir. Samples were collected monthly over a two-year period. The microbial composition of samples was determined using 16S rRNA gene pyrosequencing and real-time quantitative polymerase chain reaction analyses. Our results indicated that the microbial community structure in each production well microhabitat was dramatically altered during flooding with eutrophic water. As well as an increase in the density of microorganisms, biosurfactant producers, such as Pseudomonas, Alcaligenes, Rhodococcus, and Rhizobium, were detected in abundance. Furthermore, the density of these microorganisms was closely related to the incremental oil production. Oil emulsification and changes in the fluid-production profile were also observed. In addition, we found that microbial community structure was strongly correlated with environmental factors, such as water content and total nitrogen. These results suggest that injected nutrients increase the abundance of microorganisms, particularly biosurfactant producers. These bacteria and their metabolic products subsequently emulsify oil and alter fluid-production profiles to enhance oil recovery. PMID:24730445

  4. Geothermal reservoir temperatures estimated from the oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes

    USGS Publications Warehouse

    McKenzie, W.F.; Truesdell, A.H.

    1977-01-01

    The oxygen isotope compositions of dissolved sulfate and water from hot springs and shallow drillholes have been tested as a geothermometer in three areas of the western United States. Limited analyses of spring and borehole fluids and existing experimental rate studies suggest that dissolved sulfate and water are probably in isotopic equilibrium in all reservoirs of significant size with temperatures above ca. 140??C and that little re-equilibration occurs during ascent to the surface. The geothermometer is, however, affected by changes in ??18O of water due to subsurface boiling and dilution and by addition of sulfate of nearsurface origin. Methods are described to calculate the effects of boiling and dilution. The geothermometer, is applied to thermal systems of Yellowstone Park, Wyoming, Long Valley, California, and Raft River, Idaho to estimate deep reservoir temperatures of 360, 240, and 142??C, respectively. ?? 1976.

  5. Compaction bands in high temperature/pressure diagenetically altered unconventional shale gas reservoirs

    NASA Astrophysics Data System (ADS)

    Regenauer-Lieb, K.; Veveakis, M.; Poulet, T.

    2014-12-01

    Unconventional energy and mineral resources are typically trapped in a low porosity/permeability environment and are difficult to produce. An extreme end-member is the shale gas reservoir in the Cooper Basin (Australia) that is located at 3500-4000 m depth and ambient temperature conditions around 200oC. Shales of lacustrine origin (with high clay content) are diagenetically altered. Diagenesis involves fluid release mineral reactions of the general type Asolid ↔ Bsolid +Cfluid and switches on suddenly in the diagenetic window between 100-200oC. Diagenetic reactions can involve concentrations of smectite, aqueous silica compound, illite, potassium ions, aqueous silica, quartz, feldspar, kerogen, water and gas . In classical petroleum engineering such interlayer water/gas release reactions are considered to cause cementation and significantly reduce porosity and permeability. Yet in contradiction to the expected permeability reduction gas is successfully being produced. We propose that the success is based on the ductile equivalent of classical compaction bands in solid mechanics. The difference being that that the rate of the volumetric compaction is controlled by the diagenetic reactions. Ductile compaction bands are forming high porosity fluid channels rather than low porosity crushed grains in the solid mechanical equivalent. We show that this new type of volumetric instability appears in rate-dependent heterogenous materials as Cnoidal waves. These are nonlinear and exact periodic stationary waves, well known in the shallow water theory of fluid mechanics. Their distance is a direct function of the hydromechanical diffusivities. These instabilities only emerge in low permeability environment where the fluid diffusivity is about an order of magnitude lower than the mechanical loading. The instabilities are expected to be of the type as shown in the image below. The image shows a CT-scan of a laboratory experiment kindly provided by Papamichos (pers

  6. Temperature controlled icy dust reservoir of sodium: A possible mechanism for the formation of sporadic sodium layers

    NASA Astrophysics Data System (ADS)

    Qiu, Shican; Tang, Yihuan; Dou, Xiankang

    2015-06-01

    Using seven years, from 2006 to 2013, sodium lidar observations over Hefei, China (31.80°N, 117.3°E), we attempt to propose a possible mechanism for the formation of sporadic sodium layers (SSLs or NaS). We analyze the relationship between low temperature (<150 K) and SSL occurrence and detect a statistically significant link that the low temperature (<150 K) occur in three days before an SSL with an occurrence rate of 93.4% (57/61). The sharp decrease of water vapor concentration nearby before an SSL and the recover after the SSL are also detected frequently. Based upon these evidences and some case studies, we propose an icy dust reservoir in the formation of an SSL. The icy dust could form in the extremely cold mesopause region where the temperature falls below 150 K and it will absorb sodium atoms to form a solid sodium metal film as a sodium reservoir. The icy dust will then sublimate rapidly when meeting with warm air (e.g., 150 K < T < 190 K) and leave behind the solid metal atom film. The remanent sodium film might release vapor sodium atoms finally by some means through high temperature (e.g., >190 K and sometimes even >230 K) and form a sporadic sodium layer. Although not conclusive and highly uncertain, the icy dust reservoir model not only provides a good explanation for the observed characteristics of SSLs; it is also in good agreement with many other observations, such as the simultaneous sporadic sodium and iron layers, the behavior of SSLs on small time scale, the deviation of the sodium density profile of SSLs from the normal one, and the sharply decreased scale height above the peak of the sodium layer. These results further suggest that the icy dust might be a viable option of sodium reservoir for the formation of SSLs.

  7. Temperature and injection water source influence microbial community structure in four Alaskan North Slope hydrocarbon reservoirs

    PubMed Central

    Piceno, Yvette M.; Reid, Francine C.; Tom, Lauren M.; Conrad, Mark E.; Bill, Markus; Hubbard, Christopher G.; Fouke, Bruce W.; Graff, Craig J.; Han, Jiabin; Stringfellow, William T.; Hanlon, Jeremy S.; Hu, Ping; Hazen, Terry C.; Andersen, Gary L.

    2014-01-01

    A fundamental knowledge of microbial community structure in petroleum reservoirs can improve predictive modeling of these environments. We used hydrocarbon profiles, stable isotopes, and high-density DNA microarray analysis to characterize microbial communities in produced water from four Alaskan North Slope hydrocarbon reservoirs. Produced fluids from Schrader Bluff (24–27°C), Kuparuk (47–70°C), Sag River (80°C), and Ivishak (80–83°C) reservoirs were collected, with paired soured/non-soured wells sampled from Kuparuk and Ivishak. Chemical and stable isotope data suggested Schrader Bluff had substantial biogenic methane, whereas methane was mostly thermogenic in deeper reservoirs. Acetoclastic methanogens (Methanosaeta) were most prominent in Schrader Bluff samples, and the combined δD and δ13C values of methane also indicated acetoclastic methanogenesis could be a primary route for biogenic methane. Conversely, hydrogenotrophic methanogens (e.g., Methanobacteriaceae) and sulfide-producing Archaeoglobus and Thermococcus were more prominent in Kuparuk samples. Sulfide-producing microbes were detected in all reservoirs, uncoupled from souring status (e.g., the non-soured Kuparuk samples had higher relative abundances of many sulfate-reducers compared to the soured sample, suggesting sulfate-reducers may be living fermentatively/syntrophically when sulfate is limited). Sulfate abundance via long-term seawater injection resulted in greater relative abundances of Desulfonauticus, Desulfomicrobium, and Desulfuromonas in the soured Ivishak well compared to the non-soured well. In the non-soured Ivishak sample, several taxa affiliated with Thermoanaerobacter and Halomonas predominated. Archaea were not detected in the deepest reservoirs. Functional group taxa differed in relative abundance among reservoirs, likely reflecting differing thermal and/or geochemical influences. PMID:25147549

  8. Temperature and injection water source influence microbial community structure in four Alaskan North Slope hydrocarbon reservoirs.

    PubMed

    Piceno, Yvette M; Reid, Francine C; Tom, Lauren M; Conrad, Mark E; Bill, Markus; Hubbard, Christopher G; Fouke, Bruce W; Graff, Craig J; Han, Jiabin; Stringfellow, William T; Hanlon, Jeremy S; Hu, Ping; Hazen, Terry C; Andersen, Gary L

    2014-01-01

    A fundamental knowledge of microbial community structure in petroleum reservoirs can improve predictive modeling of these environments. We used hydrocarbon profiles, stable isotopes, and high-density DNA microarray analysis to characterize microbial communities in produced water from four Alaskan North Slope hydrocarbon reservoirs. Produced fluids from Schrader Bluff (24-27°C), Kuparuk (47-70°C), Sag River (80°C), and Ivishak (80-83°C) reservoirs were collected, with paired soured/non-soured wells sampled from Kuparuk and Ivishak. Chemical and stable isotope data suggested Schrader Bluff had substantial biogenic methane, whereas methane was mostly thermogenic in deeper reservoirs. Acetoclastic methanogens (Methanosaeta) were most prominent in Schrader Bluff samples, and the combined δD and δ(13)C values of methane also indicated acetoclastic methanogenesis could be a primary route for biogenic methane. Conversely, hydrogenotrophic methanogens (e.g., Methanobacteriaceae) and sulfide-producing Archaeoglobus and Thermococcus were more prominent in Kuparuk samples. Sulfide-producing microbes were detected in all reservoirs, uncoupled from souring status (e.g., the non-soured Kuparuk samples had higher relative abundances of many sulfate-reducers compared to the soured sample, suggesting sulfate-reducers may be living fermentatively/syntrophically when sulfate is limited). Sulfate abundance via long-term seawater injection resulted in greater relative abundances of Desulfonauticus, Desulfomicrobium, and Desulfuromonas in the soured Ivishak well compared to the non-soured well. In the non-soured Ivishak sample, several taxa affiliated with Thermoanaerobacter and Halomonas predominated. Archaea were not detected in the deepest reservoirs. Functional group taxa differed in relative abundance among reservoirs, likely reflecting differing thermal and/or geochemical influences. PMID:25147549

  9. Culture-Dependent and Culture-Independent Characterization of Microbial Assemblages Associated with High-Temperature Petroleum Reservoirs

    PubMed Central

    Orphan, V. J.; Taylor, L. T.; Hafenbradl, D.; Delong, E. F.

    2000-01-01

    Recent investigations of oil reservoirs in a variety of locales have indicated that these habitats may harbor active thermophilic prokaryotic assemblages. In this study, we used both molecular and culture-based methods to characterize prokaryotic consortia associated with high-temperature, sulfur-rich oil reservoirs in California. Enrichment cultures designed for anaerobic thermophiles, both autotrophic and heterotrophic, were successful at temperatures ranging from 60 to 90°C. Heterotrophic enrichments from all sites yielded sheathed rods (Thermotogales), pleomorphic rods resembling Thermoanaerobacter, and Thermococcus-like isolates. The predominant autotrophic microorganisms recovered from inorganic enrichments using H2, acetate, and CO2 as energy and carbon sources were methanogens, including isolates closely related to Methanobacterium, Methanococcus, and Methanoculleus species. Two 16S rRNA gene (rDNA) libraries were generated from total community DNA collected from production wellheads, using either archaeal or universal oligonucleotide primer sets. Sequence analysis of the universal library indicated that a large percentage of clones were highly similar to known bacterial and archaeal isolates recovered from similar habitats. Represented genera in rDNA clone libraries included Thermoanaerobacter, Thermococcus, Desulfothiovibrio, Aminobacterium, Acidaminococcus, Pseudomonas, Halomonas, Acinetobacter, Sphingomonas, Methylobacterium, and Desulfomicrobium. The archaeal library was dominated by methanogen-like rDNAs, with a lower percentage of clones belonging to the Thermococcales. Our results strongly support the hypothesis that sulfur-utilizing and methane-producing thermophilic microorganisms have a widespread distribution in oil reservoirs and the potential to actively participate in the biogeochemical transformation of carbon, hydrogen, and sulfur in situ. PMID:10653739

  10. Complete Fiber/Copper Cable Solution for Long-Term Temperature and Pressure Measurement in Supercritical Reservoirs and EGS Wells

    SciTech Connect

    Pastouret, Alan; Gooijer, Frans; Overton, Bob; Jonker, Jan; Curley, Jim; Constantine, Walter; Waterman, Kendall Miller

    2015-11-13

    High Temperature insulated wire and optical fiber cable is a key enabling technology for the Geothermal Technologies Program (GTP). Without insulated electrical wires and optical fiber, downhole temperature and pressure sensors, flow meters and gauges cannot communicate with the surface. Unfortunately, there are currently no insulated electrical wire or fiber cable constructions capable of surviving for extended periods of deployment in a geothermal well (240-325°C) or supercritical (374°C) reservoir. This has severely hindered engineered reservoir creation, management and utilization, as hot zones and cool water intrusions cannot be understood over time. The lack of a insulated electrical wire and fiber cable solution is a fundamental limitation to the viability of this energy source. The High Temperature Downhole Tools target specification is development of tools and sensors for logging and monitoring wellbore conditions at depths of up to 10,000 meters and temperatures up to 374oC. It well recognized in the industry that no current electronic or fiber cable can be successfully deployed in a well and function successfully for more a few days at temperatures over 240oC. The goal of this project was to raise this performance level significantly. Prysmian Group’s objective in this project was to develop a complete, multi-purpose cable solution for long-term deployment in geothermal wells/reservoirs that can be used with the widest variety of sensors. In particular, the overall project objective was to produce a manufacturable cable design that can perform without serious degradation: • At temperatures up to 374°C; • At pressures up to 220 bar; • In a hydrogen-rich environment; and • For the life of the well (> 5 years). This cable incorporates: • Specialty optical fibers, with specific glass chemistry and high temperature and pressure protective coatings for data communication and distributed temperature and pressure sensing, and • High-temperature

  11. Temperature, size, and depth of the magma reservoir for the Taylor Creek Rhyolite, New Mexico

    USGS Publications Warehouse

    Duffield, W.A.; du Bray, E.A.

    1990-01-01

    The 55 km3 mid-Tertiary Taylor Creek Rhyolite in southwestern New Mexico consists of 20 lava domes and flows. This rhyolite is metaluminous to weakly peraluminous. Compositional zonation in feldspar phenocrysts is very minor and nonsystematic. The compositions of each feldspar species vary little throughout the suite of analyzed samples. This chemical homogeneity of phenocrysts reflects similar whole-rock homogeneity and suggests that the lavas were tapped from a single large reservoir of magma. Ages of sanidine phenocrysts determined using 40Ar/39Ar indicate that the Taylor Creek Rhyolite lavas were emplaced during a period of less than 0.42 my. and possibly less than 0.13 m.y., which is consistent with the single-reservoir scenario. Two-feldspar geothermometry suggests that Taylor Creek Rhyolite phenocrysts crystallized at about 775??C, at an assumed pressure of 2 kbar. Fe-Ti-oxide geothermometry suggests phenocryst growth at about 800??C. Experimental studies suggest that quartz and potassium-feldspar crystals that grow from H2O-undersaturated granitic magmas should exhibit resorption texture, a texture ubiquitous to Taylor Creek Rhyolite quartz and sanidine phenocrysts. We tentatively conclude that the Taylor Creek Rhyolite magma was H2O undersaturated and subliquidus at an unspecified pressure greater than 0.5 kbar during phenocryst growth and that Taylor Creek Rhyolite pyroclastic deposits formed because volatile saturation developed during the ascent of magma to sites of eruption. -from Authors

  12. Interactions between walleyes and smallmouth bass in a Missouri River reservoir with consideration of the influence of temperature and prey

    USGS Publications Warehouse

    Wuellner, Melissa R.; Chipps, Steven R.; Willis, David W.; Adams, Wells E., Jr.

    2010-01-01

    Walleyes Sander vitreus are the most popular fish among South Dakota anglers, but smallmouth bass Micropterus dolomieu were introduced to provide new angling opportunities. Some walleye anglers have reported reductions in the quality of walleye fisheries since the introduction of smallmouth bass and attribute this to the consumption of young walleyes by smallmouth bass and competition for shared prey resources. We quantified the diets of walleyes and smallmouth bass in the lower reaches of Lake Sharpe (a Missouri River reservoir), calculated the diet overlap between the two predators, and determined whether they partitioned shared prey based on size. We also quantified walleye diets in the upper reach of the reservoir, which has a different prey base and allowed us to compare the growth rates of walleyes within Lake Sharpe. Age-0 gizzard shad Dorosoma cepedianum composed a substantial proportion of the diets of both predators, regardless of location, for most of the growing season; the patterns in shad vulnerability appeared to drive the observed patterns in diet overlap. Smallmouth bass appeared to consume a smaller size range of gizzard shad than did walleyes, which consumed a wide range. Smallmouth bass consumed Sander spp. in some months, but in very low quantities. Given that global climate change is expected to alter the population and community dynamics in Great Plains reservoirs, we also used a bioenergetics approach to predict the potential effects of limiting prey availability (specifically, the absence of gizzard shad and rainbow smelt Osmerus mordax) and increased water temperatures (as projected from global climate change models) on walleye and smallmouth bass growth. The models indicated that the absence of rainbow smelt from the diets of walleyes in upper Lake Sharpe would reduce growth but that the absence of gizzard shad would have a more marked negative effect on both predators at both locations. The models also indicated that higher

  13. Recently developed well test insrumentation for low-to-moderate temperature hydrothermal reservoirs

    SciTech Connect

    Solbau, R.; Goranson, C.B.; Benson, S.M.

    1981-08-01

    The engineering drawings, assembly instructions, and recommended usage for several of the instruments developed for low and moderate temperature (< 150/sup 0/C) hydrothermal well testing are presented. Included are the drawings for: a downhole pressure and temperature instrument, a multi-conductor cablehead, a line driver to be used with the downhole pressure and temperature instrument, and a fluid-level detector.

  14. Thermal dynamic in hyporheic zone response to river temperatures formed by reservoir operations in Xinanjiang River, China

    NASA Astrophysics Data System (ADS)

    Chen, X.; Zhao, J.; Chen, L.; Tao, X.; Zhao, Z.

    2012-12-01

    Understanding heat fluxes through hyporheic zones (HZ) becomes increasingly important as anthropogenic influences and changing climate alter river thermal regimes. The HZ directly interacts with river thermal regimes by storing and releasing heat over a range of timescales. Alteration of HZ can lead to shifts in aquatic species composition and changes in biogeochemical processes. In this study we examine a reach of the Xinanjiang, China downstream of the Xinanjiang Dam. The Xinanjiang Dam introduces a low temperature water (LTW) region to the downstream of a length of 23 km and an area of 9.9 km2, which greatly changes the downstream thermal regime. However, how and to what extent the LTW in stream affect the HZ temperature distribution and, ulteriorly, the full range of the river ecosystem are still not completely understood. We quantify hyporheic exchange and heat transport induced by LTW by field experiments and numerical simulations for coupled groundwater flow and heat transport. Both surface and subsurface water temperature are measured in a study region for model validation. The hydraulic head and water temperature along the water-aquifer interface are considered as the input boundaries for groundwater models. The upwelling water with short streamline paths shows the same temperature pattern as surface water but the temperature of water that comes out from the deep subsurface zones rises much higher and shows a relatively lower variation. However, with the continuing exchange of surface LTW and groundwater, the low temperature spreads over the entire domain. Detailed field characterization and groundwater modeling indicate residence times of hyporheic flux can vary from hours to months. A significant implication is that the LTW released from upstream reservoir contributes to the downstream temperature field and potential degradation of habitats in hyporheic zones.

  15. Microbial water diversion technique-designed for near well treatment in low temperature sandstone reservoirs in the North Sea

    SciTech Connect

    Paulsen, J.E.; Vatland, A.; Sorheim, R.

    1995-12-31

    A Norwegian Research Program on Improved Oil Recovery (IOR) in North Sea reservoirs was launched in 1992. Microbial methods, applied in this context, is a part of this program. The scope, the methodological approach, and results from the three first years are presented. Water profile control, using biomass to block high permeable zones of a reservoir, has been investigated using nitrate-reducing bacteria in the injected sea water as plugging agents. Emphasis has been put on developing a process that does not have disadvantages secondary to the process itself, such as souring and impairment of the overall injectivity of the field. Data from continuous culture studies indicate that souring may successfully be mitigated by adding nitrite to the injected seawater. The morphology and size of generic-nitrate-reducing seawater bacteria have been investigated. Screening of growth-promoting nutrients has been carried out, and some sources were detected as favorable. Transport and penetration of bacteria in porous media have been given special attention. Investigations with sand packs, core models, and pore micromodels have been carried out. The inherent problems connected with permeability contrasts and flow patterns, versus bacterial behavior, are believed to be critical for the success of this technology. Data from the transport and blocking experiments with the porous matrices confirm this concern. The technology is primarily being developed for temperatures less than 40{degrees}C.

  16. The Robustness of Clumped Isotope Temperatures to Bond Reordering: Evidence from Deeply Buried Carbonate Reservoirs

    NASA Astrophysics Data System (ADS)

    MacDonald, J.; John, C. M.; Girard, J. P.

    2014-12-01

    Numerous studies have shown that clumped isotope thermometry records the temperature of precipitation for carbonate minerals in surface and near-surface environments. However, the ability of a mineral to retain its clumped isotope signature at deeper, hotter burial conditions is still debated. Dolomite has been shown to be more robust to clumped isotope bond reordering than calcite. In this contribution we measure clumped isotopes in calcite veins from Southern Europe that have been buried to up to 7 km to test the robustness of calcite and dolomite to bond reordering. First, we analysed finely crystalline dolostone matrix samples collected in industry wells from Southwest France and buried to between 2 and 5.5 km, Results indicated a temperatures of ~40-60 °C, interpreted to represent formation in an early burial environment. By contrast, coarser dolomite crystals that are petrographically distinct from the fine-grained dolomite record higher temperatures and are interpreted to reflect a deeper, hotter phase of dolomite formation. Preliminary analysis of a calcite vein from a Cretaceous dolostone in Southern Europe buried to 6.3 km records a temperature of 41±3 °C; the calcite matrix around this records a similarly low temperature. This is well below the present-day well temperature of 130-140 °C. Our results indicate that both calcite and dolomite are not affected by bond reordering at the range of depths and temperatures investigated here. Furthermore, this suggests that clumped isotope thermometry can be applied to deeply-buried samples (i.e. >5km).

  17. EQUILGAS: Program to estimate temperatures and in situ two-phase conditions in geothermal reservoirs using three combined FT-HSH gas equilibria models

    NASA Astrophysics Data System (ADS)

    Barragán, Rosa María; Núñez, José; Arellano, Víctor Manuel; Nieva, David

    2016-03-01

    Exploration and exploitation of geothermal resources require the estimation of important physical characteristics of reservoirs including temperatures, pressures and in situ two-phase conditions, in order to evaluate possible uses and/or investigate changes due to exploitation. As at relatively high temperatures (>150 °C) reservoir fluids usually attain chemical equilibrium in contact with hot rocks, different models based on the chemistry of fluids have been developed that allow deep conditions to be estimated. Currently either in water-dominated or steam-dominated reservoirs the chemistry of steam has been useful for working out reservoir conditions. In this context, three methods based on the Fischer-Tropsch (FT) and combined H2S-H2 (HSH) mineral-gas reactions have been developed for estimating temperatures and the quality of the in situ two-phase mixture prevailing in the reservoir. For these methods the mineral buffers considered to be controlling H2S-H2 composition of fluids are as follows. The pyrite-magnetite buffer (FT-HSH1); the pyrite-hematite buffer (FT-HSH2) and the pyrite-pyrrhotite buffer (FT-HSH3). Currently from such models the estimations of both, temperature and steam fraction in the two-phase fluid are obtained graphically by using a blank diagram with a background theoretical solution as reference. Thus large errors are involved since the isotherms are highly nonlinear functions while reservoir steam fractions are taken from a logarithmic scale. In order to facilitate the use of the three FT-HSH methods and minimize visual interpolation errors, the EQUILGAS program that numerically solves the equations of the FT-HSH methods was developed. In this work the FT-HSH methods and the EQUILGAS program are described. Illustrative examples for Mexican fields are also given in order to help the users in deciding which method could be more suitable for every specific data set.

  18. Geothermal low-temperature reservoir assessment in northern Dona Ana County, New Mexico. Final report

    SciTech Connect

    Lohse, R.L.; Schoenmackers, R.

    1985-07-01

    Fifty-four shallow temperature gradient holes were drilled along Interstate Highway 25 and the Rio Grande, from Las Cruces to Rincon, in northern Dona Ana County, New Mexico. This shallow temperature study (a joint exploration program performed with the cooperation and financial assistance of Trans-Pacific Geothermal, Inc. of Oakland, California) resulted in the discovery and confirmation of new and suspected major low-temperature geothermal resources. Elevated temperature and heat flow data suggest a thermal anomaly which can be generally described as being a nearly continuous linear feature which extends some 25 miles in length in a northwest-southeast direction with the only break being a 5-mile gap near the southern end of the study area. The width of the anomaly is only a few miles but tends to thicken around individual anomalies located within this larger anomaly. There are five main individual anomalies situated within the major anomaly and, listed from north to south, they are the: (1) Rincon Anomaly, (2) San Diego Mountain Anomaly, (3) Radium Springs KGRA, (4) Grande Dome Anomaly, and (5) Goat Mountain Anomaly. The main anomaly is well defined by a 4 HFU contour and the individual anomalies range from about 10 HFU to a high of near 30 HFU, estimated for the Rincon Anomaly. A bottom-hole temperature of 54/sup 0/C at 50 meters was also recorded at Rincon. Deeper drilling is certainly warranted and required in the Rincon Anomaly in order to discover and confirm the true commercially exploitable potential of this geothermal resource. 12 refs., 9 figs., 3 tabs.

  19. Geomechanical Evaluation of Thermal Impact of Injected CO2 Temperature on a Geological Reservoir: Application to the FutureGen 2.0 Site

    DOE PAGESBeta

    Bonneville, Alain; USA, Richland Washington; Nguyen, Ba Nghiep; USA, Richland Washington; Stewart, Mark; USA, Richland Washington; Hou, Z. Jason; USA, Richland Washington; Murray, Christopher; USA, Richland Washington; et al

    2014-12-31

    The impact of temperature variations of injected CO2 on the mechanical integrity of a reservoir is a problem rarely addressed in the design of a CO2 storage site. The geomechanical simulation of the FutureGen 2.0 storage site presented here takes into account the complete modeling of heat exchange between the environment and CO2 during its transport in the pipeline and injection well before reaching the reservoir, as well as its interaction with the reservoir host rock. An ad-hoc program was developed to model CO2 transport from the power plant to the reservoir and an approach coupling PNNL STOMP-CO2 multiphase flowmore » simulator and ABAQUS® has been developed for the reservoir model which is fully three-dimensional with four horizontal wells and variable layer thickness. The Mohr-Coulomb fracture criterion has been employed, where hydraulic fracture was predicted to occur at an integration point if the fluid pressure at the point exceeded the least compressive principal stress. Evaluation of the results shows that the fracture criterion has not been verified at any node and time step for the CO2 temperature range predicted at the top of the injection zone.« less

  20. Geomechanical Evaluation of Thermal Impact of Injected CO2 Temperature on a Geological Reservoir: Application to the FutureGen 2.0 Site

    SciTech Connect

    Bonneville, Alain; USA, Richland Washington; Nguyen, Ba Nghiep; USA, Richland Washington; Stewart, Mark; USA, Richland Washington; Hou, Z. Jason; USA, Richland Washington; Murray, Christopher; USA, Richland Washington; Gilmore, Tyler; USA, Richland Washington

    2014-12-31

    The impact of temperature variations of injected CO2 on the mechanical integrity of a reservoir is a problem rarely addressed in the design of a CO2 storage site. The geomechanical simulation of the FutureGen 2.0 storage site presented here takes into account the complete modeling of heat exchange between the environment and CO2 during its transport in the pipeline and injection well before reaching the reservoir, as well as its interaction with the reservoir host rock. An ad-hoc program was developed to model CO2 transport from the power plant to the reservoir and an approach coupling PNNL STOMP-CO2 multiphase flow simulator and ABAQUS® has been developed for the reservoir model which is fully three-dimensional with four horizontal wells and variable layer thickness. The Mohr-Coulomb fracture criterion has been employed, where hydraulic fracture was predicted to occur at an integration point if the fluid pressure at the point exceeded the least compressive principal stress. Evaluation of the results shows that the fracture criterion has not been verified at any node and time step for the CO2 temperature range predicted at the top of the injection zone.

  1. Sensitivity of CO2 migration estimation on reservoir temperature and pressure uncertainty

    SciTech Connect

    Jordan, Preston; Doughty, Christine

    2008-11-01

    The density and viscosity of supercritical CO{sub 2} are sensitive to pressure and temperature (PT) while the viscosity of brine is sensitive primarily to temperature. Oil field PT data in the vicinity of WESTCARB's Phase III injection pilot test site in the southern San Joaquin Valley, California, show a range of PT values, indicating either PT uncertainty or variability. Numerical simulation results across the range of likely PT indicate brine viscosity variation causes virtually no difference in plume evolution and final size, but CO{sub 2} density variation causes a large difference. Relative ultimate plume size is almost directly proportional to the relative difference in brine and CO{sub 2} density (buoyancy flow). The majority of the difference in plume size occurs during and shortly after the cessation of injection.

  2. Investigation of high-temperature, igneous-related hydraulic fracturing as a reservoir control in the Blackburn and Grant Canyon/Bacon Flat oil fields, Nevada

    SciTech Connect

    Hulen, J.B.

    1991-01-01

    Research in progress to evaluate natural, igenous-related hydrothermal fracturing as a reservoir control in two eastern Nevada oil fields has revealed evidence of a far more comprehensive role for moderate- to high-temperature hydrothermal systems in Basin-and-Range oil-reservoir evolution. Fluid-inclusion and petrographic studies have shown that (now) oil-bearing dolomite breccias of the Blackburn field (Pine Valley, Eureka County) were formed when overpressured, magmatically-heated, high-temperature (>350{degrees}C) hydrothermal brines explosively ruptured their host rocks; similar studies of texturally identical breccias of the Grant Canyon/Bacon Flat field (Railroad Valley, Nye County) so far do not support such an explosive origin. At Grant Canyon, however, hydrothermal, breccia-cementing quartz hosts primary oil, aqueous/oil, and aqueous fluid inclusions (homogenization temperature = 120{degrees}C) which document a direct geothermal connection for oil migration and entrapment. Moreover, at both Blackburn and Grant Canyon/Bacon Flat, the oil reservoirs are top- and side-sealed by hydrothermally altered Tertiary ignimbrites and epiclastic rocks. Contemporary geothermal activity is also apparent at grant Canyon/Bacon Flat, where subsurface water temperatures reach 171{degrees}C, and at Blackburn, above which a petroleum-providing hot spring issues at a temperature of 90{degrees}C. We suggest that in the Basin and Range province, hydrothermal systems may have: (1) matured oil from otherwise submature source rocks; (2) transported oil to ultimate entrapment sites by convection in moderate-to high-temperature fluids; and (3) sealed reservoir traps through hydrothermal alteration of overlying Tertiary caprocks. 69 refs., 11 figs., 1 tab.

  3. Temperature-pressure conditions in coalbed methane reservoirs of the Black Warrior basin: Implications for carbon sequestration and enhanced coalbed methane recovery

    USGS Publications Warehouse

    Pashin, J.C.; McIntyre, M.R.

    2003-01-01

    Sorption of gas onto coal is sensitive to pressure and temperature, and carbon dioxide can be a potentially volatile supercritical fluid in coalbed methane reservoirs. More than 5000 wells have been drilled in the coalbed methane fields of the Black Warrior basin in west-central Alabama, and the hydrologic and geothermic information from geophysical well logs provides a robust database that can be used to assess the potential for carbon sequestration in coal-bearing strata.Reservoir temperature within the coalbed methane target zone generally ranges from 80 to 125 ??F (27-52 ??C), and geothermal gradient ranges from 6.0 to 19.9 ??F/1000 ft (10.9-36.2 ??C/km). Geothermal gradient data have a strong central tendency about a mean of 9.0 ??F/1000 ft (16.4 ??C/km). Hydrostatic pressure gradients in the coalbed methane fields range from normal (0.43 psi/ft) to extremely underpressured (<0.05 psi/ft). Pressure-depth plots establish a bimodal regime in which 70% of the wells have pressure gradients greater than 0.30 psi/ft, and 20% have pressure gradients lower than 0.10 psi/ft. Pockets of underpressure are developed around deep longwall coal mines and in areas distal to the main hydrologic recharge zone, which is developed in structurally upturned strata along the southeastern margin of the basin.Geothermal gradients within the coalbed methane fields are high enough that reservoirs never cross the gas-liquid condensation line for carbon dioxide. However, reservoirs have potential for supercritical fluid conditions beyond a depth of 2480 ft (756 m) under normally pressured conditions. All target coal beds are subcritically pressured in the northeastern half of the coalbed methane exploration fairway, whereas those same beds were in the supercritical phase window prior to gas production in the southwestern half of the fairway. Although mature reservoirs are dewatered and thus are in the carbon dioxide gas window, supercritical conditions may develop as reservoirs

  4. Functional genes (dsr) approach reveals similar sulphidogenic prokaryotes diversity but different structure in saline waters from corroding high temperature petroleum reservoirs.

    PubMed

    Guan, Jing; Zhang, Bing-Liang; Mbadinga, Serge Maurice; Liu, Jin-Feng; Gu, Ji-Dong; Mu, Bo-Zhong

    2014-02-01

    Oil reservoirs and production facilities are generally contaminated with H2S resulting from the activity of sulphidogenic prokaryotes (SRP). Sulphidogenesis plays a major role in reservoir souring and microbial influenced corrosion in oil production systems. In the present study, sulphidogenic microbial diversity and composition in saline production fluids retrieved from three blocks of corroding high temperature (79 ~ 95 °C) oil reservoirs with high sulfate concentrations were investigated by phylogenetic analyses of gene fragments of the dissimilatory sulfite reductase (dsr). Analysis of dsr gene fragments revealed the presence of several clusters of sulphidogenic prokaryotes that cover the orders Desulfovibrionales (Desulfovibrio, Desulfomicrobium thermophilum), Desulfobacterales (Desulfobacterium, Desulfosarcina, Desulfococcus, Desulfotignum, Desulfobotulus, Desulfobulbus), Syntrophobacterales (Desulfacinum, Thermodesulforhabdus, Desulforhabdus), Clostridiales (Desulfotomaculum) and Archaeoglobales (Archaeoglobus); among which sequences affiliated to members of Desulfomicrobium, Desulfotomaculum and Desulfovibrio appeared to be the most encountered genera within the three blocks. Collectively, phylogenetic and non-metric multidimensional scaling analyses indicated similar but structurally different sulphidogenic prokaryotes communities within the waters retrieved from the three Blocks. This study show the diversity and composition of sulphidogenic prokaryotes that may play a role in the souring mediated corrosion of the oilfield and also provides a fundamental basis for further investigation to control oil reservoir souring and corrosion of pipelines and topside installations. PMID:23949995

  5. Uncertainty in runoff based on Global Climate Model precipitation and temperature data - Part 2: Estimation and uncertainty of annual runoff and reservoir yield

    NASA Astrophysics Data System (ADS)

    Peel, M. C.; Srikanthan, R.; McMahon, T. A.; Karoly, D. J.

    2014-05-01

    Two key sources of uncertainty in projections of future runoff for climate change impact assessments are uncertainty between Global Climate Models (GCMs) and within a GCM. Within-GCM uncertainty is the variability in GCM output that occurs when running a scenario multiple times but each run has slightly different, but equally plausible, initial conditions. The limited number of runs available for each GCM and scenario combination within the Coupled Model Intercomparison Project phase 3 (CMIP3) and phase 5 (CMIP5) datasets, limits the assessment of within-GCM uncertainty. In this second of two companion papers, the primary aim is to approximate within-GCM uncertainty of monthly precipitation and temperature projections and assess its impact on modelled runoff for climate change impact assessments. A secondary aim is to assess the impact of between-GCM uncertainty on modelled runoff. Here we approximate within-GCM uncertainty by developing non-stationary stochastic replicates of GCM monthly precipitation and temperature data. These replicates are input to an off-line hydrologic model to assess the impact of within-GCM uncertainty on projected annual runoff and reservoir yield. To-date within-GCM uncertainty has received little attention in the hydrologic climate change impact literature and this analysis provides an approximation of the uncertainty in projected runoff, and reservoir yield, due to within- and between-GCM uncertainty of precipitation and temperature projections. In the companion paper, McMahon et al. (2014) sought to reduce between-GCM uncertainty by removing poorly performing GCMs, resulting in a selection of five better performing GCMs from CMIP3 for use in this paper. Here we present within- and between-GCM uncertainty results in mean annual precipitation (MAP), temperature (MAT) and runoff (MAR), the standard deviation of annual precipitation (SDP) and runoff (SDR) and reservoir yield for five CMIP3 GCMs at 17 world-wide catchments. Based on 100

  6. Reservoir geochemistry: A link between reservoir geology and engineering?

    SciTech Connect

    Larter, S.R.; Aplin, A.C.; Chen, M.; Taylor, P.N.; Corbett, P.W.M.; Ementon, N.

    1997-02-01

    Geochemistry provides a natural, but poorly exploited, link between reservoir geology and engineering. The authors summarize some current applications of geochemistry to reservoir description and stress that, because of their strong interactions with mineral surfaces and water, nitrogen and oxygen compounds in petroleum may exert an important influence on the pressure/volume/temperature (PVT) properties of petroleum, viscosity and wettability. The distribution of these compounds in reservoirs is heterogeneous on a submeter scale and is partly controlled by variations in reservoir quality. The implied variations in petroleum properties and wettability may account for some of the errors in reservoir simulations.

  7. Mechanism of reservoir testing

    SciTech Connect

    Bodvarsson, Gunnar

    1987-01-01

    In evaluating geothermal resources we are primarily interested in data on the distribution of temperature and fluid conductivity within the reservoir, the total volume of the productive formations, recharge characteristics and chemical quality of the thermal fluids. While geophysical exploration by surface methods may furnish some data on the temperature field and give indications as to the reservoir volume, they furnish practically no information on the fluid conductivity and production characteristics. Such information will generally have to be obtained by tests performed within the reservoir, primarily by production tests on sufficiently deep wells. Reservoir testing is therefore one of the most important tasks in a general exploration program. In principal, reservoir testing has much in common with conventional geophysical exploration. Although the physical fields applied are to some extent different, they face the same type of selection between controlled and natural drives, forward and inverse problem setting, etc. The basic philosophy (Bodvarsson, 1966) is quite similar. In the present paper, they discuss some fundamentals of the theory of reservoir testing where the fluid conductivity field is the primary target. The emphasis is on local and global aspects of the forward approach to the case of liquid saturated (dominated) Darcy type formations. Both controlled and natural driving pressure or strain fields are to be considered and particular emphasis is placed on the situation resulting from the effects of a free liquid surface at the top of the reservoir.

  8. Semi-analytical solutions for nonisothermal fluid injection including heat loss from the reservoir: Part 1. Saturation and temperature

    NASA Astrophysics Data System (ADS)

    LaForce, T.; Ennis-King, J.; Paterson, L.

    2014-11-01

    This work introduces the derivation and solution of the conservation laws for nonisothermal immiscible two-phase flow in one dimension (1D) with heat loss to surrounding strata. Purely advective flow is assumed so that the method of characteristics can be applied to the fluid flow and thermal equations with an arbitrary relative permeability model. The formulation allows for a wide class of time-dependent models for heat loss into surrounding strata. One-dimensional linear and radial displacements are considered. Thermal losses to the under- and over-burden are modelled using a heat-loss coefficient derived from the classic Lauwerier model. In order to demonstrate the two kinds of solution that may occur, examples are shown for cold methane injection into an aquifer and cold water injection into a natural gas reservoir. Finally the new analytical solutions are compared with two literature models which assume piston-like displacement, and numerical reservoir simulations. The solutions from the proposed model match the thermal profile from the reservoir simulation much better than either of the literature models in the examples considered.

  9. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions. [Lower Rio Grande Valley Test Site: Weslaco, Texas; Falco Reservoir and the Gulf of Mexico

    NASA Technical Reports Server (NTRS)

    Wiegand, C. L.; Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J. (Principal Investigator)

    1980-01-01

    The author has identified the following significant results. HCMM day/night coverage 12 hours apart cannot be obtained at 26 deg N latitude; nor have any pairs 36 hours apart been obtained. A day-IR scene and a night scene for two different dates were analyzed. A profile across the test site for the same latitude shows that the two profiles are near mirror images of each other over land surfaces and that the temperature of two large water bodies, Falcon Reservoir and the Gulf of Mexico, are nearly identical on two dates. During the time interval between overpasses, the vegetative cover remained static due to winter dormancy. The data suggest that day/night temperature differences measured weeks apart may yield meaningful information about the contrast between daytime maximum and nighttime minimum temperatures for a given site.

  10. Pore Characterization of Shale Rock and Shale Interaction with Fluids at Reservoir Pressure-Temperature Conditions Using Small-Angle Neutron Scattering

    NASA Astrophysics Data System (ADS)

    Ding, M.; Hjelm, R.; Watkins, E.; Xu, H.; Pawar, R.

    2015-12-01

    Oil/gas produced from unconventional reservoirs has become strategically important for the US domestic energy independence. In unconventional realm, hydrocarbons are generated and stored in nanopores media ranging from a few to hundreds of nanometers. Fundamental knowledge of coupled thermo-hydro-mechanical-chemical (THMC) processes that control fluid flow and propagation within nano-pore confinement is critical for maximizing unconventional oil/gas production. The size and confinement of the nanometer pores creates many complex rock-fluid interface interactions. It is imperative to promote innovative experimental studies to decipher physical and chemical processes at the nanopore scale that govern hydrocarbon generation and mass transport of hydrocarbon mixtures in tight shale and other low permeability formations at reservoir pressure-temperature conditions. We have carried out laboratory investigations exploring quantitative relationship between pore characteristics of the Wolfcamp shale from Western Texas and the shale interaction with fluids at reservoir P-T conditions using small-angle neutron scattering (SANS). We have performed SANS measurements of the shale rock in single fluid (e.g., H2O and D2O) and multifluid (CH4/(30% H2O+70% D2O)) systems at various pressures up to 20000 psi and temperature up to 150 oF. Figure 1 shows our SANS data at different pressures with H2O as the pressure medium. Our data analysis using IRENA software suggests that the principal changes of pore volume in the shale occurred on smaller than 50 nm pores and pressure at 5000 psi (Figure 2). Our results also suggest that with increasing P, more water flows into pores; with decreasing P, water is retained in the pores.

  11. Appalachian Basin Play Fairway Analysis: Natural Reservoir Analysis in Low-Temperature Geothermal Play Fairway Analysis for the Appalachian Basin (GPFA-AB)

    DOE Data Explorer

    Teresa E. Jordan

    2015-10-22

    The files included in this submission contain all data pertinent to the methods and results of this task’s output, which is a cohesive multi-state map of all known potential geothermal reservoirs in our region, ranked by their potential favorability. Favorability is quantified using a new metric, Reservoir Productivity Index, as explained in the Reservoirs Methodology Memo (included in zip file). Shapefile and images of the Reservoir Productivity and Reservoir Uncertainty are included as well.

  12. Design and screening of synergistic blends of SiO2 nanoparticles and surfactants for enhanced oil recovery in high-temperature reservoirs

    NASA Astrophysics Data System (ADS)

    Thi Le, Nhu Y.; Khanh Pham, Duy; Le, Kim Hung; Nguyen, Phuong Tung

    2011-09-01

    SiO2 nanoparticles (NPs) were synthesized by the sol–gel method in an ultrasound reactor and monodispersed NPs with an average particle size of 10–12 nm were obtained. The synergy occurring in blending NPs and anionic surfactant solutions was identified by ultra-low interfacial tension (IFT) reduction measured by a spinning drop tensiometer (Temco500). The oil displacement efficiency of the synergistic blends and surfactant solutions at Dragon South-East (DSE) reservoir temperature was evaluated using contact angle measurement (Dataphysics OCA 20). It was found that SiO2/surfactant synergistic blends displace oil as well as their original surfactant solutions at the same 1000 ppm total concentration. Abundant slag appearing in the SiO2/surfactant medium during oil displacement could be attributed to an adsorption of surfactants onto the NPs. The results indicate that at a concentration of 1000 ppm in total, the original surfactant SS16-47A and its blend with SiO2 NPs in the ratio of 8:2 exhibited an IFT reduction as high as fourfold of the IFT recorded for the DSE oil–brine interface and very high speed of oil displacement. Therefore, it could potentially be applicable to enhanced oil recovery (EOR) in high-temperature reservoirs with high hardness-injection-brine, like the one at DSE. This opens up a new direction for developing effective EOR compositions, which require less surfactant and are environmentally safer.

  13. Formate-Dependent Microbial Conversion of CO2 and the Dominant Pathways of Methanogenesis in Production Water of High-temperature Oil Reservoirs Amended with Bicarbonate.

    PubMed

    Yang, Guang-Chao; Zhou, Lei; Mbadinga, Serge M; Liu, Jin-Feng; Yang, Shi-Zhong; Gu, Ji-Dong; Mu, Bo-Zhong

    2016-01-01

    CO2 sequestration in deep-subsurface formations including oil reservoirs is a potential measure to reduce the CO2 concentration in the atmosphere. However, the fate of the CO2 and the ecological influences in carbon dioxide capture and storage (CDCS) facilities is not understood clearly. In the current study, the fate of CO2 (in bicarbonate form; 0∼90 mM) with 10 mM of formate as electron donor and carbon source was investigated with high-temperature production water from oilfield in China. The isotope data showed that bicarbonate could be reduced to methane by methanogens and major pathway of methanogenesis could be syntrophic formate oxidation coupled with CO2 reduction and formate methanogenesis under the anaerobic conditions. The bicarbonate addition induced the shift of microbial community. Addition of bicarbonate and formate was associated with a decrease of Methanosarcinales, but promotion of Methanobacteriales in all treatments. Thermodesulfovibrio was the major group in all the samples and Thermacetogenium dominated in the high bicarbonate treatments. The results indicated that CO2 from CDCS could be transformed to methane and the possibility of microbial CO2 conversion for enhanced microbial energy recovery in oil reservoirs. PMID:27047478

  14. Formate-Dependent Microbial Conversion of CO2 and the Dominant Pathways of Methanogenesis in Production Water of High-temperature Oil Reservoirs Amended with Bicarbonate

    PubMed Central

    Yang, Guang-Chao; Zhou, Lei; Mbadinga, Serge M.; Liu, Jin-Feng; Yang, Shi-Zhong; Gu, Ji-Dong; Mu, Bo-Zhong

    2016-01-01

    CO2 sequestration in deep-subsurface formations including oil reservoirs is a potential measure to reduce the CO2 concentration in the atmosphere. However, the fate of the CO2 and the ecological influences in carbon dioxide capture and storage (CDCS) facilities is not understood clearly. In the current study, the fate of CO2 (in bicarbonate form; 0∼90 mM) with 10 mM of formate as electron donor and carbon source was investigated with high-temperature production water from oilfield in China. The isotope data showed that bicarbonate could be reduced to methane by methanogens and major pathway of methanogenesis could be syntrophic formate oxidation coupled with CO2 reduction and formate methanogenesis under the anaerobic conditions. The bicarbonate addition induced the shift of microbial community. Addition of bicarbonate and formate was associated with a decrease of Methanosarcinales, but promotion of Methanobacteriales in all treatments. Thermodesulfovibrio was the major group in all the samples and Thermacetogenium dominated in the high bicarbonate treatments. The results indicated that CO2 from CDCS could be transformed to methane and the possibility of microbial CO2 conversion for enhanced microbial energy recovery in oil reservoirs. PMID:27047478

  15. The effect of clay minerals, pH, calcium and temperature on the adsorption of phosphonate scale inhibitor onto reservoir core and mineral separates

    SciTech Connect

    Jordan, M.M.; Sorbie, K.S.; Jiang, P.; Yuan, M.D.; Todd, A.C.; Thiery, L.

    1994-12-31

    During a scale inhibitor squeeze treatment, the dynamics of the inhibitor return is governed by the inhibitor/rock interaction. In the case of adsorption/desorption inhibitor treatments, this interaction is described through the inhibitor/rock adsorption isotherm. The rock mineralogy plays an important role in determining the nature of the adsorption isotherm and clays in particular are known to strongly affect the adsorption process. However, no previous work has (a) presented a systematic study of the effects of various clays on inhibitor adsorption and (b) clearly demonstrated the significance of this behavior for the squeeze process. It is the central objective of the work in this paper to carry out these tasks. In this paper, an extensive series of results from static bulk adsorption tests using pure mineral separates (quartz, kaolinite, chlorite and muscovite) as adsorbent and using phosphonate (DETPMP) as model inhibitor is presented. From these results, the order of importance of factors governing the phosphonate inhibitor level onto clays appears to be Temperature > pH > [Ca{sup 2+}]. To support the findings from the bulk adsorption tests, results from reservoir condition core floods are presented for reservoir rock from a North Sea field which contains significant quantities of clay (principally kaolinite). The field significance of these results for the inhibitor squeeze performance is demonstrated by using the field and outcrop isotherms in some model squeeze return calculations.

  16. Use of Skylab EREP data in a sea-surface temperature experiment. [Monroe Reservoir and Key West, Fla.

    NASA Technical Reports Server (NTRS)

    Anding, D. C. (Principal Investigator); Walker, J. P.

    1975-01-01

    The author has identified the following significant results. A sea surface temperature experiment was studied, demonstrating the feasibility of a procedure for the remote measurement of sea surface temperature which inherently corrects for the effect of the intervening atmosphere without recourse to climatological data. The procedure was applied to Skylab EREP S191 spectrometer data, and it is demonstrated that atmospheric effects on the observed brightness temperature can be reduced to less than 1.0 K.

  17. Microbial communities responsible for fixation of CO2 revealed by using mcrA, cbbM, cbbL, fthfs, fefe-hydrogenase genes as molecular biomarkers in petroleum reservoirs of different temperatures

    NASA Astrophysics Data System (ADS)

    Liu, J.-F.; Mbadinga, S. M.; Sun, X.-B.; Yang, G.-C.; Yang, S.-Z.; Gu, J.-D.; Mu, B.-Z.

    2015-01-01

    Sequestration of CO2 in oil reservoir is one of the feasible options for mitigating atmospheric CO2 building up. The in situ bioconversion of sequestrated CO2 to methane by microorganisms inhabiting oil reservoirs is feasible. To evaluate the potential of in situ microbial fixation and conversion of CO2 into CH4 in oil reservoirs, a comprehensive molecular survey was performed to reveal microbial communities inhabiting four oil reservoirs with different temperatures by analysis of functional genes involved in the biochemical pathways of CO2 fixation and CH4 synthesis (cbbM, cbbL, fthfs, [FeFe]-hydrogenase encoding gene, and mcrA). A rich diversity of these functional genes was found in all the samples with both high and low temperatures and they were affiliated to members of the Proteobacteria (cbbL and cbbM, fthfs), Firmicutes and Actinobacteria (fthfs), uncultured bacteria ([FeFe]-hydrogenase), and Methanomirobiales, Methanobacteriales and Methanosarcinales (mcrA). The predominant methanogens were all identified to be hydrogenotrophic CO2-reducing physiological types. These results showed that functional microbial communities capable of microbial fixation and bioconversion of CO2 into methane inhabit widely in oil reservoirs, which is helpful to microbial recycling of sequestrated CO2 to further new energy in oil reservoirs.

  18. Carbonate petroleum reservoirs

    SciTech Connect

    Roehl, P.O.; Choquette, P.W.

    1985-01-01

    This book presents papers on the geology of petroleum deposits. Topics considered include diagenesis, porosity, dolomite reservoirs, deposition, reservoir rock, reefs, morphology, fracture-controlled production, Cenozoic reservoirs, Mesozoic reservoirs, and Paleozoic reservoirs.

  19. Bacteria in the injection water differently impacts the bacterial communities of production wells in high-temperature petroleum reservoirs

    PubMed Central

    Ren, Hongyan; Xiong, Shunzi; Gao, Guangjun; Song, Yongting; Cao, Gongze; Zhao, Liping; Zhang, Xiaojun

    2015-01-01

    Water flooding is widely used for oil recovery. However, how the introduction of bacteria via water flooding affects the subsurface ecosystem remains unknown. In the present study, the distinct bacterial communities of an injection well and six adjacent production wells were revealed using denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. All sequences of the variable region 3 of the 16S rRNA gene retrieved from pyrosequencing were divided into 543 operational taxonomic units (OTUs) based on 97% similarity. Approximately 13.5% of the total sequences could not be assigned to any recognized phylum. The Unifrac distance analysis showed significant differences in the bacterial community structures between the production well and injection water samples. However, highly similar bacterial structures were shown for samples obtained from the same oil-bearing strata. More than 69% of the OTUs detected in the injection water sample were absent or detected in low abundance in the production wells. However, the abundance of two OTUs reached as high as 17.5 and 26.9% in two samples of production water, although the OTUs greatly varied among all samples. Combined with the differentiated water flow rate measured through ion tracing, we speculated that the transportation of injected bacteria was impacted through the varied permeability from the injection well to each of the production wells. Whether the injected bacteria predominate the production well bacterial community might depend both on the permeability of the strata and the reservoir conditions. PMID:26052321

  20. Bacteria in the injection water differently impacts the bacterial communities of production wells in high-temperature petroleum reservoirs.

    PubMed

    Ren, Hongyan; Xiong, Shunzi; Gao, Guangjun; Song, Yongting; Cao, Gongze; Zhao, Liping; Zhang, Xiaojun

    2015-01-01

    Water flooding is widely used for oil recovery. However, how the introduction of bacteria via water flooding affects the subsurface ecosystem remains unknown. In the present study, the distinct bacterial communities of an injection well and six adjacent production wells were revealed using denaturing gradient gel electrophoresis (DGGE) and pyrosequencing. All sequences of the variable region 3 of the 16S rRNA gene retrieved from pyrosequencing were divided into 543 operational taxonomic units (OTUs) based on 97% similarity. Approximately 13.5% of the total sequences could not be assigned to any recognized phylum. The Unifrac distance analysis showed significant differences in the bacterial community structures between the production well and injection water samples. However, highly similar bacterial structures were shown for samples obtained from the same oil-bearing strata. More than 69% of the OTUs detected in the injection water sample were absent or detected in low abundance in the production wells. However, the abundance of two OTUs reached as high as 17.5 and 26.9% in two samples of production water, although the OTUs greatly varied among all samples. Combined with the differentiated water flow rate measured through ion tracing, we speculated that the transportation of injected bacteria was impacted through the varied permeability from the injection well to each of the production wells. Whether the injected bacteria predominate the production well bacterial community might depend both on the permeability of the strata and the reservoir conditions. PMID:26052321

  1. Experimental Investigation on the Influence of High Pressure and High Temperature on the Mechanical Properties of Deep Reservoir Rocks

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Mishra, Brijes; Heasley, Keith A.

    2015-11-01

    Deep and ultra-deep resources extraction has resulted in the challenge of drilling into high-pressure, high-temperature (HPHT) environments. Drilling challenges at such extreme conditions prompted NETL to develop a specialized ultra-deep drilling simulator (UDS) for investigating drill behavior in such conditions. Using the UDS apparatus, complex laboratory tests were performed on Carthage marble (Warsaw limestone) and Crab Orchard sandstone, which represent the rocks in the basins of the Tuscaloosa trend in southern Louisiana and the Arbuckle play in Oklahoma and North Texas. Additionally, numerical models of the UDS were developed for performing parametric analyses that would be impossible with the UDS alone. Subsequently, it was found that the input properties for these two rock types at such extreme pressure and temperature conditions were unavailable. Therefore, a suite of unconfined compressive strength, indirect tensile strength, and triaxial compression tests ( σ 1 > σ 2 = σ 3) were performed on Carthage marble and Crab Orchard sandstone for investigating their behavior in HPHT environments. The HPHT experiments were performed at confining pressures ranging from atmospheric to 200 MPa, and with temperatures ranging from 25 to 180 °C. The influences of confining pressure and temperature on the mechanical properties of two rocks were investigated.

  2. Study of the influence of temperature and water level of the reservoir about the displacement of a concrete dam

    NASA Astrophysics Data System (ADS)

    Oro, S. R.; Mafioleti, T. R.; Chaves Neto, A.; Garcia, S. R. P.; Neumann Júnior, C.

    2016-02-01

    Multivariate techniques are used in this study to analyze the monitoring data displacements of a concrete dam, measured by means of pendulums, extensometer bases and multiple rod extensometers, taking into account the action of environmental conditions, bounded by the surface temperature of the concrete at ambient temperature and the tank water level. The canonical correlation analysis is used to evaluate the influence of environmental variables in the displacement of structures and dam foundations. The factor analysis is used to identify data sources of variability and order the sensors according to the action of factors. The dates of the measurements are grouped according to similarities in the present observations, by applying the cluster analysis. Then the discriminant analysis is used to assess the groups as to their homogeneity. The results demonstrate that the techniques used for distinguishing the dam responses and identify the effects of changes in environmental conditions on the displacements of the structures and dam foundations.

  3. High-temperature quartz cement and the role of stylolites in a deep gas reservoir, Spiro Sandstone, Arkoma Basin, USA

    USGS Publications Warehouse

    Worden, Richard H.; Morad, Sadoon; Spötl, C.; Houseknecht, D.W.; Riciputi, L.R.

    2000-01-01

    The Spiro Sandstone, a natural gas play in the central Arkoma Basin and the frontal Ouachita Mountains preserves excellent porosity in chloritic channel-fill sandstones despite thermal maturity levels corresponding to incipient metamorphism. Some wells, however, show variable proportions of a late-stage, non-syntaxial quartz cement, which post-dated thermal cracking of liquid hydrocarbons to pyrobitumen plus methane. Temperatures well in excess of 150°C and possibly exceeding 200°C are also suggested by (i) fluid inclusions in associated minerals; (ii) the fact that quartz post-dated high-temperature chlorite polytype IIb; (iii) vitrinite reflectance values of the Spiro that range laterally from 1.9 to ≥ 4%; and (iii) the occurrence of late dickite in these rocks. Oxygen isotope values of quartz cement range from 17.5 to 22.4‰ VSMOW (total range of individual in situ ion microprobe measurements) which are similar to those of quartz cement formed along high-amplitude stylolites (18.4–24.9‰). We favour a model whereby quartz precipitation was controlled primarily by the availability of silica via deep-burial stylolitization within the Spiro Sandstone. Burial-history modelling showed that the basin went from a geopressured to a normally pressured regime within about 10–15 Myr after it reached maximum burial depth. While geopressure and the presence of chlorite coats stabilized the grain framework and inhibited nucleation of secondary quartz, respectively, stylolites formed during the subsequent high-temperature, normal-pressured regime and gave rise to high-temperature quartz precipitation. Authigenic quartz growing along stylolites underscores their role as a significant deep-burial silica source in this sandstone.

  4. Determining majors fluid-flow zones in a geothermal sandstone reservoir from thermal conductivity and temperature logs

    NASA Astrophysics Data System (ADS)

    Haffen, S.; Géraud, Y.; Diraison, M.; Dezayes, C.

    2012-04-01

    A method, based on thermal gradient analysis, is presented for locating hot fluid flow in a rock formation. The method involves determining the thermal gradient from thermal conductivity measurements on core samples and also from borehole temperature logs run in the same borehole. With a heat flow density calculation and thermal conductivity measurements, one can apply Fourier's law to calculate the thermal gradient in a rock system where the heat transfer is assumed to be controlled only by conduction. The thermal gradient calculated from a measured temperature log profile takes into account both the conductive and the convective or advective part due to fluid circulation. On the one hand, if the thermal gradient deduced from temperature logs indicates similar values to the thermal gradient calculated with Fourier's law, the heat transfer is assumed to be controlled solely by conduction in the rock formation and thus involves no relative hot or cold fluid circulation. If, on the other hand, the thermal gradient deduced from the temperature logs indicates higher or lower values than that calculated with Fourier's law, then respectively hot or cold fluid flow could be suspected. We applied this method to borehole EPS1 (Soultz-sous-Forêts, Upper Rhine Graben) for which temperature logs and core samples from the Buntsandstein are available. Variations between the two determined thermal gradient curves revealed three main hot fluid flow levels alternating with non-flow zones in the sandstone formation. The pattern was then compared against the fracture distribution, and also against sedimentological analyses determined from the borehole cores, in order to determine the driving components of the fluid flows. The flow zones in the Buntsandstein are controlled on the one hand by a macroscopic network with two major fault zones providing a flow path for the deep heat source and on the other hand by a matrix network formed during sedimentary or diagenetic processes within

  5. Rates of Litter Decomposition and Soil Respiration in Relation to Soil Temperature and Water in Different-Aged Pinus massoniana Forests in the Three Gorges Reservoir Area, China

    PubMed Central

    Zeng, Lixiong; Huang, Zhilin; Lei, Jingpin; Zhou, Benzhi; Li, Maihe

    2014-01-01

    To better understand the soil carbon dynamics and cycling in terrestrial ecosystems in response to environmental changes, we studied soil respiration, litter decomposition, and their relations to soil temperature and soil water content for 18-months (Aug. 2010–Jan. 2012) in three different-aged Pinus massoniana forests in the Three Gorges Reservoir Area, China. Across the experimental period, the mean total soil respiration and litter respiration were 1.94 and 0.81, 2.00 and 0.60, 2.19 and 0.71 µmol CO2 m−2 s−1, and the litter dry mass remaining was 57.6%, 56.2% and 61.3% in the 20-, 30-, and 46-year-old forests, respectively. We found that the temporal variations of soil respiration and litter decomposition rates can be well explained by soil temperature at 5 cm depth. Both the total soil respiration and litter respiration were significantly positively correlated with the litter decomposition rates. The mean contribution of the litter respiration to the total soil respiration was 31.0%–45.9% for the three different-aged forests. The present study found that the total soil respiration was not significantly affected by forest age when P. masonniana stands exceed a certain age (e.g. >20 years old), but it increased significantly with increased soil temperature. Hence, forest management strategies need to protect the understory vegetation to limit soil warming, in order to reduce the CO2 emission under the currently rapid global warming. The contribution of litter decomposition to the total soil respiration varies across spatial and temporal scales. This indicates the need for separate consideration of soil and litter respiration when assessing the climate impacts on forest carbon cycling. PMID:25004164

  6. Mathematical simulation of temperatures in deep impoundments: verification tests of the Water Resources Engineers, Inc. model - Horsetooth and Flaming Gorge Reservoirs

    USGS Publications Warehouse

    King, D.L.; Sartoris, Jim J.

    1973-01-01

    Successful use of predictive mathematical models requires verification of the accuracy of the models by applying them to existing situations where the prediction can be compared with reality. A Corps of Engineers' modification of a deep reservoir thermal stratification model developed by Water Resources Engineers, Inc., was applied to two existing Bureau of Reclamation reservoirs for verification. Diffusion coefficients used for the Corps' Detroit Reservoir were found to apply to Horsetooth Reservoir in Colorado, for which very food computer input data were available. The Detroit diffusion coefficients gave a reasonable simulation of Flaming Gorge Reservoir in Wyoming and Utah, which has very complex and variable physical characteristics and for which only average-quality computer input data were available.

  7. Reservoir Technology

    SciTech Connect

    Renner, J.L.

    1992-03-24

    The reservoir technology program supports the utilization of geothermal resources through development and verification of new earth science technologies for: exploration, fluid production and injection; and prediction of reservoir lifetimes. A two-fold strategy of conducting DOE-sponsored research to meet higher-risk, longer-term needs and cost-shared research with industry in areas of greatest current need is utilized to maximize the benefit of the program to the geothermal industry. The program uses a coordinated, multi-disciplinary approach to investigating and solving reservoir problems facing the industry. Research at The Geysers geothermal field has received major emphasis in the past three years. Recent progress in that work will be reviewed in detail by The Geysers operators, federal, state and local regulators and other interested parties during a meeting in Santa Rosa on May 5 and 6, 1992. Hence the papers by Lipman, Bodvarsson et al., Wannamaker, et al., Horne, and Shook in this proceedings volume emphasize non-Geysers research in the program.

  8. Resource investigation of low- and moderate-temperature geothermal areas in San Bernardino, California. Part of the third year report, 1980-81, of the US Department of Energy-California State-Coupled Program for Reservoir Assessment and Confirmation

    SciTech Connect

    Youngs, L.G.; Bezore, S.P.; Chapman, R.H.; Chase, G.W.

    1981-08-01

    Ninety-seven geothermal wells and springs were identified and plotted on a compiled geologic map of the 40-square-mile study area. These wells and springs were concentrated in three distinguishable resource areas: Arrowhead Hot Springs; South San Bernardino; and Harlem Hot Springs - in each of which detailed geophysical, geochemical, and geological surveys were conducted. The Arrowhead Hot Springs geothermal area lies just north of the City of San Bernardino in the San Bernardino Mountains astride a shear zone (offshoot of the San Andreas fault) in pre-Cambrian gneiss and schist. The Harlem Hot Springs geothermal area, on the east side of the City, and the south San Bernardino geothermal area, on the south side, have geothermal reservoirs in Quaternary alluvial material which overlies a moderately deep sedimentary basin bound on the southwest by the San Jacinto fault (a ground water barrier). Geothermometry calculations suggest that the Arrowhead Hot Springs geothermal area, with a maximum reservoir temperature of 142/sup 0/C, may have the highest maximum reservoir temperature of the three geothermal areas. The maximum temperature recorded by CDMG in the south San Bernardino geothermal area was 56/sup 0/C from an artesian well, while the maximum temperature recorded in the Harlem Hot Springs geothermal area was 49.5/sup 0/C at 174 meters (570 feet) in an abandoned water well. The geophysical and geological surveys delineated fault traces in association with all three of the designated geothermal areas.

  9. I. Fundamental Practicum: Temperature Measurements of Falling Droplets, July, 1989. II. Industrial Practicum: Interaction and Effect of Adsorbed Organics on Reference Clays and Reservoir Rock, April, 1988. III. Apprenticeship Practicum: Studies of Group XIII Metal Inclusion Complexes, March, 1987

    NASA Astrophysics Data System (ADS)

    Wells, Mark Richard

    The temperature of 225 μm decane droplets falling through a hot, quiescent, oxygen -free environment were measured using laser-induced exciplex fluorescence thermometry. The temperature of the droplets was found to increase approximately 0.42^ circC/^circC increase in the environment temperature as the environment temperature was increased to 250^circ C. Less than 10% evaporation of the droplets was observed at the highest environment temperatures. This represents one of the first successful applications of a remote-sensing technique for the temperature determination of droplets in a dynamic system. Industrial practicum. The industrial practicum report, entitled "Interaction and Effect of Adsorbed Organics on Reference Clays and Reservoir Rock," is a discussion of the measurement of the effect adsorbed organic material, especially from crude petroleum, has on the surface area, cation exchange capacity, and zeta potential of reference clay material and reservoir rock. In addition, the energetics of adsorption of a petroleum extract onto several reference clays and reservoir rock were measured using both flow and batch microcalorimetry. These results are very important in evaluating and understanding the wettability of reservoir rock and its impact on the recovery of crude oil from a petroleum reservoir. Apprenticeship practicum. "Studies of Group XIII Metal Inclusion Complexes" investigates the structure and dynamics of liquid inclusion complexes having the general formula (R_4N) (Al_2 Me_6I) cdot (C_6H_6) _{rm x}. ^1H and ^{13}C spin-lattice relaxation times, nuclear Overhauser enhancements, and molecular correlation times were measured as well as diffusion coefficients of the various species in solution. The dynamics of transfer between "guest" and free solvent molecules were measured using a variety of techniques. The inherent structure of liquid inclusion complexes as an ordered medium for homogeneous catalysis was studied using hydrogenation catalyzed by

  10. Gas reaction in the Cerro Prieto reservoir

    SciTech Connect

    Nehring, N.L.; Valette-Silver, J.N.

    1982-08-10

    Gases in an undisturbed geothermal reservoir should be in equilibrium with the surrounding rock and water. Production of fluid at rapid rates may cause physical changes in the reservoir that are reflected as changes in gas composition. At Cerro Prieto production has lowered the reservoir pressure enough in places to induce boiling in the aquifer, leading to high enthalpy, low production and eventual drawndown of cold water into the reservoir. These changes are reflected in gas compositions. Differences, in gas composition between well and surface samples reflect changing equilibrium in temperature-dependent chemical reactions and a mixture of gases dissolved in groundwater.

  11. Economics of Developing Hot Stratigraphic Reservoirs

    SciTech Connect

    Greg Mines; Hillary Hanson; Rick Allis; Joseph Moore

    2014-09-01

    Stratigraphic geothermal reservoirs at 3 – 4 km depth in high heat-flow basins are capable of sustaining 100 MW-scale power plants at about 10 c/kWh. This paper examines the impacts on the levelized cost of electricity (LCOE) of reservoir depth and temperature, reservoir productivity, and drillhole/casing options. For a reservoir at 3 km depth with a moderate productivity index by hydrothermal reservoir standards (about 50 L/s/MPa, 5.6 gpm/psi), an LCOE of 10c/kWh requires the reservoir to be at about 200°C. This is the upper temperature limit for pumps. The calculations assume standard hydrothermal drilling costs, with the production interval completed with a 7 inch liner in an 8.5 inch hole. If a reservoir at 4 km depth has excellent permeability characteristics with a productivity index of 100 L/s/MPa (11.3 gpm/psi), then the LCOE is about 11 c/kWh assuming the temperature decline rate with development is not excessive (< 1%/y, with first thermal breakthrough delayed by about 10 years). Completing wells with modest horizontal legs (e.g. several hundred meters) may be important for improving well productivity because of the naturally high, sub-horizontal permeability in this type of reservoir. Reducing the injector/producer well ratio may also be cost-effective if the injectors are drilled as larger holes.

  12. Destratification of an impounding reservoir using compressed air??case of Mudi reservoir, Blantyre, Malawi

    NASA Astrophysics Data System (ADS)

    Chipofya, V. H.; Matapa, E. J.

    This paper reviews the operational and cost effectiveness of a compressed air destratification system that was installed in the Mudi reservoir for destratifying the reservoir. Mudi reservoir is a raw water source for the Blantyre Water Board. It has a capacity of 1,400,000 cubic metres. The reservoir is 15.3 m deep at top water level. In the absence of any artificial circulation of air, the reservoir stratifies into two layers. There is a warm epilimnion in the top 3 m of the reservoir, with temperatures ranging from 23 to 26 °C. There is prolific algal growth in this layer. The bottom layer has much lower temperatures, and is oxygen deficient. Under such anaerobic conditions, ammonia, sulphides, iron and manganese are released from the sediments of the reservoir. As a result of nutrient inflow from the catchments, coupled with tropical ambient temperatures, the reservoir is most times infested with blue-green algae. This results into water treatment problems in respect of taste and odour and iron and manganese soluble salts. To abate such problems, air is artificially circulated in the reservoir, near the intake tower, through a perforated pipe that is connected to an electrically driven compressor. This causes artificial circulation of water in the hypolimnion region of the reservoir. As a result of this circulation, a hostile environment that inhibits the propagation of algae is created. Dissolved oxygen and temperature profiles are practically uniform from top to bottom of reservoir. Concentrations of iron and manganese soluble salts are much reduced at any of the draw-off points available for the water treatment process. The paper concludes by highlighting the significant cost savings in water treatment that are accrued from the use of compressed air destratification in impounding water storage reservoirs for the control of algae and other chemical pollutants.

  13. Miniature Reservoir Cathode: An Update

    NASA Technical Reports Server (NTRS)

    Vancil, Bernard K.; Wintucky, Edwin G.

    2002-01-01

    We report on recent work to produce a small low power, low cost reservoir cathode capable of long life (more than 100,000 hours) at high loading (> 5 A/sq cm). Our objective is a highly manufacturable, commercial device costing less than $30. Small highly loaded cathodes are needed, especially for millimeter wave tubes, where focusing becomes difficult when area convergence ratios are too high. We currently have 3 models ranging from .060-inch diameter to. 125-inch diameter. Reservoir type barium dispenser cathodes have a demonstrated capability for simultaneous high emission density and long life. Seven reservoir cathodes continue to operate on the cathode life test facility at NSWC, Crane, Indiana at 2 and 4 amps/sq cm. They have accumulated nearly 100,000 hours with practically no change in emission levels or knee temperature.

  14. Status of Norris Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Norris Reservoir summarizes reservoir and watershed characteristics, reservoir uses, conditions that impair reservoir uses, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most up-to-date publications and data available, and from interviews with water resource professionals in various federal, state, and local agencies, and in public and private water supply and wastewater treatment facilities. 14 refs., 3 figs.

  15. Prokaryotic Community Structure and Sulfate Reducer Activity in Water from High-Temperature Oil Reservoirs with and without Nitrate Treatment▿ †

    PubMed Central

    Gittel, Antje; Sørensen, Ketil Bernt; Skovhus, Torben Lund; Ingvorsen, Kjeld; Schramm, Andreas

    2009-01-01

    Sulfate-reducing prokaryotes (SRP) cause severe problems like microbial corrosion and reservoir souring in seawater-injected oil production systems. One strategy to control SRP activity is the addition of nitrate to the injection water. Production waters from two adjacent, hot (80°C) oil reservoirs, one with and one without nitrate treatment, were compared for prokaryotic community structure and activity of SRP. Bacterial and archaeal 16S rRNA gene analyses revealed higher prokaryotic abundance but lower diversity for the nitrate-treated field. The 16S rRNA gene clone libraries from both fields were dominated by sequences affiliated with Firmicutes (Bacteria) and Thermococcales (Archaea). Potential heterotrophic nitrate reducers (Deferribacterales) were exclusively found at the nitrate-treated field, possibly stimulated by nitrate addition. Quantitative PCR of dsrAB genes revealed that archaeal SRP (Archaeoglobus) dominated the SRP communities, but with lower relative abundance at the nitrate-treated site. Bacterial SRP were found in only low abundance at both sites and were nearly exclusively affiliated with thermophilic genera (Desulfacinum and Desulfotomaculum). Despite the high abundance of archaeal SRP, no archaeal SRP activity was detected in [35S]sulfate incubations at 80°C. Sulfate reduction was found at 60°C in samples from the untreated field and accompanied by the growth of thermophilic bacterial SRP in batch cultures. Samples from the nitrate-treated field generally lacked SRP activity. These results indicate that (i) Archaeoglobus can be a major player in hot oil reservoirs, and (ii) nitrate may act in souring control—not only by inhibiting SRP, but also by changing the overall community structure, including the stimulation of competitive nitrate reducers. PMID:19801479

  16. Modeling the Entrepeñas Reservoir.

    PubMed

    Wiese, Bernd U; Palancar, María C; Aragón, José M; Sánchez, Fernando; Gil, Roberto

    2006-08-01

    The Entrepeñas Reservoir is a monomictic reservoir located in River Tagus (Spain). The aim of this work is to establish a feasible model to predict the depth of the thermocline that is developed in the reservoir during the period of natural thermal stratification. Entrainment, eddy diffusion, inflow of external energy, and other factors are considered to calibrate the parameters of the model. The methodology involves the measure of actual temperature and electrical conductivity profiles, use of meteorological data and reservoir parameters, and selection and application of several models from the literature. The calculations and predictions are integrated to a software packet that is able to predict thermocline depth and water temperature profile during a 1-year period on a day-by-day basis. In the thermocline depth, the prediction error, on the basis of real data, is less than 6% and, in the water temperature, it is 2 degrees C. PMID:17059129

  17. Reservoir management applications to oil reservoirs

    SciTech Connect

    Martin, F.D.; Ouenes, A.; Weiss, W.W.; Chawathe, A.

    1996-02-01

    Winnipegosis and Red River oil production in the Bainville North Field in Roosevelt County, Montana began in 1979. The Red River is at 12,500 ft and one well is completed in the Nisku formation at 10,200 ft. This well produced 125,000 bbl from the Nisku during its first 41 months. Since operating conditions inhibit dual completions and Nisku wells cost $900,000, the need for a Nisku development plan is apparent. The size of the reservoir and optimum well density are the key unknowns. Recognizing the need for additional Nisku data, a 5000 acre 3-D seismic survey was processed and the results used to map the top of the Nisku. The reservoir thickness, porosity, and water saturation were known from the openhole logs at eight well locations on an average of 320 acres spacing. The thickness of the thin pay limited the seismic information to areal extent of reservoir depth. Static reservoir pressure from drillstem test was available at two wells. Additional reservoir pressure data in the form of transient tests were available at two wells. Under Los Alamos National Laboratory Basic Ordering Agreement 9-XU3-0402J-1, the New Mexico Petroleum Recovery Research Center (PRRC) characterized the Nisku to develop a reservoir management plan. Nance Petroleum provided all available field and laboratory data for characterizing the Nisku formation. Due to sparse well coverage, and the lack of producing wells, the PRRC had to develop a new reservoir description approach to reach an acceptable characterization of the entire reservoir. This new approach relies on the simultaneous use of 3-D seismic and reservoir simulation to estimate key reservoir properties.

  18. Characterization of oil and gas reservoir heterogeneity

    SciTech Connect

    Sharma, G.D.

    1992-01-01

    The ultimate objective of this cooperative research project is to characterize Alaskan petroleum reservoirs in terms of their reserves, physical and chemical properties, geologic configuration in relation to lithofacies and structure, and development potential. The project has two tasks: Task 1 is a geological description of the reservoirs including petrophysical properties, i.e., porosity, permeability, permeability variation, formation depth, temperature, and net pay, facies changes and reservoir structures as drawn from cores, well logs, and other geological data. Task 2 is reservoir fluid characterization-determination of physical properties of reservoir fluids including density, viscosity, phase distributions and composition as well as petrogenesis-source rock identification; and the study of asphaltene precipitation for Alaskan crude oils. Results are discussed.

  19. Characterization of oil and gas reservoir heterogeneity

    SciTech Connect

    Sharma, G.D.

    1992-01-01

    The ultimate objective of this cooperative research project is to characterize Alaskan petroleum reservoirs in terms of their reserves, physical and chemical properties, geologic configuration in relation to lithofacies and structure, and development potential. The project has two tasks: Task 1 is a geological description of the reservoirs including petrophysical properties, i.e., porosity, permeability, permeability variation, formation depth, temperature, and net pay, facies changes and reservoir structures as drawn from cores, well logs, and other geological data. Task 2 is reservoir fluid characterization -- determination of physical properties of reservoir fluids including density, viscosity, phase distributions and composition as well as petrogenesis -- source rock identification; and the study of asphaltene precipitation for Alaskan crude oils.

  20. Characterization of oil and gas reservoir heterogeneity

    SciTech Connect

    Sharma, G.D.

    1992-01-01

    The ultimate oojective of this cooperative research project is to characterize Alaskan petroleum reservoirs in terms of their reserves, physical and chemical properties, geologic configuration in relation to lithofacies and structure, and development potential. The project has two tasks: Task 1 is a geological description of the reservoirs including petrophysical properties, i.e., porosity, permeability, permeability variation, formation depth, temperature, and net pay, facies changes and reservoir structures as drawn from cores, well logs, and other geological data. Task 2 is reservoir fluid characterization--determination of physical properties of reservoir fluids including density, viscosity, phase distributions and composition as well as petrogenesis--source rock identification; and the study of asphaltene precipitation for Alaskan crude oils. This report presents a summary of technical progress of the well log analysis of Kuparuk Field, Northslope, Alaska.

  1. Wireline well logging an underutilized technique in reservoir evaluation

    SciTech Connect

    Mathews, M.

    1981-01-01

    Wireline well logs have three general uses in geothermal exploration and reservoir evaluation: reservoir parameter analysis, lithologic column determination, and reservoir size resolution. Reservoir flow testing data are acquired to understand the flow rate, life, and production potential of the geothermal reservoir. These data are a coarse subsurface measurement of the geothermal prospect. Wireline logs acquired from wells in a geothermal prospect are used to define in detail, or estimate the reservoir parameters of temperature, thickness, lateral size, amount of fracture and intergranular pore space, and the quantity and quality of fluid that might be produced. Laboratory measurements can be made on core samples and drill cuttings samples to define the intrinsic behavior of the materials and fluid that compose the geotheraml reservoir. Wireline log measurements are needed to correlate and link the reservoir testing and core analysis, reduce the amount of time needed for flow testing, and predict the production life (amount of heat and fluid available) in a geothermal field.

  2. Status of Cherokee Reservoir

    SciTech Connect

    Not Available

    1990-08-01

    This is the first in a series of reports prepared by Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overviews of Cherokee Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports, publications, and data available, and interviews with water resource professionals in various Federal, state, and local agencies and in public and private water supply and wastewater treatment facilities. 11 refs., 4 figs., 1 tab.

  3. Status of Wheeler Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  4. Dolomite reservoirs: Porosity evolution and reservoir characteristics

    SciTech Connect

    Sun, S.Q.

    1995-02-01

    Systematic analyses of the published record of dolomite reservoirs worldwide reveal that the majority of hydrocarbon-producing dolomite reservoirs occurs in (1) peritidal-dominated carbonate, (2) subtidal carbonate associated with evaporitic tidal flat/lagoon, (3) subtidal carbonate associated with basinal evaporite, and (4) nonevaporitic carbonate sequence associated with topographic high/unconformity, platform-margin buildup or fault/fracture. Reservoir characteristics vary greatly from one dolomite type to another depending upon the original sediment fabric, the mechanism by which dolomite was formed, and the extent to which early formed dolomite was modified by post-dolomitization diagenetic processes (e.g., karstification, fracturing, and burial corrosion). This paper discusses the origin of dolomite porosity and demonstrates the porosity evolution and reservoir characteristics of different dolomite types.

  5. Quantification of Libby Reservoir Levels Needed to Maintain or Enhance Reservior Fisheries, 1984 Annual Report.

    SciTech Connect

    Shepard, Bradley B.

    1985-06-01

    We are evaluating the potential impacts of Libby Reservoir operation on the fishery in Libby Reservoir. The sampling program has been tested and modified to provide data for developing an understanding of how reservoir operation impacts the reservoir fishery. Temperature appears to be an important variable influenced by reservoir operation which regulates fish and fish food production and distribution. 39 refs., 21 figs., 19 tabs.

  6. Reservoir technology research at the INEL

    SciTech Connect

    Renner, J.L.; Shook, G.M.; Faulder, D.D.

    1996-05-01

    Reservoir engineering research at INEL was aimed at developing a better understanding of The Geysers and developing better tools with which to study flow in fractured geothermal reservoirs in general. Two specific topics were studies in the last year: matrix fracture interactions and decline curve analysis. A third project, revisiting the behavior of the `high-temperature reservoir` (HTR), was started near the end of 1995. These projects are being conducted in collaboration with other researchers and/or private industry. For example, our HTR studies are motivated in part because of new isotopic analyses conducted elsewhere (Walters et al., in preparation). The ultimate goal of these projects is to improve predictive capabilities and reservoir management practices and to extend the commercial life of The Geysers. In addition to conducting engineering research for the Reservoir Technology Program, INEL also continued to assist the Geothermal Technology Organization (GTO) with the development and execution of cooperative research projects. In support of the overall mission of the Reservoir Technology program, INEL also entered into a broad program of subcontracts with industrial groups and universities. These programs support the Reservoir Technology mission by providing support for research topics considered particularly important by the geothermal industry. The GTO projects are summarized below.

  7. 95. BOUQUET RESERVOIR LOOKING UP VALLEY TO RESERVOIR LOOKING EAST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    95. BOUQUET RESERVOIR LOOKING UP VALLEY TO RESERVOIR LOOKING EAST - Los Angeles Aqueduct, From Lee Vining Intake (Mammoth Lakes) to Van Norman Reservoir Complex (San Fernando Valley), Los Angeles, Los Angeles County, CA

  8. Boone Reservoir bacteriological assessment

    SciTech Connect

    Crouch, H.A.

    1990-03-01

    Since 1984, the bacteriological water quality of Boone Reservoir has improved. The actual reservoir pool consistently meets State bacteriological criteria for fecal coliform. Areas of the reservoir that remain impacted by high fecal coliform densities are the riverine portions upstream from SFHRM 35 on the South Fork Holston arm and WRM 13 on the Watauga River am of the reservoir. Improvements have resulted from a combined effort of water resource agencies, local municipalities, and private citizens. Both TVA and the TDHE have conducted monitoring programs over the last six years to assess the condition of the reservoir. Wastewater treatment facility improvements have been made by the cities of Bristol, Tennessee and Virginia, Bluff City, Elizabethton, and Johnson City to increase treatment efficiency and thereby improve Boone Reservoir water quality. Storm runoff events were correlated with elevated fecal coliform measurements in the Boone River watershed, with the greatest impact observed on the Watauga River arm and in the upper portion of the South Fork Holston River arm of the reservoir. Storm events increased the occurrence of wastewater bypasses from the Elizabethton STP and are primarily responsible for the high fecal coliform counts on the Watauga arm. However, nonpoint sources of pollution including animal waste and effluent from malfunctioning septic tank systems may also have a significant impact on Boone Reservoir water quality.

  9. Microbial Communities in Long-Term, Water-Flooded Petroleum Reservoirs with Different in situ Temperatures in the Huabei Oilfield, China

    PubMed Central

    Tang, Yue-Qin; Li, Yan; Zhao, Jie-Yu; Chi, Chang-Qiao; Huang, Li-Xin; Dong, Han-Ping; Wu, Xiao-Lei

    2012-01-01

    The distribution of microbial communities in the Menggulin (MGL) and Ba19 blocks in the Huabei Oilfield, China, were studied based on 16S rRNA gene analysis. The dominant microbes showed obvious block-specific characteristics, and the two blocks had substantially different bacterial and archaeal communities. In the moderate-temperature MGL block, the bacteria were mainly Epsilonproteobacteria and Alphaproteobacteria, and the archaea were methanogens belonging to Methanolinea, Methanothermobacter, Methanosaeta, and Methanocella. However, in the high-temperature Ba19 block, the predominant bacteria were Gammaproteobacteria, and the predominant archaea were Methanothermobacter and Methanosaeta. In spite of shared taxa in the blocks, differences among wells in the same block were obvious, especially for bacterial communities in the MGL block. Compared to the bacterial communities, the archaeal communities were much more conserved within blocks and were not affected by the variation in the bacterial communities. PMID:22432032

  10. Use of wireline logs at Cerro Prieto in identification of the distribution of hydrothermally altered zones and dike locations, and their correlation with reservoir temperatures

    SciTech Connect

    Seamount, D.T. Jr.; Elders, W.A.

    1981-01-01

    Downhole electrical and gamma-gamma density logs from nine wells weere studed and these wireline log parameters with petrologic, temperature, and petrophysical data were correlated. Here, wells M-43, T-366, and M-107 are discussed in detail as typical cases. Log data for shales show good correlation with four zones of hydrothermal alteration previously recognized on the basis of characteristic mineral assemblages and temperatures. These zones are the unaltered montmorillonite zone (< 150/sup 0/C), the illite zone (150/sup 0/C to 230/sup 0/C to 245/sup 0/C), the chlorite zone (235/sup 0/C to 300/sup 0/C, equivalent to the calc-silicate I zone in sands), and the feldspar zone (> 300/sup 0/C, equivalent to the calc-silicate II zone in sands),

  11. Geysers reservoir studies

    SciTech Connect

    Bodvarsson, G.S.; Lippmann, M.J.; Pruess, K.

    1993-04-01

    LBL is conducting several research projects related to issues of interest to The Geysers operators, including those that deal with understanding the nature of vapor-dominated systems, measuring or inferring reservoir processes and parameters, and studying the effects of liquid injection. All of these topics are directly or indirectly relevant to the development of reservoir strategies aimed at stabilizing or increasing production rates of non-corrosive steam, low in non-condensable gases. Only reservoir engineering studies will be described here, since microearthquake and geochemical projects carried out by LBL or its contractors are discussed in accompanying papers. Three reservoir engineering studies will be described in some detail, that is: (a) Modeling studies of heat transfer and phase distribution in two-phase geothermal reservoirs; (b) Numerical modeling studies of Geysers injection experiments; and (c) Development of a dual-porosity model to calculate mass flow between rock matrix blocks and neighboring fractures.

  12. Geothermal reservoir engineering research

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  13. Quantification of Libby Reservoir Levels Needed to Maintain or Enhance Reservoir Fisheries, Appendices, 1984 Annual Report.

    SciTech Connect

    Shepard, Bradley B.

    1985-06-01

    The appendices include: (1) stream habitat inventory procedures; (2) lengths and volumes across hydroacoustic transects in Libby Reservoir; (3) temperature, pH, dissolved oxygen, and conductivity profiles in Libby Reservoir; (4) habitat survey information by reach; (5) gill net catches by species; (6) annual catches of fish in floating gill nets; (7) vertical distributions of fish and zooplankton; (8) timing of juvenile and adult movement through traps; (9) food habits information for collected fish; (10) estimated densities and composition of zooplankton by genera; (11) seasonal catch of macroinvertebrates; and (12) initial modeling effort on the Libby Reservoir fishery. (ACR)

  14. Reservoir assessment of The Geysers Geothermal field

    SciTech Connect

    Thomas, R.P.; Chapman, R.H.; Dykstra, H.

    1981-01-01

    Big Sulphur Creek fault zone, in The Geysers Geothermal field, may be part of a deep-seated, wrench-style fault system. Hydrothermal fluid in the field reservoir may rise through conduits beneath the five main anomalies associated with the Big Sulphur Creek wrench trend. Some geophysical anomalies (electrical resistivity and audio-magnetotelluric) evidently are caused by the hot water geothermal field or zones of altered rocks; others (gravity, P-wave delays, and possibly electrical resistivity) probably respresent the underlying heat source, a possible magma chamber; and others (microearthquake activity) may be related to the steam reservoir. A large negative gravity anomaly and a few low-resistivity anomalies suggest areas generally favorable for the presence of steam zones, but these anomalies apparently do not directly indicate the known steam reservoir. At the current generating capacity of 930 MWe, the estimated life of The Geysers Geothermal field reservoir is 129 years. The estimated reservoir life is 60 years for the anticipated maximum generating capacity of 2000 MWe as of 1990. Wells at The Geysers are drilled with conventional drilling fluid (mud) until the top of the steam reservoir is reached; then, they are drilled with air. Usually, mud, temperature, caliper, dual induction, and cement bond logs are run on the wells.

  15. EUTROPHICATION INVESTIGATION OF AMERICAN FALLS RESERVOIR, IDAHO. 1968-1969

    EPA Science Inventory

    During the 1967 irrigation season, there was a prolonged long period of high temperatures that adversely affected the American Falls Reservoir, Idaho (17040206). The Idaho Public Health Department reported a very heavy algae bloom, resulting in septic conditions in the reservoir...

  16. Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

    SciTech Connect

    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.

  17. NEXIS Reservoir Cathode 2000 Hour Life Test

    NASA Technical Reports Server (NTRS)

    Vaughn, Jason; Schneider, Todd; Polk, Jay; Goebel, Dan; Ohlinger, Wayne; Hill, D. Norm

    2004-01-01

    The current design of the Nuclear Electric Xenon Ion System (NEXIS) employs a reservoir cathode as both the discharge and neutralizer cathode to meet the 10 yr thruster design life. The main difference between a reservoir cathode and a conventional discharge cathode is the source material (barium-containing compound) is contained within a reservoir instead of in an impregnated insert in the hollow tube. However, reservoir cathodes do not have much life test history associated with them. In order to demonstrate the feasibility of using a reservoir cathode as an integral part of the NEXIS ion thruster, a 2000 hr life test was performed. Several proof-of-concept (POC) reservoir cathodes were built early in the NEXIS program to conduct performance testing as well as life tests. One of the POC cathodes was sent to Marshall Space Flight Center (MSFC) where it was tested for 2000 hrs in a vacuum chamber. The cathode was operated at the NEXIS design point of 25 A discharge current and a xenon flow rate of 5.5 sccm during the 2000 hr test. The cathode performance parameters, including discharge current, discharge voltage, keeper current; keeper voltage, and flow rate were monitored throughout test. Also, the temperature upstream of cathode heater, the temperature downstream of the cathode heater, and the temperature of the orifice plate were monitored throughout the life of the test. The results of the 2000 hr test will be described in this paper. Included in the results will be time history of discharge current, discharge voltage, and flow rate. Also, a time history of the cathode temperature will be provided.

  18. Potential Mammalian Filovirus Reservoirs

    PubMed Central

    Carroll, Darin S.; Mills, James N.; Johnson, Karl M.

    2004-01-01

    Ebola and Marburg viruses are maintained in unknown reservoir species; spillover into human populations results in occasional human cases or epidemics. We attempted to narrow the list of possibilities regarding the identity of those reservoir species. We made a series of explicit assumptions about the reservoir: it is a mammal; it supports persistent, largely asymptomatic filovirus infections; its range subsumes that of its associated filovirus; it has coevolved with the virus; it is of small body size; and it is not a species that is commensal with humans. Under these assumptions, we developed priority lists of mammal clades that coincide distributionally with filovirus outbreak distributions and compared these lists with those mammal taxa that have been tested for filovirus infection in previous epidemiologic studies. Studying the remainder of these taxa may be a fruitful avenue for pursuing the identity of natural reservoirs of filoviruses. PMID:15663841

  19. Session: Reservoir Technology

    SciTech Connect

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

    1992-01-01

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

  20. Geothermal reservoir simulation

    NASA Technical Reports Server (NTRS)

    Mercer, J. W., Jr.; Faust, C.; Pinder, G. F.

    1974-01-01

    The prediction of long-term geothermal reservoir performance and the environmental impact of exploiting this resource are two important problems associated with the utilization of geothermal energy for power production. Our research effort addresses these problems through numerical simulation. Computer codes based on the solution of partial-differential equations using finite-element techniques are being prepared to simulate multiphase energy transport, energy transport in fractured porous reservoirs, well bore phenomena, and subsidence.

  1. Tracing fluid flow in geothermal reservoirs

    SciTech Connect

    Rose, P.E.; Adams, M.C.

    1997-12-31

    A family of fluorescent compounds, the polycyclic aromatic sulfonates, were evaluated for application in intermediate- and high-temperature geothermal reservoirs. Whereas the naphthalene sulfonates were found to be very thermally stable and reasonably detectable, the amino-substituted naphthalene sulfonates were found to be somewhat less thermally stable, but much more detectable. A tracer test was conducted at the Dixie Valley, Nevada, geothermal reservoir using one of the substituted naphthalene sulfonates, amino G, and fluorescein. Four of 9 production wells showed tracer breakthrough during the first 200 days of the test. Reconstructed tracer return curves are presented that correct for the thermal decay of tracer assuming an average reservoir temperature of 227{degrees}C. In order to examine the feasibility of using numerical simulation to model tracer flow, we developed simple, two-dimensional models of the geothermal reservoir using the numerical simulation programs TETRAD and TOUGH2. By fitting model outputs to measured return curves, we show that numerical reservoir simulations can be calibrated with the tracer data. Both models predict the same order of elution, approximate tracer concentrations, and return curve shapes. Using these results, we propose a method for using numerical models to design a tracer test.

  2. Paonia Reservoir Sediment Management

    NASA Astrophysics Data System (ADS)

    Kimbrel, S.; Collins, K.; Williams, C.

    2014-12-01

    Paonia Dam and Reservoir are located on Muddy Creek, a tributary of the North Fork Gunnison River in western Colorado. Since dam closure in 1962, the 2002 survey estimates an annual sedimentation rate of 153,000 m3/y, resulting in a 25% loss of total reservoir capacity. Long before sediment levels completely fill the reservoir, the outlet works have recently plugged with sediment and debris, adversely impacting operations, and emphasizing the urgency of formulating an effective sediment management plan. Starting in 2010-2011, operations were changed to lower the reservoir and flush sediment through the outlet works in early spring before filling the pool for irrigation. Even though the flushing strategy through the long, narrow reservoir (~5 km long and 0.3 km wide) has prevented outlet works plugging, a long term plan is needed to manage inflowing and deposited sediment more efficiently. Reclamation's Sedimentation and River Hydraulics Group is leading an effort to study the past and current sediment issues at Paonia Dam and Reservoir, evaluate feasible sediment management alternatives, and formulate a plan for future operations and monitoring. The study is building on previously collected data and the existing knowledge base to develop a comprehensive, sustainable sediment management plan. The study is being executed in three phases: Phase 1 consisted of an initial site visit to map and sample existing reservoir bottom sediments, a preliminary site evaluation upstream and downstream of the dam, and establishment of time-lapse photo sites and taking initial ground-based photos. Phase 2 includes a bathymetric survey of entire reservoir and 11 km of the river downstream of the dam, continuous suspended sediment monitoring upstream and downstream of the reservoir, and collection of additional core samples of reservoir bottom sediments. Phase 3 involves the evaluation of current and past operations and sediment management practices, evaluate feasible sediment

  3. Water quality of Rob Roy Reservoir and Lake Owen, Albany County, and Granite Springs and Crystal Lake Reservoirs, Laramie County, Wyoming, 1997-98

    USGS Publications Warehouse

    Ogle, Kathy Muller; Peterson, D.A.; Spillman, Bud; Padilla, Rosie

    1999-01-01

    The water quality of four reservoirs was assessed during 1997 and 1998 as a cooperative project between the Cheyenne Board of Public Utilities and the U. S. Geological Survey. The four reservoirs, Rob Roy, Lake Owen, Granite Springs, and Crystal Lake, provide approximately 75 percent of the public water supply for Cheyenne, Wyoming. Samples of water and bottom sediment were collected and analyzed for selected physical, chemical, and biological characteristics to provide data about the reservoirs. Water flows between the reservoirs through a series of pipelines and stream channels. The reservoirs differ in physical characteristics such as elevation, volume, and depth.Profiles of temperature, dissolved oxygen, specific conductance, and pH were examined. Three of the four reservoirs exhibited stratification during the summer. The profiles indicate that stratification develops in all reservoirs except Lake Owen. Stratification developed in Rob Roy, Granite Springs, and Crystal Lake Reservoirs by mid-July in 1998 and continued until September, with the thickness of the epilimnion increasing during that time. Secchi disk readings indicated Rob Roy Reservoir had the clearest water of the four reservoirs studied.The composition of the phytoplankton community was different in the upper two reservoirs from that in the lower two reservoirs. Many of the species found in Rob Roy Reservoir and Lake Owen are associated with oligotrophic, nutrient-poor conditions. In contrast, many of the species found in Granite Springs and Crystal Lake Reservoirs are associated with mesotrophic or eutrophic conditions. The total number of taxa identified also increased downstream.The chemical water type in the reservoirs was similar, but dissolved-solids concentrations were greater in the downstream reservoirs. Water in all four reservoirs was a calcium-bicarbonate type. In the fall of 1997, Rob Roy Reservoir had the lowest dissolved-solids concentration (19 milligrams per liter), whereas

  4. The Ahuachapan geothermal field, El Salvador: Reservoir analysis

    SciTech Connect

    Aunzo, Z.; Bodvarsson, G.S.; Laky, C.; Lippmann, M.J.; Steingrimsson, B.; Truesdell, A.H.; Witherspoon, P.A.; Icelandic National Energy Authority, Reykjavik; Geological Survey, Menlo Park, CA; Lawrence Berkeley Lab., CA )

    1989-08-01

    These are appendices F through I of the Ahuachapan Geothermal Field Reservoir Analysis. The volume contains: well logs, water chemistry plots, gas chemistry plots, temperature plots, and flow plots. (JEF)

  5. The Ahuachapan geothermal field, El Salvador: Reservoir analysis

    SciTech Connect

    Aunzo, Z.; Bodvarsson, G.S.; Laky, C.; Lippmann, M.J.; Steingrimsson, B.; Truesdell, A.H.; Witherspoon, P.A.; Icelandic National Energy Authority, Reykjavik; Geological Survey, Menlo Park, CA )

    1989-08-01

    These are appendices A thru E of the Ahuachapan geothermal field reservoir analysis. The volume contains: mineralogy contours, ionic chlorine and silicon dioxide contours, well summaries, and temperature and pressure effects. (JEF)

  6. Optoelectronic Reservoir Computing

    PubMed Central

    Paquot, Y.; Duport, F.; Smerieri, A.; Dambre, J.; Schrauwen, B.; Haelterman, M.; Massar, S.

    2012-01-01

    Reservoir computing is a recently introduced, highly efficient bio-inspired approach for processing time dependent data. The basic scheme of reservoir computing consists of a non linear recurrent dynamical system coupled to a single input layer and a single output layer. Within these constraints many implementations are possible. Here we report an optoelectronic implementation of reservoir computing based on a recently proposed architecture consisting of a single non linear node and a delay line. Our implementation is sufficiently fast for real time information processing. We illustrate its performance on tasks of practical importance such as nonlinear channel equalization and speech recognition, and obtain results comparable to state of the art digital implementations. PMID:22371825

  7. Lakes and reservoirs

    SciTech Connect

    Taub, F.B.

    1984-01-01

    This volume in the Ecosystems of the World series studies lakes and reservoirs. The book opens with a discussion of the ecosystem processes that are common to all lakes and reservoirs and then proceeds to a description of mathematical models of these processes. The chapters concentrate on lakes and reservoirs in different parts of the world, ranging from polar to tropical lakes, and in many of the chapters the effects of human activities such as dam construction, increased nutrient inputs, toxic contaminants and fish introduction, are also considered. The book concludes with a summary of the efforts at lake restoration that are being undertaken in many communities in an attempt to undo the damage that has resulted from some of these activities.

  8. Manicouagin Reservoir of Canada

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Recorded by the Space Shuttle Atlantis STS-110 mission, this is a photograph of the ice- covered Manicouagin Reservoir located in the Canadian Shield of Quebec Province in Eastern Canada, partially obscured by low clouds. This reservoir marks the site of an impact crater, 60 miles (100 kilometers) wide, which according to geologists was formed 212 million years ago when a meteorite crashed into this area. Over millions of years, the crater has been worn down by glaciers and other erosional processes. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002.

  9. Estimation of Reservoir Geotemperatures from Multicomponent and Classical Geothermometry of the Bath Geothermal Reservoir: An Integrated Approach

    NASA Astrophysics Data System (ADS)

    Wishart, D. N.

    2014-12-01

    An integrated approach incorporating multicomponent and classical solute geothermometry was used to evaluate its utility to estimate the temperature of the Bath geothermal reservoir, a low-enthalpy system on the island of Jamaica. Reservoir temperatures were estimated from (1) empirical geothermometric equations; (2) simulations of solute geothermometers using SolGeo software; (3) computations of saturation indices [Log(Q/K)] of reservoir minerals from full chemically-analyzed thermal water samples over a temperature range of 25-220°C in PHREEQC; and (4) the Giggenbach Na-K-Mg geothermometer. A principal component analysis (PCA) shows strong, positive correlations between Na+, K+, and Mg2+ and is regarded as significant for these ions in their reliance as useful reservoir geoindicators. However, a negative correlation exists between Na+, K+, Mg2+ and silica (SiO2). The more realistic estimates of the geothermal reservoir temperature were provided by the Na-K and Na-K-Mg geothermometers, whereas the Na-K-Ca geothermometer overestimated reservoir temperatures. Estimated geotemperatures from silica-quartz geothermometers were the lowest. The discrepancy in estimated geotemperatures may be due to processes such as boiling, degassing, dilution, rock dissolution, and mixing during the ascent of geothermal fluids. Log (Q/K) curves cluster over a range of equilibrium temperatures closest to Na-K and Na-K-Mg geothermometers at 80-102°C. Reservoir temperatures estimated for the Bath geothermal system range between 79-118°C. Comparisons of the estimated geotemperatures using the integrated approach to geothermometry show a favorable agreement. Based on the results of this investigation, the integrated geothermometric approach provided a more reliable approach to reconstruct the fluid composition at depth and estimate the geothermal reservoir temperature.

  10. Interpreting isotopic analyses of microbial sulfate reduction in oil reservoirs

    NASA Astrophysics Data System (ADS)

    Hubbard, C. G.; Engelbrektson, A. L.; Druhan, J. L.; Cheng, Y.; Li, L.; Ajo Franklin, J. B.; Coates, J. D.; Conrad, M. E.

    2013-12-01

    Microbial sulfate reduction in oil reservoirs is often associated with secondary production of oil where seawater (28 mM sulfate) is commonly injected to maintain reservoir pressure and displace oil. The hydrogen sulfide produced can cause a suite of operating problems including corrosion of infrastructure, health exposure risks and additional processing costs. We propose that monitoring of the sulfur and oxygen isotopes of sulfate can be used as early indicators that microbial sulfate reduction is occurring, as this process is well known to cause substantial isotopic fractionation. This approach relies on the idea that reactions with reservoir (iron) minerals can remove dissolved sulfide, thereby delaying the transport of the sulfide through the reservoir relative to the sulfate in the injected water. Changes in the sulfate isotopes due to microbial sulfate reduction may therefore be measurable in the produced water before sulfide is detected. However, turning this approach into a predictive tool requires (i) an understanding of appropriate fractionation factors for oil reservoirs, (ii) incorporation of isotopic data into reservoir flow and reactive transport models. We present here the results of preliminary batch experiments aimed at determining fractionation factors using relevant electron donors (e.g. crude oil and volatile fatty acids), reservoir microbial communities and reservoir environmental conditions (pressure, temperature). We further explore modeling options for integrating isotope data and discuss whether single fractionation factors are appropriate to model complex environments with dynamic hydrology, geochemistry, temperature and microbiology gradients.

  11. CE-QUAL-W2 Modeling of Head-of-Reservoir Conditions at Shasta Reservoir, California

    NASA Astrophysics Data System (ADS)

    Clancey, K. M.; Saito, L.; Svoboda, C.; Bender, M. D.; Hannon, J.

    2014-12-01

    Restoration of Chinook salmon and steelhead is a priority in the Sacramento River Basin since they were listed under the Endangered Species Act in 1989 and 1998, respectively. Construction of Shasta Dam and Reservoir obstructed fish migration, resulting in severe population declines. Efforts have been undertaken to restore the fisheries, including evaluation of opportunities for reintroducing Chinook salmon upstream of the dam and providing juvenile fish passage downstream past Shasta Dam. Shasta Reservoir and the Sacramento River and McCloud River tributaries have been modeled with CE-QUAL-W2 (W2) to assess hydrodynamic and temperature conditions with and without surface curtains to be deployed in the tributaries. Expected head-of-reservoir tributary conditions of temperature and water depth are being simulated under dry, median and wet year conditions. Model output is analyzed during months of downstream migration of fish from upstream Sacramento and McCloud River tributaries. W2 will be used to determine presence of favorable conditions for juvenile rearing with proposed surface temperature curtains. Evaluation of favorable conditions for fish includes assessment of water temperature, velocities, and depth. Preliminary results for head-of-reservoir conditions and the influence of temperature curtains modeled with W2 will be presented. Study findings may assist in formulation of juvenile fish passage alternatives for Shasta Lake.

  12. Reinjection into geothermal reservoirs

    SciTech Connect

    Bodvarsson, G.S.; Stefansson, V.

    1987-08-01

    Reinjection of geothermal wastewater is practiced as a means of disposal and for reservoir pressure support. Various aspects of reinjection are discussed, both in terms of theoretical studies as well as specific field examples. The discussion focuses on the major effects of reinjection, including pressure maintenance and chemical and thermal effects. (ACR)

  13. Applying reservoir characterization technology

    SciTech Connect

    Lake, L.W.

    1994-12-31

    While reservoir characterization is an old discipline, only within the last 10 years have engineers and scientists been able to make quantitative descriptions, due mostly to improvements in high-resolution computational power, sophisticated graphics, and geostatistics. This paper summarizes what has been learned during the past decade by using these technologies.

  14. Reservoirs 3 carbonates

    SciTech Connect

    Beaumont, E.A.; Foster, N.H.

    1988-01-01

    This book covers the topics of Carbonates; Carbonate depositional environments and Carbonate diagenesis. Included are the following papers: pore geometry of carbonate rocks as revealed by pore casts and capillary pressure; a review of carbonate reservoirs; the chemistry of dolomitization and dolomite precipitation.

  15. Reservoirs III carbonates

    SciTech Connect

    Beaumont, E.A.; Foster, N.H.

    1988-01-01

    This text is part of a three volume set on petroleum and natural gas reservoir rocks. This volume deals with carbonate rocks and their properties as they relate to oil and gas production. Papers deal specifically with depositional environments, diagenesis, and chemical and physical properties of the rock.

  16. Biological souring and mitigation in oil reservoirs.

    PubMed

    Gieg, Lisa M; Jack, Tom R; Foght, Julia M

    2011-10-01

    Souring in oil field systems is most commonly due to the action of sulfate-reducing prokaryotes, a diverse group of anaerobic microorganisms that respire sulfate and produce sulfide (the key souring agent) while oxidizing diverse electron donors. Such biological sulfide production is a detrimental, widespread phenomenon in the petroleum industry, occurring within oil reservoirs or in topside processing facilities, under low- and high-temperature conditions, and in onshore or offshore operations. Sulfate reducers can exist either indigenously in deep subsurface reservoirs or can be "inoculated" into a reservoir system during oil field development (e.g., via drilling operations) or during the oil production phase. In the latter, souring most commonly occurs during water flooding, a secondary recovery strategy wherein water is injected to re-pressurize the reservoir and sweep the oil towards production wells to extend the production life of an oil field. The water source and type of production operation can provide multiple components such as sulfate, labile carbon sources, and sulfate-reducing communities that influence whether oil field souring occurs. Souring can be controlled by biocides, which can non-specifically suppress microbial populations, and by the addition of nitrate (and/or nitrite) that directly impacts the sulfate-reducing population by numerous competitive or inhibitory mechanisms. In this review, we report on the diversity of sulfate reducers associated with oil reservoirs, approaches for determining their presence and effects, the factors that control souring, and the approaches (along with the current understanding of their underlying mechanisms) that may be used to successfully mitigate souring in low-temperature and high-temperature oil field operations. PMID:21858492

  17. Dynamic-reservoir lubricating device

    NASA Technical Reports Server (NTRS)

    Ficken, W. H.; Schulien, H. E.

    1968-01-01

    Dynamic-reservoir lubricating device supplies controlled amounts of lubricating oil to ball bearings during operation of the bearings. The dynamic reservoir lubricating device includes a rotating reservoir nut, a hollow cylinder filled with lubricating oil, flow restrictors and a ball bearing retainer.

  18. Stream, Lake, and Reservoir Management.

    PubMed

    Mei, Ying; Chang, Chein-Chi; Dong, Zhanfeng; Wei, Li

    2016-10-01

    This review on stream, lake, and reservoir management covers selected 2015 publications on the focus of the following sections: • Biota • Climate effect • Models • Remediation and restoration • Reservoir operations • Stream, Lake, and Reservoir Management • Water quality. PMID:27620102

  19. Reservoir geochemistry: A link between reservoir geology and engineering?

    SciTech Connect

    Larter, S.R.; Aplin, A.C.; Corbett, P.; Ementon, N.

    1994-12-31

    Geochemistry provides a natural but poorly exploited link between reservoir geology and engineering. The authors summarize some current applications of geochemistry to reservoir description and stress that because of their strong interactions with mineral surfaces and water, nitrogen and oxygen compounds in petroleum may exert an important influence on the PVT properties of petroleum, viscosity and wettability. The distribution of these compounds in reservoirs is heterogeneous on a sub-meter scale and is partly controlled by variations in reservoir quality. The implied variations in petroleum properties and wettability may account for some of the errors in reservoir simulations.

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

    NASA Astrophysics Data System (ADS)

    Cho, Jae Kyoung

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

  1. Surrogate Reservoir Model

    NASA Astrophysics Data System (ADS)

    Mohaghegh, Shahab

    2010-05-01

    Surrogate Reservoir Model (SRM) is new solution for fast track, comprehensive reservoir analysis (solving both direct and inverse problems) using existing reservoir simulation models. SRM is defined as a replica of the full field reservoir simulation model that runs and provides accurate results in real-time (one simulation run takes only a fraction of a second). SRM mimics the capabilities of a full field model with high accuracy. Reservoir simulation is the industry standard for reservoir management. It is used in all phases of field development in the oil and gas industry. The routine of simulation studies calls for integration of static and dynamic measurements into the reservoir model. Full field reservoir simulation models have become the major source of information for analysis, prediction and decision making. Large prolific fields usually go through several versions (updates) of their model. Each new version usually is a major improvement over the previous version. The updated model includes the latest available information incorporated along with adjustments that usually are the result of single-well or multi-well history matching. As the number of reservoir layers (thickness of the formations) increases, the number of cells representing the model approaches several millions. As the reservoir models grow in size, so does the time that is required for each run. Schemes such as grid computing and parallel processing helps to a certain degree but do not provide the required speed for tasks such as: field development strategies using comprehensive reservoir analysis, solving the inverse problem for injection/production optimization, quantifying uncertainties associated with the geological model and real-time optimization and decision making. These types of analyses require hundreds or thousands of runs. Furthermore, with the new push for smart fields in the oil/gas industry that is a natural growth of smart completion and smart wells, the need for real time

  2. Quantification of Libby Reservoir Levels Needed to Maintain or Enhance Reservoir Fisheries, 1985 Annual Report.

    SciTech Connect

    Chisholm, Ian

    1985-01-01

    The goal was to quantify seasonal water levels needed to maintain or enhance the reservoir fishery in Libby. This report summarizes data collected from July 1984 through July 1985, and, where appropriate, presents data collected since 1983. The Canada, Rexford, and Tenmile areas of the reservoir are differentially affected by drawdown. Relative changes in water volume and surface area are greatest in the Canada area and smallest in the Tenmile area. Reservoir morphology and hydraulics probably play a major role in fish distribution through their influence on water temperature. Greatest areas of habitat with optimum water temperature for Salmo spp. and kokanee occurred during the spring and fall months. Dissolved oxygen, pH and conductivity levels were not limiting during any sampling period. Habitat enhancement work was largely unsuccessful. Littoral zone vegetation plantings did not survive well, primarily the result of extreme water level fluctuations. Relative abundances of fish species varied seasonally within and between the three areas. Water temperature is thought to be the major influence in fish distribution patterns. Other factors, such as food availability and turbidity, may mitigate its influence. Sampling since 1975 illustrates a continued increase in kokanee numbers and a dramatic decline in redside shiners. Salmo spp., bull trout, and burbot abundances are relatively low while peamouth and coarsescale sucker numbers remain high. A thermal dynamics model and a trophic level components model will be used to quantify the impact of reservoir operation on the reservoir habitat, primary production, secondary production and fish populations. Particulate carbon will be used to track energy flow through trophic levels. A growth-driven population dynamics simulation model that will estimate the impacts of reservoir operation on fish population dynamics is also being considered.

  3. Status of Blue Ridge Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Blue Ridge Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports and data available, as well as interview with water resource professionals in various federal, state, and local agencies. Blue Ridge Reservoir is a single-purpose hydropower generating project. When consistent with this primary objective, the reservoir is also operated to benefit secondary objectives including water quality, recreation, fish and aquatic habitat, development of shoreline, aesthetic quality, and other public and private uses that support overall regional economic growth and development. 8 refs., 1 fig.

  4. Interactive reservoir simulation

    SciTech Connect

    Regtien, J.M.M. Por, G.J.A.; Stiphout, M.T. van; Vlugt, F.F. van der

    1995-12-31

    Shell`s new Modular Reservoir Simulator (MoReS) has been equipped with a comprehensive and versatile user interface called FrontEnd. Apart from providing a user-friendly environment for interactive reservoir simulation, FrontEnd serves a software platform for other dynamic simulation and reservoir-engineering applications. It offers to all supported applications a common user interface, enables the re-use of code and reduces overall maintenance and support costs associated with the embedded applications. Because of its features, FrontEnd facilitates the transfer of research results in the form of operational software to end users. When coupled with MoReS, FrontEnd can be used for pre- and post-processing and interactive simulation. The pre-processing options allow data to be inputted by means of various OSF/Motif widgets containing a spreadsheet, text editors, dialogues and graphical input. The display of the input data as well as the post-processing of all simulation results is made possible by a variety of user-defined plot of tabular (e.g. timestep summary) and array (simulation grid) data. During a simulation user-defined plots can be displayed and edited, allowing a close inspection of the results as they are being calculated. FrontEnd has been equipped with a powerful input command language, which gives the batch user as much flexibility and control over the input as the interactive user.

  5. Trends in reservoir simulation

    SciTech Connect

    Nolen, J.S.

    1995-06-01

    The future of reservoir simulation is driven by two different and, on the surface, paradoxical trends. On the one hand, the user base is on average becoming less experienced, and on the other, increasingly complex models are being built to honor the advances in reservoir-description technology. The job of the software development community is to create software that satisfies both the ease-of-use needs of the novice and the accuracy needs of the integrated geoscience team. One of the near-term effects of these demands will be to improve the capabilities and quality of the fully integrated geoscience work-station. This will include the need for implementation of industry-wide data standards. Reservoir simulators will need to incorporate increasing amounts of interactivity and built-in expertise. Accuracy of results will be improved by increased use of unstructured grids, including automatic gridding software with dynamic capabilities. Additional research will focus on complex wells, including both in-flow performance and wellbore hydraulics. Finally, grid size will continue to escalate in step with advances in hardware and software. The growth of grid size will be mitigated by substantial efforts in upscaling, but ultimately parallel computing must provide the mechanism for continued growth.

  6. Which Microbial Communities Are Present? Application of Clone Libraries: Syntrophic Acetate Degradation to Methane in a High-Temperature Petroleum Reservoir - Culture-Based and 16S rRNA Genes Characterisation

    NASA Astrophysics Data System (ADS)

    Shestakova, Natalya M.; Ivoilov, Valeriy S.; Tourova, Tatiana P.; Belyaev, Sergey S.; Poltaraus, Andrei B.; Nazina, Tamara N.

    The presence of microorganisms in petroleum reservoirs has been established about 100 years ago. Microbiological, radioisotope, molecular biological and biogeochemical techniques have been used to investigate microbial diversity and activity in the oilfields. These techniques were applied separately and the composition of the microbial community and its geochemical activity remained poorly understood.

  7. Continuous-variable-entanglement dynamics in structured reservoirs

    SciTech Connect

    Vasile, Ruggero; Maniscalco, Sabrina; Olivares, Stefano; Paris, Matteo G. A.

    2009-12-15

    We address the evolution of entanglement in bimodal continuous variable quantum systems interacting with two independent structured reservoirs. We derive an analytic expression for the entanglement of formation without performing the Markov and the secular approximations and study in details the entanglement dynamics for various types of structured reservoirs and for different reservoir temperatures, assuming the two modes initially excited in a twin-beam state. Our analytic solution allows us to identify three dynamical regimes characterized by different behaviors of the entanglement: the entanglement sudden death, the non-Markovian revival and the non-secular revival regimes. Remarkably, we find that, contrarily to the Markovian case, the short-time system-reservoir correlations in some cases destroy quickly the initial entanglement even at zero temperature.

  8. GPFA-AB_Phase1ReservoirTask2DataUpload

    SciTech Connect

    Teresa E. Jordan

    2015-10-22

    This submission to the Geothermal Data Repository (GDR) node of the National Geothermal Data System (NGDS) in support of Phase 1 Low Temperature Geothermal Play Fairway Analysis for the Appalachian Basin. The files included in this zip file contain all data pertinent to the methods and results of this task’s output, which is a cohesive multi-state map of all known potential geothermal reservoirs in our region, ranked by their potential favorability. Favorability is quantified using a new metric, Reservoir Productivity Index, as explained in the Reservoirs Methodology Memo (included in zip file). Shapefile and images of the Reservoir Productivity and Reservoir Uncertainty are included as well.

  9. Research on water quality of reservoir tailwaters

    SciTech Connect

    Dortch, M.S.; Hamlin, D.E.

    1988-01-01

    Many reservoirs experience seasonal thermal stratification often accompanied by dissolved oxygen (DO) depletion in bottom waters. When water is released to the downstream environment, reaeration occurs. Eventually, the water quality recovers to a more natural stream condition. The recovery distance, which depends on physical and biogeochemical factors, is often on the order of miles. To address this need, a study was conducted on poor water quality associated with deep, anoxic releases at four sites: (1) the tailwater of Lake Greeson, Little Missouri River, Arkansas; (2) tailwater of Nimrod Reservoir (Fourche La Fave River, Arkansas); (3) tailwater of Rough River Reservoir, Kentucky; and (4) Buford Dam tailwater on the Chattahoochee River, Georgia. The objectives were: to develop an improved understanding of chemical transformation in tailwaters; to provide guidance on sampling and analysis of tailwater quality; and to develop an easy-to-use PC model to predict impacts of reservoir releases on tailwater quality. Preliminary results are reported for the Greeson tailwater study only. The major process affecting DO concentrations was stream reaeration. Flow rate was shown to affect oxidation rates (e.g. for iron and manganese) so that a generalized formulation for reduced iron and manganese oxidation kinetics may need to account for the local temperature, DO concentration, pH, possible a flow-related variable, and the type of substrate in the stream. 14 refs., 2 figs., 1 tab.

  10. Organic carbon burial efficiency in a large tropical hydroelectric reservoir

    NASA Astrophysics Data System (ADS)

    Mendonça, Raquel; Sobek, Sebastian; Kosten, Sarian; Cole, Jonathan; Cardoso, Simone; Roland, Fábio

    2014-05-01

    temperature. Among hydroelectric reservoirs, OC burial efficiency will probably be higher in more eutrophic and in colder systems and lower in warm systems receiving relatively low terrestrial OC inputs.

  11. Geothermal Reservoir Well Stimulation Program: technology transfer

    SciTech Connect

    Not Available

    1980-05-01

    A literature search on reservoir and/or well stimulation techniques suitable for application in geothermal fields is presented. The literature on stimulation techniques in oil and gas field applications was also searched and evaluated as to its relevancy to geothermal operations. The equivalent low-temperature work documented in the open literature is cited, and an attempt is made to evaluate the relevance of this information as far as high-temperature stimulation work is concerned. Clays play an important role in any stimulation work. Therefore, special emphasis has been placed on clay behavior anticipated in geothermal operations. (MHR)

  12. A vapor-dominated reservoir exceeding 600{degrees}F at the Geysers, Sonoma County, California

    SciTech Connect

    Walters, M.A.; Sternfeld, J.N.; Haizlip, J.R.; Drenick, A.F.; Combs, Jim

    1988-01-01

    A high-temperature vapor-dominated reservoir underlies a portion of the Northwest Geysers area, Sonoma County, California. The high-temperature reservoir (HTR) is defined by flowing fluid temperatures exceeding 500º F, rock temperatures apparently exceeding 600º F and steam enthalpies of about 1320 BTU/lb. Steam from existing wells drilled in the Northwest Geysers is produced from both a “typical” Geysers reservoir and the HTR. In all cases, the HTR is in the lower portion of the wells and is overlain by a “typical” Geysers reservoir. Depth to the high-temperature reservoir is relatively uniform at about -5900 ft subsea. There are no identified lithologic or mineralogic conditions that separate the HTR from the “typical” reservoir, although the two reservoirs are vertically distinct and can be located in most wells to within about 200 ft by the use of downhole temperature-depth measurements. Gas concentrations in steam from the HTR are higher (6 to 9 wt %) than from the “typical” Geysers reservoir (0.85 to 2.6 wt %). Steam from the HTR is enriched in chloride and the heavy isotopes of water relative to the “typical” reservoir. Available static and dynamic measurements show pressures are subhydrostatic in both reservoirs with no anomalous differences between the two: the HTR pressure being near 520 psia at sea level datum. The small observed differences in pressure between the reservoirs appear to vary along a steam density gradient. It is postulated that the Northwest Geysers area evolved more slowly toward vapor-dominated conditions than other parts of The Geysers field because of its poor connection with the surface. In this paper, a model is presented in which the boundary between the HTR and “typical” reservoir is a thermodynamic feature only, resulting from recent deep venting of a liquid-dominated system in which conduction is still an important component of heat transfer.

  13. [Human reservoirs of Pneumocystis].

    PubMed

    Wissmann, Gustavo; Morilla, Ruben; Friaza, Vicente; Calderón, Enrique; Varela, Jose M

    2010-01-01

    Pneumocystis jirovecii, the fungal agent that causes Pneumocystis pneumonia (PCP), is known to exclusively infect humans. Molecular studies have enabled detection of this fungus in individuals who have been colonized by P. jirovecii. Such colonization, found in several populations, seems to act as a human reservoir for the fungus. Various studies have reported mutations associated with sulfa resistance in P. jirovecii strains isolated from colonized patients, who can transmit the mutant genotype to PCP-susceptible individuals. The growing interest in P. jirovecii colonization may prompt the design of new prevention and management strategies for PCP. PMID:19403207

  14. Reservoir management cost-cutting

    SciTech Connect

    Gulati, M.S.

    1996-12-31

    This article by Mohinder S. Gulati, Chief Engineer, Unocal Geothermal Operations, discusses cost cutting in geothermal reservoir management. The reservoir engineer or geoscientist can make a big difference in the economical outcome of a project by improving well performance and thus making geothermal energy more competitive in the energy marketplace. Bringing plants online in less time and proving resources to reduce the cycle time are some of the ways to reduce reservoir management costs discussed in this article.

  15. Encapsulated microsensors for reservoir interrogation

    DOEpatents

    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.

  16. Tracer testing for reservoir description

    SciTech Connect

    Brigham, W.E.; Abbaszadeh-Dehghani, M.

    1987-05-01

    When a reservoir is studied in detail for an EOR project, well-to-well tracers should be used as a tool to help understand the reservoir in a quantitative way. Tracers complement the more traditional reservoir evaluation tools. This paper discusses the concepts underlying tracer testing, the analysis methods used to produce quantitative results, and the meaning of these results in terms of conceptual picture of the reservoir. Some of the limitations of these analysis methods are discussed, along with ongoing research on tracer flow.

  17. The Tiwi geothermal reservoir: Geology, geochemistry, and response to production

    SciTech Connect

    Hoagland, J.R.; Bodell, J.M. )

    1990-06-01

    The Tiwi geothermal field is located on the Bicol Peninsula of Southern Luzon in the Philippines. The field is associated with the extinct Quaternary stratovolcano Mt. Malinao, one of a chain of volcanos formed as a result of crustal subduction along the Philippine Trench to the east. The geothermal reservoir is contained within a sequence of interlayered andesite flows and pyroclastic deposits that unconformably overlie a basement complex of marine sediments, metamorphic, and intrusive rocks. In its initial state, the Tiwi reservoir was an overpressured liquid-filled system containing near-neutral sodium chloride water at temperatures exceeding 260{degree}C. The reservoir is partially sealed at its top and sides by hydrothermal argillic alteration products and calcite deposition. Isolated portions of the reservoir contain a corrosive acid chloride-sulfate water associated with a distinctive advanced argillic mineral assemblage. Withdrawal of fluid for electricity generation has caused widespread boiling in the reservoir and the formation of steam zones. The resultant solids deposition in wellbores and near-wellbore formation has been mitigated by a combination of mechanical and chemical well stimulation. Mass withdrawal from the reservoir has also caused invasion of cold groundwater into the reservoir through former fluid outflow channels. During 1983-1987, several wells were flooded with cold water and ceased flowing. In response, PGI moved development drilling west to largely unaffected areas and undertook recompletion and stimulation programs. These programs effectively halted the decline in generation by 1988.

  18. Limnology of Blue Mesa, Morrow Point, and Crystal Reservoirs, Curecanti National Recreation area, during 1999, and a 25-year retrospective of nutrient conditions in Blue Mesa Reservoir, Colorado

    USGS Publications Warehouse

    Bauch, Nancy J.; Malick, Matt

    2003-01-01

    The U.S. Geological Survey and the National Park Service conducted a water-quality investigation in Curecanti National Recreation Area in Colorado from April through December 1999. Current (as of 1999) limnological characteristics, including nutrients, phytoplankton, chlorophyll-a, trophic status, and the water quality of stream inflows and reservoir outflows, of Blue Mesa, Morrow Point, and Crystal Reservoirs were assessed, and a 25-year retrospective of nutrient conditions in Blue Mesa Reservoir was conducted. The three reservoirs are in a series on the Gunnison River, with an upstream to downstream order of Blue Mesa, Morrow Point, and Crystal Reservoirs. Physical properties and water-quality samples were collected four times during 1999 from reservoir, inflow, and outflow sites in and around the recreation area. Samples were analyzed for nutrients, phytoplankton and chlorophyll-a (reservoir sites only), and suspended sediment (stream inflows only). Nutrient concentrations in the reservoirs were low; median total nitrogen and phosphorus concentrations were less than 0.4 and 0.06 milligram per liter, respectively. During water-column stratification, samples collected at depth had higher nutrient concentrations than photic-zone samples. Phytoplankton community and density were affected by water temperature, nutrients, and water residence time. Diatoms were the dominant phytoplankton throughout the year in Morrow Point and Crystal Reservoirs and during spring and early winter in Blue Mesa Reservoir. Blue-green algae were dominant in Blue Mesa Reservoir during summer and fall. Phytoplankton density was highest in Blue Mesa Reservoir and lowest in Crystal Reservoir. Longer residence times and warmer temperatures in Blue Mesa Reservoir were favorable for phytoplankton growth and development. Shorter residence times and cooler temperatures in the downstream reservoirs probably limited phytoplankton growth and development. Median chlorophyll-a concentrations were higher

  19. Recovery of heavy oils from deep reservoirs

    SciTech Connect

    Stoller, H. M.; Fox, R. L.

    1980-01-01

    The objective of Project DEEP STEAM is to develop the technology required to economically produce heavy oil from deep reservoirs. Two approaches are being pursued: improving the thermal efficiency of injection string components and the development of downhole steam generators to achieve steam injection. The first approach has seen the testing of commercially available components at a high temperature (650/sup 0/F)/high pressure (2100 psi) simulation facility. Promising components will be tested shortly in a field test conducted by Husky Oil at Lloydminster, Canada. The second approach has seen the prototype development and laboratory testing of low-pressure and high-pressure hydrocarbon-fueled downhole steam generators. Concurrently, a modified high pressure steam generator has undergone extensive laboratory combustion studies and is currently being employed in a field test at Chevron's Kern River field. This field test is examining the effects of simultaneous injection of steam and combustion products on the reservoir and oil recovery. 9 figures.

  20. Soybean yield in relation to distance from the Itaipu reservoir

    NASA Astrophysics Data System (ADS)

    de Faria, Rogério Teixeira; Junior, Ruy Casão; Werner, Simone Silmara; Junior, Luiz Antônio Zanão; Hoogenboom, Gerrit

    2015-11-01

    Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.

  1. Soybean yield in relation to distance from the Itaipu reservoir

    NASA Astrophysics Data System (ADS)

    de Faria, Rogério Teixeira; Junior, Ruy Casão; Werner, Simone Silmara; Junior, Luiz Antônio Zanão; Hoogenboom, Gerrit

    2016-07-01

    Crops close to small water bodies may exhibit changes in yield if the water mass causes significant changes in the microclimate of areas near the reservoir shoreline. The scientific literature describes this effect as occurring gradually, with higher intensity in the sites near the shoreline and decreasing intensity with distance from the reservoir. Experiments with two soybean cultivars were conducted during four crop seasons to evaluate soybean yield in relation to distance from the Itaipu reservoir and determine the effect of air temperature and water availability on soybean crop yield. Fifteen experimental sites were distributed in three transects perpendicular to the Itaipu reservoir, covering an area at approximately 10 km from the shoreline. The yield gradient between the site closest to the reservoir and the sites farther away in each transect did not show a consistent trend, but varied as a function of distance, crop season, and cultivar. This finding indicates that the Itaipu reservoir does not affect the yield of soybean plants grown within approximately 10 km from the shoreline. In addition, the variation in yield among the experimental sites was not attributed to thermal conditions because the temperature was similar within transects. However, the crop water availability was responsible for higher differences in yield among the neighboring experimental sites related to water stress caused by spatial variability in rainfall, especially during the soybean reproductive period in January and February.

  2. Evaluation of small diameter coreholes for reservoir information

    SciTech Connect

    Petty, Susan; Adair, Richard G.; Livesay, Bill

    1992-01-01

    Geothermal exploration has been highly successful to date in locating targets for drilling. However, the requirements for an economically successful geothermal well are both high flow rate and high temperature. Most geophysical and geochemical exploration methods have not been highly accurate in predicting the depth and actual temperature of a reservoir, nor have they been able to locate high permeability zones. The result is that most geothermal exploration is conducted by drilling core holes to better understand the heat flow in an area followed by drilling of production diameter exploration wells which can be flow tested to ascertain the permeability. The goal of any exploration program is to determine reservoir economics. The cost of wells makes up between one quarter and one half the total cost of producing geothermal power. The number, design, depth of wells and placement of injectors are important to the optimal exploitation of the reservoir. Although early efforts at development have focused on rapid plant construction to begin cash flow, the history of producing fields emphasizes that understanding reservoirs can reduce the risk of rapid temperature or pressure declines and increase the success of step out drilling following initial exploitation. The high cost of large diameter production wells makes the collecting of exploration data on the reservoir through some less expensive method desirable. Geothermal developers are still drilling resources with surface expression, hot springs and surface mappable fractures and faults. As these obvious resources are developed and as the obvious targets in productive fields are exhausted, new exploration tools are needed. One possibility is the use of deep core holes drilled for temperature gradient data to provide more reservoir information. Two methods not previously applied to geothermal reservoir assessment are suggested to augment other data obtained from coreholes.

  3. Reservoir Modeling for Production Management

    SciTech Connect

    Brown, Donald W.

    1989-03-21

    For both petroleum and geothermal resources, many of the reservoirs are fracture dominated--rather than matrix-permeability controlled. For such reservoirs, a knowledge of the pressure-dependent permeability of the interconnected system of natural joints (i.e., pre-existing fractures) is critical to the efficient exploitation of the resource through proper pressure management. Our experience and that reported by others indicates that a reduction in the reservoir pressure sometimes leads to an overall reduction in production rate due to the ''pinching off'' of the joint network, rather than the anticipated increase in production rate. This effect occurs not just in the vicinity of the wellbore, where proppants are sometimes employed, but throughout much of the reservoir region. This follows from the fact that under certain circumstances, the decline in fracture permeability (or conductivity) with decreasing reservoir pressure exceeds the far-field reservoir ''drainage'' flow rate increase due to the increased pressure gradient. Further, a knowledge of the pressure-dependent joint permeability could aid in designing more appropriate secondary recovery strategies in petroleum reservoirs or reinjection procedures for geothermal reservoirs.

  4. Climate change impacts on reservoir inflow in the United States

    NASA Astrophysics Data System (ADS)

    Naz, B. S.; Kao, S. C.; Ashfaq, M.; Gangrade, S.; Mei, R.; Ratogi, D.

    2014-12-01

    This study describes the impacts of projected climate change on reservoir inflows across the United States. For this purpose, we focused on several large U.S. reservoirs where inflow to reservoir is non-regulated (i.e. unaffected by human influence or upstream regulation) and also have long-term streamflow observations. We first simulated the 1980-2012 historic hydrologic conditions using the marco-scale Variable Infiltration Capacity (VIC) hydrological model at 1/24th degree grid cell resolution. The VIC-routing model was then used to simulate and compare with observed streamflow at the selected reservoir inflow locations. To project the climate change effects on reservoir inflows, the VIC model was then driven by 12-member dynamically downscaled and bias corrected meteorological forcings ensemble, which was generated by using 12 selected Global Climate Models from Coupled Model Intercomparison Project Phase-5 as an initial and boundary conditions in a regional climate model, RegCM4. Each set of dynamical downscaling experiment was carried out at 18 km horizontal grid spacing over the continental U.S. and parts of Canada and Mexico, and consisted of 41 years in the historic period (1965-2005) and 41 years in the near-term future period (2010-2050) under the Representative Concentration Pathway 8.5. To better understand the impact of projected future changes in temperature and precipitation on shifts in streamflow discharge and distribution, and its implications on reservoir storage, temporal trends in reservoir inflows were also explored. Furthermore, hydrologic sensitivities experiments were conducted to identify the factors affecting the streamflow response to changes in precipitation and temperature. This study provides estimates for changes in the reservoir inflows over the next several decades in response to potential climate variations that can be used for optimized water supply management in the downstream areas.

  5. Tertiary carbonate reservoirs in Indonesia

    SciTech Connect

    Nayoan, G.A.S.; Arpandi; Siregar, M.

    1981-01-01

    Hydrocarbon production from Tertiary carbonate reservoirs accounted for ca. 10% of daily Indonesian production at the beginning of 1978. Environmentally, the reservoirs appear as parts of reef complexes and high-energy carbonate deposits within basinal areas situated mainly in the back arc of the archipelago. Good porosities of the reservoirs are represented by vugular/moldic and intergranular porosity types. The reservoirs are capable of producing prolific amounts of hydrocarbons: production tests in Salawati-Irian Jaya reaches maximum values of 32,000 bpd, and in Arun-North Sumatra tests recorded 200 MMCF gas/day. Significant hydrocarbon accumulations are related to good reservoir rocks in carbonates deposited as patch reefs, pinnacle reefs, and platform complexes. Exploration efforts expand continuously within carbonate formations which are extensive horizontally as well as vertically in the Tertiary stratigraphic column.

  6. Stochastic thermodynamics with information reservoirs.

    PubMed

    Barato, Andre C; Seifert, Udo

    2014-10-01

    We generalize stochastic thermodynamics to include information reservoirs. Such information reservoirs, which can be modeled as a sequence of bits, modify the second law. For example, work extraction from a system in contact with a single heat bath becomes possible if the system also interacts with an information reservoir. We obtain an inequality, and the corresponding fluctuation theorem, generalizing the standard entropy production of stochastic thermodynamics. From this inequality we can derive an information processing entropy production, which gives the second law in the presence of information reservoirs. We also develop a systematic linear response theory for information processing machines. For a unicyclic machine powered by an information reservoir, the efficiency at maximum power can deviate from the standard value of 1/2. For the case where energy is consumed to erase the tape, the efficiency at maximum erasure rate is found to be 1/2. PMID:25375481

  7. FRACTURED PETROLEUM RESERVOIRS

    SciTech Connect

    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

  8. Reservoir Systems in Changing Climate

    NASA Astrophysics Data System (ADS)

    Lien, W.; Tung, C.; Tai, C.

    2007-12-01

    Climate change may cause more climate variability and further results in more frequent extreme hydrological events which may greatly influence reservoir¡¦s abilities to provide service, such as water supply and flood mitigation, and even danger reservoir¡¦s safety. Some local studies have identified that climate change may cause more flood in wet period and less flow in dry period in Taiwan. To mitigate climate change impacts, more reservoir space, i.e. less storage, may be required to store higher flood in wet periods, while more reservoir storage may be required to supply water for dry periods. The goals to strengthen adaptive capacity of water supply and flood mitigation are conflict under climate change. This study will focus on evaluating the impacts of climate change on reservoir systems. The evaluation procedure includes hydrological models, a reservoir water balance model, and a water supply system dynamics model. The hydrological models are used to simulate reservoir inflows under different climate conditions. Future climate scenarios are derived from several GCMs. Then, the reservoir water balance model is developed to calculate reservoir¡¦s storage and outflows according to the simulated inflows and operational rules. The ability of flood mitigation is also evaluated. At last, those outflows are further input to the system dynamics model to assess whether the goal of water supply can still be met. To mitigate climate change impacts, the implementing adaptation strategies will be suggested with the principles of risk management. Besides, uncertainties of this study will also be analyzed. The Feitsui reservoir system in northern Taiwan is chosen as a case study.

  9. Reservoir studies of the Seltjarnarnes geothermal field, Iceland

    SciTech Connect

    Tulinius, H.; Spencer, A.L.; Bodvarsson, G.S.; Kristmannsdottir, H.; Thorsteinsson, T.; Sveinbjornsdottir, A.E.

    1986-10-01

    The Seltjarnarnes geothermal field in Iceland has been exploited for space heating for the last 16 years. A model of the field has been developed that integrates all available data. The model has been calibrated against the flow rate and pressure decline histories of the wells and the temperature and chemical changes of the produced fluids. This has allowed for the estimation of the permeability and porosity distribution of the system, and the volume of the hot reservoir. Predictions of future reservoir behavior using the model suggest small pressure and temperature changes, but a continuous increase in the salinity of the fluids produced.

  10. Water resources review: Ocoee reservoirs, 1990

    SciTech Connect

    Cox, J.P.

    1990-08-01

    Tennessee Valley Authority (TVA) is preparing a series of reports to make technical information on individual TVA reservoirs readily accessible. These reports provide a summary of reservoir purpose and operation; physical characteristics of the reservoir and watershed; water quality conditions; aquatic biological conditions; and designated, actual and potential uses of the reservoir and impairments of those use. This reservoir status report addressed the three Ocoee Reservoirs in Polk County, Tennessee.

  11. Collapsible sheath fluid reservoirs for flow cytometers

    DOEpatents

    Mark, Graham A.

    2000-01-01

    The present invention is a container in the form of a single housing for holding fluid, including a first collapsible reservoir having a first valve. The first reservoir initially contains a volume of fluid. The container also includes a second reservoir, initially empty (or substantially empty), expandable to a second volume. The second reservoir has a second valve. As the volume of said first reservoir decreases, the volume of the second reservoir proportionally increases.

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

    SciTech Connect

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

    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

  13. Data requirements and acquisition for reservoir characterization

    SciTech Connect

    Jackson, S.; Chang, Ming Ming; Tham, Min.

    1993-03-01

    This report outlines the types of data, data sources and measurement tools required for effective reservoir characterization, the data required for specific enhanced oil recovery (EOR) processes, and a discussion on the determination of the optimum data density for reservoir characterization and reservoir modeling. The two basic sources of data for reservoir characterization are data from the specific reservoir and data from analog reservoirs, outcrops, and modern environments. Reservoir data can be divided into three broad categories: (1) rock properties (the container) and (2) fluid properties (the contents) and (3)interaction between reservoir rock and fluid. Both static and dynamic measurements are required.

  14. Reservoir evaporation in central Colorado

    USGS Publications Warehouse

    Spahr, N.E.; Ruddy, B.C.

    1983-01-01

    Evaporation losses from seven reservoirs operated by the Denver Water Department in central Colorado were determined during various periods from 1974 to 1980. The reservoirs studies were Ralston, Cheesman, Antero, Williams Fork, Elevenmile Canyon, Dillon, and Gross. Energy-budget and mass-transfer methods were used to determine evaporation. Class-A pan data also were collected at each reservoir. The energy-budget method was the most accurate of the methods used to determine evaporation. At Ralston, Cheesman, Antero, and Williams Fork Reservoirs the energy-budget method was used to calibrate the mass-transfer coefficients. Calibrated coefficients already were available for Elevenmile Canyon, Dillon, and Gross Reservoirs. Using the calibrated coefficients, long-term mass-transfer evaporation rates were determined. Annual evaporation values were not determined because the instrumentation was not operated for the entire open-water season. Class-A pan data were used to determine pan coefficients for each season at each reservoir. The coefficients varied from season to season and between reservoirs, and the seasonal values ranged from 0.29 to 1.05. (USGS)

  15. Identifying compartmentalization in gas reservoirs

    SciTech Connect

    Junkin, J.; Cooper, K.; Sippel, M.

    1997-01-01

    Compartmentalization as a function of depositional systems is now recognized as a common type of reservoir heterogeneity that limits recovery from oil and gas reservoirs. US Department of Energy (DOE) estimates indicate that substantial quantities of gas resources will not be recovered from presently identified reservoirs under historic development practices. The Secondary Natural Gas Recovery (SGR) project sponsored by the Gas Research Institute (GRI), state of Texas and DOE quantified compartmentalization over intervals as large as 2,000 feet in several different fluvial deltaic reservoirs. Early recognition of compartmentalized behavior can be used to pursue a more rapid development plan including efficient well spacing and elimination of redundant wells. Three classes of reservoir compartment sizes were delineated in the SGR project using methods discussed in this article. Forward stochastic modeling of gas recovery from these compartment-size classes established well spacing requirements that would yield maximum gas contact efficiency. The presence of reservoir compartmentalization was also shown to correlate with reserve growth. Also, those reservoirs classified as having smaller compartment sizes exhibited the greatest reserve growth potential. Utilization of tools, such as personal computer-based methods discussed, enables better engineering interpretation of actual field behavior. Some of these tools require minimal production data, which is readily available on CD-ROM or via modem at very low cost.

  16. TRITIUM RESERVOIR STRUCTURAL PERFORMANCE PREDICTION

    SciTech Connect

    Lam, P.S.; Morgan, M.J

    2005-11-10

    The burst test is used to assess the material performance of tritium reservoirs in the surveillance program in which reservoirs have been in service for extended periods of time. A materials system model and finite element procedure were developed under a Savannah River Site Plant-Directed Research and Development (PDRD) program to predict the structural response under a full range of loading and aged material conditions of the reservoir. The results show that the predicted burst pressure and volume ductility are in good agreement with the actual burst test results for the unexposed units. The material tensile properties used in the calculations were obtained from a curved tensile specimen harvested from a companion reservoir by Electric Discharge Machining (EDM). In the absence of exposed and aged material tensile data, literature data were used for demonstrating the methodology in terms of the helium-3 concentration in the metal and the depth of penetration in the reservoir sidewall. It can be shown that the volume ductility decreases significantly with the presence of tritium and its decay product, helium-3, in the metal, as was observed in the laboratory-controlled burst tests. The model and analytical procedure provides a predictive tool for reservoir structural integrity under aging conditions. It is recommended that benchmark tests and analysis for aged materials be performed. The methodology can be augmented to predict performance for reservoir with flaws.

  17. Microbial Life in an Underground Gas Storage Reservoir

    NASA Astrophysics Data System (ADS)

    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

  18. Operation of TVA reservoirs. Annual report, 1981

    SciTech Connect

    Not Available

    1984-09-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1981. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Plates are included in this report tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1981. Additional plates are included for the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storage and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of Reservoir Operations. Tables of monthly and annual storages and flows (in inches) for the principal Tennessee River Basin tributary projects are included at the end of their respective annual operations summary. Individual plotting of midnight reservoir elevations during calendar year 1981 are included for the principal tributary storage reservoirs and Normandy Reservoir. Group charts are included showing midnight reservoir elevations for other tributary reservoirs, the Tennessee River reservoirs, and the principal Cumberland Basin reservoirs.

  19. Operation of TVA reservoirs: annual 1980

    SciTech Connect

    Not Available

    1983-10-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1980. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Plates are included in this report tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1980. Additional plates are included for the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storage and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of Reservoir Operations. Tables of monthly and annual storage and flows (in inches) for the principal Tennessee River Basin tributary projects are included at the end of their respective annual operations summary. Individual plottings of midnight reservoir elevations are included for the principal tributary storage reservoirs and Normandy Reservoir. Group charts are included showing midnight reservoir elevations for other tributary reservoirs, the Tennessee River reservoirs, and the principal Cumberland Basin reservoirs.

  20. An ecological assessment of factors determining bacterioplankton dynamics in Tsimlyanskaya reservoir

    SciTech Connect

    Katretskii, Y.A.

    1984-07-01

    In this paper the author establishes that the abundance of bacterioplankton in Tsimlyanskaya reservoir is affected by such ecological factors as temperature, quality of organic solutes as well as intrapopulation factors. He concludes that factors dependent on density (consumption by zooplankton, sorption of suspensions) are the main regulators of the volume of bacterial population in the reservoir plankton.

  1. Evaluation of conditions and improvement options for Upper Bear Creek Reservoir. Appendix B

    SciTech Connect

    Bohac, C.E.; Angus, R.A.; Marion, K.R.

    1993-04-01

    This report presents data related to an evaluation of the Bear Creek Reservoir. Data is presented pertaining to temperature, DO, ORP, sulfides, Managanese, and Iron, by rivermile. Information related to fish population studies taken from 46 reservoirs from the Tennessee and Cumberland River drainage basins from 1947--1983 is included.

  2. Development of the Phase I Fenton Hill HDR Reservoir. Part I, Fracture Dimension

    SciTech Connect

    Fisher, Henry N.

    1981-02-24

    Sufficient data now exists to allow a description of the general and probable growth of the Fenton Hill HDR reservoir. The reservoir discussed here is that associated with the original EE-1 to GT-2B connection (Phase I, Segments 2 and 3) and the EE-1 to GT-2B connection after the recementing of the EE-1 casing (Phase I, Segments 4 and 5). Many aspects of the reservoir development are discussed in Refs. 1 through 3. Here the growth and general characteristics of the reservoir are discussed in terms of the general aspects of the pressure transient, tracer, and temperature measurements.

  3. Fully analogue photonic reservoir computer.

    PubMed

    Duport, François; Smerieri, Anteo; Akrout, Akram; Haelterman, Marc; Massar, Serge

    2016-01-01

    Introduced a decade ago, reservoir computing is an efficient approach for signal processing. State of the art capabilities have already been demonstrated with both computer simulations and physical implementations. If photonic reservoir computing appears to be promising a solution for ultrafast nontrivial computing, all the implementations presented up to now require digital pre or post processing, which prevents them from exploiting their full potential, in particular in terms of processing speed. We address here the possibility to get rid simultaneously of both digital pre and post processing. The standalone fully analogue reservoir computer resulting from our endeavour is compared to previous experiments and only exhibits rather limited degradation of performances. Our experiment constitutes a proof of concept for standalone physical reservoir computers. PMID:26935166

  4. Reservoir evaporation in Texas, USA

    NASA Astrophysics Data System (ADS)

    Wurbs, Ralph A.; Ayala, Rolando A.

    2014-03-01

    The role of reservoir surface evaporation in river/reservoir water budgets and water management is explored using a modeling system that combines historical natural hydrology with current conditions of water resources development and management. The long-term mean evaporation from the 3415 reservoirs in the Texas water rights permit system is estimated to be 7.53 billion m3/year, which is equivalent to 61% of total agricultural or 126% of total municipal water use in the state during the year 2010. Evaporation varies with the hydrologic conditions governing reservoir surface areas and evaporation rates. Annual statewide total evaporation volumes associated with exceedance probabilities of 75%, 50%, and 25% are 7.07, 7.47, and 7.95 billion m3/year, respectively. Impacts of evaporation are greatest during extended severe droughts that govern water supply capabilities.

  5. Trends in reservoir performance prediction

    SciTech Connect

    Mackenzie, A.S.

    1994-12-31

    Stronger links between geoscience and petroleum engineering are being fostered by new tools and organizations. These linkages are improving the effectiveness of business decisions concerning reservoir performance, and are generating new challenges for the next generation of tools.

  6. Fully analogue photonic reservoir computer

    PubMed Central

    Duport, François; Smerieri, Anteo; Akrout, Akram; Haelterman, Marc; Massar, Serge

    2016-01-01

    Introduced a decade ago, reservoir computing is an efficient approach for signal processing. State of the art capabilities have already been demonstrated with both computer simulations and physical implementations. If photonic reservoir computing appears to be promising a solution for ultrafast nontrivial computing, all the implementations presented up to now require digital pre or post processing, which prevents them from exploiting their full potential, in particular in terms of processing speed. We address here the possibility to get rid simultaneously of both digital pre and post processing. The standalone fully analogue reservoir computer resulting from our endeavour is compared to previous experiments and only exhibits rather limited degradation of performances. Our experiment constitutes a proof of concept for standalone physical reservoir computers. PMID:26935166

  7. Climate variability, soil conservation, and reservoir sedimentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rivers carry sediments which, upon entering a reservoir, settle to the bottom. The process of deposition and gradual accumulation of sediments in the reservoir is referred to as reservoir sedimentation. As reservoir sedimentation progresses, the storage capacity allocated for sediment deposition wil...

  8. Permeability of naturally fractured reservoirs

    SciTech Connect

    Teufel, L.W. )

    1991-03-01

    Hydraulic fracture stress data collected from carbonate and clastic reservoirs show that the minimum horizontal in situ stress decreases with reservoir depletion and pore pressure drawdown. The reduction in minimum horizontal stress is, in part, a poro-elastic effect that is linear with pore pressure drawdown and can be approximated by an unlaxial compaction model. The observed change in horizontal stress is equal to 40% to 80% of the net change in pore pressure. This type of stress behavior has important implications for reservoir management of naturally fractured reservoirs, because conductivity of fractures is highly stress sensitive. Laboratory studies clearly demonstrate that with increasing effective normal stress fracture apertures close and conductivity decreases. Accordingly, in sharp contrast to the standard procedure, predictions of changes in fracture permeability during reservoir depletion should not be made simply as a function of pore pressure drawdown, but more importantly should be based on how the effective in situ stresses change during drawdown and the orientation of natural fractures relative to the in situ stress field. The increase in the effective overburden stress will be the largest and equal to the magnitude of the pore pressure decline because the overburden stress is constant and does not change with drawdown. However, the increase in the effective minimum horizontal stress will be much smaller. Accordingly, for a reservoir with several sets of fractures with similar morphology, the reduction in fracture conductivity during drawdown will be greatest for horizontal fractures and least for vertical fractures aligned with the maximum horizontal stress direction.

  9. Capacity sharing of water reservoirs

    NASA Astrophysics Data System (ADS)

    Dudley, Norman J.; Musgrave, Warren F.

    1988-05-01

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

  10. Chickamauga reservoir embayment study - 1990

    SciTech Connect

    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.

  11. Petroleum reservoir data for testing simulation models

    SciTech Connect

    Lloyd, J.M.; Harrison, W.

    1980-09-01

    This report consists of reservoir pressure and production data for 25 petroleum reservoirs. Included are 5 data sets for single-phase (liquid) reservoirs, 1 data set for a single-phase (liquid) reservoir with pressure maintenance, 13 data sets for two-phase (liquid/gas) reservoirs and 6 for two-phase reservoirs with pressure maintenance. Also given are ancillary data for each reservoir that could be of value in the development and validation of simulation models. A bibliography is included that lists the publications from which the data were obtained.

  12. Reservoir characterization of Pennsylvanian Sandstone Reservoirs. Annual report

    SciTech Connect

    Kelkar, M.

    1992-09-01

    This annual report describes the progress during the second year of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description and scale-up procedures; (ii) outcrop investigation; (iii) in-fill drilling potential. The first section describes the methods by which a reservoir can be characterized, can be described in three dimensions, and can be scaled up with respect to its properties, appropriate for simulation purposes. The second section describes the progress on investigation of an outcrop. The outcrop is an analog of Bartlesville Sandstone. We have drilled ten wells behind the outcrop and collected extensive log and core data. The cores have been slabbed, photographed and the several plugs have been taken. In addition, minipermeameter is used to measure permeabilities on the core surface at six inch intervals. The plugs have been analyzed for the permeability and porosity values. The variations in property values will be tied to the geological descriptions as well as the subsurface data collected from the Glen Pool field. The third section discusses the application of geostatistical techniques to infer in-fill well locations. The geostatistical technique used is the simulated annealing technique because of its flexibility. One of the important reservoir data is the production data. Use of production data will allow us to define the reservoir continuities, which may in turn, determine the in-fill well locations. The proposed technique allows us to incorporate some of the production data as constraints in the reservoir descriptions. The technique has been validated by comparing the results with numerical simulations.

  13. Visualizing the Entropy Change of a Thermal Reservoir

    ERIC Educational Resources Information Center

    Langbeheim, Elon; Safran, Samuel A.; Yerushalmi, Edit

    2014-01-01

    When a system exchanges energy with a constant-temperature environment, the entropy of the surroundings changes. A lattice model of a fluid thermal reservoir can provide a visualization of the microscopic changes that occur in the surroundings upon energy transfer from the system. This model can be used to clarify the consistency of phenomena such…

  14. Remotely sensed small reservoir monitoring

    NASA Astrophysics Data System (ADS)

    Eilander, Dirk; Annor, Frank; Iannini, Lorenzo; van de Giesen, Nick

    2013-04-01

    A new 'growing' maximum likelihood classification algorithm for small reservoir delineation has been developed and is tested with Radarsat-2 data for reservoirs in the semi-arid Upper East Region, Ghana. The delineation algorithm is able to find the land-water boundary from SAR imagery for different weather and environmental conditions. As such, the algorithm allows for remote sensed operational monitoring of small reservoirs. Multipurpose small reservoirs (1-100 ha) are important for many livelihoods in rural semi-arid West Africa. In order 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 fluctuation. Several studies on remotely sensed reservoir mapping have recently been published, but no single method yields good results for all weather and environmental conditions. Detection of small reservoirs from optical satellite imagery using supervised maximum likelihood classification is a well proved method. The application of this method for the monitoring of small reservoirs is however limited because of its dependence on cloud-free day-acquisitions. Delineation from SAR images is promising, but because of difficulties with wind induced Bragg-scattering and low contrast between the water surface and the dried-out surroundings at the end of the dry season, only quasi manual methods have been applied successfully. A smart combination of optical satellite based detection combined with a delineation method for SAR imagery is proposed. From the optical satellite based small reservoir detection the reservoir window is determined in which the 'growing' maximum likelihood classification on SAR images is performed. A water-class seed and land-class seed are implemented and grown dependent on the likelihood of a pixel to belong to one class. The likelihood is calculated based on the probability distributions of the growing land and water populations. Combinations of single

  15. Operation of TVA reservoirs. Annual 1979

    SciTech Connect

    Not Available

    1982-04-01

    Data for 1979 on the operation of TVA reservoirs for flood control, power generation and navigational purposes are reported. The operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1979 is described. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army, Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir, operated by Carolina Power and Light Company; and Woods Reservoir, operated by the US Air Force. Any reference in this report to all reservoirs in the Tennessee or Cumberland River Basins refer to these specific reservoirs. Tabulated data are included on: reservation elevation and storage volume; turbine and gate discharges; and head water elevation. (LCL)

  16. Potential methane reservoirs beneath Antarctica.

    PubMed

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

    2012-08-30

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage. PMID:22932387

  17. Climate-water quality relationships in Texas reservoirs

    USGS Publications Warehouse

    Gelca, Rodica; Hayhoe, Katharine; Scott-Fleming, Ian; Crow, Caleb; Dawson, D.; Patino, Reynaldo

    2015-01-01

    Water temperature, dissolved oxygen, and concentrations of salts in surface water bodies can be affected by the natural environment, local human activities such as surface and ground water withdrawals, land use, and energy extraction, and variability and long-term trends in atmospheric conditions including temperature and precipitation. Here, we quantify the relationship between 121 indicators of mean and extreme temperature and precipitation and 24 water quality parameters in 57 Texas reservoirs using observational data records covering the period 1960 to 2010. We find that water temperature, dissolved oxygen, pH, specific conductance, chloride, sulfate, and phosphorus all show consistent correlations with atmospheric predictors, including high and low temperature extremes, dry days, heavy precipitation events, and mean temperature and precipitation over time scales ranging from one week to two years. Based on this analysis and published future projections for this region, we expect climate change to increase water temperatures, decrease dissolved oxygen levels, decrease pH, increase specific conductance, and increase levels of sulfate, chloride in Texas reservoirs. Over decadal time scales, this may affect aquatic ecosystems in the reservoirs, including altering the risk of conditions conducive to algae occurrence, as well as affecting the quality of water available for human consumption and recreation.

  18. Water resources review: Chatuge Reservoir, 1991

    SciTech Connect

    Cox, J.; Wallus, R.

    1992-06-01

    TVA is preparing a series of reports that provide technical information on the characteristics and uses of individual TVA reservoirs. These reports present a summary of (1) reservoir purpose and operation; (2) physical characteristics of the reservoir and the watershed; (3) water quality conditions; (4) aquatic biological conditions; and (5) designated, actual, and potential uses of the reservoir and impairments of those uses. This report is for Chatuge Reservoir.

  19. The Quality of Water and Bottom Material in Lunga Reservoir, Virginia, September 2004 through August 2005

    USGS Publications Warehouse

    Lotspeich, R. Russell

    2007-01-01

    Lunga Reservoir is on the U.S. Marine Corps Base in Quantico, which is in the Potomac River basin and the Piedmont Physiographic Province of northern Virginia. Because of the potential use of the reservoir for scuba-diver training and public water supply in addition to current recreational activities, the U.S. Marine Corps wanted to know more about the water quality of Lunga Reservoir and how it compared to Virginia Department of Environmental Quality and Virginia State Water Control Board ambient water-quality standards. Water samples and physical properties were collected by the U.S. Geological Survey at 6 locations throughout Lunga Reservoir, and physical properties were collected at 11 additional locations in the reservoir from September 2004 through August 2005. Water samples for analysis of pesticides and bottom-material trace elements were collected once during the study at four of the sampling locations. Water temperature, dissolved-oxygen concentration, specific conductance, pH, and total chlorophyll concentration in Lunga Reservoir all had similar seasonal and spatial variations as in other lakes and reservoirs in this geographic region - thermal gradient in the summer and fall and isothermal conditions in the winter and early spring. Concentrations of water-quality indicators in Lunga Reservoir were within comparable levels of those in other reservoirs and did not violate the Virginia State Water Control Board standards for public water supplies. Water temperatures throughout Lunga Reservoir during the study period ranged from 4.4 to 30.1 degrees Celsius, well below the State Water Control Board maximum water temperature criteria of 32 degrees Celsius. Dissolved-oxygen concentrations ranged from 0.05 to 14.1 milligrams per liter throughout the reservoir during the study period, but never fell below the State Water Control Board minimum dissolved-oxygen criterion of 4.0 milligrams per liter at the surface of Lunga Reservoir. Specific conductance

  20. Multiple Reservoirs in the Mofete Field, Naples, Italy

    SciTech Connect

    Carella, R.; Guglielminetti, M.

    1983-12-15

    Mofete field, located near Naples, in southern Italy, lies within the large Campi Flegrei caldera. Drilling for geothermal fluids was carried out unsuccessfully in 1939-1954. AGIP, in joint venture with the national utility ENEL, after intensive exploration efforts, resumed drilling at the end of 1978; several new deep wells indicate the presence of a water dominated field in Mofete with three reservoirs (only the shallowest of which was reached by previous wells). The deepest aquifer, tapped by well Mofete 5 at the depth of about 2700 m, contains hypersaline fluids (about 516000 ppm TDS at atmospheric conditions corresponding to about 150000 ppm in the reservoir) with a bottom hole temperature of about 360{degrees}C. The intermediate level, reached by well Mofete 2 at 1900 m depth, is characterized by low salinity fluids (about 38000 ppm TDS at the surface corresponding to 18000 ppm calculated in the reservoir) with a reservoir temperature of 340{degrees}C. The uppermost reservoir, tapped by wells Mofete 1, 3D, 7D, 8D and 9D ranges between 550 and 1500 m depth and has water with salinity ranging from 40000 to 76000 ppm TDS at the surface corresponding to 28000 to 52000 ppm in the reservoir with a bottom temperature of 230-308{degrees}C. The uppermost aqifer is in fractured volcanic rocks while the other two are in a metamorphosed volcano-sedimentary complex. Long term production and injection tests will be carried out shortly to ascertain the main characteristics of the field.

  1. Hatch Timing Variations Among Reservoir Gizzard Shad Populations: Implications for Stocked Sander spp. Fingerlings

    USGS Publications Warehouse

    Zweifela, Richard D.; Bunnell, David B.; Bremiganc, Mary T.; Hale, R. Scott

    2009-01-01

    Growth and survival of stocked Sander spp. fingerlings can be influenced by timing of stocking in relation to the peak in density of larval gizzard shad Dorosoma cepedianum. However, coordinating stockings to coincide with peaks in gizzard shad density is difficult due to temporal variation in spawn timing among reservoirs. We used weekly estimates of larval gizzard shad density and length distributions to identify dates of peak hatching and peak total density in Ohio reservoirs and to explore the influence of spring water temperature regimes on timing of peak larval density. Gizzard shad density peaked over 21–32 d among reservoirs but generally varied by 12 d or less among years for any given population. Density peaks were driven by hatching, as larvae smaller than 10 mm accounted for a majority of the gizzard shad collected on the peak date. Peaks in gizzard shad density corresponded to water temperatures of 17–22°C and occurred most frequently when water temperatures had been stable or rising. Reservoirs in the southern portion of the state were 2–5°C warmer than northern reservoirs throughout the spring; thus, gizzard shad spawning and date of peak larval density were earliest in southern reservoirs and became progressively later for populations in more northerly reservoirs. Historical stocking dates for fingerling walleyes S. vitreus and saugeyes (sauger S. canadensis × walleye) in Ohio reservoirs indicated that southern reservoirs were often stocked after the expected peak in gizzard shad density and northern reservoirs were stocked before the peak. A statewide approach to stocking that incorporates latitudinal variations in gizzard shad hatch timing whereby southern reservoirs are stocked earliest would better align stockings with peak gizzard shad density, potentially improving survival of fingerling walleyes and saugeyes.

  2. In situ heat transfer in man-made geothermal energy reservoirs

    SciTech Connect

    Murphy, H.D.; Tester, J.W.; Grigsby, C.O.; Potter, R.M.

    1980-01-01

    Two hot dry rock geothermal energy reservoirs were created by hydraulic fracturing of Precambrian granitic rock on the west flank of the Valles Caldera, a dormant volcanic complex, in the Jemez Mountains of northern New Mexico. Heat was extracted in a closed-loop mode of operation, injecting water into one well and extracting the heated water from a separate production well. The first reservoir was produced by fracturing the injection well at a depth of 2.75 km (9020 ft) where the indigenous rock temperature was 185/sup 0/C. The relatively rapid thermal drawdown of the water produced from the first reservoir, 100/sup 0/C in 74 days, indicated that its effective fracture radius was about 60 m (200 ft). Average thermal power extracted was 4 MW. A second, larger reservoir was created by refracturing the injection well 180 m (600 ft) deeper. Downhole measurements of the water temperature at the reservoir outlet as well as temperatures inferred from chemical geothermometry showed that the thermal drawdown of this reservoir was negligible; the effective heat transfer area of the new reservoir must be at least 45,000 m/sup 2/ (480,000 ft/sup 2/), nearly six times larger than the first reservoir. In addition reservoir residence time studies employing visible dye tracers indicated that the mean volume of the second reservoir is nine times larger. Other measurements showed that flow impedances were low, downhole water losses from these reservoirs should be manageable, that the geochemistry of the produced water was essentially benign, with no scaling problems apparent, and that the level of induced seismic activity was insignificantly small.

  3. Cross well seismic reservoir characterization

    SciTech Connect

    Sheline, H.E.

    1995-08-01

    A striking example of how Cross Well Seismic reflection data can help characterize a reservoir, has resulted from an ongoing Multi-Discipline study of the carbonate Mishrif reservoir offshore Dubai, U.A.E. Because the study objectives include a more detailed description of intra reservoir structure and layering, Dubai Petroleum Company (DPC) analyzed the feasibility of Cross Well Seismic (CWS) and decided to acquire two surveys between three wells 337 to 523 feet apart. DPC has concluded that CWS can be cost effectively acquired offshore, in a Carbonate reservoir; as well as processed and interpreted. However, generally it is not often easy to acquire cross well seismic when and where it will be most useful. A CWS survey can provide multiple images such as a velocity Tomogram, P-wave reflections, and S-wave reflections. To date, Tomograms and P-wave reflections have been produced, and the reflection data has proven to be the most useful for reservoir characterization. Cross Well Seismic Reflection data have provided a level of vertical seismic reflection resolution of around 2 feet, which is more than 10 times better than surface seismic data (2D or 3D). The increase in vertical resolution has provided important detailed information about the reservoir, it`s continuity/heterogeneity; it`s detailed structure, stratigraphy and layering; and definition of any faults with more than 2 feet of offset. The CWS has shown detailed intra Mishrif reflectors. These reflectors have verified or changed detailed correlations between well bores, and show significant intra Mishrif thinning. These reflectors imply time stratigraphic layering which is consistent with tracer study results and regional sequence stratigraphy. This new data will be used to improve the reservoir model description.

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

    USGS Publications Warehouse

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

    2011-01-01

    temperature, reservoir storage, reservoir elevation, specific conductance, dissolved oxygen, pH, unfiltered salinity, unfiltered total nitrogen, filtered total nitrogen, unfiltered nitrate plus nitrite, unfiltered phosphorus, filtered phosphorus, unfiltered carbon, carbon in suspended sediment, total hardness, unfiltered noncarbonate hardness, filtered noncarbonate hardness, unfiltered calcium, filtered calcium, unfiltered magnesium, filtered magnesium, unfiltered sodium, filtered sodium, unfiltered potassium, filtered potassium, filtered chloride, filtered sulfate, unfiltered fluoride, and filtered fluoride. When possible, USGS and Texas Commission on Environmental Quality water-quality properties and constituents were matched using the database parameter codes for individual physical properties and constituents, descriptions of each physical property or constituent, and their reporting units. This report presents a collection of delimited text files of source-aggregated, spatially pooled, depth-dependent, instantaneous water-quality data as well as instantaneous, daily, and monthly storage and elevation reservoir data.

  5. Quality of water and bottom material in Breckenridge Reservoir, Virginia, September 2008 through August 2009

    USGS Publications Warehouse

    Lotspeich, Russell

    2012-01-01

    Breckenridge Reservoir is located within the U.S. Marine Corps Base in Quantico, which is in the Potomac River basin and the Piedmont Physiographic Province of northern Virginia. Because it serves as the principal water supply for the U.S. Marine Corps Base in Quantico, an assessment of the water-quality of Breckenridge Reservoir was initiated. Water samples were collected and physical properties were measured by the U.S. Geological Survey at three sites in Breckenridge Reservoir, and physical properties were measured at six additional reservoir sites from September 2008 through August 2009. Water samples were also collected and physical properties were measured in each of the three major tributaries to Breckenridge Reservoir: North Branch Chopawamsic Creek, Middle Branch Chopawamsic Creek, and South Branch Chopawamsic Creek. One site on each tributary was sampled at least five times during the study. Monthly profiles were conducted for water temperature, dissolved-oxygen concentrations, specific conductance, pH, and turbidity measured at 2-foot intervals throughout the water column of the reservoir. These profiles were conducted at nine sites in the reservoir, and data values were measured at these sites from the water surface to the bottom of the reservoir. These profiles were conducted along three cross sections and were used to define the characteristics of the entire water column of the reservoir. The analytical results of reservoir and tributary samples collected and physical properties measured during this study were compared to ambient water-quality standards of the Virginia Department of Environmental Quality and Virginia State Water Control Board. Water temperature, dissolved-oxygen concentration, specific conductance, pH, and turbidity measured in Breckenridge Reservoir generally indicated a lack of stratification in the water column of the reservoir throughout the study period. This is unlike most other reservoirs in the region and may be influenced by

  6. Sedimentary reservoir oxidation during geologic CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Lammers, Laura N.; Brown, Gordon E.; Bird, Dennis K.; Thomas, Randal B.; Johnson, Natalie C.; Rosenbauer, Robert J.; Maher, Katharine

    2015-04-01

    Injection of carbon dioxide into subsurface geologic reservoirs during geologic carbon sequestration (GCS) introduces an oxidizing supercritical CO2 phase into a subsurface geologic environment that is typically reducing. The resulting redox disequilibrium provides the chemical potential for the reduction of CO2 to lower free energy organic species. However, redox reactions involving carbon typically require the presence of a catalyst. Iron oxide minerals, including magnetite, are known to catalyze oxidation and reduction reactions of C-bearing species. If the redox conditions in the reservoir are modified by redox transformations involving CO2, such changes could also affect mineral stability, leading to dissolution and precipitation reactions and alteration of the long-term fate of CO2 in GCS reservoirs. We present experimental evidence that reservoirs with reducing redox conditions are favorable environments for the relatively rapid abiotic reduction of CO2 to organic molecules. In these experiments, an aqueous suspension of magnetite nanoparticles was reacted with supercritical CO2 under pressure and temperature conditions relevant to GCS in sedimentary reservoirs (95-210 °C and ∼100 bars of CO2). Hydrogen production was observed in several experiments, likely caused by Fe(II) oxidation either at the surface of magnetite or in the aqueous phase. Heating of the Fe(II)-rich system resulted in elevated PH2 and conditions favorable for the reduction of CO2 to acetic acid. Implications of these results for the long-term fate of CO2 in field-scale systems were explored using reaction path modeling of CO2 injection into reservoirs containing Fe(II)-bearing primary silicate minerals, with kinetic parameters for CO2 reduction obtained experimentally. The results of these calculations suggest that the reaction of CO2 with reservoir constituents will occur in two primary stages (1) equilibration of CO2 with organic acids resulting in mineral-fluid disequilibrium, and

  7. Application of Integrated Reservoir management and Reservoir Characterization to Optimize Infill Drilling

    SciTech Connect

    B. Pregger; D. Davies; D. Moore; G. Freeman; J. Callard; J.W. Nevans; L. Doublet; R. Vessell; T. Blasingame

    1997-08-31

    Infill drilling if wells on a uniform spacing without regard to reservoir performance and characterization foes not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations.

  8. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    SciTech Connect

    1998-03-12

    Infill drilling if wells on a uniform spacing without regard to reservoir performance and characterization foes not optimize reservoir development because it fails to account for the complex nature of reservoir heterogeneities present in many low permeability reservoirs, and carbonate reservoirs in particular. New and emerging technologies, such as geostatistical modeling, rigorous decline curve analysis, reservoir rock typing, and special core analysis can be used to develop a 3-D simulation model for prediction of infill locations.

  9. Thermoelastic properties of the Rotokawa Andesite: A geothermal reservoir constraint

    NASA Astrophysics Data System (ADS)

    Siratovich, P. A.; von Aulock, F. W.; Lavallée, Y.; Cole, J. W.; Kennedy, B. M.; Villeneuve, M. C.

    2015-08-01

    Knowledge of the thermal properties of geothermal reservoir rocks is essential to constraining important engineering concerns such as wellbore stability, reservoir forecasting and stimulation procedures. The thermo-mechanical evolution of geological material is also important to assess when considering natural processes such as magmatic dyke propagation, contact metamorphism and magma/lava emplacement and cooling effects. To better constrain these properties in the geothermal reservoir, thermal measurements were carried out on core samples from production wells drilled in the Rotokawa Andesite geothermal reservoir, located in the Taupo Volcanic Zone, New Zealand. Linear thermal expansion testing, thermogravimetric analysis, and differential scanning calorimetry were used, employing experimental heating rates of 2, 5 and 20 °C/min. Thermal property analyses can elucidate whether thermal expansion values measured under varied heating (and cooling) rates are rate dependent and if thermo-chemical reactions influence the resultant expansivity. Measured thermal expansion coefficients of the Rotokawa Andesite are shown not to be heating rate dependent. We have also found that significant thermochemical reactions occur during heating above 500 °C resulting in non-reversible changes to the thermomechanical properties. The combined thermogravimetric, calorimetric and thermomechanical analysis allows insight to the reactions occurring and how the thermomechanical properties are affected at high temperature. We incorporated results of tensile strength testing on the Rotokawa Andesite to apply our thermal property measurements to a one-dimensional thermal stress model. The developed model provides a failure criterion for the Rotokawa Andesite under thermal stress. The importance of this study is to further understand the critical heating and cooling rates at which thermal stress may cause cracking within the Rotokawa reservoir. Thermal cracking in the reservoir can be

  10. Maximum ecological potential of tropical reservoirs and benthic invertebrate communities.

    PubMed

    Molozzi, Joseline; Feio, Maria João; Salas, Fuensanta; Marques, João Carlos; Callisto, Marcos

    2013-08-01

    The Reference Condition Approach (RCA) is now widely adopted as a basis for the evaluation of the ecological quality of water bodies. In accordance with the RCA, the integrity of communities found in a given location should be analyzed according to their deviation from the communities that would be expected in the absence of anthropogenic disturbances. The RCA was used here with the aim of defining the Maximum Ecological Potential (MEP) of tropical reservoirs located in the hydrographical basin of the Paraopeba River in the state of Minas Gerais, Brazil. Among the reservoirs, Serra Azul is used as a water supply and is located in a core area of environmental protection where tourism is not allowed and the native vegetation is conserved. The benthic macroinvertebrate communities at 90 sites located in three reservoirs were analyzed and sampled every 3 months over 2 years. The temporal patterns of the communities in the three reservoirs were analyzed (2nd-STAGE MDS and ANOSIM) and were not significantly related to seasonal fluctuations in temperature and precipitation. Twenty-eight sites belonging to the Serra Azul reservoir were selected to define the MEP of these reservoirs because these sites had the lowest human disturbance levels. The macroinvertebrate taxa present in the selected MEP sites are similar to those of natural lakes and different from the communities of disturbed sites. The biological classification of these sites revealed two groups with distinct macroinvertebrate communities. This distinction was related to climatic variables, bottom substrate type, the presence of gravel/boulders, coarse sand, silt, clay or muck, depth, and the shoreline substrate zone. These two subsets of biological communities and respective environmental conditions can serve as a basis for the future implementation of ecological quality monitoring programs for tropical reservoirs in the study area. This approach can also, however, be implemented in other geographic areas

  11. Appalachian Basin Low-Permeability Sandstone Reservoir Characterizations

    SciTech Connect

    Ray Boswell; Susan Pool; Skip Pratt; David Matchen

    1993-04-30

    A preliminary assessment of Appalachian basin natural gas reservoirs designated as 'tight sands' by the Federal Energy Regulatory Commission (FERC) suggests that greater than 90% of the 'tight sand' resource occurs within two groups of genetically-related units; (1) the Lower Silurian Medina interval, and (2) the Upper Devonian-Lower Mississippian Acadian clastic wedge. These intervals were targeted for detailed study with the goal of producing geologic reservoir characterization data sets compatible with the Tight Gas Analysis System (TGAS: ICF Resources, Inc.) reservoir simulator. The first phase of the study, completed in September, 1991, addressed the Medina reservoirs. The second phase, concerned with the Acadian clastic wedge, was completed in October, 1992. This report is a combined and updated version of the reports submitted in association with those efforts. The Medina interval consists of numerous interfingering fluvial/deltaic sandstones that produce oil and natural gas along an arcuate belt that stretches from eastern Kentucky to western New York. Geophysical well logs from 433 wells were examined in order to determine the geologic characteristics of six separate reservoir-bearing intervals. The Acadian clastic wedge is a thick, highly-lenticular package of interfingering fluvial-deltaic sandstones, siltstones, and shales. Geologic analyses of more than 800 wells resulted in a geologic/engineering characterization of seven separate stratigraphic intervals. For both study areas, well log and other data were analyzed to determine regional reservoir distribution, reservoir thickness, lithology, porosity, water saturation, pressure and temperature. These data were mapped, evaluated, and compiled into various TGAS data sets that reflect estimates of original gas-in-place, remaining reserves, and 'tight' reserves. The maps and data produced represent the first basin-wide geologic characterization for either interval. This report outlines the methods and

  12. Reservoirs performances under climate variability: a case study

    NASA Astrophysics Data System (ADS)

    Longobardi, A.; Mautone, M.; de Luca, C.

    2014-09-01

    A case study, the Piano della Rocca dam (southern Italy) is discussed here in order to quantify the system performances under climate variability conditions. Different climate scenarios have been stochastically generated according to the tendencies in precipitation and air temperature observed during recent decades for the studied area. Climate variables have then been filtered through an ARMA model to generate, at the monthly scale, time series of reservoir inflow volumes. Controlled release has been computed considering the reservoir is operated following the standard linear operating policy (SLOP) and reservoir performances have been assessed through the calculation of reliability, resilience and vulnerability indices (Hashimoto et al. 1982), comparing current and future scenarios of climate variability. The proposed approach can be suggested as a valuable tool to mitigate the effects of moderate to severe and persistent droughts periods, through the allocation of new water resources or the planning of appropriate operational rules.

  13. Application of Integrated Reservoir Management and Reservoir Characterization to Optimize Infill Drilling

    SciTech Connect

    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

  14. Perchlorate reduction by microbes inhabiting oil reservoirs

    NASA Astrophysics Data System (ADS)

    Liebensteiner, Martin; Stams, Alfons; Lomans, Bart

    2014-05-01

    Microbial perchlorate and chlorate reduction is a unique type of anaerobic respiration as during reduction of (per)chlorate chlorite is formed, which is then split into chloride and molecular oxygen. In recent years it was demonstrated that (per)chlorate-reducing bacteria may employ oxygenase-dependent pathways for the degradation of aromatic and aliphatic hydrocarbons. These findings suggested that (per)chlorate may be used as oxygen-releasing compound in anoxic environments that contain hydrocarbons, such as polluted soil sites and oil reservoirs. We started to study perchlorate reduction by microbes possibly inhabiting oil reservoirs. One of the organisms studied was Archaeoglobus fulgidus. This extremely thermophilic archaeon is known as a major contributor to souring in hot oil reservoirs. A. fulgidus turned out to be able to use perchlorate as terminal electron acceptor for growth with lactate (Liebensteiner et al 2013). Genome based physiological experiments indicated that A. fulgidus possesses a novel perchlorate reduction pathway. Perchlorate is first reduced to chlorite, but chlorite is not split into chloride and molecular oxygen as occurs in bacteria. Rather, chlorite reacts chemically with sulfide, forming oxidized sulfur compounds, which are reduced to sulfide in the electron transport chain by the archaeon. The dependence of perchlorate reduction on sulfur compounds could be shown. The implications of our findings as novel strategy for microbiological enhanced oil recovery and for souring mitigation are discussed. Liebensteiner MG, Pinkse MWH, Schaap PJ, Stams AJM and Lomans BP (2013) Archaeal (per)chlorate reduction at high temperature, a matter of abiotic-biotic reactions. Science 340: 85-87

  15. Effects of reservoir hydrology on reproduction by largemouth bass and spotted bass in Normandy Reservoir, Tennessee

    USGS Publications Warehouse

    Sammons, S.M.; Dorsey, L.G.; Bettoli, P.W.; Fiss, F.C.

    1999-01-01

    Age-O largemouth bass Micropterus salmoides and spotted bass M. punctulatus were collected from Normandy Reservoir, Tennessee, 1992-1996, to evaluate effects of reservoir hydrology and hatching of shad Dorosoma spp. on hatching and first-year growth and survival of these two species. Fish were collected in cove rotenone samples in early August and electrofishing samples biweekly throughout the summer; hatch dates and age-specific growth for both species were determined from cove samples with sagittal otoliths. Hatching of both species ranged from early April to early June. Initiation of largemouth bass spawning, but not spotted bass spawning, was positively related to the first day water levels achieved full pool. Mean hatch dates of both species were positively related to the first day of full pool. Timing of spawning for both species was not related to water temperature, Largemouth bass exhibited bimodal length-frequency distributions by midsummer in two wet years and length frequencies were unimodal in dry years; spotted bass always formed unimodal length-frequency distributions. When largemouth bass exhibited bimodal length distributions, earlier hatched fish grew faster than later hatched fish. Spotted bass grew at similar rates, regardless of hatch date, every year except during 1992 when later hatched fish grew faster than earlier hatched fish. Weekly survival of largemouth bass in their first summer was positively related to reservoir water level. First-year growth of both species was not directly affected by the timing of threadfin shad D. petenense or gizzard shad D. cepedianum hatching.

  16. Pleasant Bayou Geopressured-Geothermal Reservoir Analysis - January 1991

    SciTech Connect

    Riney, T.D.

    1991-01-01

    Many sedimentary basins contain formations with pore fluids at pressures higher than hydrostatic value; these formations are called geopressured. The pore pressure is generally well in excess of hydrostatic and the fluids vary in scalinity, temperature, and dissolved methane. As part of its program to define the magnitude and recoverability of the geopressured-geothermal energy resource, the US Department of Energy has drilled and tested deep wells in geopressured formations in the Texas-Louisiana Gulf Coast region. Geological information for the Pleasant Bayou geopressured geothermal resource is most extensive among the reservoirs tested. Earlier testing of the DOE well (Pleasant Bayou Well No.2) was conducted in several phases during 1979-1983. Long-term testing was resumed in May 1988 and is currently in progress. This report summarizes the pertinent field and laboratory test data available through December 31, 1990. A numerical reservoir simulator is employed as a tool for synthesizing and integrating the reservoir information, formation rock and fluid properties data from laboratory tests, well data from the earlier testing (1979-1983), and the ongoing long-term production testing (1988-1990) of Pleasant Bayou Well No.2. A reservoir simulation model has been constructed which provides a detailed match to the well test history to date. This model is constructed within a geologic framework described by the Texas Bureau of Economic Geology and relies heavily on the pressure transient data from the 1980 Reservoir Limits Test in conjunction with the 1988-1990 production testing.

  17. Horizontal drilling in shallow reservoirs

    SciTech Connect

    Murray, W.F. Jr.; Schrider, L.A.; McCallister, J.V.; Mazza, R.L.

    1993-12-31

    Belden & Blake and the US DOE will cofund a horizontal well to be drilled in the Clinton Sandstone as part of the DOE`s multi well program titled ``Horizontal Drilling in Shallow Geologic Complex Reservoirs.`` This well will be located in Mahoning County, Ohio in an area which has demonstrated above average Clinton gas production. To the best of our knowledge, this will be the first horizontal well drilled to the Clinton Sand formation in Ohio. Since many of the remaining Clinton Sand drilling sites are of poorer reservoir quality, they may not be developed unless technology such as horizontal drilling can be successfully demonstrated.

  18. Lumbar reservoir for intrathecal chemotherapy.

    PubMed

    Dyck, P

    1985-06-15

    The Ommaya ventricular reservoir has been the standby of intrathecal chemotherapy for more than a decade, in spite of some specific drawbacks. A general anaesthetic is often required. The scalp must be shaven. Ventricular puncture may not always be easy and keeping the ventricular catheter patent is sometimes difficult. Hence the author has adapted a commercially available lumbar peritoneal shunt system to function as a lumbar intrathecal reservoir. The procedure is simple and can be performed expeditiously under local anaesthesia. To date, eight cases have received intrathecal chemotherapy by this means. PMID:3838918

  19. Prediction of the Fate and Transport Processes of Atrazine in a Reservoir

    NASA Astrophysics Data System (ADS)

    Chung, Se-Woong; Gu, Roy R.

    2009-07-01

    The fate and transport processes of a toxic chemical such as atrazine, an herbicide, in a reservoir are significantly influenced by hydrodynamic regimes of the reservoir. The two-dimensional (2D) laterally-integrated hydrodynamics and mass transport model, CE-QUAL-W2, was enhanced by incorporating a submodel for toxic contaminants and applied to Saylorville Reservoir, Iowa. The submodel describes the physical, chemical, and biological processes and predicts unsteady vertical and longitudinal distributions of a toxic chemical. The simulation results from the enhanced 2D reservoir model were validated by measured temperatures and atrazine concentrations in the reservoir. Although a strong thermal stratification was not identified from both observed and predicted water temperatures, the spatial variation of atrazine concentrations was largely affected by seasonal flow circulation patterns in the reservoir. In particular, the results showed the effect of flow circulation on spatial distribution of atrazine during summer months as the river flow formed an underflow within the reservoir and resulted in greater concentrations near the surface of the reservoir. Atrazine concentrations in the reservoir peaked around the end of May and early June. A good agreement between predicted and observed times and magnitudes of peak concentrations was obtained. The use of time-variable decay rates of atrazine led to more accurate prediction of atrazine concentrations, while the use of a constant half-life (60 days) over the entire period resulted in a 40% overestimation of peak concentrations. The results provide a better understanding of the fate and transport of atrazine in the reservoir and information useful in the development of reservoir operation strategies with respect to timing, amount, and depth of withdrawal.

  20. Simulations of Flow Circulations and Atrazine Concentrations in a Midwest U.S. Reservoir

    NASA Astrophysics Data System (ADS)

    Zhao, Xianggui; Gu, Roy R.; Guo, Chuling; Wang, Kui; Li, Shijie

    Atrazine is the most commonly used herbicide in the spring for pre-emergent weed control in the corn cropping area in the Midwestern United States. A frequent high level of herbicide concentrations in reservoirs is a great concern for public health and aquatic ecosystems. In this study, a two-dimensional hydrodynamics and toxic contaminant transport model was applied to Saylorville Reservoir, Iowa, USA. The model simulates physical, chemical, and biological processes and predicts unsteady vertical and longitudinal distributions of a toxic chemical. Model results were validated by measured temperatures and atrazine concentrations. Simulated flow velocities, water temperatures, and chemical concentrations demonstrated that the spatial variation of atrazine concentrations was largely affected by seasonal flow circulation patterns in the reservoir. In particular, the simulated fate and transport of atrazine showed the effect of flow circulation on spatial distribution of atrazine during summer months as the river flow formed an underflow within the reservoir and resulted in greater concentrations near the surface of the reservoir. Atrazine concentrations in the reservoir peaked around the end of May and early June. A thorough understanding of the fate and transport of atrazine in the reservoir can assist in developing operation and pollution prevention strategies with respect to timing, amount, and depth of withdrawal. The responses of atrazine transport to various boundary conditions provide useful information in assessing environmental impact of alternative upstream watershed management practices on the quality of reservoir water.

  1. Abiotic factors affecting summer distribution and movement of male paddlefish, Polyodon spathula, in a prairie reservoir

    USGS Publications Warehouse

    Paukert, C.P.; Fisher, W.L.

    2000-01-01

    Six male paddlefish, Polyodon spathula, were implanted with ultrasonic temperature-sensing transmitters and tracked during June through August 1997 to quantify effects of physicochemical conditions on their distribution and movement in Keystone Reservoir, Oklahoma. Paddlefish moved about twice as much during night than day. Movement rate of paddlefish was related to reservoir water level, inflow, and discharge from the reservoir at night; however, none of these variables was significant during the day. Location in the reservoir (distance from the dam) was negatively related to water level and positively related to inflow during day and night periods. Location in the reservoir was negatively related to discharge during the day. Paddlefish avoided the highest available water temperatures, but did not always avoid low dissolved oxygen concentrations. Paddlefish avoided the Cimarron River arm of the reservoir in summer, possibly because of high salinity. Our study demonstrates that distribution of paddlefish during summer and movement in Keystone Reservoir was influenced by physicochemical and hydrologic conditions in the system. However, biotic factors (e.g., food availability) not measured in this study may have been influenced by abiotic conditions in the reservoir.

  2. Analysis of stream-temperature variations in the Upper Delaware River Basin, New York

    USGS Publications Warehouse

    Williams, Owen O.

    1971-01-01

    The effect of climatologic conditions and reservoir releases on downstream conditions was determined by means of statistical and graphical analyses of stream-temperature variations measured in the upper Delaware River basin, May-September 1964-67. Climatologic conditions normally increase water temperatures from February through July and decrease them from August through January. Summer releases from New York City's Cannonsville Reservoir were observed to decrease water temperatures by 13?C (Celsius) in 8.1 miles and by 1?C, 55.9 miles downstream from this reservoir. Releases from New York City's Pepacton Reservoir were observed to decrease water temperatures by 11?C in 31.0 miles and between 1?-3?C in 71.0 miles downstream from this reservoir. The influence of releases from these reservoirs is dependent upon five factors: thermal stratification in the reservoir, depth at which water is withdrawn from the reservoir, rate of release, distance downstream from the reservoir, and climatologic conditions.

  3. Quantification of geologic descriptions for reservoir characterization in carbonate reservoirs

    SciTech Connect

    Lucia, F.J.; Vander Stoep, G.W. )

    1990-05-01

    Recognition that a large volume of oil remains in carbonate reservoirs at the end of primary depletion and waterflooding has prompted the reevaluation of the reserve-growth potential of many existing carbonate reservoirs. Types of numerical data required include porosity, absolute permeability, relative permeability, fluid saturation, and capillary pressure, all of which are related to the size and distribution of pore space. Rock fabrics control the size and distribution of pore space and define facies that best characterize carbonate reservoirs. Thus, the link between facies descriptions and numerical engineering data is the relationship between pore-size distribution and present carbonate rock fabric. The most effective way to convert facies descriptions into engineering parameters is by considering three basic rock-fabric categories. The first category is interparticle pore space (both intergranular and intercrystalline pore types) with pore-size distribution controlled primarily by the size and shape of grains or crystals. Grain or crystal size is the key geologic measurement and, along with porosity, provides the basis for converting geologic descriptions into values for permeability, saturation, and capillarity. The second category is separate-vug pore space, such as moldic or intraparticle pore space. Separate-vug pore space adds porosity but little permeability to the reservoir rock. The contribution to saturation and capillarity depends upon the size of the separate-vug pore space. For example, moldic separate vugs will be saturated with oil, whereas microporous grains will be saturated with water. The third category is touching-vug pore space, which is vuggy pore space that is interconnected on a reservoir scale. The engineering parameters for this category are related to three diagenetic and tectonic factors.

  4. Spatial and seasonal distribution of macroinvertebrates in high altitude reservoir (Beyler Reservoir, Turkey)

    NASA Astrophysics Data System (ADS)

    Findik, Özlem

    2013-09-01

    A highland reservoir in the West Black Sea region of Turkey which belongs to the Mediterranean climatic zone was examined. Both littoral and profundal zones were sampled from October 2009 to September 2010, to determine taxonomic composition, biodiversity and abundance of benthic invertebrates as well as the seasonal variation of these measures. A total of 35 taxa were identified, of which 12 belong to Chironomidae and 10 to Oligochaeta groups. The highest diversity and abundance of benthic macroinvertebrates were found at the littoral stations. Macroinvertebrates showed significant positive correlations with water temperature and NO2 and NO3 concentrations, and negative correlation with dissolved oxygen.

  5. Integration of seismic methods with reservoir simulation, Pikes Peak heavy oil field, Saskatchewan

    NASA Astrophysics Data System (ADS)

    Zou, Ying

    The Pikes Peak heavy oil field has been operated by Husky Energy Ltd since 1981. Steam injection has been successfully employed to increase production. Efforts in geophysics and reservoir engineering have been made to improve interpretations in the mapping of reservoir conditions. This dissertation developed tools and a working flow for integrating the analysis of time-lapse seismic surveys with reservoir simulation, and applied them to the Pikes Peak field. Two time-lapse 2D seismic lines acquired in February 1991 and March 2000 in the eastern part of the field were carefully processed to produce wavelet and structure matched final sections. Reservoir simulation based on the field reservoir production history was carried out. It provided independent complementary information for the time-lapse seismic analysis. A rock physics procedure based on Gassmann's equation and Batzle and Wang's empirical relationship successfully linked the reservoir engineering to the seismic method. Based on the resultant seismic models, synthetic seismic sections were generated as the analogy of field seismic sections. The integrated interpretation for the Pikes Peak reservoir drew the following conclusions: The areas with a gas saturation difference, between two compared time steps, have seismic differences. Thicker gas zones correspond with large reflectivity changes on the top of the reservoir and larger traveltime delays in the seismic section. The thin gas zones only induce large reflectivity changes on the top of the reservoir, and do not have large time delays below the reservoir zone. High temperature regions also correlate with areas having large seismic energy differences. High temperature with thick gas (steam and methane) zones may be evidence for steam existence. The seismic differences at locations far from the production zone are due to the lower pressure that causes solution gas to evolve from the oil. Pressure changes propagate much faster (˜20 m in one month) than

  6. Glacial isostasy - possible tilting of petroleum reservoirs

    NASA Astrophysics Data System (ADS)

    Fjeldskaar, Willy; Amantov, Aleksey

    2015-04-01

    Scandinavia has experienced major uplift after the last ice age. The rate of uplift along the coasts is so high that its effects have been observed within one generation. Glaciers, sediments and erosion act as loads on the Earth's surface - positive or negative. When a load is applied to the lithosphere covering the asthenosphere, part of the applied load will be supported by the elastic stiffness of the lithosphere, and part by the buoyant forces of the asthenosphere. This process is called isostasy, and the rebound over the last thousands of years has revealed how the Earth reacts to loads. Prior to the last glaciation, northern Europe has experienced more than 30 glaciations. Glacial erosion and repeated ice loading over the last millions of years has significantly influenced the temperature history of sedimentary basins, and associated hydrocarbon maturation in potential source rocks. In addition, repeated loading of glaciers leads to an isostatic response of the lithosphere, which may cause tilting of potential reservoirs, and possible remigration of hydrocarbons. The effects of glaciations are assumed to have caused parts of the accumulation in the Johan Sverdrup field (Utsira High) due to changed migration pathways. Glacial isostasy will lead to tilting of potential reservoirs on the entire Norwegian Continental Shelf. In the western Barents Sea and offshore mid Norway the tilts could exceed 4 m/km, dipping towards east during the glaciations.

  7. Reservoir engineering in microwave cavity optomechanics

    NASA Astrophysics Data System (ADS)

    Lecocq, Florent; Clark, Jeremy; Aumentado, Jose; Simmonds, Raymond; Teufel, John

    2015-03-01

    Microwave cavity optomechanics is an architecture in which a freely suspended membrane modulates the frequency of a superconducting microwave resonant circuit. The resulting parametric interactions influence both the mechanical degree of freedom and the microwave light emerging from the cavity. Even at cryogenic temperatures, the mechanical oscillator resonating at 10 MHz is typically dominated by its thermal reservoir, washing out any quantum behavior. However, in the presence of coherent drives to the cavity, the bare mechanical properties can be overwhelmed by the strong opto-mechanical interactions from the light field. By choosing wisely the frequency and amplitude of the drives, one can engineer the environment seen by the mechanical oscillator, a technique known as ``reservoir engineering''. From an experimentalist point of view, I will discuss how using two-tone driving schemes, we exploit correlations in the vacuum noise to: (1) eliminate the backaction imparted on the mechanical quadrature being measured, a technique so-called Back-Action Evasion, or (2) strongly couple the mechanical mode to a squeezed microwave bath.

  8. Comparison of thermal cooldown estimates in the Russkie Komarovtsy petrogeothermal reservoir

    SciTech Connect

    Kruger, Paul; Dyadkin, Yuri; Gendler, Semon; Artemieva, Elena; Smirnova, Nina

    1991-01-01

    A comparison of several models to estimate the rate of thermal cooldown in artificial circulation geothermal reservoirs was made for the Russkie Komarovtsy fracture-stimulated reservoir, which will be located near the town of Uzhgorod in the Zakarpate region of the Ukraine SSR. The economic viability of this moderate-temperature resource depends on sustained flow above the minimum abandonment temperature for a period sufficient to recover investment and operating costs. The rate of heat extraction for the required flowrate depends on the fracture distribution in the reservoir. Results of the SGP 1-D Heat Sweep model are compared to approximate analytical and numerical models developed at the Leningrad Mining Institute, based on a common set of initial conditions for the Russkie Komarovtsy reservoir. The comparison shows that all of the models yielded reasonably similar thermal decline estimates with a satisfactory lifetime of about 25 years to abandonment temperature.

  9. Unconventional Reservoirs: Ideas to Commercialization

    NASA Astrophysics Data System (ADS)

    Tinker, S. W.

    2015-12-01

    There is no shortage of coal, oil, and natural gas in the world. What are sometimes in short supply are fresh ideas. Scientific innovation combined with continued advances in drilling and completion technology revitalized the natural gas industry in North America by making production from shale economic. Similar advances are now happening in shale oil. The convergence of ideas and technology has created a commercial environment in which unconventional reservoirs could supply natural gas to the North American consumer for 50 years or more. And, although not as far along in terms of resource development, oil from the Eagle Ford and Bakken Shales and the oil sands in Alberta could have a similar impact. Without advanced horizontal drilling, geosteering, staged hydraulic-fracture stimulation, synthetic and natural proppants, evolution of hydraulic fluid chemistry, and high-end monitoring and simulation, many of these plays would not exist. Yet drilling and completion technology cannot stand alone. Also required for success are creative thinking, favorable economics, and a tolerance for risk by operators. Current understanding and completion practices will leave upwards of 80% of oil and natural gas in the shale reservoirs. The opportunity to enhance recovery through advanced reservoir understanding and imaging, as well as through recompletions and infill drilling, is considerable. The path from ideas to commercialization will continue to provide economic results in unconventional reservoirs.

  10. Prevention of Reservoir Interior Discoloration

    SciTech Connect

    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.

  11. Nitrifying Bacteria in Wastewater Reservoirs

    PubMed Central

    Abeliovich, Aharon

    1987-01-01

    Deep wastewater reservoirs are used throughout Israel to store domestic wastewater effluents for summer irrigation. These effluents contain high concentrations of ammonia (≤5 mM) that are frequently toxic to photosynthetic microorganisms and that lead to development of anoxic conditions. Population dynamics of nitrifying bacteria and rates of nitrification were studied in two wastewater reservoirs that differed in organic load and degree of oxygenation and in the laboratory under controlled conditions, both by serial dilutions in mineral medium and microscopically with fluorescein isothiocyanate-conjugated antibodies prepared against local isolates. The difference in counts by the two methods was within 1 order of magnitude. In the laboratory, an O2 concentration of 0.2 mg liter−1 was close to optimal with respect to growth of NH3 oxidizers on domestic wastewater, while O2 concentrations of 0.05 mg liter−1 supported significant rates of nitrification. It was found that even hypertrophic anaerobic environments such as the anaerobic hypolimnion of the wastewater reservoir or the anaerobic settling ponds are capable of sustaining a viable, although not actively nitrifying, population of Nitrosomonas spp. and Nitrobacter spp., in contrast to their rapid decline when maintained anaerobically in mineral medium in the laboratory. Nitrification rates of NH3 in effluents during storage in the reservoirs were slower by 1 to 2 orders of magnitude compared with corresponding rates in water samples brought to the laboratory. The factors causing this inhibition were not identified. PMID:16347319

  12. Assessment Framework for Sustainable Reservoir Planning

    NASA Astrophysics Data System (ADS)

    Tsao, J.; Lien, W.; Tung, C.

    2011-12-01

    Reservoirs are one of the most important sources of water in Taiwan. This study constructs a framework for assessing the sustainability of reservoirs. This framework identifies key issues that affect reservoir planning and operation, and provides a tool for supporting decision-making. This study also contributes to the planning of sustainable reservoirs. It develops a framework for assessing sustainable reservoirs and establishes standard processes for evaluating the sustainability of a reservoir. Not only are the indexes of the sustainability of reservoirs identified but also information concerning economic development and social impact is methodically obtained. The assessment framework and indexes are established through an expert forum, and then used to a case study to demonstrate their feasibility. Finally, the framework provides a foundation for decision making of the renovation and development of reservoirs.

  13. Scaling minerals from deep-seated granitic geothermal reservoir

    NASA Astrophysics Data System (ADS)

    Yanagisawa, Norio

    2016-04-01

    To promote geothermal energy use and sustainable production, the information of scaling situation from deep-seated geothermal reservoir is important. In Japan, at the Kakkonda geothermal field, Iwate prefecture, north-eastern of Japan, there is 80MW geothermal power plant using about 300 degree C fluid from the reservoir at the boundary between Quaternary Kakkonda granite and Pre-Tertiary formations about 3km depth and more deep-seated reservoir survey was carried out by NEDO. Then, to understand the mechanism of deep-seated reservoir, we survey the metal sulphide minerals deposited at production wellhead and pipeline and compare with the brine And the brine of WD-1a at 3.7km depth, into Quaternary Kakkonda granite rock. In Kakkonda geothermal system, the scales are classified into two types based on sulphide mineralogy, which are Pb-Zn rich type and Cu rich type. Pb-Zn rich scales, for example galena (PbS) and Sphalerite (ZnS), are found in Well-19 located at the marginal part of the Kakkonda granite And Cu-rich scales, for example chalcocite (Cu2S), loellingite (FeAs2) and native antimony (Sb), are found in Well-13, located at the central part of the Kakkonda granite. And the brine of WD-1a at 3.7km depth about 500 degree C, into Quaternary Kakkonda granite rock near Well-19 is rich in Pb and Zn and similar composition as the Well-19 scale. Therefore, deep reservoir of Kakkonda field evolves with mixing the fluid of shallow reservoir and the brine of occurred in the Quaternary Kakkonda granite. Then, the existence of both Pb-Zn rich scale and Cu rich scale is a characteristic feature of Kakkonda geothermal and this fact suggest to have similar zoning as found in Porphyry Copper Zoning. On progress of production the fluids from deep reservoir continue to be suffered by the fluid of shallow reservoir and meteoritic water. With temperature of production well decreasing and chemical composition changed, silica precipitation decreased and the metal sulfide mineral

  14. Gas condensate reservoir characterisation for CO2 geological storage

    NASA Astrophysics Data System (ADS)

    Ivakhnenko, A. P.

    2012-04-01

    During oil and gas production hydrocarbon recovery efficiency is significantly increased by injecting miscible CO2 gas in order to displace hydrocarbons towards producing wells. This process of enhanced oil recovery (EOR) might be used for the total CO2 storage after complete hydrocarbon reservoir depletion. This kind of potential storage sites was selected for detailed studies, including generalised development study to investigate the applicability of CO2 for storages. The study is focused on compositional modelling to predict the miscibility pressures. We consider depleted gas condensate field in Kazakhstan as important target for CO2 storage and EOR. This reservoir being depleted below the dew point leads to retrograde condensate formed in the pore system. CO2 injection in the depleted gas condensate reservoirs may allow enhanced gas recovery by reservoir pressurisation and liquid re-vaporisation. In addition a number of geological and petrophysical parameters should satisfy storage requirements. Studied carbonate gas condensate and oil field has strong seal, good petrophysical parameters and already proven successful containment CO2 and sour gas in high pressure and high temperature (HPHT) conditions. The reservoir is isolated Lower Permian and Carboniferous carbonate platform covering an area of about 30 km. The reservoir contains a gas column about 1.5 km thick. Importantly, the strong massive sealing consists of the salt and shale seal. Sour gas that filled in the oil-saturated shale had an active role to form strong sealing. Two-stage hydrocarbon saturation of oil and later gas within the seal frame were accompanied by bitumen precipitation in shales forming a perfect additional seal. Field hydrocarbon production began three decades ago maintaining a strategy in full replacement of gas in order to maintain pressure of the reservoir above the dew point. This was partially due to the sour nature of the gas with CO2 content over 5%. Our models and

  15. Modeling Permeability Alteration in Diatomite Reservoirs During Steam Drive, SUPRI TR-113

    SciTech Connect

    Bhat, Suniti Kumar; Kovscek, Anthony R.

    1999-08-09

    There is an estimated 10 billion barrels of original oil in place (OOIP) in diatomaceous reservoirs in Kern County, California. These reservoirs have low permeability ranging from 0.1 to 10 mD. Injection pressure controlled steam drive has been found to be an effective way to recover oil from these reservoir. However, steam drive in these reservoirs has its own complications. The rock matrix is primarily silica (SiO2). It is a known fact that silica is soluble in hot water and its solubility varies with temperature and pH. Due to this fact, the rock matrix in diatomite may dissolve into the aqueous phase as the temperature at a location increases or it may precipitate from the aqueous phase onto the rock grains as the temperature decreases. Thus, during steam drive silica redistribution will occur in the reservoir along with oil recovery. This silica redistribution causes the permeability and porosity of the reservoir to change. Understanding and quantifying these silica redistribution effects on the reservoir permeability might prove to be a key aspect of designing a steam drive project in these formations.

  16. Transport process and local thermal reservoirs.

    PubMed

    Trimper, Steffen; Schulz, Michael

    2007-09-01

    A random walk of N particles on a lattice with M sites is studied under the constraint that each lattice site is coupled to its own mesoscopic heat bath. Such a situation can be conveniently described by using the master equation in a quantized Hamiltonian formulation where the exclusion principle is included by using Pauli operators. If all reservoirs are mutually in contact, giving rise to a temperature gradient, an evolution equation for the particle density with two different currents already results in the mean-field approximation. One is the conventional diffusive current, driven by the density gradient, whereas the other includes a coupling between the local density and the temperature gradient. Due to the competitive currents, the system exhibits a stationary solution, where the local density is determined by the local temperature field and depends on the filling factor M/N. The stability of the solution is related to the eigenvalues of a Schrödinger-like equation. In the case of a fixed temperature gradient the stationary density distribution remains stable. The approach used is totally different from and an alternative to the conventional Onsager ansatz. PMID:17930201

  17. Modeling surface energy fluxes and thermal dynamics of a seasonally ice-covered hydroelectric reservoir.

    PubMed

    Wang, Weifeng; Roulet, Nigel T; Strachan, Ian B; Tremblay, Alain

    2016-04-15

    The thermal dynamics of human created northern reservoirs (e.g., water temperatures and ice cover dynamics) influence carbon processing and air-water gas exchange. Here, we developed a process-based one-dimensional model (Snow, Ice, WAater, and Sediment: SIWAS) to simulate a full year's surface energy fluxes and thermal dynamics for a moderately large (>500km(2)) boreal hydroelectric reservoir in northern Quebec, Canada. There is a lack of climate and weather data for most of the Canadian boreal so we designed SIWAS with a minimum of inputs and with a daily time step. The modeled surface energy fluxes were consistent with six years of observations from eddy covariance measurements taken in the middle of the reservoir. The simulated water temperature profiles agreed well with observations from over 100 sites across the reservoir. The model successfully captured the observed annual trend of ice cover timing, although the model overestimated the length of ice cover period (15days). Sensitivity analysis revealed that air temperature significantly affects the ice cover duration, water and sediment temperatures, but that dissolved organic carbon concentrations have little effect on the heat fluxes, and water and sediment temperatures. We conclude that the SIWAS model is capable of simulating surface energy fluxes and thermal dynamics for boreal reservoirs in regions where high temporal resolution climate data are not available. SIWAS is suitable for integration into biogeochemical models for simulating a reservoir's carbon cycle. PMID:26849343

  18. High temperature refrigerator

    DOEpatents

    Steyert, Jr., William A.

    1978-01-01

    A high temperature magnetic refrigerator which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle said working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot.

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

    SciTech Connect

    Nurhandoko, Bagus Endar B. E-mail: bagusnur@rock-fluid.com; Susilowati E-mail: bagusnur@rock-fluid.com

    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.

  20. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  1. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  2. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  3. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  4. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Reservoir areas. 211.81 Section... Lands in Reservoir Areas Under Jurisdiction of Department of the Army for Cottage Site Development and Use § 211.81 Reservoir areas. Delegations, rules and regulations in §§ 211.71 to 211.80 are...

  5. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Reservoir areas. 211.81 Section... Lands in Reservoir Areas Under Jurisdiction of Department of the Army for Cottage Site Development and Use § 211.81 Reservoir areas. Delegations, rules and regulations in §§ 211.71 to 211.80 are...

  6. 49 CFR 236.792 - Reservoir, equalizing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Reservoir, equalizing. 236.792 Section 236.792 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Reservoir, equalizing. An air reservoir connected with and adding volume to the top portion of...

  7. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Reservoir areas. 211.81 Section... Lands in Reservoir Areas Under Jurisdiction of Department of the Army for Cottage Site Development and Use § 211.81 Reservoir areas. Delegations, rules and regulations in §§ 211.71 to 211.80 are...

  8. Heat pipe with hot gas reservoir

    NASA Technical Reports Server (NTRS)

    Marcus, B. D.

    1974-01-01

    Heat pipe can reverse itself with gas reservoir acting as evaporator, leading to rapid recovery from liquid in reservoir. Single layer of fine-mesh screen is included inside reservoir to assure uniform liquid distribution over hottest parts of internal surface until liquid is completely removed.

  9. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  10. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  11. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  12. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  13. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Reservoir bag. 868.5320 Section 868.5320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5320 Reservoir bag. (a) Identification. A reservoir bag is...

  14. Tenth workshop on geothermal reservoir engineering: proceedings

    SciTech Connect

    Not Available

    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)

  15. Operation of TVA reservoirs. Annual 1982

    SciTech Connect

    Not Available

    1985-09-01

    This report describes the operation of TVA, ALCOA, and Cumberland Basin reservoirs that were scheduled daily by Reservoir Operations Branch personnel during calendar year 1982. These include all TVA reservoirs, eight reservoirs in the Cumberland River Basin owned by the US Army Corps of Engineers, and six reservoirs in the Tennessee River Basin owned by ALCOA. In addition, storage and flow computations include Walters Reservoir and Woods Reservoir. Data for the Cumberland Basin projects of the US Army Corps of Engineers have been included beginning with the 1954 report. Plates are included tabulating daily elevations, storage volumes, and/or average discharges for 48 reservoirs for 1982. Additional plates show the daily average flow in Barkley Canal, monthly and annual emptyings and water use at each lock in the Tennessee River Basin, monthly and annual capacity factors at each TVA scheduled hydro plant, combined monthly and annual storages and flows (in inches) for reservoirs above Chickamauga and Kentucky Dams, and a summary of reservoir operations. Tables of monthly and annual storages and flows (in inches) for the principal Tennessee River Basin tributary projects are included. Individual plottings of midnight reservoir elevations during calendar year 1982 are included for all principal reservoirs.

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

    SciTech Connect

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

    2001-08-07

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

  17. Preliminary evaluation of the second hot dry rock geothermal energy reservoir: results of phase 1, run segment 4

    SciTech Connect

    Murphy, H.D.; Aamodt, R.L.; Albright, J.N.

    1980-05-01

    Results of the preliminary assessment of the second hot dry rock reservoir at the Fenton Hill field site are presented. This second reservoir was created by fracturing a deeper interval of granite rock located at a depth of 2.93 km (9620 ft) in the same wellbore pair used in the creation of the first reservoir; no additional redrilling was required. The new fracture system has a vertical extent of at least 320 m (1050 ft), suggesting that the combined heat-transfer area of the old and new fracture systems is 11 times that of the old system. The virgin rock temperature at the bottom of the deeper interval was 197/sup 0/C (386/sup 0/F). Water at a flow rate of 6 l/s (100 gpm) was circulated through the reservoir for a period of 23 days. Downhole measurements of the water temperature at the reservoir outlet, as well as temperatures inferred from geothermometry, showed that the thermal drawdown of the reservoir was negligible and preliminary estimates indicate that the minimum effective heat-transfer area of the new reservoir is 45,000 m/sup 2/ (480,000 ft/sup 2/), which is six times larger than the first reservoir. The following are presented: operational plan, reservoir geometry and flow paths, flow impedance, geochemistry, heat extraction, dye tracer flow distribution studies, and seismicity. (MHR)

  18. Role of fish distribution on estimates of standing crop in a cooling reservoir

    USGS Publications Warehouse

    Barwick, D. Hugh

    1984-01-01

    Estimates of fish standing crop from coves in Keowee Reservoir, South Carolina, were obtained in May and August for 3 consecutive years. Estimates were significantly higher in May than in August for most of the major species of fish collected, suggesting that considerable numbers of fish had migrated from the coves by August. This change in fish distribution may have resulted from the operation of a 2,580-megawatt nuclear power plant which altered reservoir stratification. Because fish distribution is sensitive to conditions of reservoir stratification, and because power plants often alter reservoir stratification, annual cove sampling in August may not be sufficient to produce comparable estimates of fish standing crop on which to assess the impact of power plant operations on fish populations. Comparable estimates of fish standing crop can probably be obtained from cooling reservoirs by collecting annual samples at similar water temperatures and concentrations of dissolved oxygen.

  19. Characterization of oil and gas reservoir heterogeneity. Technical progress report, April 1, 1992--June 30, 1992

    SciTech Connect

    Sharma, G.D.

    1992-10-01

    The ultimate objective of this cooperative research project is to characterize Alaskan petroleum reservoirs in terms of their reserves, physical and chemical properties, geologic configuration in relation to lithofacies and structure, and development potential. The project has two tasks: Task 1 is a geological description of the reservoirs including petrophysical properties, i.e., porosity, permeability, permeability variation, formation depth, temperature, and net pay, facies changes and reservoir structures as drawn from cores, well logs, and other geological data. Task 2 is reservoir fluid characterization-determination of physical properties of reservoir fluids including density, viscosity, phase distributions and composition as well as petrogenesis-source rock identification; and the study of asphaltene precipitation for Alaskan crude oils. Results are discussed.

  20. Characterization of oil and gas reservoir heterogeneity. Technical progress report, January 1, 1992--March 31, 1992

    SciTech Connect

    Sharma, G.D.

    1992-08-01

    The ultimate objective of this cooperative research project is to characterize Alaskan petroleum reservoirs in terms of their reserves, physical and chemical properties, geologic configuration in relation to lithofacies and structure, and development potential. The project has two tasks: Task 1 is a geological description of the reservoirs including petrophysical properties, i.e., porosity, permeability, permeability variation, formation depth, temperature, and net pay, facies changes and reservoir structures as drawn from cores, well logs, and other geological data. Task 2 is reservoir fluid characterization -- determination of physical properties of reservoir fluids including density, viscosity, phase distributions and composition as well as petrogenesis -- source rock identification; and the study of asphaltene precipitation for Alaskan crude oils.

  1. Characterization of oil and gas reservoir heterogeneity. Technical progress report, July 1, 1992--September 30, 1992

    SciTech Connect

    Sharma, G.D.

    1992-12-01

    The ultimate oojective of this cooperative research project is to characterize Alaskan petroleum reservoirs in terms of their reserves, physical and chemical properties, geologic configuration in relation to lithofacies and structure, and development potential. The project has two tasks: Task 1 is a geological description of the reservoirs including petrophysical properties, i.e., porosity, permeability, permeability variation, formation depth, temperature, and net pay, facies changes and reservoir structures as drawn from cores, well logs, and other geological data. Task 2 is reservoir fluid characterization--determination of physical properties of reservoir fluids including density, viscosity, phase distributions and composition as well as petrogenesis--source rock identification; and the study of asphaltene precipitation for Alaskan crude oils. This report presents a summary of technical progress of the well log analysis of Kuparuk Field, Northslope, Alaska.

  2. Exploitation of subsea gas hydrate reservoirs

    NASA Astrophysics Data System (ADS)

    Janicki, Georg; Schlüter, Stefan; Hennig, Torsten; Deerberg, Görge

    2016-04-01

    Natural gas hydrates are considered to be a potential energy resource in the future. They occur in permafrost areas as well as in subsea sediments and are stable at high pressure and low temperature conditions. According to estimations the amount of carbon bonded in natural gas hydrates worldwide is two times larger than in all known conventional fossil fuels. Besides technical challenges that have to be overcome climate and safety issues have to be considered before a commercial exploitation of such unconventional reservoirs. The potential of producing natural gas from subsea gas hydrate deposits by various means (e.g. depressurization and/or injection of carbon dioxide) is numerically studied in the frame of the German research project »SUGAR«. The basic mechanisms of gas hydrate formation/dissociation and heat and mass transport in porous media are considered and implemented into a numerical model. The physics of the process leads to strong non-linear couplings between hydraulic fluid flow, hydrate dissociation and formation, hydraulic properties of the sediment, partial pressures and seawater solution of components and the thermal budget of the system described by the heat equation. This paper is intended to provide an overview of the recent development regarding the production of natural gas from subsea gas hydrate reservoirs. It aims at giving a broad insight into natural gas hydrates and covering relevant aspects of the exploitation process. It is focused on the thermodynamic principles and technological approaches for the exploitation. The effects occurring during natural gas production within hydrate filled sediment layers are identified and discussed by means of numerical simulation results. The behaviour of relevant process parameters such as pressure, temperature and phase saturations is described and compared for different strategies. The simulations are complemented by calculations for different safety relevant problems.

  3. Characterizing CO2 storage reservoir for above-zone monitoring

    NASA Astrophysics Data System (ADS)

    Zahid, K. M.; Hovorka, S. D.

    2011-12-01

    CO2 enhanced oil recovery (EOR) provides an excellent opportunity for commercial sequestration of anthropogenic CO2. Fluvial, strand plain, and deltaic sandstones of Oligocene and Miocene formations that extend across the Gulf Coast Basin were prolific oil producers for many decades and are also considered to be effective reservoirs for large scale carbon storage. A deep-seated salt dome, faulted anticlinal structure from Gulf coastal region is currently under investigation to develop a monitoring, verification, and accounting (MVA) plan as coordinated with commercial surveillance of an EOR site for injecting large volume (>1 Million ton/year) of CO2. Geophysical logs have been used to characterize the injection zone reservoir and overburden. One novel MVA element in design is above-zone pressure and geochemical monitoring for out-of-zone migration. Initial characterization with wireline logs demonstrates the extent and areal continuity of reservoir sands and geometries of faults that cut the reservoir. To develop the monitoring plan, we focus characterization on several elements: (1) input data for quick-look dynamic model of the extent of CO2 plume and amount and extent of accompanying pressure elevation, (2) characterization of the zones above the top-reservoir seal for above-zone pressure monitoring, and (3) intersection of faults with well-bores in intervals above the top-reservoir seal for thermal monitoring. Other uncertainties addressed during characterization are the upper extent of faults and juxtaposition of layers to assess the potential for cross-fault fluid migration. Such detail characterization will allow realistic assessment of the sensitivity of monitoring techniques such as temperature logging for tracking up-fault fluid migration and pressure change for out-of zone fluid migration. Successful use of such geophysical techniques for MVA based on uniting elements of existing regulatory monitoring expectations with commercial best practices will be

  4. 4. International reservoir characterization technical conference

    SciTech Connect

    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.

  5. The role of reservoir characterization in the reservoir management process (as reflected in the Department of Energy`s reservoir management demonstration program)

    SciTech Connect

    Fowler, M.L.; Young, M.A.; Madden, M.P.

    1997-08-01

    Optimum reservoir recovery and profitability result from guidance of reservoir practices provided by an effective reservoir management plan. Success in developing the best, most appropriate reservoir management plan requires knowledge and consideration of (1) the reservoir system including rocks, and rock-fluid interactions (i.e., a characterization of the reservoir) as well as wellbores and associated equipment and surface facilities; (2) the technologies available to describe, analyze, and exploit the reservoir; and (3) the business environment under which the plan will be developed and implemented. Reservoir characterization is the essential to gain needed knowledge of the reservoir for reservoir management plan building. Reservoir characterization efforts can be appropriately scaled by considering the reservoir management context under which the plan is being built. Reservoir management plans de-optimize with time as technology and the business environment change or as new reservoir information indicates the reservoir characterization models on which the current plan is based are inadequate. BDM-Oklahoma and the Department of Energy have implemented a program of reservoir management demonstrations to encourage operators with limited resources and experience to learn, implement, and disperse sound reservoir management techniques through cooperative research and development projects whose objectives are to develop reservoir management plans. In each of the three projects currently underway, careful attention to reservoir management context assures a reservoir characterization approach that is sufficient, but not in excess of what is necessary, to devise and implement an effective reservoir management plan.

  6. Enhanced lifetime hybrid-diffuser cesium reservoir photocathode

    NASA Astrophysics Data System (ADS)

    Montgomery, Eric J.; Pan, Zhigang; Riddick, Blake C.; O'Shea, Patrick G.; Feldman, Donald W.; Jensen, Kevin L.; Ives, R. Lawrence; Falce, Louis R.

    2013-01-01

    A novel self-healing hybrid-diffuser cesium reservoir photocathode is demonstrated. The model-driven design optimizes operating temperature to match diffusion and evaporation rates and maximize quantum efficiency of the cesiated tungsten surface. A sintered-wire tungsten emitter promotes surface uniformity. Cesium loss is less than 0.023 µg/cm2/hr at 125°C, and conservatively extrapolated reservoir lifetime exceeds 30,000 hours. Contamination robustness to a direct atmospheric leak with room-temperature contamination by over 200 Langmuirs of oxidizing gases is excellent, with 90% of maximum QE repeatedly restored via in situ self-healing recesiation under gentle 90°C heating.

  7. Enhanced lifetime hybrid-diffuser cesium reservoir photocathode

    NASA Astrophysics Data System (ADS)

    Montgomery, Eric J.; Pan, Zhigang; Riddick, Blake C.; O'Shea, Patrick G.; Feldman, Donald W.; Jensen, Kevin L.; Ives, R. Lawrence; Falce, Louis R.

    2012-12-01

    A novel self-healing hybrid-diffuser cesium reservoir photocathode is demonstrated. The model-driven design optimizes operating temperature to match diffusion and evaporation rates and maximize quantum efficiency of the cesiated tungsten surface. A sintered-wire tungsten emitter promotes surface uniformity. Cesium loss is less than 0.023 µg/cm2/hr at 125°C, and conservatively extrapolated reservoir lifetime exceeds 30,000 hours. Contamination robustness to a direct atmospheric leak with room-temperature contamination by over 200 Langmuirs of oxidizing gases is excellent, with 90% of maximum QE repeatedly restored via in situ self-healing recesiation under gentle 90°C heating.

  8. Effects of reservoir squeezing on quantum systems and work extraction.

    PubMed

    Huang, X L; Wang, Tao; Yi, X X

    2012-11-01

    We establish a quantum Otto engine cycle in which the working substance contacts with squeezed reservoirs during the two quantum isochoric processes. We consider two working substances: (1) a qubit and (2) two coupled qubits. Due to the effects of squeezing, the working substance can be heated to a higher effective temperature, which leads to many interesting features different from the ordinary ones, such as (1) for the qubit as working substance, if we choose the squeezed parameters properly, the positive work can be exported even when T(H) temperatures of the hot and cool reservoirs, respectively; (2) the efficiency can be higher than classical Carnot efficiency. These results do not violate the second law of thermodynamics and it can be understood as quantum fuel is more efficient than the classical one. PMID:23214736

  9. Changes in thermodynamic conditions of the Ahuachapán reservoir due to production and injection

    USGS Publications Warehouse

    Steingrimsson, B.; Aunzo, Z.; Bodvarsson, G.S.; Truesdell, A.; Cuellar, G.; Escobar, C.; Quintanilla, A.

    1991-01-01

    Since large-scale exploitation of the Ahuachapán reservoir began in 1975 large changes in the reservoir thermodynamic conditions have occurred. Drawdown of up to 15 bars and significant temperature changes have been observed in the wellfield. Temperatures have declined due to boiling in the reservoir in response to the pressure drawdown; localized and minor cooling due to reinjection of spent geothermal fluids have also been observed. There are indications of cold fluid influx deep into the reservoir from the west and north. Reservoir temperatures show that a significant amount of hot fluid recharge comes to the wellfield from the southeast, and temperatures also indicate that the recharge rate has increased with time as pressure declines in the reservoir. Chemical analyses of the produced fluids show that most wells are fed by a mixture of geothermal fluids and cooler, less-saline waters. The cold water inflow has increased due to exploitation, as demonstrated by decreased salinity of the produced fluids.

  10. Modeling white sturgeon movement in a reservoir: The effect of water quality and sturgeon density

    USGS Publications Warehouse

    Sullivan, A.B.; Jager, H.I.; Myers, R.

    2003-01-01

    We developed a movement model to examine the distribution and survival of white sturgeon (Acipenser transmontanus) in a reservoir subject to large spatial and temporal variation in dissolved oxygen and temperature. Temperature and dissolved oxygen were simulated by a CE-QUAL-W2 model of Brownlee Reservoir, Idaho for a typical wet, normal, and dry hydrologic year. We compared current water quality conditions to scenarios with reduced nutrient inputs to the reservoir. White sturgeon habitat quality was modeled as a function of temperature, dissolved oxygen and, in some cases, suitability for foraging and depth. We assigned a quality index to each cell along the bottom of the reservoir. The model simulated two aspects of daily movement. Advective movement simulated the tendency for animals to move toward areas with high habitat quality, and diffusion simulated density dependent movement away from areas with high sturgeon density in areas with non-lethal habitat conditions. Mortality resulted when sturgeon were unable to leave areas with lethal temperature or dissolved oxygen conditions. Water quality was highest in winter and early spring and lowest in mid to late summer. Limiting nutrient inputs reduced the area of Brownlee Reservoir with lethal conditions for sturgeon and raised the average habitat suitability throughout the reservoir. Without movement, simulated white sturgeon survival ranged between 45 and 89%. Allowing movement raised the predicted survival of sturgeon under all conditions to above 90% as sturgeon avoided areas with low habitat quality. ?? 2003 Elsevier B.V. All rights reserved.

  11. Factors affecting water quality in Cherokee Reservoir

    SciTech Connect

    Iwanski, M.L.; Higgins, J.M.; Kim, B.R.; Young, R.C.

    1980-07-01

    The purpose was to: (1) define reservoir problems related to water quality conditions; (2) identify the probable causes of these problems; and (3) recommend procedures for achieving needed reservoir water quality improvements. This report presents the project findings to date and suggests steps for upgrading the quality of Cherokee Reservoir. Section II presents background information on the characteristics of the basin, the reservoir, and the beneficial uses of the reservoir. Section III identifies the impacts of existing reservoir water quality on uses of the reservoir for water supply, fishery resources, recreation, and waste assimilation. Section IV presents an assessment of cause-effect relationships. The factors affecting water quality addressed in Section IV are: (1) reservoir thermal stratification and hydrodynamics; (2) dissolved oxygen depletion; (3) eutrophication; (4) toxic substances; and (5) reservoir fisheries. Section V presents a preliminary evaluation of alternatives for improving the quality of Cherokee Reservoir. Section VI presents preliminary conclusions and recommendations for developing and implementing a reservoir water quality management plan. 7 references, 22 figures, 21 tables.

  12. Trophic status evaluation of TVA reservoirs

    SciTech Connect

    Placke, J.F.

    1983-10-01

    TVA tributary and mainstem reservoirs show generalized differences in morphometry, hydraulics, nutrient loads, and response to nutrient concentrations. Neither type of reservoir is strictly comparable to the natural lakes on which classical eutrophication studies have been based. The majority of published trophic state indices and standards (e.g., hypolimnetic dissolved oxygen depletion, Secchi depth, areas nutrient loading rates, in-reservoir phosphorus concentrations) are inappropriate for evaluation of some or all TVA reservoirs. No single trophic potential or trophic response variable summarizes the mechanisms and manifestations of eutrophication sufficiently to be used as a sole criterion for judging or regulating TVA reservoir water quality. Relative multivariate trophic state indices were developed for mainstem and tributary reservoirs. Ranking of the mainstem reservoirs is based on chlorophyll, macrophyte coverage, hydraulic retention time, reservoir area less than five feet deep, annual pool elevation drawdown, and Secchi depth. Based on available data, the rank from least eutrophic to most eutrophic is: Pickwick, Kentucky, Chickamauga, Nickajack, Wilson, Fort Loudoun, Watts Bar, Wheeler, and Guntersville Reservoirs. Ranking of the tributary reservoirs is based on chlorophyll, total phosphorus and total nitrogen weighted by the N:P ratio, and bio-available inorganic carbon levels. The rank from least eutrophic to most eutrophic is: Hiwassee, Blue Ridge, Chatuge, Norris and Fontana, Watauga, South Holston, Tims Ford, Cherokee, Douglas, and Boone Reservoirs. 130 references, 18 figures, 30 tables.

  13. Reservoir floodplains support distinct fish assemblages

    USGS Publications Warehouse

    Miranda, Leandro E.; Wigen, S. L.; Dagel, Jonah D.

    2014-01-01

    Reservoirs constructed on floodplain rivers are unique because the upper reaches of the impoundment may include extensive floodplain environments. Moreover, reservoirs that experience large periodic water level fluctuations as part of their operational objectives seasonally inundate and dewater floodplains in their upper reaches, partly mimicking natural inundations of river floodplains. In four flood control reservoirs in Mississippi, USA, we explored the dynamics of connectivity between reservoirs and adjacent floodplains and the characteristics of fish assemblages that develop in reservoir floodplains relative to those that develop in reservoir bays. Although fish species richness in floodplains and bays were similar, species composition differed. Floodplains emphasized fish species largely associated with backwater shallow environments, often resistant to harsh environmental conditions. Conversely, dominant species in bays represented mainly generalists that benefit from the continuous connectivity between the bay and the main reservoir. Floodplains in the study reservoirs provided desirable vegetated habitats at lower water level elevations, earlier in the year, and more frequently than in bays. Inundating dense vegetation in bays requires raising reservoir water levels above the levels required to reach floodplains. Therefore, aside from promoting distinct fish assemblages within reservoirs and helping promote diversity in regulated rivers, reservoir floodplains are valued because they can provide suitable vegetated habitats for fish species at elevations below the normal pool, precluding the need to annually flood upland vegetation that would inevitably be impaired by regular flooding. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  14. Twin reservoir heat transfer circuit

    SciTech Connect

    Urch, J.F.

    1986-09-23

    This patent describes a heat transfer means comprising circuitry defining a closed flow path for working fluid; a primary circuit forming part of the path and having two ends at one of which the working fluid is at a high pressure and at the other of which the working fluid is at a low pressure. The circuitry defines a fluid supply reservoir and a fluid collection reservoir disposed respectively at the two ends; ejector means in the primary circuit; a drive fluid inlet, and exhaust outlet and a suction inlet provided on the ejector means. Also included are a branch circuit bridging a section of the primary circuit and an outlet end of the branch circuit connected to the suction inlet of the ejector means.

  15. Costs of reservoir releases aeration

    SciTech Connect

    Lewis, A.R.; Bohac, C.E.

    1984-12-01

    Reservoir releases sometimes lack sufficient amounts of dissolved oxygen (DO) to assimilate wastes or to support aquatic life. Various types of aeration technology have been investigated, including turbine hub baffles, draft tube baffles, compressed air injected into the draft tube, compressed air injected through the headcover, and oxygen injected into the reservoir. To evaluate the feasibility of improving DO by various aeration techniques, TVA installed temporary aeration systems at several sites and conducted tests of their performance. Based on these experiments, TVA estimated the costs of installing and operating permanent aeration systems at several of its hydropower projects. This report describes the aeration alternatives investigated, documents current estimates of initial and annual costs for each alternative, and presents a general evaluation of the aeration methods based on their estimated costs and aeration capabilities.

  16. Falcon Reservoir, Brownsville, TX, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Rio Grande River extends across the center of this photo from Falcon Reservoir, Brownsville (26.0N, 98.0W) to its bulging delta, joining the Gulf of Mexico. Sediment brought down by the river flows both north and south by the alongshore currents to form the barrier chain of Padre Island and its protected Laguna Madre. Agricultural land use patterns in the river valley contrast with the rangeland to the north and forests in Mexico to the south.

  17. Reservoir characterization using wavelet transforms

    NASA Astrophysics Data System (ADS)

    Rivera Vega, Nestor

    Automated detection of geological boundaries and determination of cyclic events controlling deposition can facilitate stratigraphic analysis and reservoir characterization. This study applies the wavelet transformation, a recent advance in signal analysis techniques, to interpret cyclicity, determine its controlling factors, and detect zone boundaries. We tested the cyclostratigraphic assessments using well log and core data from a well in a fluvio-eolian sequence in the Ormskirk Sandstone, Irish Sea. The boundary detection technique was tested using log data from 10 wells in the Apiay field, Colombia. We processed the wavelet coefficients for each zone of the Ormskirk Formation and determined the wavelengths of the strongest cyclicities. Comparing these periodicities with Milankovitch cycles, we found a strong correspondence of the two. This suggests that climate exercised an important control on depositional cyclicity, as had been concluded in previous studies of the Ormskirk Sandstone. The wavelet coefficients from the log data in the Apiay field were combined to form features. These vectors were used in conjunction with pattern recognition techniques to perform detection in 7 boundaries. For the upper two units, the boundary was detected within 10 feet of their actual depth, in 90% of the wells. The mean detection performance in the Apiay field is 50%. We compared our method with other traditional techniques which do not focus on selecting optimal features for boundary identification. Those methods resulted in detection performances of 40% for the uppermost boundary, which lag behind the 90% performance of our method. Automated determination of geologic boundaries will expedite studies, and knowledge of the controlling deposition factors will enhance stratigraphic and reservoir characterization models. We expect that automated boundary detection and cyclicity analysis will prove to be valuable and time-saving methods for establishing correlations and their

  18. Research on Oil Recovery Mechanisms in Heavy Oil Reservoirs

    SciTech Connect

    Louis M. Castanier; William E. Brigham

    1998-03-31

    The goal of this project is to increase recovery of heavy oils. Towards that goal studies are being conducted in how to assess the influence of temperature and pressure on the absolute and relative permeability to oil and water and on capillary pressure; to evaluate the effect of different reservoir parameters on the in site combustion process; to develop and understand mechanisms of surfactants on for the reduction of gravity override and channeling of steam; and to improve techniques of formation evaluation.

  19. 1982 THERMAL SHALLOW RESERVOIR TESTING

    SciTech Connect

    Mogen, P.; Pittinger, L.; Magers, M.

    1985-01-22

    An extensive study of the Thermal Shallow Reservoir at The Geysers was performed in 1982 to improve our understanding of the source and flow patterns of steam in the shallow anomaly and how they relate to the Thermal 4 blowout. This project included gathering and analyzing pressure transient, enthalpy, tracer and chemical data and developing a reservoir model that was consistent with this data. Following the pressure transient testing and analysis, a convection-plume with lateral-flow model was proposed. Subsequent analysis of enthalpy, tracer and chemical data corroborated this model. The high flowrate wells--Thermal 4, Thermal 10, Thermal 11 and Magma 1--produce from the high-pressure, high-permeability upflow zone. The source of this upflow is a limited fracture system connecting the shallow anomaly with the underlying main reservoir. The outlying low-pressure, low-permeability wells are supplied by lateral flow of steam from the central area. The pressure gradient from the core to the periphery is caused by condensation in the flanks.

  20. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    SciTech Connect

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  1. Geology, reservoir engineering and methane hydrate potential of the Walakpa Gas Field, North Slope, Alaska

    SciTech Connect

    Glenn, R.K.; Allen, W.W.

    1992-12-01

    The Walakpa Gas Field, located near the city of Barrow on Alaska's North Slope, has been proven to be methane-bearing at depths of 2000--2550 feet below sea level. The producing formation is a laterally continuous, south-dipping, Lower Cretaceous shelf sandstone. The updip extent of the reservoir has not been determined by drilling, but probably extends to at least 1900 feet below sea level. Reservoir temperatures in the updip portion of the reservoir may be low enough to allow the presence of in situ methane hydrates. Reservoir net pay however, decreases to the north. Depths to the base of permafrost in the area average 940 feet. Drilling techniques and production configuration in the Walakpa field were designed to minimize formation damage to the reservoir sandstone and to eliminate methane hydrates formed during production. Drilling development of the Walakpa field was a sequential updip and lateral stepout from a previously drilled, structurally lower confirmation well. Reservoir temperature, pressure, and gas chemistry data from the development wells confirm that they have been drilled in the free-methane portion of the reservoir. Future studies in the Walakpa field are planned to determine whether or not a component of the methane production is due to the dissociation of updip in situ hydrates.

  2. A chemical EOR benchmark study of different reservoir simulators

    NASA Astrophysics Data System (ADS)

    Goudarzi, Ali; Delshad, Mojdeh; Sepehrnoori, Kamy

    2016-09-01

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

  3. Effects of a thermal effluent on macroinvertebrates in a central Texas reservoir

    SciTech Connect

    Wellborn, G.A.; Robinson, J.V.

    1996-07-01

    We investigated the impact of a thermal effluent from an electricity-generating plant on the macroarthropod community in a central Texas reservoir for 1 yr by comparing the community of a 60-ha pond directly receiving the effluent to an area in the main body of the reservoir relatively unaffected by the effluent. Temperature of the pond averaged 7.2 C warmer than the main reservoir sites. Samples of artificial substrates constructed to mimic macrophytic vegetation indicated that the pond generally had lower macroinvertebrate abundance and reduced taxonomic diversity, though direction and severity of effects varied over time for most taxa. Deleterious effects were most severe in summer when temperatures of 40-42 C in the pond eliminated macroinvertebrates. Although taxa recolonized the pond after the summer defaunation, with some taxa briefly obtaining very high population levels, most taxa maintained lower population levels in the pond than the main reservoir throughout the winter. 32 refs., 3 figs., 1 tab.

  4. Water-quality data for Orwell reservoir and the Otter Tail River near Fergus Falls, Minnesota

    USGS Publications Warehouse

    Have, M.R.; Tornes, L.H.

    1987-01-01

    Water-quality data were collected at five sites on Orwell Reservoir and two sites on the Otter Tail River, at the inflow and outflow points of the reservoir. The data, collected from April 1983 to July 1966, consist mainly of streamflow and nutrient concentrations at the river sites and nutrient concentrations, alkalinity, Secchi-disk transparency, phytoplankton counts, chlorophyll concentrations, and profiles of specific conductance, temperature, pU, and dissolved oxygen at the reservoir sites. Additional data collected at the outflow site include alkalinity and concentrations of major ions and organic carbon.

  5. An efficient cooling loop for connecting cryocooler to a helium reservoir

    SciTech Connect

    Taylor, C.E.; Abbott, C.S.R.; Leitner, D.; Leitner, M.; Lyneis, C.M.

    2003-09-21

    The magnet system of the VENUS ECR Ion Source at LBNL has two 1.5-watt cryocoolers suspended in the cryostat vacuum. Helium vapor from the liquid reservoir is admitted to a finned condenser bolted to the cryocooler 2nd stage and returns as liquid via gravity. Small-diameter flexible tubes allow the cryocoolers to be located remotely from the reservoir. With 3.1 watts load, the helium reservoir is maintained at 4.35 K, 0.05K above the cryocooler temperature. Design, analysis, and performance are presented.

  6. Hydrogeochemistry and reservoir model of Fuzhou geothermal field, China

    NASA Astrophysics Data System (ADS)

    Huang, H. F.; Goff, Fraser

    1986-03-01

    Fuzhou geothermal field is a low- to intermediate-temperature geothermal system consisting of meteoric water that circulates deeply along faults. The area of the field is about 9 km 2 but it is elongated in a NNW-trending direction. Fluids in the field are controlled by a series of four NNW extensional faults in Cretaceous granitic basement (Fuzhou fault zone). These faults feed warm waters into overlying permeable Quaternary sediments. The hydrothermal system consists of north and south parts whose chemical compositions are subtly different. In the northern part the system discharges sulfate/chloride waters with relatively low chloride concentrations, but in the south the system discharges chloride waters having relatively high chloride concentrations. Maximum wellhead temperatures are 97°C, which agrees with the chalcedony geothermometer in many cases. Based on the solubility of quartz, the deep-reservoir temperature cannot exceed 123 to 131°C. From heat and mass balance calculations, we conclude that the present total extracted capacity of fluid from the reservoir (20,000 tons/day) could be doubled without noticeable drawdown. We estimate the recoverable heat in the reservoir to be about 1.71 × 10 11 MJ.

  7. New Heat Flow Models in Fractured Geothermal Reservoirs - Final Report

    SciTech Connect

    Reis, John

    2001-03-31

    This study developed new analytical models for predicting the temperature distribution within a geothermal reservoir following reinjection of water having a temperature different from that of the reservoir. The study consisted of two parts: developing new analytical models for the heat conduction rate into multi-dimensional, parallelepiped matrix blocks and developing new analytical models for the advance of the thermal front through the geothermal reservoir. In the first part of the study, a number of semi-empirical models for the multi-dimensional heat conduction were developed to overcome the limitations to the exact solutions. The exact solution based on a similarity solution to the heat diffusion equation is the best model for the early-time period, but fails when thermal conduction fronts from opposing sides of the matrix block merge. The exact solution based on an infinite series solution was found not to be useful because it required tens of thousands of terms to be include d for accuracy. The best overall model for the entire conduction time was a semi-empirical model based on an exponential conduction rate. In the second part of the study, the early-time period exact solution based on similarity methods and the semi-empirical exponential model were used to develop new analytical models for the location of the thermal front within the reservoir during injection. These equations were based on an energy balance on the water in the fractured network. These convective models allowed for both dual and triple porosity reservoirs, i.e., one or two independent matrix domains. A method for incorporating measured fracture spacing distributions into these convective models was developed. It was found that there were only minor differences in the predicted areal extent of the heated zone between the dual and triple porosity models. Because of its simplicity, the dual porosity model is recommended. These new models can be used for preliminary reservoir studies

  8. An intelligent agent for optimal river-reservoir system management

    NASA Astrophysics Data System (ADS)

    Rieker, Jeffrey D.; Labadie, John W.

    2012-09-01

    A generalized software package is presented for developing an intelligent agent for stochastic optimization of complex river-reservoir system management and operations. Reinforcement learning is an approach to artificial intelligence for developing a decision-making agent that learns the best operational policies without the need for explicit probabilistic models of hydrologic system behavior. The agent learns these strategies experientially in a Markov decision process through observational interaction with the environment and simulation of the river-reservoir system using well-calibrated models. The graphical user interface for the reinforcement learning process controller includes numerous learning method options and dynamic displays for visualizing the adaptive behavior of the agent. As a case study, the generalized reinforcement learning software is applied to developing an intelligent agent for optimal management of water stored in the Truckee river-reservoir system of California and Nevada for the purpose of streamflow augmentation for water quality enhancement. The intelligent agent successfully learns long-term reservoir operational policies that specifically focus on mitigating water temperature extremes during persistent drought periods that jeopardize the survival of threatened and endangered fish species.

  9. Production of superheated steam from vapor-dominated geothermal reservoirs

    USGS Publications Warehouse

    Truesdell, A.H.; White, D.E.

    1973-01-01

    Vapor-dominated geothermal systems such as Larderello, Italy, The Geysers, California, and Matsukawa, Japan yield dry or superheated steam when exploited. Models for these systems are examined along with production data and the thermodynamic properties of water, steam and rock. It is concluded that these systems initially consist of a water and steam filled reservoir, a water-saturated cap rock, and a water or brine-saturated deep reservoir below a water table. Most liquid water in all parts of the system is relatively immobilized in small pores and crevices; steam dominates the large fractures and voids of the reservoir and is the continuous, pressure-controlling phase. With production, the pressure is lowered and the liquid water boils, causing massive transfer of heat from the rock and its eventual drying. Passage of steam through already dried rock produces superheating. After an initial vaporization of liquid water in the reservoir, the decrease in pressure produces increased boiling below the deep water table. With heavy exploitation, boiling extends deeper into hotter rock and the temperature of the steam increases. This model explains most features of the published production behavior of these systems and can be used to guide exploitation policies. ?? 1973.

  10. Artificial neural network modeling of dissolved oxygen in reservoir.

    PubMed

    Chen, Wei-Bo; Liu, Wen-Cheng

    2014-02-01

    The water quality of reservoirs is one of the key factors in the operation and water quality management of reservoirs. Dissolved oxygen (DO) in water column is essential for microorganisms and a significant indicator of the state of aquatic ecosystems. In this study, two artificial neural network (ANN) models including back propagation neural network (BPNN) and adaptive neural-based fuzzy inference system (ANFIS) approaches and multilinear regression (MLR) model were developed to estimate the DO concentration in the Feitsui Reservoir of northern Taiwan. The input variables of the neural network are determined as water temperature, pH, conductivity, turbidity, suspended solids, total hardness, total alkalinity, and ammonium nitrogen. The performance of the ANN models and MLR model was assessed through the mean absolute error, root mean square error, and correlation coefficient computed from the measured and model-simulated DO values. The results reveal that ANN estimation performances were superior to those of MLR. Comparing to the BPNN and ANFIS models through the performance criteria, the ANFIS model is better than the BPNN model for predicting the DO values. Study results show that the neural network particularly using ANFIS model is able to predict the DO concentrations with reasonable accuracy, suggesting that the neural network is a valuable tool for reservoir management in Taiwan. PMID:24078053

  11. Thermal Drawdown-Induced Flow Channeling in Fractured Geothermal Reservoirs

    NASA Astrophysics Data System (ADS)

    Fu, Pengcheng; Hao, Yue; Walsh, Stuart D. C.; Carrigan, Charles R.

    2016-03-01

    We investigate the flow-channeling phenomenon caused by thermal drawdown in fractured geothermal reservoirs. A discrete fracture network-based, fully coupled thermal-hydrological-mechanical simulator is used to study the interactions between fluid flow, temperature change, and the associated rock deformation. The responses of a number of randomly generated 2D fracture networks that represent a variety of reservoir characteristics are simulated with various injection-production well distances. We find that flow channeling, namely flow concentration in cooled zones, is the inevitable fate of all the scenarios evaluated. We also identify a secondary geomechanical mechanism caused by the anisotropy in thermal stress that counteracts the primary mechanism of flow channeling. This new mechanism tends, to some extent, to result in a more diffuse flow distribution, although it is generally not strong enough to completely reverse flow channeling. We find that fracture intensity substantially affects the overall hydraulic impedance of the reservoir but increasing fracture intensity generally does not improve heat production performance. Increasing the injection-production well separation appears to be an effective means to prolong the production life of a reservoir.

  12. Tandem-type pulse tube refrigerator without reservoir

    NASA Astrophysics Data System (ADS)

    Ki, Taekyung; Jeong, Sangkwon; Ko, Junseok; Park, Jiho

    2015-12-01

    In this paper, a tandem-type pulse tube refrigerator without a reservoir is discussed and investigated. For its practical application a tandem-type compressor is designed to generate two pulsating pressure waves with opposite phases, simultaneously. A tandem-type pulse tube refrigerator consists of a tandem-type compressor and two identical pulse tube refrigerators. The two identical pulse tube refrigerators share the same heat exchangers and one can be connected with the other by an inertance tube without a reservoir. In this proposed configuration, the mechanical vibration and temperature oscillations in the cold-end heat exchanger can be internally suppressed due to its intrinsic opposite-characteristic operation. To examine the quantitative evaluation of the tandem feature which does not require a reservoir in the pulse tube, an evolutionary approach has been attempted. A general structure of a pulse tube refrigerator is modified into tandem Stirling-type and GM-type machines and the transformed configuration has been simulated for tandem operation. The simulation results clearly demonstrate that a properly designed tandem-type pulse tube refrigerator without a reservoir can function favorably.

  13. Modeling reservoir density underflow and interflow from a chemical spill

    USGS Publications Warehouse

    Gu, R.; McCutcheon, S.C.; Wang, P.-F.

    1996-01-01

    An integral simulation model has been developed for understanding and simulating the process of a density current and the transport of spilled chemicals in a stratified reservoir. The model is capable of describing flow behavior and mixing mechanisms in different flow regimes (plunging flow, underflow, and interflow). It computes flow rate, velocity, flow thickness, mixing parameterized by entrainment and dilution, depths of plunging, separation and intrusion, and time of travel. The model was applied to the Shasta Reservoir in northern California during the July 1991 Sacramento River chemical spill. The simulations were used to assist in the emergency response, confirm remediation measures, and guide data collection. Spill data that were available after the emergency response are used to conduct a postaudit of the model results. Predicted flow parameters are presented and compared with observed interflow intrusion depth, travel time, and measured concentrations of spilled chemicals. In the reservoir, temperature difference between incoming river flow and ambient lake water played a dominant role during the processes of flow plunging, separation, and intrusion. With the integral approach, the gross flow behavior can be adequately described and information useful in the analysis of contaminated flow in a reservoir after a spill is provided.

  14. Experimental Results of Hydrate Reservoir Destabilization Through Heating

    NASA Astrophysics Data System (ADS)

    Leeman, J.; Hornbach, M. J.; Elwood-Madden, M.; Phelps, T. J.; Rawn, C. J.

    2011-12-01

    Gas clathrate reservoirs have been considered as possible sources of energy, as hazards to deep water drilling operations, and as contributors to global climate change. Clathrate destabilization may occur through depressurization of the reservoir, addition of chemical inhibitors, or heating the reservoir. Meso-scale heat conduction experiments were conducted in the Seafloor Process Simulator (SPS) at Oak Ridge National Laboratory in an attempt to apply experimental constraints to purely numerical models of heat transfer within a nearly isobaric reservoir. A column of saturated sediment was place inside the pressure vessel and pressurized to conditions sufficient to form methane clathrate at seafloor temperatures, while the system remained at room temperature (298K). Once pressurized, the temperature of the vessel was then lowered to approximately 275K, forming pore filling clathrate in the sediment column. Following hydrate formation, heat was supplied to the center of the clathrate reservoir through a hot fluid heat exchanger embedded in the sediment column to dissociate the methane hydrate. Relative changes in temperature within the hydrate-sediment column were monitored with a fiber optic quasi-distributed sensing system (DSS), along with temperature and pressure within the vessel headspace. Using the DSS Plotter analysis software, it was determined that an axis-symmetric section of clathrate was dissociated around the heat exchanger. Clathrate dissociation was accompanied by a small rise in vessel headspace pressure in addition to the expected thermal expansion of the headspace gas. The quantity of heat input to the system was calculated from the drop in fluid temperature as it flowed through the heat exchanger. Increased heat input resulted in an increase in the volume of hydrate dissociated. Clathrate rapidly reformed immediately upon the removal of the heat energy. A simple numerical model has been developed to simulate the heat flow in the system. Early

  15. Reconstructing magma reservoir dynamics from field evidence

    NASA Astrophysics Data System (ADS)

    Verberne, R.; Muntener, O.; Ulmer, P.

    2013-12-01

    Reconstructing the dynamics within magma reservoirs during and after emplacement greatly enhance our understanding of their formation and evolution. By determining the length and timescales over which magma remains mobile within magma reservoirs, fluxes of magma that is possibly extractable can be quantified, providing a link between plutonic and volcanic systems, and constraints on the likelihood of a pluton feeding volcanic eruptions. However, the general absence of marker beds and uncertainties regarding at which crystal fractions super-solidus foliation patterns are recorded make it difficult to reconstruct and quantify deformation inside plutons, especially the deformation that occurred at low crystal fractions. Here we present a case study of the Listino Ring Structure (LRS) of the Adamello Batholith in N-Italy, a 300-500 m-wide semi-circular zone of intensely foliated tonalite containing abundant evidence for magmatic deformation and magma mingling (Brack, 1984). The differences in the interaction between felsic and mafic magmas recorded in the form of mafic dikes, sheets and enclaves can be used to determine spatial and/or temporal differences of magma rheology during evolution of the reservoir. Detailed field mapping shows a clear difference in intrusion style between the southern and eastern sides of the LRS, as mafic magma intrudes into different felsic host magmas. An attempt is made to quantify these differences in terms of the physical state of the host magmas, using a variety of analyses pertaining to the breakup of mafic dikes into enclaves, the assimilation of phenocrysts from the host magma by the mafic magma, and the back-veining of mafic dikes and enclaves. The common component of these analyses is a parametrization of the phase petrology of the magmas as a function of temperature, which allows for the determination of melt fraction and composition at super-solidus conditions, from which physical properties such as density and viscosity can be

  16. Redesigning reservoir compensation releases for ecological beenfit

    NASA Astrophysics Data System (ADS)

    Maynard, Carly

    2010-05-01

    River regulation is commonplace in England and much of the UK. Regulation for the purposes of public water supply causes flows downstream of a reservoir to be attenuated and the flow regime of the channel to be altered. The impact of channel impoundment on a small, upland UK river, has been assessed and methods for mitigation of ecological impacts explored. The method utilised a unique macroinvertebrate data set for pre- and post-impoundment periods to quantify the impact of Derwent Reservoir and the steady, continuous compensation release into the River Derwent, Northumberland. Impacts on the hydrological regime were also investigated and links drawn between changes in flow regime and changes in macroinvertebrate richness and diversity as a result of impoundment. In response to the claim that the impoundment has caused a change in flow regime and had deleterious effects on fish and macroinvertebrates, a compensation redesign tool (CRAB: Compensation Release Assessment at the Broad scale) was employed to design new compensation release regimes from the reservoir which account for the seasonal flow requirements of a number of key fish species. The impact of impoundment on the current flow regime was modelled and the impacts of predicted new regimes were predicted, using a 1D hydrodynamic model (HEC-RAS), as part of a modelling process known as CRAM (Compensation Release Assessment at the Meso-scale). Depth and velocity were the foci of the analysis as they are the two habitat requirements most well documented for the fish species in question, they could be modelled using HEC-RAS and they can act as surrogates for other habitat parameters such as temperature and substrate. The suitability of the depth and velocity combinations predicted using the HEC-RAS model were assessed using fuzzy-rule based modelling, which allowed the habitat quality of a given parameter combination to be quantified. Based on the results of the investigation it was concluded that there has

  17. Storage capacity in hot dry rock reservoirs

    DOEpatents

    Brown, D.W.

    1997-11-11

    A method is described for extracting thermal energy, in a cyclic manner, from geologic strata which may be termed hot dry rock. A reservoir comprised of hot fractured rock is established and water or other liquid is passed through the reservoir. The water is heated by the hot rock, recovered from the reservoir, cooled by extraction of heat by means of heat exchange apparatus on the surface, and then re-injected into the reservoir to be heated again. Water is added to the reservoir by means of an injection well and recovered from the reservoir by means of a production well. Water is continuously provided to the reservoir and continuously withdrawn from the reservoir at two different flow rates, a base rate and a peak rate. Increasing water flow from the base rate to the peak rate is accomplished by rapidly decreasing backpressure at the outlet of the production well in order to meet periodic needs for amounts of thermal energy greater than a baseload amount, such as to generate additional electric power to meet peak demands. The rate of flow of water provided to the hot dry rock reservoir is maintained at a value effective to prevent depletion of the liquid inventory of the reservoir. 4 figs.

  18. Reservoir characterization of the Upper Jurassic geothermal target formations (Molasse Basin, Germany): role of thermofacies as exploration tool

    NASA Astrophysics Data System (ADS)

    Homuth, S.; Götz, A. E.; Sass, I.

    2015-06-01

    The Upper Jurassic carbonates of the southern German Molasse Basin are the target of numerous geothermal combined heat and power production projects since the year 2000. A production-orientated reservoir characterization is therefore of high economic interest. Outcrop analogue studies enable reservoir property prediction by determination and correlation of lithofacies-related thermo- and petrophysical parameters. A thermofacies classification of the carbonate formations serves to identify heterogeneities and production zones. The hydraulic conductivity is mainly controlled by tectonic structures and karstification, whilst the type and grade of karstification is facies related. The rock permeability has only a minor effect on the reservoir's sustainability. Physical parameters determined on oven-dried samples have to be corrected, applying reservoir transfer models to water-saturated reservoir conditions. To validate these calculated parameters, a Thermo-Triaxial-Cell simulating the temperature and pressure conditions of the reservoir is used and calorimetric and thermal conductivity measurements under elevated temperature conditions are performed. Additionally, core and cutting material from a 1600 m deep research drilling and a 4850 m (total vertical depth, measured depth: 6020 m) deep well is used to validate the reservoir property predictions. Under reservoir conditions a decrease in permeability of 2-3 magnitudes is observed due to the thermal expansion of the rock matrix. For tight carbonates the matrix permeability is temperature-controlled; the thermophysical matrix parameters are density-controlled. Density increases typically with depth and especially with higher dolomite content. Therefore, thermal conductivity increases; however the dominant factor temperature also decreases the thermal conductivity. Specific heat capacity typically increases with increasing depth and temperature. The lithofacies-related characterization and prediction of reservoir

  19. Seismic Imaging of Reservoir Structure at The Geysers Geothermal Reservoir

    NASA Astrophysics Data System (ADS)

    Gritto, R.; Yoo, S.; Jarpe, S.

    2013-12-01

    Three-dimensional Vp/Vs-ratio structure is presented for The Geysers geothermal field using seismic travel-time data. The data were recorded by the Lawrence Berkeley National Laboratory (LBNL) using a 34-station seismic network. The results are based on 32,000 events recorded in 2011 and represent the highest resolution seismic imaging campaign at The Geysers to date. The results indicate low Vp/Vs-ratios in the central section of The Geysers within and below the current reservoir. The extent of the Vp/Vs anomaly deceases with increasing depth. Spatial correlation with micro-seismicity, used as a proxy for subsurface water flow, indicates the following. Swarms of seismicity correlate well with areas of high and intermediate Vp/Vs estimates, while regions of low Vp/Vs estimates appear almost aseismic. This result supports past observations that high and low Vp/Vs-ratios are related to water and gas saturated zones, respectively. In addition, the correlation of seismicity to intermediate Vp/Vs-ratios is supportive of the fact that the process of water flashing to steam requires four times more energy than the initial heating of the injected water to the flashing point. Because this energy is dawn from the reservoir rock, the associated cooling of the rock generates more contraction and thus seismic events than water being heated towards the flashing point. The consequences are the presence of some events in regions saturated with water, most events in regions of water flashing to steam (low steam saturation) and the absence of seismicity in regions of high steam concentrations where the water has already been converted to steam. Furthermore, it is observed that Vp/Vs is inversely correlated to Vs but uncorrelated to Vp, leading support to laboratory measurements on rock samples from The Geysers that observe an increase in shear modulus while the core samples are dried out. As a consequence, traditional poroelastic theory is no applicable at The Geysers geothermal

  20. Optical Thermometry of an Electron Reservoir Coupled to a Single Quantum Dot in the Millikelvin Range

    NASA Astrophysics Data System (ADS)

    Seilmeier, F.; Hauck, M.; Schubert, E.; Schinner, G. J.; Beavan, S. E.; Högele, A.

    2014-08-01

    We show how resonant laser spectroscopy of the trion optical transitions in a self-assembled quantum dot can be used to determine the temperature of a nearby electron reservoir. At finite magnetic field, the spin-state occupation of the Zeeman-split quantum-dot electron ground states is governed by thermalization with the electron reservoir via cotunneling. With resonant spectroscopy of the corresponding excited trion states, we map out the spin occupation as a function of magnetic field to establish optical thermometry for the electron reservoir. We demonstrate the implementation of the technique in the subkelvin temperature range where it is most sensitive and where the electron temperature is not necessarily given by the cryostat base temperature.

  1. Semi-analytical solutions for nonisothermal fluid injection including heat loss from the reservoir: Part 2. Pressure and stress

    NASA Astrophysics Data System (ADS)

    LaForce, T.; Mijić, A.; Ennis-King, J.; Paterson, L.

    2014-11-01

    In this work semi-analytical solutions for saturation, temperature, pressure and in situ reservoir stress are found for immiscible nonisothermal injection into a radial porous medium. A model for advection-dominated, nonisothermal, two-phase flow from a previous work is used to estimate the reservoir pressure and stress that result from injection of cold CO2. Flow is assumed to be one-dimensional and purely advective, while temperature has radial advection in the reservoir and transverse diffusion into the surrounding media. A simplified thermal solution is developed to allow for easier analysis of the reservoir stress. Two pressure models are presented, one which requires numerical integration of the pressure in the two-phase region, and one which is fully analytical, but simplifies the pressure profile. Two models are used to calculate reservoir stress, one which uses the full pressure and temperature profiles and must be numerically integrated, and one which uses the simplified models and has a closed-form analytical solution. The resulting radial and tangential (hoop) stress profiles in the reservoir are compared and it is shown that the simplified model is adequate for estimating the reservoir stresses. The impact of outer boundary conditions on reservoir pressure and stresses is also explored.

  2. New Simulator for Non-Equilibrium Modeling of Hydrate Reservoirs

    NASA Astrophysics Data System (ADS)

    Kvamme, B.; Qorbani Nashaqi, K.; Jemai, K.; Vafaei, M.

    2014-12-01

    Due to Gibbs phase rule and combination of first and second law of thermodynamics, hydrate in nature cannot be in equilibrium since they come from different parent phases. In this system hydrate formation and dissociation is affected by local variables such as pressure, temperature and composition with mass and energy transport restrictions. Available simulators have attempted to model hydrate phase transition as an equilibrium reaction. Although those which treated the processes of formation and dissociation as kinetics used model of Kim and Bishnoi based on laboratory PVT experiment, and consequently hard to accept up scaling to real reservoirs condition. Additionally, they merely check equilibrium in terms of pressure and temperature projections and disregard thermodynamic requirements for equilibrium especially along axes of concentrations in phases. Non-equilibrium analysis of hydrate involves putting aside all the phase transitions which are not possible and use kinetic evaluation to measure phase transitions progress in each grid block for each time step. This procedure is Similar to geochemical reservoir simulators logic. As a result RetrasoCodeBright has been chosen as hydrate reservoir simulator and our work involves extension of this code. RetrasoCodeBright (RCB) is able to handle competing processes of formation and dissociation of hydrates as pseudo reactions at each node and each time step according to the temperature, pressure and concentration. Hydrates can therefore be implemented into the structure as pseudo minerals, with appropriate kinetic models. In order to implement competing nature of phase transition kinetics of hydrate formation, we use classical nucleation theory based on Kvamme et al. as a simplified model inside RCB and use advanced theories to fit parameters for the model (PFT). Hydrate formation and dissociation can directly be observed through porosity changes in the specific areas of the porous media. In this work which is in

  3. Particle dynamics in high-Alpine proglacial reservoirs modified by pumped-storage operation

    NASA Astrophysics Data System (ADS)

    Bonalumi, Matteo; Anselmetti, Flavio S.; Kaegi, Ralf; Wüest, Alfred

    2011-09-01

    Temperature and suspended particle distribution were surveyed and modeled in two high-Alpine reservoirs in Switzerland, connected by pumped-storage operations for ˜30 years. Due to different glacier coverage of the catchments, the two reservoirs exhibit different particle concentrations and temperatures. After ice-breakup, the lower reservoir with a higher glacier cover in its catchment experiences a higher particle input becoming more turbid than the upper reservoir, which in contrast becomes warmer and thermally more stratified. The pumped-storage operations, which replace the basin volumes annually at least 6 (larger lower basin) to 10 (smaller upper basin) times, modify the physical characteristics of the two reservoirs. This is especially so in winter, when they are ice-covered, without riverine input and at low water level. Our reservoir investigations between 2007 and 2009 and the subsequent particle-balance model show that the upper and lower basins have become more and less turbid, respectively. Pumped-storage operations modify the stratification and particle distribution in both reservoirs and therefore alter the particle outflow and sedimentation. However, on the basis of particle concentrations and reservoir volumes, it is evident that the annually integrated particle release to downstream (˜40% of total) and to overall sedimentation (˜60%) have hardly changed. The budget model was useful in the prediction of particle distribution and sedimentation dynamics in the pumped-storage system. It implies that this approach can be useful for further employment during planning stages of power plants in order to modify and mitigate downstream particle loads in reservoir operations.

  4. Reservoir monitoring: 1990 summary of vital signs and use impairment monitoring on Tennessee Valley Reservoirs

    SciTech Connect

    Dycus, D.L.; Meinert, D.L.

    1991-08-01

    The Tennessee Valley Authority (TVA) initiated a Reservoir Monitoring Program on 12 TVA reservoirs (the nine main stream Tennessee river reservoirs -- Kentucky through Fort Loudoun and three major tributary storage reservoirs -- Cherokee, Douglas, and Norris) in autumn 1989. The objective of the Reservoir Monitoring Program is to provide basic information on the health'' or integrity of the aquatic ecosystem in each TVA reservoir ( Vital Signs'') and to provide screening level information for describing how well each reservoir meets the swimmable and fishable goals of the Clean Water Act (Use Impairments). This is the first time in the history of the agency that a commitment to a long-term, systematic sampling of major TVA reservoirs has been made. The basis of the Vital Signs Monitoring is examination of appropriate physical, chemical, and biological indicators in three areas of each reservoir. These three areas are the forebay immediately upstream of the dam; the transition zone (the mid-reservoir region where the water changes from free flowing to more quiescent, impounded water); and the inflow or headwater region of the reservoir. The Use Impairments monitoring provides screening level information on the suitability of selected areas within TVA reservoirs for water contact activities (swimmable) and suitability of fish from TVA reservoirs for human consumption (fishable).

  5. IMPROVING CO2 EFFICIENCY FOR RECOVERING OIL IN HETEROGENEOUS RESERVOIRS

    SciTech Connect

    Reid B. Grigg

    2003-10-31

    The second annual report of ''Improving CO{sub 2} Efficiency for Recovery Oil in Heterogeneous Reservoirs'' presents results of laboratory studies with related analytical models for improved oil recovery. All studies have been undertaken with the intention to optimize utilization and extend the practice of CO{sub 2} flooding to a wider range of reservoirs. Many items presented in this report are applicable to other interest areas: e.g. gas injection and production, greenhouse gas sequestration, chemical flooding, reservoir damage, etc. Major areas of studies include reduction of CO{sub 2} mobility to improve conformance, determining and understanding injectivity changes in particular injectivity loses, and modeling process mechanisms determined in the first two areas. Interfacial tension (IFT) between a high-pressure, high-temperature CO{sub 2} and brine/surfactant and foam stability are used to assess and screen surfactant systems. In this work the effects of salinity, pressure, temperature, surfactant concentration, and the presence of oil on IFT and CO{sub 2} foam stability were determined on the surfactant (CD1045{trademark}). Temperature, pressure, and surfactant concentration effected both IFT and foam stability while oil destabilized the foam, but did not destroy it. Calcium lignosulfonate (CLS) can be used as a sacrificial and an enhancing agent. This work indicates that on Berea sandstone CLS concentration, brine salinity, and temperature are dominant affects on both adsorption and desorption and that adsorption is not totally reversible. Additionally, CLS adsorption was tested on five minerals common to oil reservoirs; it was found that CLS concentration, salinity, temperature, and mineral type had significant effects on adsorption. The adsorption density from most to least was: bentonite > kaolinite > dolomite > calcite > silica. This work demonstrates the extent of dissolution and precipitation from co-injection of CO{sub 2} and brine in limestone core

  6. Global Carbon Reservoir Oxidative Ratios

    NASA Astrophysics Data System (ADS)

    Masiello, C. A.; Gallagher, M. E.; Hockaday, W. C.

    2010-12-01

    Photosynthesis and respiration move carbon and oxygen between the atmosphere and the biosphere at a ratio that is characteristic of the biogeochemical processes involved. This ratio is called the oxidative ratio (OR) of photosynthesis and respiration, and is defined as the ratio of moles of O2 per moles of CO2. This O2/CO2 ratio is a characteristic of biosphere-atmosphere gas fluxes, much like the 13C signature of CO2 transferred between the biosphere and the atmosphere has a characteristic signature. OR values vary on a scale of 0 (CO2) to 2 (CH4), with most ecosystem values clustered between 0.9 and 1.2. Just as 13C can be measured for both carbon fluxes and carbon pools, OR can also be measured for fluxes and pools and can provide information about the processes involved in carbon and oxygen cycling. OR values also provide information about reservoir organic geochemistry because pool OR values are proportional to the oxidation state of carbon (Cox) in the reservoir. OR may prove to be a particularly valuable biogeochemical tracer because of its ability to couple information about ecosystem gas fluxes with ecosystem organic geochemistry. We have developed 3 methods to measure the OR of ecosystem carbon reservoirs and intercalibrated them to assure that they yield accurate, intercomparable data. Using these tools we have built a large enough database of biomass and soil OR values that it is now possible to consider the implications of global patterns in ecosystem OR values. Here we present a map of the natural range in ecosystem OR values and begin to consider its implications. One striking pattern is an apparent offset between soil and biospheric OR values: soil OR values are frequently higher than that of their source biomass. We discuss this trend in the context of soil organic geochemistry and gas fluxes.

  7. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    SciTech Connect

    Joel Walls; M.T. Taner; Gary Mavko; Jack Dvorkin

    2002-04-01

    Wave-induced variations of pore pressure in a partially-saturated reservoir result in oscillatory liquid flow. The viscous losses during this flow are responsible for wave attenuation. The same viscous effects determine the changes in the dynamic bulk modulus of the system versus frequency. These changes are necessarily linked to attenuation via the causality condition. We analytically quantify the frequency dependence of the bulk modulus of a partially saturated rock by assuming that saturation is patchy and then link these changes to the inverse quality factor. As a result, the P-wave attenuation is quantitatively linked to saturation and thus can serve as a saturation indicator.

  8. Evaporation study at Warm Springs Reservoir, Oregon

    USGS Publications Warehouse

    Harris, D.D.

    1968-01-01

    The mass transfer-water budget method of computing reservoir evaporation was tested on Warm Springs Reservoir, whose contents and surface area change greatly from early spring to late summer. The mass-transfer coefficient computed for the reservoir is two to three times greater than expected and results in a computed evaporation much greater than that from a land pan. Because of the remoteness of the area, the recommended study technique was modified, which could have reduced the accuracy of the results.

  9. A virtual company concept for reservoir management

    SciTech Connect

    Martin, F.D.; Kendall, R.P.; Whitney, E.M.

    1998-12-31

    This paper describes how reservoir management problems were pursued with a virtual company concept via the Internet and World Wide Web. The focus of the paper is on the implementation of virtual asset management teams that were assembled with small independent oil companies. The paper highlights the mechanics of how the virtual team transferred data and interpretations, evaluated geological models of complex reservoirs, and used results of simulation studies to analyze various reservoir management strategies.

  10. Oil recovery from naturally fractured reservoirs by steam injection methods. Final report

    SciTech Connect

    Reis, J.C.; Miller, M.A.

    1995-05-01

    Oil recovery by steam injection is a proven, successful technology for nonfractured reservoirs, but has received only limited study for fractured reservoirs. Preliminary studies suggest recovery efficiencies in fractured reservoirs may be increased by as much as 50% with the application of steam relative to that of low temperature processes. The key mechanisms enhancing oil production at high temperature are the differential thermal expansion between oil and the pore volume, and the generation of gases within matrix blocks. Other mechanisms may also contribute to increased production. These mechanisms are relatively independent of oil gravity, making steam injection into naturally fractured reservoirs equally attractive to light and heavy oil deposits. The objectives of this research program are to quantify the amount of oil expelled by these recovery mechanisms and to develop a numerical model for predicting oil recovery in naturally fractured reservoirs during steam injection. The experimental study consists of constructing and operating several apparatuses to isolate each of these mechanisms. The first measures thermal expansion and capillary imbibition rates at relatively low temperature, but for various lithologies and matrix block shapes. The second apparatus measures the same parameters, but at high temperatures and for only one shape. A third experimental apparatus measures the maximum gas saturations that could build up within a matrix block. A fourth apparatus measures thermal conductivity and diffusivity of porous media. The numerical study consists of developing transfer functions for oil expulsion from matrix blocks to fractures at high temperatures and incorporating them, along with the energy equation, into a dual porosity thermal reservoir simulator. This simulator can be utilized to make predictions for steam injection processes in naturally-fractured reservoirs. Analytical models for capillary imbibition have also been developed.

  11. Climate Impacts on Reservoir Operations for Fish Sustainability on the Sacramento River

    NASA Astrophysics Data System (ADS)

    Saito, L.; Caldwell, R. J.; Rajagopalan, B.

    2011-12-01

    The propagation of the endangered winter-run Chinook salmon fishery on the Sacramento River in California is an ongoing concern that may be exacerbated by climate change. The construction of numerous dams on the river (most notably, Shasta Dam and Reservoir in 1945) prevented the salmon from reaching their native cold-water spawning habitat, causing populations to decline. Since 1989, operations at Shasta Dam have attempted to provide cold-water habitat downstream of the dam to promote salmon spawning. We have partnered stochastic weather generation with two-dimensional hydrodynamic modeling of reservoir operations to examine the feasibility of meeting downstream temperature targets for the salmon fishery. Stochastically generated climate and inflow scenarios created with historical data from 1994 to 2007 are input into a CE-QUAL-W2 model of the reservoir that can simulate reservoir operations, including selective withdrawal from multiple gates to meet water delivery and temperature targets. Results of these simulations will be presented. Ultimately, simulated outflows and release temperatures from the reservoir will be used with statistical models of stream temperature to examine the feasibility of meeting Sacramento River temperature targets at Balls Ferry under different future climate scenarios. We also plan to partner reservoir simulation results with bioenergetics scope for growth models to assess impacts of climate and reservoir operations on upstream and downstream fisheries. The goal of the integrated modeling system is to provide seasonal and longer time-scale planning tools to operators on the river that will assist in the maintenance of cold-water supply for salmon. Once complete, the framework will allow testing of alternative operating criteria to meet the thermal requirements on the river.

  12. Storage capacity in hot dry rock reservoirs

    DOEpatents

    Brown, Donald W.

    1997-01-01

    A method of extracting thermal energy, in a cyclic manner, from geologic strata which may be termed hot dry rock. A reservoir comprised of hot fractured rock is established and water or other liquid is passed through the reservoir. The water is heated by the hot rock, recovered from the reservoir, cooled by extraction of heat by means of heat exchange apparatus on the surface, and then re-injected into the reservoir to be heated again. Water is added to the reservoir by means of an injection well and recovered from the reservoir by means of a production well. Water is continuously provided to the reservoir and continuously withdrawn from the reservoir at two different flow rates, a base rate and a peak rate. Increasing water flow from the base rate to the peak rate is accomplished by rapidly decreasing backpressure at the outlet of the production well in order to meet periodic needs for amounts of thermal energy greater than a baseload amount, such as to generate additional electric power to meet peak demands. The rate of flow of water provided to the hot dry rock reservoir is maintained at a value effective to prevent depletion of the liquid

  13. Drought Prediction Technique For Reservoir Operation

    NASA Astrophysics Data System (ADS)

    Khayyat Kholghi, M.

    After three years critical drought period, Iran is facing a great problem on water re- sources. In this situation, several reservoir dams in this country can play an efficient role for solving an important part of this problem. One of the essential parameters in reservoir simulation is the inflow discharge. Predicting the likelihood of a drought markedly enhance the efficiency of reservoir operation. This study applies the kriging method to predict inflows to Dez reservoir dam in Southern Iran. Thirty-eight years of the one, ten, fifteen and monthly period reservoir inflow data were used in this study. A subsequent reservoir operation simulation is employed to determine the drought lead-time. An efficient reservoir operational strategy can be established with the aid of this time and the probability of successful drought prediction. According to simu- lation results, the kriging approach in terms of the number droughts being correctly predicted the drought lead-time and the probability of success of drought prediction. Keywords: Drought-prediction-kriging-reservoir operation-simulation-Dez reservoir dam-Iran

  14. Geothermal reservoirs in hydrothermal convection systems

    SciTech Connect

    Sorey, M.L.

    1982-01-01

    Geothermal reservoirs commonly exist in hydrothermal convection systems involving fluid circulation downward in areas of recharge and upwards in areas of discharge. Because such reservoirs are not isolated from their surroundings, the nature of thermal and hydrologic connections with the rest of the system may have significant effects on the natural state of the reservoir and on its response to development. Conditions observed at numerous developed and undeveloped geothermal fields are discussed with respect to a basic model of the discharge portion of an active hydrothermal convection system. Effects of reservoir development on surficial discharge of thermal fluid are also delineated.

  15. Stretch due to Penile Prosthesis Reservoir Migration

    PubMed Central

    Baten, E.; Vandewalle, T.; van Renterghem, K.

    2016-01-01

    A 43-year old patient presented to the emergency department with stretch, due to impossible deflation of the penile prosthesis, 4 years after successful implant. A CT-scan showed migration of the reservoir to the left rectus abdominis muscle. Refilling of the reservoir was inhibited by muscular compression, causing stretch. Removal and replacement of the reservoir was performed, after which the prosthesis was well-functioning again. Migration of the penile prosthesis reservoir is extremely rare but can cause several complications, such as stretch. PMID:26793592

  16. Modelling sub-daily evaporation from a small reservoir.

    NASA Astrophysics Data System (ADS)

    McGloin, Ryan; McGowan, Hamish; McJannet, David; Burn, Stewart

    2013-04-01

    Accurate quantification of evaporation from small water storages is essential for water management and is also required as input in some regional hydrological and meteorological models. Global estimates of the number of small storages or lakes (< 0.1 kilometers) are estimated to be in the order of 300 million (Downing et al., 2006). However, direct evaporation measurements at small reservoirs using the eddy covariance or scintillometry techniques have been limited due to their expensive and complex nature. To correctly represent the effect that small water bodies have on the regional hydrometeorology, reliable estimates of sub-daily evaporation are necessary. However, evaporation modelling studies at small reservoirs have so far been limited to quantifying daily estimates. In order to ascertain suitable methods for accurately modelling hourly evaporation from a small reservoir, this study compares evaporation results measured by the eddy covariance method at a small reservoir in southeast Queensland, Australia, to results from several modelling approaches using both over-water and land-based meteorological measurements. Accurate predictions of hourly evaporation were obtained by a simple theoretical mass transfer model requiring only over-water measurements of wind speed, humidity and water surface temperature. An evaporation model that was recently developed for use in small reservoir environments by Granger and Hedstrom (2011), appeared to overestimate the impact stability had on evaporation. While evaporation predictions made by the 1-dimensional hydrodynamics model, DYRESM (Dynamic Reservoir Simulation Model) (Imberger and Patterson, 1981), showed reasonable agreement with measured values. DYRESM did not show any substantial improvement in evaporation prediction when inflows and out flows were included and only a slighter better correlation was shown when over-water meteorological measurements were used in place of land-based measurements. Downing, J. A., Y. T

  17. Estimating Reservoir Sedimentation Rates: Long-Term Implications for California's Reservoirs

    NASA Astrophysics Data System (ADS)

    Minear, J. T.; Kondolf, G. M.

    2004-12-01

    This paper presents a compilation and analysis of reservoir sedimentation rates applied to unsurveyed reservoirs in California. A number of reservoirs, primarily in the Coast Ranges, have already filled or are nearly filled with sediment and are being considered for removal, including the Matilija, San Clemente, Rindge and Searsville Dams. Of the over 1,400 dams in California listed in the National Inventory of Dams (NID), only 213 (15%) have been surveyed for reservoir sedimentation, presenting a significant gap in current knowledge. Using previously published reports on reservoir sedimentation rates (excluding flood control and debris flow basins), we determined the median reservoir sedimentation rates for the nine different geomorphic regions in California. For the geomorphic regions with sedimentation data, the median sedimentation rate +/- standard error in m3 km-2 yr-1, and (number of measured reservoirs) are: Siskiyou: 340 +/- 170 (3), Coast Range: 220 +/- 50 (49), Central Valley: 145 +/- 90 (5), Sierra Nevada: 95 +/- 25 (23), Transverse Range: 500 +/- 200 (18), and Peninsular Range: 260 +/- 185 (4). These reservoir sedimentation rates were then applied to the unsurveyed reservoirs. Of the approximately 42 million acre-feet of water storage in the state, approximately 5.14 million acre-feet may be currently occupied by sediment, representing a significant decrease of 12% of the state's water supply. Using the same rates to forecast the effects after 50-years, we found that the reservoirs with most risk of sedimentation are primarily small reservoirs (<2,500 acre-feet), such as municipal water-supply reservoirs, especially those operated by coastal towns and cities. Reservoirs in the Coast and Transverse Ranges are the most at risk, with high sedimentation rates, small reservoirs on large watersheds, and older reservoirs. There are over twenty reservoirs that will likely be full or nearly full in 50-years, including Tinemaha, Pleasant Valley, Lee Lake

  18. Analysis of formation pressure test results in the Mount Elbert methane hydrate reservoir through numerical simulation

    USGS Publications Warehouse

    Kurihara, M.; Sato, A.; Funatsu, K.; Ouchi, H.; Masuda, Y.; Narita, H.; Collett, T.S.

    2011-01-01

    Targeting the methane hydrate (MH) bearing units C and D at the Mount Elbert prospect on the Alaska North Slope, four MDT (Modular Dynamic Formation Tester) tests were conducted in February 2007. The C2 MDT test was selected for history matching simulation in the MH Simulator Code Comparison Study. Through history matching simulation, the physical and chemical properties of the unit C were adjusted, which suggested the most likely reservoir properties of this unit. Based on these properties thus tuned, the numerical models replicating "Mount Elbert C2 zone like reservoir" "PBU L-Pad like reservoir" and "PBU L-Pad down dip like reservoir" were constructed. The long term production performances of wells in these reservoirs were then forecasted assuming the MH dissociation and production by the methods of depressurization, combination of depressurization and wellbore heating, and hot water huff and puff. The predicted cumulative gas production ranges from 2.16??106m3/well to 8.22??108m3/well depending mainly on the initial temperature of the reservoir and on the production method.This paper describes the details of modeling and history matching simulation. This paper also presents the results of the examinations on the effects of reservoir properties on MH dissociation and production performances under the application of the depressurization and thermal methods. ?? 2010 Elsevier Ltd.

  19. Reservoir Engineering for Unconventional Gas Reservoirs: What Do We Have to Consider?

    SciTech Connect

    Clarkson, Christopher R

    2011-01-01

    The reservoir engineer involved in the development of unconventional gas reservoirs (UGRs) is required to integrate a vast amount of data from disparate sources, and to be familiar with the data collection and assessment. There has been a rapid evolution of technology used to characterize UGR reservoir and hydraulic fracture properties, and there currently are few standardized procedures to be used as guidance. Therefore, more than ever, the reservoir engineer is required to question data sources and have an intimate knowledge of evaluation procedures. We propose a workflow for the optimization of UGR field development to guide discussion of the reservoir engineer's role in the process. Critical issues related to reservoir sample and log analysis, rate-transient and production data analysis, hydraulic and reservoir modeling and economic analysis are raised. Further, we have provided illustrations of each step of the workflow using tight gas examples. Our intent is to provide some guidance for best practices. In addition to reviewing existing methods for reservoir characterization, we introduce new methods for measuring pore size distribution (small-angle neutron scattering), evaluating core-scale heterogeneity, log-core calibration, evaluating core/log data trends to assist with scale-up of core data, and modeling flow-back of reservoir fluids immediately after well stimulation. Our focus in this manuscript is on tight and shale gas reservoirs; reservoir characterization methods for coalbed methane reservoirs have recently been discussed.

  20. Hot Dry Rock Geothermal Reservoir Model Development at Los Alamos

    SciTech Connect

    Robinson, Bruce A.; Birdsell, Stephen A.

    1989-03-21

    Discrete fracture and continuum models are being developed to simulate Hot Dry Rock (HDR) geothermal reservoirs. The discrete fracture model is a two-dimensional steady state simulator of fluid flow and tracer transport in a fracture network which is generated from assumed statistical properties of the fractures. The model's strength lies in its ability to compute the steady state pressure drop and tracer response in a realistic network of interconnected fractures. The continuum approach models fracture behavior by treating permeability and porosity as functions of temperature and effective stress. With this model it is practical to model transient behavior as well as the coupled processes of fluid flow, heat transfer, and stress effects in a three-dimensional system. The model capabilities being developed will also have applications in conventional geothermal systems undergoing reinjection and in fractured geothermal reservoirs in general.

  1. Hot Dry Rock geothermal reservoir model development at Los Alamos

    SciTech Connect

    Robinson, B.A.; Birdsell, S.A.

    1989-01-01

    Discrete fracture and continuum models are being developed to simulate Hot Dry Rock (HDR) geothermal reservoirs. The discrete fracture model is a two-dimensional steady state simulator of fluid flow and tracer transport in a fracture network which is generated from assumed statistical properties of the fractures. The model's strength lies in its ability to compute the steady state pressure drop and tracer response in a realistic network of interconnected fractures. The continuum approach models fracture behavior by treating permeability and porosity as functions of temperature and effective stress. With this model it is practical to model transient behavior as well as the coupled processes of fluid flow, heat transfer, and stress effects in a three-dimensional system. The model capabilities being developed will also have applications in conventional geothermal systems undergoing reinjection and in fractured geothermal reservoirs in general. 15 refs., 7 figs.

  2. Research on oil recovery mechanisms in heavy oil reservoirs

    SciTech Connect

    Brigham, W.E.; Aziz, K.; Ramey, H.J. Jr.

    1991-01-01

    The goal of the Stanford University Petroleum Research Institute is to conduct research directed toward increasing the recovery of heavy oils. Presently, SUPRI is working in five main directions: Assess the influence of different reservoir conditions (temperature and pressure) on the absolute and relative permeability to oil and water and on capillary pressure; evaluate the effect of different reservoir parameters on the in-situ combustion process. This project includes the study of the kinetics of the reactions; investigate the mechanisms of the process using commercially available surfactants for reduction of gravity override and channeling of steam; investigate and improve techniques of formation evaluation such as tracer tests and pressure transient tests; and provide technical support for design and monitoring of DOE sponsored or industry initiated field projects.

  3. Laboratory techniques for investigating recovery in heavy oil reservoirs

    SciTech Connect

    Maini, B.; Sayegh, S.

    1983-01-01

    Although general guidelines have been published in the literature for selecting the most suitable tertiary recovery technique for a given reservoir, the actual design of a commercial enhanced recovery scheme is a time- consuming and expensive process requiring computer simulations, experimental field pilots, and extensive laboratory tests. The objective of this work is to review laboratory testing procedures related to heavy oil recovery and to provide reservoir and production engineers with an insight into such procedures so that they may better appreciate their potentials and limitations. The topics discussed include characterization of stock tank oils, phase behavior measurements of oil/gas systems, measurements of relative permeability, and its temperature dependence and core tests for evaluation of CO/sub 2/ stimulation. 22 references.

  4. Carbon Sequestration in Unconventional Reservoirs: Advantages and Limitations

    NASA Astrophysics Data System (ADS)

    Zakharova, N. V.; Slagle, A. L.; Goldberg, D.

    2014-12-01

    by temperature difference between injected fluid and the host formation, may be particularly important for reservoir stability in high-temperature offshore locations. Overall, unconventional reservoirs in offshore locations offer the potential benefits of vast and safe storage for captured CO2 emissions.

  5. 49 CFR 229.49 - Main reservoir system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Main reservoir system. 229.49 Section 229.49... Main reservoir system. (a)(1) The main reservoir system of each locomotive shall be equipped with at... reservoir of air under pressure to be used for operating those power controls. The reservoir shall...

  6. 49 CFR 229.49 - Main reservoir system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Main reservoir system. 229.49 Section 229.49... Main reservoir system. (a)(1) The main reservoir system of each locomotive shall be equipped with at... reservoir of air under pressure to be used for operating those power controls. The reservoir shall...

  7. 49 CFR 229.49 - Main reservoir system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Main reservoir system. 229.49 Section 229.49... Main reservoir system. (a)(1) The main reservoir system of each locomotive shall be equipped with at... reservoir of air under pressure to be used for operating those power controls. The reservoir shall...

  8. 49 CFR 229.49 - Main reservoir system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Main reservoir system. 229.49 Section 229.49... Main reservoir system. (a)(1) The main reservoir system of each locomotive shall be equipped with at... reservoir of air under pressure to be used for operating those power controls. The reservoir shall...

  9. 49 CFR 229.49 - Main reservoir system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Main reservoir system. 229.49 Section 229.49... Main reservoir system. (a)(1) The main reservoir system of each locomotive shall be equipped with at... reservoir of air under pressure to be used for operating those power controls. The reservoir shall...

  10. Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management

    SciTech Connect

    Koerner, Roy; Clarke, Don; Walker, Scott

    1999-11-09

    The objectives of this quarterly report was to summarize the work conducted under each task during the reporting period April - June 1998 and to report all technical data and findings as specified in the ''Federal Assistance Reporting Checklist''. The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology.

  11. Increasing Waterflooding Reservoirs in the Wilmington Oil Field through Improved Reservoir Characterization and Reservoir Management

    SciTech Connect

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

    1999-11-09

    The objectives of this quarterly report are to summarize the work conducted under each task during the reporting period July - September 1998 and to report all technical data and findings as specified in the ''Federal Assistance Reporting Checklist''. The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology.

  12. Spatial isolation and environmental factors drive distinct bacterial and archaeal communities in different types of petroleum reservoirs in China

    PubMed Central

    Gao, Peike; Tian, Huimei; Wang, Yansen; Li, Yanshu; Li, Yan; Xie, Jinxia; Zeng, Bing; Zhou, Jiefang; Li, Guoqiang; Ma, Ting

    2016-01-01

    To investigate the spatial distribution of microbial communities and their drivers in petroleum reservoir environments, we performed pyrosequencing of microbial partial 16S rRNA, derived from 20 geographically separated water-flooding reservoirs, and two reservoirs that had not been flooded, in China. The results indicated that distinct underground microbial communities inhabited the different reservoirs. Compared with the bacteria, archaeal alpha-diversity was not strongly correlated with the environmental variables. The variation of the bacterial and archaeal community compositions was affected synthetically, by the mining patterns, spatial isolation, reservoir temperature, salinity and pH of the formation brine. The environmental factors explained 64.22% and 78.26% of the total variance for the bacterial and archaeal communities, respectively. Despite the diverse community compositions, shared populations (48 bacterial and 18 archaeal genera) were found and were dominant in most of the oilfields. Potential indigenous microorganisms, including Carboxydibrachium, Thermosinus, and Neptunomonas, were only detected in a reservoir that had not been flooded with water. This study indicates that: 1) the environmental variation drives distinct microbial communities in different reservoirs; 2) compared with the archaea, the bacterial communities were highly heterogeneous within and among the reservoirs; and 3) despite the community variation, some microorganisms are dominant in multiple petroleum reservoirs. PMID:26838035

  13. Spatial isolation and environmental factors drive distinct bacterial and archaeal communities in different types of petroleum reservoirs in China

    NASA Astrophysics Data System (ADS)

    Gao, Peike; Tian, Huimei; Wang, Yansen; Li, Yanshu; Li, Yan; Xie, Jinxia; Zeng, Bing; Zhou, Jiefang; Li, Guoqiang; Ma, Ting

    2016-02-01

    To investigate the spatial distribution of microbial communities and their drivers in petroleum reservoir environments, we performed pyrosequencing of microbial partial 16S rRNA, derived from 20 geographically separated water-flooding reservoirs, and two reservoirs that had not been flooded, in China. The results indicated that distinct underground microbial communities inhabited the different reservoirs. Compared with the bacteria, archaeal alpha-diversity was not strongly correlated with the environmental variables. The variation of the bacterial and archaeal community compositions was affected synthetically, by the mining patterns, spatial isolation, reservoir temperature, salinity and pH of the formation brine. The environmental factors explained 64.22% and 78.26% of the total variance for the bacterial and archaeal communities, respectively. Despite the diverse community compositions, shared populations (48 bacterial and 18 archaeal genera) were found and were dominant in most of the oilfields. Potential indigenous microorganisms, including Carboxydibrachium, Thermosinus, and Neptunomonas, were only detected in a reservoir that had not been flooded with water. This study indicates that: 1) the environmental variation drives distinct microbial communities in different reservoirs; 2) compared with the archaea, the bacterial communities were highly heterogeneous within and among the reservoirs; and 3) despite the community variation, some microorganisms are dominant in multiple petroleum reservoirs.

  14. Identifying the factors affecting phytoplankton abundance dynamics in Shihmen Reservoir, Taiwan

    NASA Astrophysics Data System (ADS)

    Kuo, Yi-Ming; Chuang, Illy; Chu, Hone-Jay; Wu, Jiunn-Tzong; Jang, Cheng-Shin

    2013-04-01

    Investigations of multiple temporal distributions of phytoplankton dynamics through environmental variables in water bodies over extensive areas remain relatively scarce. This study focused on the determination of the key factors regulating temporal and spatial variations of phytoplankton abundance at three monitoring sites in Shihmen Reservoir within five years (2006-2010). Dynamic factor analysis (DFA), a dimension-reduction technique, was designed to identify the underlying latent effects in multiple time series and interactions between explanatory variables (i.e., environmental variables) and the response variable (phytoplankton abundance). The optimal DFA model successfully described the dynamics of phytoplankton abundance in the Shihmen Reservoir. The results demonstrated that water temperature, water level, COD, BOD, and DO considerably affected phytoplankton abundance at most of the monitoring sites. Among them, water temperature, water level, and COD significantly affected phytoplankton abundance at all three sites, indicating that these variables contributed more to the long-term dynamics of phytoplankton abundance than other variables at the surface water of Shihmen Reservoir. The influx and efflux of Reservoir altering hydrological conditions in Shihmen Reservoir may attenuate the nutrients effects on phytoplankton abundance. In this study, BOD and DO are the other crucial water quality factors that control variations of phytoplankton. The explanatory variables mainly explain the dynamics of phytoplankton abundance than common trends do. In the future, the water manager may consider these variables to propose strategies to manage water quality in Shihmen Reservoir.

  15. Predicting effects of global climate change on reservoir water quality and fish habitat

    SciTech Connect

    Chang, L H; Railsback, S F

    1989-01-01

    This paper demonstrates the use of general circulation models (GCMs) for assessing global climate change effects on reservoir water quality and illustrates that general conclusions about the effects of increased carbon dioxide (CO{sub 2}) concentrations on water resources can be made by using GCMs. These conclusions are based on GCM predictions of the climatic effects of doubling CO{sub 2} concentrations (the 2 {times} CO{sub 2} scenario). We also point out inadequacies in using information from GCM output alone to simulate reservoir water quality effects of climate change. Our investigation used Douglas Lake, a large multipurpose reservoir in eastern Tennessee, as an example. We studied water temperature and dissolved oxygen (DO), important water quality parameters that are expected to respond to a changed climate. Finally, we used the temperature and DO requirements of striped bass as an indicator of biological effects of combined changes in temperature and DO. 3 refs., 1 fig.

  16. Gas content of Gladys McCall reservoir brine

    SciTech Connect

    Hayden, C.G.; Randolph, P.L.

    1987-05-29

    On October 8, 1983, after the first full day of production from Sand No.8 in the Gladys McCall well, samples of separator gas and separator brine were collected for laboratory P-V-T (pressure, volume, temperature) studies. Recombination of amounts of these samples based upon measured rates at the time of sample collection, and at reservoir temperature (290 F), revealed a bubble point pressure of 9200 psia. This is substantially below the reported reservoir pressure of 12,783 psia. The gas content of the recombined fluids was 30.19 SCF of dry gas/STB of brine. In contrast, laboratory studies indicate that 35.84 SCF of pure methane would dissolve in each STB of 95,000 mg/L sodium chloride brine. These results indicate that the reservoir brine was not saturated with natural gas. By early April, 1987, production of roughly 25 million barrels of brine had reduced calculated flowing bottomhole pressure to about 6600 psia at a brine rate of 22,000 STB/D. If the skin factor(s) were as high as 20, flowing pressure drop across the skin would still be only about 500 psi. Thus, some portion of the reservoir volume was believed to have been drawn down to below the bubble point deduced from the laboratory recombination of separator samples. When the pressure in a geopressured geothermal reservoir is reduced to below the bubble point pressure for solution gas, gas is exsolved from the brine flowing through the pores in the reservoir rock. This exsolved gas is trapped in the reservoir until the fractional gas saturation of pore volume becomes large enough for gas flow to commence through a continuous gas-filled channel. At the same time, the gas/brine ratio becomes smaller and the chemistry of the remaining solution gas changes for the brine from which gas is exsolved. A careful search was made for the changes in gas/brine ratio or solution gas chemistry that would accompany pressure dropping below the bubble point pressure. Changes of about the same magnitude as the scatter in

  17. Use of slim holes for geothermal exploration and reservoir assessment: A preliminary report on Japanese experience

    SciTech Connect

    Garg, S.K.; Combs, J.

    1993-06-01

    The publicly available Japanese data on the use of slim holes in geothermal exploration and reservoir assessment are reviewed in this report. Slim holes have been used for (1) obtaining core for geological studies, (2) delineating the stratigraphic structure, (3) characterizing reservoir fluid state (pressure, temperature, etc.), and (4) defining the permeability structure for reservoir assessment. Examples of these uses of slim hole data are presented from the Hohi Geothermal Area and the Sumikawa Geothermal Field. Discharge data from slim holes and production wells from the Oguni Geothermal Field indicate that it may be possible to infer the discharge rate of production wells based on slim hole measurements. The Japanese experience suggests that slim holes can provide useful data for cost-effective geothermal reservoir assessment. Therefore, plans for a full scale evaluation of Japanese slim hole data are outlined.

  18. Isotopic changes in the fluids of the Cerro Prieto {Beta} Reservoir

    SciTech Connect

    Verma, Mahendra; Quijano, Luis; Gutierrez, Hector; Iglesias, Eduardo; Truesdell, Alfred

    1996-01-24

    Monitoring changes with time of the isotopes of water (18O and D) in wellhead fluids is an effective way of indicating reservoir changes and processes. Because 18O concentrations in water are altered by high-temperature exchange with rock oxygen and because both 18O and D are fractionated in vapor-liquid separation processes at the surface (separators and cooling towers), these isotopes are excellent indicators of inflow and distribution of fluids from outside the reservoir, either natural or injected. Studies of the isotopic compositions of fluids from the Cerro Prieto field in Baja California, Mexico show that pressure drawdown in the major β (beta) reservoir has caused intense boiling followed by inflow of water from outside the reservoir. A method of field exploitation based on this behavior is discussed.

  19. Carbon emission from global hydroelectric reservoirs revisited.

    PubMed

    Li, Siyue; Zhang, Quanfa

    2014-12-01

    Substantial greenhouse gas (GHG) emissions from hydropower reservoirs have been of great concerns recently, yet the significant carbon emitters of drawdown area and reservoir downstream (including spillways and turbines as well as river reaches below dams) have not been included in global carbon budget. Here, we revisit GHG emission from hydropower reservoirs by considering reservoir surface area, drawdown zone and reservoir downstream. Our estimates demonstrate around 301.3 Tg carbon dioxide (CO2)/year and 18.7 Tg methane (CH4)/year from global hydroelectric reservoirs, which are much higher than recent observations. The sum of drawdown and downstream emission, which is generally overlooked, represents 42 % CO2 and 67 % CH4 of the total emissions from hydropower reservoirs. Accordingly, the global average emissions from hydropower are estimated to be 92 g CO2/kWh and 5.7 g CH4/kWh. Nonetheless, global hydroelectricity could currently reduce approximate 2,351 Tg CO2eq/year with respect to fuel fossil plant alternative. The new findings show a substantial revision of carbon emission from the global hydropower reservoirs. PMID:24943886

  20. Water quality management plan for Cherokee Reservoir

    SciTech Connect

    Not Available

    1984-01-01

    The management plan provides an assessment of Cherokee Reservoir's current water quality, identifies those factors which affect reservoir water quality, and develops recommendations aimed at restoring or maintaining water quality at levels sufficient to support diverse beneficial uses. 20 references, 8 figures, 15 tables. (ACR)

  1. Geothermal reservoir insurance study. Final report

    SciTech Connect

    Not Available

    1981-10-09

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

  2. Climate variations, soil conservation and reservoir sedimentation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The integrated effects of soil conservation and a wetter climate on reservoir sedimentation were investigated for the Fort Cobb Reservoir watershed in west-central Oklahoma. A 12% wetter climate since the mid-1980s led to an increase in soil erosion and downstream sediment yield that offset the redu...

  3. Water resources review: Wheeler Reservoir, 1990

    SciTech Connect

    Wallus, R.; Cox, J.P.

    1990-09-01

    Protection and enhancement of water quality is essential for attaining the full complement of beneficial uses of TVA reservoirs. The responsibility for improving and protecting TVA reservoir water quality is shared by various federal, state, and local agencies, as well as the thousands of corporations and property owners whose individual decisions affect water quality. TVA's role in this shared responsibility includes collecting and evaluating water resources data, disseminating water resources information, and acting as a catalyst to bring together agencies and individuals that have a responsibility or vested interest in correcting problems that have been identified. This report is one in a series of status reports that will be prepared for each of TVA's reservoirs. The purpose of this status report is to provide an up-to-date overview of the characteristics and conditions of Wheeler Reservoir, including: reservoir purposes and operation; physical characteristics of the reservoir and the watershed; water quality conditions: aquatic biological conditions: designated, actual, and potential uses of the reservoir and impairments of those uses; ongoing or planned reservoir management activities. Information and data presented here are form the most recent reports, publications, and original data available. 21 refs., 8 figs., 29 tabs.

  4. Seismic determination of saturation in fractured reservoirs

    USGS Publications Warehouse

    Brown, R.L.; Wiggins, M.L.; Gupta, A.

    2002-01-01

    Detecting the saturation of a fractured reservoir using shear waves is possible when the fractures have a geometry that induces a component of movement perpendicular to the fractures. When such geometry is present, vertically traveling shear waves can be used to examine the saturation of the fractured reservoir. Tilted, corrugated, and saw-tooth fracture models are potential examples.

  5. Electromagnetic Heating Methods for Heavy Oil Reservoirs

    SciTech Connect

    Sahni, A.; Kumar, M.; Knapp, R.B.

    2000-05-01

    The most widely used method of thermal oil recovery is by injecting steam into the reservoir. A well-designed steam injection project is very efficient in recovering oil, however its applicability is limited in many situations. Simulation studies and field experience has shown that for low injectivity reservoirs, small thickness of the oil-bearing zone, and reservoir heterogeneity limits the performance of steam injection. This paper discusses alternative methods of transferring heat to heavy oil reservoirs, based on electromagnetic energy. They present a detailed analysis of low frequency electric resistive (ohmic) heating and higher frequency electromagnetic heating (radio and microwave frequency). They show the applicability of electromagnetic heating in two example reservoirs. The first reservoir model has thin sand zones separated by impermeable shale layers, and very viscous oil. They model preheating the reservoir with low frequency current using two horizontal electrodes, before injecting steam. The second reservoir model has very low permeability and moderately viscous oil. In this case they use a high frequency microwave antenna located near the producing well as the heat source. Simulation results presented in this paper show that in some cases, electromagnetic heating may be a good alternative to steam injection or maybe used in combination with steam to improve heavy oil production. They identify the parameters which are critical in electromagnetic heating. They also discuss past field applications of electromagnetic heating including technical challenges and limitations.

  6. An index of reservoir habitat impairment

    USGS Publications Warehouse

    Miranda, L.E.; Hunt, K.M.

    2011-01-01

    Fish habitat impairment resulting from natural and anthropogenic watershed and in-lake processes has in many cases reduced the ability of reservoirs to sustain native fish assemblages and fisheries quality. Rehabilitation of impaired reservoirs is hindered by the lack of a method suitable for scoring impairment status. To address this limitation, an index of reservoir habitat impairment (IRHI) was developed by merging 14 metrics descriptive of common impairment sources, with each metric scored from 0 (no impairment) to 5 (high impairment) by fisheries scientists with local knowledge. With a plausible range of 5 to 25, distribution of the IRHI scores ranged from 5 to 23 over 482 randomly selected reservoirs dispersed throughout the USA. The IRHI reflected five impairment factors including siltation, structural habitat, eutrophication, water regime, and aquatic plants. The factors were weakly related to key reservoir characteristics including reservoir area, depth, age, and usetype, suggesting that common reservoir descriptors are poor predictors of fish habitat impairment. The IRHI is rapid and inexpensive to calculate, provides an easily understood measure of the overall habitat impairment, allows comparison of reservoirs and therefore prioritization of restoration activities, and may be used to track restoration progress. The major limitation of the IRHI is its reliance on unstandardized professional judgment rather than standardized empirical measurements. ?? 2010 US Government.

  7. Mycobacterium bovis: characteristics of wildlife reservoir hosts.

    PubMed

    Palmer, M V

    2013-11-01

    Mycobacterium bovis is the cause of tuberculosis in animals and sometimes humans. Many developed nations have long-standing programmes to eradicate tuberculosis in livestock, principally cattle. As disease prevalence in cattle decreases these efforts are sometimes impeded by passage of M. bovis from wildlife to cattle. In epidemiological terms, disease can persist in some wildlife species, creating disease reservoirs, if the basic reproduction rate (R0) and critical community size (CCS) thresholds are achieved. Recognized wildlife reservoir hosts of M. bovis include the brushtail possum (Trichosurus vulpecula) in New Zealand, European badger (Meles meles) in Great Britain and Ireland, African buffalo (Syncerus caffer) in South Africa, wild boar (Sus scrofa) in the Iberian Peninsula and white-tailed deer (Odocoileus virginianus) in Michigan, USA. The epidemiological concepts of R0 and CCS are related to more tangible disease/pathogen characteristics such as prevalence, pathogen-induced pathology, host behaviour and ecology. An understanding of both epidemiological and disease/pathogen characteristics is necessary to identify wildlife reservoirs of M. bovis. In some cases, there is a single wildlife reservoir host involved in transmission of M. bovis to cattle. Complexity increases, however, in multihost systems where multiple potential reservoir hosts exist. Bovine tuberculosis eradication efforts require elimination of M. bovis transmission between wildlife reservoirs and cattle. For successful eradication identification of true wildlife reservoirs is critical, as disease control efforts are most effective when directed towards true reservoirs. PMID:24171844

  8. European Rabbits as Reservoir for Coxiella burnetii

    PubMed Central

    González-Barrio, David; Maio, Elisa; Vieira-Pinto, Madalena

    2015-01-01

    We studied the role of European rabbits (Oryctolagus cuniculus) as a reservoir for Coxiella burnetii in the Iberian region. High individual and population seroprevalences observed in wild and farmed rabbits, evidence of systemic infections, and vaginal shedding support the reservoir role of the European rabbit for C. burnetii. PMID:25988670

  9. Increasing Waterflood Reserves in the Wilmington Oil Field Through Reservoir Characterization and Reservoir Management

    SciTech Connect

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

    1997-04-10

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

  10. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Faruk; Hughes, Richard G.

    2003-02-11

    This research was directed toward developing a systematic reservoir characterization methodology which can be used by the petroleum industry to implement infill drilling programs and/or enhanced oil recovery projects in naturally fractured reservoir systems in an environmentally safe and cost effective manner. It was anticipated that the results of this research program will provide geoscientists and engineers with a systematic procedure for properly characterizing a fractured reservoir system and a reservoir/horizontal wellbore simulator model which can be used to select well locations and an effective EOR process to optimize the recovery of the oil and gas reserves from such complex reservoir systems.

  11. Impacts of operation of CVP regulating reservoirs on water temperature

    SciTech Connect

    Vail, L.W.

    1996-06-01

    The Western Area Power Administration (Western) markets and transmits electric power throughout 15 western states. Western's Sierra Nevada Customer Service Region (Sierra Nevada Region) markets approximately 1,480 megawatts (MW) of firm power (and 100 MW of seasonal peaking capacity) from the Central Valley Project (CVP) and other sources and markets available nonfirm power from the Washoe Project. Western's mission is to sell and deliver electricity generated from CVP powerplants. The hydroelectric facilities of the CVP are operated by the Bureau of Reclamation (Reclamation). Reclamation manages and releases water in accordance with the various acts authorizing specific projects and with enabling legislation. Western's capacity and energy sales must be in conformance with the laws that govern its sale of electrical power. Further, Western's hydropower operations at each facility must comply with minimum and maximum flows and other constraints set by Reclamation, the U.S. Fish and Wildlife Service, or other agencies, acting in accord with law or policy.

  12. Mechanisms of arsenic enrichment in geothermal and petroleum reservoirs fluids in Mexico.

    PubMed

    Birkle, Peter; Bundschuh, Jochen; Sracek, Ondra

    2010-11-01

    The lack of chemical similarity between thermal fluids in geothermal and petroleum reservoirs in Mexico indicates a distinct origin for arsenic in both types of reservoirs. Deep fluids from geothermal reservoirs along the Transmexican Volcanic Belt (TMVB) are characterized by elevated arsenic concentrations, within a range between 1 and 100 mg L(-1) at a depth from 600 to 3000 m b.s.l. Based on hierarchical cluster analysis (HCA), arsenic is linked to typical geothermal species like lithium, silica, and boron. The lack of correlation between arsenic and salinity reflects the importance of secondary water-rock interaction processes. The predominance of arsenic compared to Fe- and Cu-concentrations, and the occurrence of secondary minerals (sulfides and clay minerals) in temperature-dependent hydrothermal zones, supports this hypothesis. Neither magmatic fluids input, nor As mineralization is a prerequisite for As enrichment in Mexican geothermal fluids. In contrast, petroleum reservoir waters from sedimentary basins in SE-Mexico show maximum As concentrations of 2 mg L(-1), at depths from 2900 to 6100 m b.s.l. The linear chloride-arsenic correlation indicates that evaporated seawater represents the major source for aqueous arsenic in oil reservoirs, and only minor arsenic proportions are derived from interaction with carbonate host rock. Speciation modeling suggests the lack of arsenic solubility control in both geothermal and petroleum reservoirs, but precipitation/co-precipitation of As with secondary sulfides could occur in petroleum reservoirs with high iron concentrations. Geothermal fluids from magmatic-type reservoirs (Los Azufres and Los Humeros at the TMVB and Las Tres Vírgenes with a granodioritic basement) show relative constant arsenic concentrations through varying temperature conditions, which indicates that temperatures above 230-250 °C provide optimal and stable conditions for arsenic mobility. In contrast, temperature conditions for sedimentary

  13. Rodent reservoirs of future zoonotic diseases

    PubMed Central

    Han, Barbara A.; Schmidt, John Paul; Bowden, Sarah E.; Drake, John M.

    2015-01-01

    The increasing frequency of zoonotic disease events underscores a need to develop forecasting tools toward a more preemptive approach to outbreak investigation. We apply machine learning to data describing the traits and zoonotic pathogen diversity of the most speciose group of mammals, the rodents, which also comprise a disproportionate number of zoonotic disease reservoirs. Our models predict reservoir status in this group with over 90% accuracy, identifying species with high probabilities of harboring undiscovered zoonotic pathogens based on trait profiles that may serve as rules of thumb to distinguish reservoirs from nonreservoir species. Key predictors of zoonotic reservoirs include biogeographical properties, such as range size, as well as intrinsic host traits associated with lifetime reproductive output. Predicted hotspots of novel rodent reservoir diversity occur in the Middle East and Central Asia and the Midwestern United States. PMID:26038558

  14. Next generation oil reservoir simulations

    SciTech Connect

    Joubert, W.

    1996-04-01

    This paper describes a collaborative effort between Amoco Production Company, Los Alamos National Laboratory and Cray Research Inc. to develop a next-generation massively parallel oil reservoir simulation code. The simulator, code-named Falcon, enables highly detailed simulations to be performed on a range of platforms such as the Cray T3D and T3E. The code is currently being used by Amoco to perform a sophisticated field study using multiple geostatistical realizations on a scale of 2-5 million grid blocks and 1000-2000 wells. In this paper we discuss the nature of this collaborative effort, the software design and engineering aspects of the code, parallelization experiences, and performance studies. The code will be marketed to the oil industry by a third-party independent software vendor in mid-1996.

  15. 10. 'Y' CONNECTOR TO PICACHO RESERVOIR ON MAIN CANAL. VIEW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. 'Y' CONNECTOR TO PICACHO RESERVOIR ON MAIN CANAL. VIEW LOOKING EAST FROM PICACHO RESERVOIR INLET CHANNEL - San Carlos Irrigation Project, Marin Canal, Amhurst-Hayden Dam to Picacho Reservoir, Coolidge, Pinal County, AZ

  16. The Obtaining of Oil from an Oil Reservoir.

    ERIC Educational Resources Information Center

    Dawe, R. A.

    1979-01-01

    Discusses the mechanics of how an actual oil reservoir works and provides some technical background in physics. An experiment which simulates an oil reservoir and demonstrates quantitatively all the basic concepts of oil reservoir rock properties is also presented. (HM)

  17. 13. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING EAST FROM ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING EAST FROM NORTHWEST CORNER OF RESERVOIR. POST OF ORIGINAL FENCE IS IN FOREGROUND - Portland Reservoir No. 2, 6007 Southeast Division Street, Portland, Multnomah County, OR

  18. 9. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING SOUTHWEST, SHOWING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF PORTLAND RESERVOIR NO. 2, LOOKING SOUTHWEST, SHOWING CHAIN-LINK FENCE IN FOREGROUND AND FOUNDATION STRUCTURE IN THE MIDDLE OF RESERVOIR BASIN - Portland Reservoir No. 2, 6007 Southeast Division Street, Portland, Multnomah County, OR

  19. Fracturing operations in a dry geothermal reservoir

    SciTech Connect

    Rowley, J.C.; Hendron, R.H.; Nicholson, R.W.; Pettitt, R.A.; Sinclair, A.R.

    1983-10-01

    Fracturing and completing deep wells in hot, non-porous crystalline basement rock challenges conventional equipment use, procedures, and techniques common in oil and gas and normal geothermal completions. Fracturing operations at the Fenton Hill, New Mexico, Hot Dry Rock (HDR) Geothermal Test Site initiated unique developments necessary to solve problems caused by an extremely harsh downhole environment. Two deep wells were drilled to approximately 15,000 ft (4.6 km); formation temperatures are in excess of 600/sup 0/F (315/sup 0/C). The wells were drilled during 1979-1981, inclined at 35 degrees, one above the other, and directionally drilled in an azimuthal direction orthogonal to the least principal in-situ crustal stress field. The pair of wells form the injection and production wells of an energy extraction system which will be unique in reservoir development. Hydraulic fracturing experiments to connect the two wells have used openhole packers, hydraulic jet notching of the borehole wall, cemented-in isolation liners and casing packers. Problems were encountered with hole drag, high fracture gradients, H/sub 2/S in vent back fluids, stress corrosion cracking of tubulars, and the complex nature of three-dimensional fracture growth that requires very large volumes of injected water. Two fractured zones have been formed by hydraulic fracturing and defined by close-in, borehole deployed, microseismic detectors.

  20. Geologic characterization of tight gas reservoirs

    SciTech Connect

    Law, B.E.

    1990-12-01

    The objectives of US Geological Survey (USGS) work during FY 89 were to conduct geologic research characterizing tight gas-bearing sandstone reservoirs and their resources in the western United States. Our research has been regional in scope but, in some basins, our investigations have focused on single wells or small areas containing several wells where a large amount of data is available. The investigations, include structure, stratigraphy, petrography, x-ray mineralogy, source-rock evaluation, formation pressure and temperature, borehole geophysics, thermal maturity mapping, fission-track age dating, fluid-inclusion thermometry, and isotopic geochemistry. The objectives of these investigations are to provide geologic models that can be compared and utilized in tight gas-bearing sequences elsewhere. Nearly all of our work during FY 89 was devoted to developing a computer-based system for the Uinta basin and collecting, analyzing, and storage of data. The data base, when completed will contain various types of stratigraphic, organic chemistry, petrographic, production, engineering, and other information that relate to the petroleum geology of the Uinta basin, and in particular, to the tight gas-bearing strata. 16 refs., 3 figs.

  1. Temperature Oscillation in a Loop Heat Pipe with Gravity Assist

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Garrison, Matt; Patel, Deepak; Ottenstein, Laura; Robinson, Frank

    2014-01-01

    ATLAS Laser Thermal Control System (LTCS) thermal vacuum testing where the condenser-radiator was placed in a vertical position, it was found that the loop heat pipe (LHP) reservoir required much more control heater power than the analytical model had predicted. The required control heater power was also higher than the liquid subcooling entering the reservoir using the measured temperatures and the calculated mass flow rate based on steady state LHP operation. This presentation describes the investigation of the LHP behaviors under a gravity assist mode with a very cold radiator sink temperature and a large thermal mass attached to the evaporator. It is concluded that gravity caused the cold liquid to drop from the condenser-radiator to the reservoir, resulting in a rapid decrease of the reservoir temperature. When the reservoir temperature was increasing, a reverse flow occurred in the liquid line, carrying warm liquid to the condenser-radiator. Both events consumed the reservoir control heater power. The fall and rise of the reservoir temperature also caused the net heat input to the evaporator to vary due to the release and storage of the sensible heat of the thermal mass. The combination of these effects led to a persistent reservoir temperature oscillation and a repeated influx of cold liquid from the condenser. This was the root cause of the extraordinary high control heater power requirement in the LTCS TV test. Without gravity assist, such a persistent temperature oscillation will not be present.

  2. 5. EASTSIDE RESERVOIR, LOOKING WEST. WEST DAM UNDER CONSTRUCTION, QUARRIES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. EASTSIDE RESERVOIR, LOOKING WEST. WEST DAM UNDER CONSTRUCTION, QUARRIES TO LEFT MIDDLE GROUND OF PICTURE. - Eastside Reservoir, Diamond & Domenigoni Valleys, southwest of Hemet, Hemet, Riverside County, CA

  3. Scale Model Simulation of Enhanced Geothermal Reservoir Creation

    NASA Astrophysics Data System (ADS)

    Gutierrez, M.; Frash, L.; Hampton, J.

    2012-12-01

    Geothermal energy technology has successfully provided a means of generating stable base load electricity for many years. However, implementation has been spatially limited to limited availability of high quality traditional hydro-thermal resources possessing the combination of a shallow high heat flow anomaly and an aquifer with sufficient permeability and continuous fluid recharge. Enhanced Geothermal Systems (EGS) has been proposed as a potential solution to enable additional energy production from the non-conventional hydro-thermal resources. Hydraulic fracturing is considered the primary means of creating functional EGS reservoirs at sites where the permeability of the rock is too limited to allow cost effective heat recovery. EGS reservoir creation requires improved fracturing methodology, rheologically controllable fracturing fluids, and temperature hardened proppants. Although large fracture volumes (several cubic km) have been created in the field, circulating fluid through these full volumes and maintaining fracture volumes have proven difficult. Stimulation technology and methodology as used in the oil and gas industry for sedimentary formations are well developed; however, they have not sufficiently been demonstrated for EGS reservoir creation. Insufficient data and measurements under geothermal conditions make it difficult to directly translate experience from the oil and gas industries to EGS applications. To demonstrate the feasibility of EGS reservoir creation and subsequent geothermal energy production, and to improve the understanding of hydraulic and propping in EGS reservoirs, a heated true-triaxial load cell with a high pressure fluid injection system was developed to simulate an EGS system from stimulation to production. This apparatus is capable of loading a 30x30x30 cubic cm rock sample with independent principal stresses up to 13 MPa while simultaneously providing heating up to 180 degree C. Multiple orientated boreholes of 5 to 10 mm

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

    PubMed

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

    2016-05-01

    Reservoir behavior due to injection and circulation of cold fluid is studied with a shear displacement model based on the distributed dislocation technique, in a poro-thermoelastic environment. The approach is applied to a selected volume of Soultz geothermal reservoir at a depth range of 3600 to 3700 m. Permeability enhancement and geothermal potential of Soultz geothermal reservoir are assessed over a stimulation period of 3 months and a fluid circulation period of 14 years. This study-by shedding light onto another source of uncertainty-points toward a special role for the fracture surface asperities in predicting the shear dilation of fractures. It was also observed that thermal stress has a significant impact on changing the reservoir stress field. The effect of thermal stresses on reservoir behavior is more evident over longer circulation term as the rock matrix temperature is significantly lowered. Change in the fracture permeability due to the thermal stresses can also lead to the short circuiting between the injection and production wells which in turn decreases the produced fluid temperature significantly. The effect of thermal stress persists during the whole circulation period as it has significant impact on the continuous increase in the flow rate due to improved permeability over the circulation period. In the current study, taking into account the thermal stress resulted in a decrease of about 7 °C in predicted produced fluid temperature after 14 years of cold fluid circulation; a difference which notably influences the potential prediction of an enhanced geothermal system. PMID:26340088

  5. Diagenesis of an 'overmature' gas reservoir: The Spiro sand of the Arkoma Basin, USA

    USGS Publications Warehouse

    Spotl, C.; Houseknecht, D.W.; Burns, S.J.

    1996-01-01

    The Spiro sand is a laterally extensive thin sandstone of earliest Atokan (Pennsylvanian) age that forms a major natural gas reservoir in the western Arkoma Basin, Oklahoma. Petrographic analysis reveals a variety of diagenetic alterations, the majority of which occurred during moderate to deep burial. Early diagenetic processes include calcite cementation and the formation of Fe-clay mineral peloids and coatings around quartz framework grains. These clays, which underwent transformation to well-crystallized chamosite [polytype Ib(?? = 90??)] on burial, are particularly abundant in medium-grained channel sandstones, whereas illitic clays are predominant in fine-grained interchannel sandstones. Subsequent to mechanical compaction, saddle ankerite precipitated in the reservoir at temperatures in excess of 70??C. Crude oil collected in favourable structural locations during and after ankeritization. Whereas hydrocarbons apparently halted inorganic diagenesis in oil-saturated zones, cementation continued in the underlying water-saturated zones. As reservoir temperatures increased further, hydrocarbons were cracked and a solid pyrobitumen residue remained in the reservoir. At temperatures exceeding ???140-150??C, non-syntaxial quartz cement, ferroan calcite and traces of dickite(?) locally reduced the reservoir quality. Local secondary porosity was created by carbonate cement dissolution. This alteration post-dated hydrocarbon emplacement and is probably related to late-stage infiltration of freshwater along 'leaky' faults. The study shows that the Spiro sandstone locally retained excellent porosities despite deep burial and thermal conditions that correspond to the zone of incipient very low grade metamorphism.

  6. Dynamics of the Toxin Cylindrospermopsin and the Cyanobacterium Chrysosporum (Aphanizomenon) ovalisporum in a Mediterranean Eutrophic Reservoir

    PubMed Central

    Fadel, Ali; Atoui, Ali; Lemaire, Bruno J.; Vinçon-Leite, Brigitte; Slim, Kamal

    2014-01-01

    Chrysosporum ovalisporum is a cylindrospermopsin toxin producing cyanobacterium that was reported in several lakes and reservoirs. Its growth dynamics and toxin distribution in field remain largely undocumented. Chrysosporum ovalisporum was reported in 2009 in Karaoun Reservoir, Lebanon. We investigated the factors controlling the occurrence of this cyanobacterium and vertical distribution of cylindrospermopsin in Karaoun Reservoir. We conducted bi-weekly sampling campaigns between May 2012 and August 2013. Results showed that Chrysosporum ovalisporum is an ecologically plastic species that was observed in all seasons. Unlike the high temperatures, above 26 °C, which is associated with blooms of Chrysosporum ovalisporum in Lakes Kinneret (Israel), Lisimachia and Trichonis (Greece) and Arcos Reservoir (Spain), Chrysosporum ovalisporum in Karaoun Reservoir bloomed in October 2012 at a water temperature of 22 °C during weak stratification. Cylindrospermopsin was detected in almost all water samples even when Chrysosporum ovalisporum was not detected. Chrysosporum ovalisporum biovolumes and cylindrospermopsin concentrations were not correlated (n = 31, r2 = −0.05). Cylindrospermopsin reached a maximum concentration of 1.7 µg L−1. The vertical profiles of toxin concentrations suggested its possible degradation or sedimentation resulting in its disappearance from the water column. The field growth conditions of Chrysosporum ovalisporum in this study revealed that it can bloom at the subsurface water temperature of 22 °C increasing the risk of its development and expansion in lakes located in temperate climate regions. PMID:25354130

  7. Dynamics of the toxin cylindrospermopsin and the cyanobacterium Chrysosporum (Aphanizomenon) ovalisporum in a Mediterranean eutrophic reservoir.

    PubMed

    Fadel, Ali; Atoui, Ali; Lemaire, Bruno J; Vinçon-Leite, Brigitte; Slim, Kamal

    2014-11-01

    Chrysosporum ovalisporum is a cylindrospermopsin toxin producing cyanobacterium that was reported in several lakes and reservoirs. Its growth dynamics and toxin distribution in field remain largely undocumented. Chrysosporum ovalisporum was reported in 2009 in Karaoun Reservoir, Lebanon. We investigated the factors controlling the occurrence of this cyanobacterium and vertical distribution of cylindrospermopsin in Karaoun Reservoir. We conducted bi-weekly sampling campaigns between May 2012 and August 2013. Results showed that Chrysosporum ovalisporum is an ecologically plastic species that was observed in all seasons. Unlike the high temperatures, above 26 °C, which is associated with blooms of Chrysosporum ovalisporum in Lakes Kinneret (Israel), Lisimachia and Trichonis (Greece) and Arcos Reservoir (Spain), Chrysosporum ovalisporum in Karaoun Reservoir bloomed in October 2012 at a water temperature of 22 °C during weak stratification. Cylindrospermopsin was detected in almost all water samples even when Chrysosporum ovalisporum was not detected. Chrysosporum ovalisporum biovolumes and cylindrospermopsin concentrations were not correlated (n = 31, r² = -0.05). Cylindrospermopsin reached a maximum concentration of 1.7 µg L⁻¹. The vertical profiles of toxin concentrations suggested its possible degradation or sedimentation resulting in its disappearance from the water column. The field growth conditions of Chrysosporum ovalisporum in this study revealed that it can bloom at the subsurface water temperature of 22 °C increasing the risk of its development and expansion in lakes located in temperate climate regions. PMID:25354130

  8. Characterization of oil and gas reservoir heterogeneity. [Quarterly technical progress report], April 1, 1993--June 30, 1993

    SciTech Connect

    Sharma, G.D.

    1993-08-01

    The ultimate objective of this cooperative research project is to characterize Alaskan petroleum reservoirs in terms of their reserves, physical and chemical properties, geologic configuration in relation to lithofacies and structure, and development potential. The project has two tasks: Task I is a geological description of the reservoirs including petrophysical properties, i.e., porosity, permeability, permeability variation, formation depth, temperature, and net pay, facies changes and reservoir structures as drawn from cores, well logs, and other geological data. Task 2 is reservoir fluid characterization--determination of physical properties of reservoir fluids including density, viscosity, phase distributions and composition as well as petrogenesis--source rock identification; and the study of asphaltene precipitation for Alaskan crude oils.

  9. Analysis of numerical simulations and influencing factors of seasonal manganese pollution in reservoirs.

    PubMed

    Peng, Hui; Zheng, Xilai; Chen, Lei; Wei, Yang

    2016-07-01

    Seasonal manganese pollution has become an increasingly pressing water quality issue for water supply reservoirs in recent years. Manganese is a redox-sensitive element and is released from sediment under anoxic conditions near the sediment-water interface during summer and autumn, when water temperature stratification occurs. The reservoir water temperature and water dynamic conditions directly influence the formation of manganese pollution. Numerical models are useful tools to quantitatively evaluate manganese pollution and its influencing factors. This paper presents a reservoir manganese pollution model by adding a manganese biogeochemical module to a water quality model-CE-QUAL-W2. The model is applied to the Wangjuan reservoir (Qingdao, China), which experiences manganese pollution during summer and autumn. Field data are used to verify the model, and the results show that the model can reproduce the main features of the thermal stratification and manganese distribution. The model is used to evaluate the manganese pollution process and its four influencing factors, including air temperature, water level, wind speed, and wind directions, through different simulation scenarios. The results show that all four factors can influence manganese pollution. High air temperature, high water level, and low wind speed aggravate manganese pollution, while low air temperature, low water level, and high wind speed reduce manganese pollution. Wind that travels in the opposite direction of the flow aggravates manganese pollution, while wind in the same direction as the flow reduces manganese pollution. This study provides useful information to improve our understanding of seasonal manganese pollution in reservoirs, which is important for reservoir manganese pollution warnings and control. PMID:27068892

  10. Optimizing Reservoir Operation to Adapt to the Climate Change

    NASA Astrophysics Data System (ADS)

    Madadgar, S.; Jung, I.; Moradkhani, H.

    2010-12-01

    Climate change and upcoming variation in flood timing necessitates the adaptation of current rule curves developed for operation of water reservoirs as to reduce the potential damage from either flood or draught events. This study attempts to optimize the current rule curves of Cougar Dam on McKenzie River in Oregon addressing some possible climate conditions in 21th century. The objective is to minimize the failure of operation to meet either designated demands or flood limit at a downstream checkpoint. A simulation/optimization model including the standard operation policy and a global optimization method, tunes the current rule curve upon 8 GCMs and 2 greenhouse gases emission scenarios. The Precipitation Runoff Modeling System (PRMS) is used as the hydrology model to project the streamflow for the period of 2000-2100 using downscaled precipitation and temperature forcing from 8 GCMs and two emission scenarios. An ensemble of rule curves, each associated with an individual scenario, is obtained by optimizing the reservoir operation. The simulation of reservoir operation, for all the scenarios and the expected value of the ensemble, is conducted and performance assessment using statistical indices including reliability, resilience, vulnerability and sustainability is made.

  11. Top-Down, Intelligent Reservoir Model

    NASA Astrophysics Data System (ADS)

    Mohaghegh, Shahab

    2010-05-01

    Conventional reservoir simulation and modeling is a bottom-up approach. It starts with building a geological model of the reservoir that is populated with the best available petrophysical and geophysical information at the time of development. Engineering fluid flow principles are added and solved numerically so as to arrive at a dynamic reservoir model. The dynamic reservoir model is calibrated using the production history of multiple wells and the history matched model is used to strategize field development in order to improve recovery. Top-Down, Intelligent Reservoir Modeling approaches the reservoir simulation and modeling from an opposite angle by attempting to build a realization of the reservoir starting with the measured well production behavior (history). The production history is augmented by core, log, well test and seismic data in order to increase the accuracy of the Top-Down modeling technique. Although not intended as a substitute for the conventional reservoir simulation of large, complex fields, this novel approach to reservoir modeling can be used as an alternative (at a fraction of the cost) to conventional reservoir simulation and modeling in cases where performing conventional modeling is cost (and man-power) prohibitive. In cases where a conventional model of a reservoir already exists, Top-Down modeling should be considered as a compliment to, rather than a competition for the conventional technique, to provide an independent look at the data coming from the reservoir/wells for optimum development strategy and recovery enhancement. Top-Down, Intelligent Reservoir Modeling starts with well-known reservoir engineering techniques such as Decline Curve Analysis, Type Curve Matching, History Matching using single well numerical reservoir simulation, Volumetric Reserve Estimation and calculation of Recovery Factors for all the wells (individually) in the field. Using statistical techniques multiple Production Indicators (3, 6, and 9 months cum

  12. Magma reservoir systems inferred from tilt patterns

    NASA Astrophysics Data System (ADS)

    Schimozuru, D.

    1981-09-01

    Inflation patterns based on water-tube tiltmeter and levelling observation show different features for Krafla Volcano in Iceland and Kilauea Volcano in Hawaii. Monotonous sawtooth shape inflation is observed at Krafla, while inflation curves at Kileauea are more or less complicated. The difference was attributed to differences in the system of magma reservoir for the two volcanoes. By using the electrical equivalent of a magma reservoir and volcanic conduit as a capacitor and a resistor, an electrical oseillator was considered to be a possible model for a magma reservoir system. In the case of Krafla, the magma reservoir system is replaced with one electric oscillator called «Single system» or «Icelandic type» system. The complicated inflation pattern of Kilauea was interpreted as the assembly of a main magma reservoir and the group of surrounding small reservoirs. The equivalent electric analogue is the composite parallel and serial connection of a single oscillator which generates irregular output voltage during a charging process. The proposed magma reservoir system of Kilauea is called «Multi-coupled system» or «Hawaiian type system» which also help in interpreting the wondering of the uplift center and tidal phenomena of the Halemaumau lava lake.

  13. Assessment of Artificial Recharge at Sand Hollow Reservoir, Washington County, Utah, Updated to Conditions through 2006

    USGS Publications Warehouse

    Heilweil, Victor M.; Susong, David D.

    2007-01-01

    Sand Hollow, Utah, is the site of a surface-water reservoir completed in March 2002 and operated by the Washington County Water Conservancy District (WCWCD) primarily as an aquifer storage and recovery project. The reservoir is an off-channel facility that receives water from the Virgin River, diverted near the town of Virgin, Utah. Hydrologic data collected are described and listed in this report, including ground-water levels, reservoir stage, reservoir-water temperature, meteorology, evaporation, and estimated ground-water recharge. Since the construction of the reservoir in 2002, diversions from the Virgin River have resulted in generally rising stage and surface area. Large spring run-off volumes during 2005-06 allowed the WCWCD to fill the reservoir to near capacity, with a surface area of about 1,300 acres in 2006. Reservoir stage reached a record altitude of about 3,060 feet in May 2006, resulting in a depth of nearly 90 feet and a reservoir storage of about 51,000 acre-feet. Water temperature in the reservoir shows large seasonal variation and has ranged from about 5 to 32?C. Estimated ground-water recharge rates have ranged from 0.01 to 0.43 feet per day. Estimated recharge volumes have ranged from about 200 to about 3,500 acre-feet per month. Total ground-water recharge from March 2002 through August 2006 is estimated to be about 51,000 acre-feet. Estimated evaporation rates have varied from 0.05 to 0.97 feet per month, resulting in evaporation losses of 20 to 1,200 acre-feet per month. Total evaporation from March 2002 through August 2006 is estimated to be about 17,000 acre-feet. The combination of generally declining recharge rates and increasing reservoir altitude and area explains the trend of an increasing ratio of evaporation to recharge volume over time, with the total volume of water lost through evaporation nearly as large as the volume of ground-water recharge during the first 8 months of 2006. With removal of the viscosity effects (caused by

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

    NASA Astrophysics Data System (ADS)

    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

  15. [Ecotoxicological value of sediments state from reservoir R-11 of Techa River reservoir cascade].

    PubMed

    Priakhin, E A; Bogdanov, G O; Traipitsyna, G A; Deriabina, L V; Stukalov, P M; Aleksandrova, O A; Akleev, A V

    2010-01-01

    Researches of sediments state from reservoir R-11 of tandem Techa river reservoir cascade were made. Shershni (Shershni's reservoir, Chelyabinsk region) was used as reference reservoir. Radiochemical analysis of sediments and water from those reservoirs were made (radioactivity in sediments of R-11 ranged from 240 to 360 kBq/kg of dry weight for 90Sr and from 10 to 161 kBq/kg of dry weight for 137Cs). Hydrobiological researches were included (1) detection of quantitative progress and species composition of Oligochaeta fauna in reservoirs and (2) bioassay of sediments in laboratory conditions with using test-organisms Tubifex culture. Calculation of absorbed dose for Oligochaeta from reservoir R-11 was performed on basis of radiochemical analysis data. Our results indicated that quantitative progress of Oligochaeta in reservoir R-11 was less then progress in Shershni's reservoir. R-11 sediments bioassay did not show any toxic effect by tubificidae in laboratory experiments. Significant dependence for quantitative progress Oligochaeta in reservoir R-11, survival rate and breeding power from absorbed dose rate weren't found. However in subacute research breeding power for animals with higher radiation (absorbed) dose was reduced. PMID:20464971

  16. Integrated Forecast and Reservoir Management for Northern California

    NASA Astrophysics Data System (ADS)

    Georgakakos, K. P.; Graham, N.; Georgakakos, A. P.; Yao, H.

    2011-12-01

    The INFORM (Integrated Forecast and Reservoir Management) Demonstration Project was created to demonstrate the utility of climate, weather and hydrologic predictions for water resources management in Northern California (includes Trinity River, the Sacramento River, the Feather River, the American River, the San Joaquin River, and the Sacramento-San Joaquin Delta). The INFORM system integrates climate-weather-hydrology forecasting and adaptive reservoir management methods, explicitly accounting for system input and model uncertainties. Operational ensemble forecasts from the Global Forecast System (GFS) and the Climate Forecast System (CFS) of the National Centers of Environmental Prediction (NCEP) are used to drive the WRF model and an Intermediate Complexity Regional Model (ICRM) to produce ensemble precipitation and temperature forecasts with a 10km x 10km resolution and from 6 hours to 30 days. These forecasts feed hydrologic models and provide ensemble inflow forecasts for the major reservoirs of Northern California. The ensemble inflow forecasts are input to a multiobjective and multisite adaptive decision support system designed to support the planning and management processes by deriving real time trade-offs among all relevant water management objectives (i.e., water supply and conservation, hydroelectric power production, flood control, and fisheries and environmental management) at user preferred risk levels. Operational tests over an initial three-year demonstration phase showed good operational performance both for wet and dry years. The presentation focuses on (1) modeling aspects of the current forecast and reservoir components and recent tests and (2) use of recent forecasts for the generation of applicable operational tradeoffs. The test results corroborate the operational value of the integrated forecast-management system.

  17. Variation of metals in bed sediments of Qaraaoun Reservoir, Lebanon.

    PubMed

    Korfali, Samira Ibrahim; Jurdi, Mey; Davies, Brian E

    2006-04-01

    The Qaraaoun Reservoir (impoundment of the River Litani) is the only artificial surface water body in the country, Lebanon. Earlier study on the water quality of the Qaraaoun Reservoir identified three water quality zoning with a central distinct zone suitable for multipurpose water usage. The objective of this study was to extend the earlier work by considering the total metal content of reservoir bed sediments and hence to evaluate factors that control metal deposition or capture. Water samples were collected from 15 sampling sites and sediment samples were simultaneously collected from 9 sites. Water parameters analyzed were pH, Eh, DO and temperature. Sediment samples were dried and sieved and sediment < 75 microm was retained for analysis. Sediments were subjected to a stepwise heating process with aqua regia to extract the metals, and their content in sediments determined by ICP-MS. The sediment data revealed higher metal contents where the river entered the reservoir which matched higher concentrations of water parameters at the influx site. Regression analysis of total metals in sediments with distance from the river Litani influx point to the dam revealed a log trend for Fe, Cr and Ni, whereas, the concentrations of Cu, Zn, Cd, Pb were better described by a polynomial regression. Three sediment zones were identified: entrance, oxidation (central) and reducing (near dam) zones. Sediment contents of Zn, Cu and Pb correlated with organic content, whereas sediment Cr and Ni were associated with iron. It was concluded that sediments act as a sink for metals and the deposition of metals is primarily related to sediment organic content and the level of dissolved oxygen in water. PMID:16649137

  18. Dispersivity as an oil reservoir rock characteristic

    SciTech Connect

    Menzie, D.E.; Dutta, S.

    1989-12-01

    The main objective of this research project is to establish dispersivity, {alpha}{sub d}, as an oil reservoir rock characteristic and to use this reservoir rock property to enhance crude oil recovery. A second objective is to compare the dispersion coefficient and the dispersivity of various reservoir rocks with other rock characteristics such as: porosity, permeability, capillary pressure, and relative permeability. The dispersivity of a rock was identified by measuring the physical mixing of two miscible fluids, one displacing the other in a porous medium. 119 refs., 27 figs., 12 tabs.

  19. Adsorption of water vapor on reservoir rocks

    SciTech Connect

    Not Available

    1993-07-01

    Progress is reported on: adsorption of water vapor on reservoir rocks; theoretical investigation of adsorption; estimation of adsorption parameters from transient experiments; transient adsorption experiment -- salinity and noncondensible gas effects; the physics of injection of water into, transport and storage of fluids within, and production of vapor from geothermal reservoirs; injection optimization at the Geysers Geothermal Field; a model to test multiwell data interpretation for heterogeneous reservoirs; earth tide effects on downhole pressure measurements; and a finite-difference model for free surface gravity drainage well test analysis.

  20. Safety drain system for fluid reservoir

    NASA Technical Reports Server (NTRS)

    England, John Dwight (Inventor); Kelley, Anthony R. (Inventor); Cronise, Raymond J. (Inventor)

    2012-01-01

    A safety drain system includes a plurality of drain sections, each of which defines distinct fluid flow paths. At least a portion of the fluid flow paths commence at a side of the drain section that is in fluid communication with a reservoir's fluid. Each fluid flow path at the side communicating with the reservoir's fluid defines an opening having a smallest dimension not to exceed approximately one centimeter. The drain sections are distributed over at least one surface of the reservoir. A manifold is coupled to the drain sections.

  1. A Reservoir of Nitrate Beneath Desert Soils

    USGS Publications Warehouse

    Walvoord, M.A.; Phillips, F.M.; Stonestrom, D.A.; Evans, R.D.; Hartsough, P.C.; Newman, B.D.; Striegl, R.G.

    2003-01-01

    A large reservoir of bioavailable nitrogen (upto ???104 kilograms of nitrogen per hectare, as nitrate) has been previously overlooked in studies of global nitrogen distribution. The reservoir has been accumulating in subsoil zones of and regions throughout the Holocene. Consideration of the subsoil reservoir raises estimates of vadose-zone nitrogen inventories by 14 to 71% for warm deserts and arid shrublands worldwide and by 3 to 16% globally. Subsoil nitrate accumulation indicates long-term leaching from desert soils, impelling further evaluation of nutrient dynamics in xeric ecosystems. Evidence that subsoil accumulations are readily mobilized raises concern about groundwater contamination after land-use or climate change.

  2. THM modelling of hydrothermal circulation in deep geothermal reservoirs

    NASA Astrophysics Data System (ADS)

    Magnenet, Vincent; Fond, Christophe; Schmittbuhl, Jean; Genter, Albert

    2014-05-01

    Numerous models have been developped for describing deep geothermal reservoirs. Using the opensource finite element software ASTER developped by EDF R&D, we carried out 2D simulations of the hydrothermal circulation in the deep geothermal reservoir of Soultz-sous-Forêts. The model is based on the effective description of Thermo-Hydro-Mechanical (THM) coupling at large scale. Such a model has a fourfold interest: a) the physical integration of laboratory measurements (rock physics), well logging, well head parameters, geological description, and geophysics field measurements; b) the construction of a direct model mechanically based for geophysical inversion: fluid flow, fluid pressure, temperature profile, seismicity monitoring, deformation of the ground surface (INSAR/GPS) related to reservoir modification, gravity or electromagnetic geophysical measurements; c) the sensitivity analysis of the parameters involved in the hydrothermal circulation and identification of the dominant ones; d) the development of a decision tool for drilling planning, stimulation and exploitation. In our model, we introduced extended Thermo-Hydro-Mechanical coupling including not only poro-elastic behavior but also the sensitivity of the fluid density, viscosity, and heat capacity to temperature and pressure. The behavior of solid rock grains is assumed to be thermo-elastic and linear. Hydraulic and thermal phenomena are governed by Darcy and Fourier laws respectively, and most rock properties (like the specific heat at constant stress csσ(T), or the thermal conductivity Λ(T,φ)) are assumed to depend on the temperature T and/or porosity φ. The radioactivity of the rocks is taken into account through a heat source term appearing in the balance equation of enthalpy. To characterize as precisely as possible the convective movement of water and the associated heat flow, water properties (specific mass ρw(T,pw), specific enthalpy hmw(T,pw) dynamic viscosity μw(T), thermal dilation

  3. Phytoplankton distribution in three thermally different but edaphically similar reactor cooling reservoirs

    SciTech Connect

    Wilde, E W

    1982-01-01

    Phytoplankton community structure and the physicochemical characteristics of three reactor cooling reservoirs in close proximity and of similar age and bottom type were studied during 1978. The three reservoirs differed in thermal alteration resulting from reactor cooling water as follows: (1) considerable heating with lake-wide temperatures >30/sup 0/C, even in winter; (2) a maximal 5/sup 0/C increase occurring in only one of three major arms of the reservoir; and (3) no thermal effluent received during the study period. Considerable spatial and temporal differences in water quality and phytoplankton community structure were observed; however, water temperature independent of other environmental factors (e.g., light and nutrients) was found to be a relatively unimportant variable for explaining phytoplankton periodicity.

  4. Application of mineralogical methods to assess the thermal stabilities of geothermal reservoirs

    SciTech Connect

    Browne, Patrick R.L.

    1993-01-28

    Estimates of temperatures, past and present, in geothermal reservoirs can be made by using now standard mineralogical techniques, including fluid inclusion geothermometry, vitrinite reflectance, calc-silicate and clay occurrence, the extent of clay interlayering, and measuring clay crystallinity. Recent studies of clays in 60 drillcores from 6 wells at Wairakei, for example, show an inverse relationship between reservoir temperatures and crystallinities from 90° to 225°C (195 to 435°F) (Kübler Indices: 1.40 to 0.44 D°2q). Fluid inclusion geothermometry results require careful interpretation but the method need not be calibrated with respect to the reservoir, as do other geothermometric methods.

  5. Reservoirs override seasonal variability of phytoplankton communities in a regulated Mediterranean river.

    PubMed

    Tornés, E; Pérez, M C; Durán, C; Sabater, S

    2014-03-15

    Water hydrology, temperature and transparency, as well as nutrient retention downstream of the reservoirs alter the temporal and spatial distribution patterns of phytoplankton communities in regulated rivers. The seasonal dynamics of phytoplankton communities in the Ebro was analysed in contrasting water flow periods in sections upstream and downstream of three large reservoirs, as well as in an intermediate site. Phytoplankton communities changed in response to seasonal variations in the areas not influenced by the reservoirs, but the phytoplankton distribution downstream of the reservoirs was driven by their particular hydrodynamics. The change in environmental conditions promoted by reservoirs influenced the pattern of replacement between diatoms and green algae of the upstream section. Differences in the phytoplankton community structure, abundance and environmental variables between upstream and downstream sites were maximal during low flow periods. Chlorophytes and dinoflagellates were present during low flow periods upstream of the reservoirs and in the intermediate site. Cocconeis cf. placentula characterized the downstream section, associated to the presence of macrophytes in that section. The present study sheds light on the consequences of river regulation under potential scenarios of climate change, and results could be used to anticipate ecological problems in large regulated rivers under these circumstances. PMID:23706480

  6. HEAT AND MASS TRANSFER IN A FAULT-CONTROLLED GEOTHERMAL RESERVOIR CHARGED AT CONSTANT PRESSURE

    SciTech Connect

    Goyal, K. P.; Narasimhan, T. N.

    1981-12-01

    A two-dimensional mathematical model of a fault controlled geothermal reservoir has been developed. Heated lighter water, rising in the fault, is assumed to charge a reservoir which, in turn, is overlain by a thin impermeable, thermally conducting cap rock. The mass flow rate or the pressure associated with the charging process at the fault inlet is unknown and can only be estimated. Thus, in this paper, the pressure in the fault at the bottom of the reservoir is assumed to be prescribed. Quasi-analytic solutions for the velocity, pressure, and temperature are obtained in the fault-reservoir system for a high Rayleigh number flow. In this approximation, the upwelling fluid does not cool off appreciably until it reaches the cold upper boundary of the reservoir and encounters conductive heat loss. This thermal boundary layer, which is thin at the top of the fault, grows outward laterally and occupies the full thickness of the aquifer far away from the fault. The mathematical model is based on the flow of liquid water in a saturated porous medium. The solution techniques involve the combination of perturbation methods, boundary layer theory and numerical methods. The analysis of this generic model can be applied to liquid dominated geothermal systems where the thickness of the impermeable caprock is very small compared to the depth of the reservoir.

  7. [Application of in situ cryogenic Raman spectroscopy to analysis of fluid inclusions in reservoirs].

    PubMed

    Chen, Yong; Lin, Cheng-yan; Yu, Wen-quan; Zheng, Jie; Wang, Ai-guo

    2010-01-01

    Identification of salts is a principal problem for analysis of fluid inclusions in reservoirs. The fluid inclusions from deep natural gas reservoirs in Minfeng sub-sag were analyzed by in situ cryogenic Raman spectroscopy. The type of fluid inclusions was identified by Raman spectroscopy at room temperature. The Raman spectra show that the inclusions contain methane-bearing brine aqueous liquids. The fluid inclusions were analyzed at -180 degrees C by in situ cryogenic Raman spectroscopy. The spectra show that inclusions contain three salts, namely NaCl2, CaCl2 and MgCl2. Sodium chloride is most salt component, coexisting with small calcium chloride and little magnesium chloride. The origin of fluids in inclusions was explained by analysis of the process of sedimentation and diagenesis. The mechanism of diagenesis in reservoirs was also given in this paper. The results of this study indicate that in situ cryogenic Raman spectroscopy is an available method to get the composition of fluid inclusions in reservoirs. Based on the analysis of fluid inclusions in reservoirs by in situ cryogenic Raman spectroscopy with combination of the history of sedimentation and diagenesis, the authors can give important evidence for the type and mechanism of diagenesis in reservoirs. PMID:20302090

  8. Preliminary estimation of the reservoir capacity and the longevity of the Baca Geothermal Field, New Mexico

    SciTech Connect

    Bodvarsson, G.S.; Vonder Haar, S.; Wilt, M.; Tsang, C.F.

    1980-07-01

    A 50 MW geothermal power plant is currently under development at the Baca site in the Valles Caldera, New Mexico, as a joint venture of the Department of Energy (DOE), Union Oil Company of California, and the Public Service Company of New Mexico (PNM). To date, over 20 wells have been drilled on the prospect, and the data from these wells indicate the presence of a high-temperature liquid dominated reservoir. Data from open literature on the field are used to estimate the amount of hot water in place (reservoir capacity) and the length of time the reservoir can supply steam for a 50 MW power plant (reservoir longevity). The reservoir capacity is estimated by volumetric calculations using existing geological, geophysical, and well data. The criteria used are described and the sensitivity of the results discussed. The longevity of the field is studied using a two-phase numerical simulator (SHAFT79). A number of cases are studied based upon different boundary conditions, and injection and production criteria. Constant or variable mass production is employed in the simulations with closed, semi-infinite or infinite reservoir boundaries. In one of the cases, a fault zone feeding the production region is modeled. The injection strategy depends on the available waste water. The results of these simulations are discussed and the sensitivity of the results, with respect to mesh size and the relative permeability curves used, are briefly studied.

  9. Thermal-Hydrologic-Mechanical Behavior of Single Fractures in EGS Reservoirs

    NASA Astrophysics Data System (ADS)

    Zyvoloski, G.; Kelkar, S.; Yoshioka, K.; Rapaka, S.

    2010-12-01

    Enhanced Geothermal Systems (EGS) rely on the creation a connected fracture system or the enhancement of existing (natural) fractures by hydraulic and chemical treatments. EGS studies at Fenton Hill (New Mexico, USA) and Hijiori (Japan) have revealed that only a limited number of fractures contribute to the effective heat transfer surface area. Thus, the economic viability of EGS depends strongly on the creation and spacing of single fractures in order to efficiently mine heat from given volume of rock. Though there are many similarities between EGS and natural geothermal reservoirs, a major difference between the reservoir types is the (typically) high pumping pressures and induced thermal stresses at the injection wells of an EGS reservoir. These factors can be responsible for fracture dilation/extension and thermal short circuiting and depend strongly on the surrounding state of stress in the reservoir and mechanical properties. We will present results from our study of the thermal-hydrologic-mechanical (THM) behavior of a single fracture in a realistic subsurface stress field. We will show that fracture orientation, the stress environment, fracture permeability structure, and the relationship between permeability changes in a fracture resulting from mechanical displacement are all important when designing and managing an EGS reservoir. Lastly, we present a sensitivity analysis of the important parameters that govern fracture behavior with respect to field measurements. Temperature in high permeability fracture in an EGS reservoir

  10. Water quality of the Lexington Reservoir, Santa Clara County, California, 1978-80

    USGS Publications Warehouse

    Iwatsubo, R.T.; Sylvester, M.A.; Gloege, I.S.

    1988-01-01

    Analysis of water samples from Lexington Reservoir and Los Gatos Creek upstream from the reservoir from June 1978 through September 1980 showed that water generally met water-quality objectives identified by California Regional Water Quality Control Board, San Francisco Bay Region. Water-temperature profiles show that Lexington Reservoir is a warm monomictic lake. During summer, dissolved-oxygen concentrations generally were not reduced below 5.0 mg/L in the hyplimnion; only once during the study did bottom waters become anoxic. Water transparency decreased with depth. The euphotic zone ranged from 1.0 to 5.4 m, depending on suspended solids and algae, and was greater in summer than in spring. Calcium and bicarbonate were dominant ions at all stations except during spring, following the rainy season, when waters were a mixed cation bicarbonate type. Nitrogen concentrations were greater in samples from reservoir stations than in those from Los Gatos Creek, with most of the nitrogen in ammonia and organic forms. The amount of dissolved nitrate appeared to be related to phytoplankton abundance. Phosphorus and trace-element concentrations were low at all stations. Estimates of net primary productivity and Carlson 's trophic-state index, based on chlorophyll-a concentrations, indicated that reservoir classification ranges from oligotrophic to mesotrophic. Blue-green algae generally were predominant in reservoir samples. (USGS)

  11. Mathematical modeling of the thermal and hydrodynamic structure of the cooling reservoir

    NASA Astrophysics Data System (ADS)

    Saminskiy, G.; Debolskaya, E.

    2012-04-01

    Hydrothermal conditions of the cooling reservoir is determined by the heat and mass transfer from the water surface to the atmosphere and the processes of heat transfer directly in the water mass of the reservoir. As the capacity of power plants, the corresponding increase in the volume of heated water and the use of deep lakes and reservoirs as coolers there is a need to develop new, more accurate, and the application of existing methods for the numerical simulation. In calculating the hydrothermal regime it must take into account the effect of wind, density (buoyancy) forces, and other data of the cooling reservoir. In addition to solving practical problems it is important to know not only the magnitude of the average temperature, but also its area and depth distribution. A successful solution can be achieved through mathematical modeling of general systems of equations of transport processes and the correct formulation of the problem, based on appropriate initial data. The purpose of the work is application of software package GETM for simulating the hydrothermal regime of cooling reservoir with an estimate of three-dimensional structure of transfer processes, the effects of wind, the friction of the water surface. Three-dimensional models are rarely applied, especially for far-field problems. If such models are required, experts in the field must develop and apply them. Primary physical processes included are surface heat transfer, short-wave and long-wave radiation and penetration, convective mixing, wind and flow induced mixing, entrainment of ambient water by pumped-storage inflows, inflow density stratification as impacted by temperature and dissolved and suspended solids. The model forcing data consists of the system bathymetry developed into the model grid; the boundary condition flow and temperature; the tributary and flow and temperature; and the system meteorology. Ivankovskoe reservoir belongs to the reservoirs of valley type (Tver region, Russia). It

  12. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    SciTech Connect

    Joel Walls; M.T. Taner; Gary Mavko; Jack Dvorkin

    2002-07-01

    In fully-saturated rock and at ultrasonic frequencies, the microscopic squirt flow induced between the stiff and soft parts of the pore space by an elastic wave is responsible for velocity-frequency dispersion and attenuation. In the seismic frequency range, it is the macroscopic cross-flow between the stiffer and softer parts of the rock. We use the latter hypothesis to introduce simple approximate equations for velocity-frequency dispersion and attenuation in a fully water saturated reservoir. The equations are based on the assumption that in heterogeneous rock and at a very low frequency, the effective elastic modulus of the fully-saturated rock can be estimated by applying a fluid substitution procedure to the averaged (upscaled) dry frame whose effective porosity is the mean porosity and the effective elastic modulus is the Backus-average (geometric mean) of the individual dry-frame elastic moduli of parts of the rock. At a higher frequency, the effective elastic modulus of the saturated rock is the Backus-average of the individual fully-saturated-rock elastic moduli of parts of the rock. The difference between the effective elastic modulus calculated separately by these two methods determines the velocity-frequency dispersion. The corresponding attenuation is calculated from this dispersion by using (e.g.) the standard linear solid attenuation model.

  13. Mechanistic models of unconventional reservoirs

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Pouyan Lialekol

    Rock physics models are mathematical relations between porosity, composition and elastic properties of a rock. Unlike in conventional silisiclastic rocks where seismic-to-rock properties are predicted successfully by rock physics models, their application in unconventional reservoirs such as shale, hydrate and carbonates is not fully understood. In light of the vast untapped potential of unconventional resources, their exploration will be easier if a suitable rock physics models become available for quantitative interpretation of seismic data. In this thesis generic, rock physics models that were developed for conventional siliciclastic systems have been used to infer rock properties such as porosity, composition, fluid saturation and pore pressure in shale, gas hydrates and carbonates. Results indicate that elastic properties of these rocks including shale and gas hydrates which can be viewed as grain assemblages can be best predicted by Hashin Shtrikman bounds. For rocks with non-spherical pores and a rather unified matrix such as carbonates where grain-to-grain contacts are not very clear, the Kuster and Toksoz model provide a good description of their dry elastic properties.

  14. Exploration, Drilling and Development Operations in the Bottle Rock Area of the Geysers Steam Field, With New Geologic Insights and Models Defining Reservoir Parameters

    SciTech Connect

    Hebein, Jeffrey J.

    1983-12-15

    MCR Geothermal Corporation pioneered successful exploratiory drilling the Bottle Rock area of the Geysers Steam Field in 1976. The wellfield is characterized by a deep reservoir with varied flowrates, temperatures, pressures, and stem chemistries being quite acceptable. More detailed reservoir engineering tests will follow as production commences.

  15. Progress report on the long-term flow testing of the HDR reservoir at Fenton Hill, New Mexico

    SciTech Connect

    Brown, Donald W.; Du Teau, Robert

    1993-01-28

    Through mid-December 1992, long-term flow testing of the Phase I1 Hot Dry Rock (HDR) reservoir at Fenton Hill, NM has been conducted for an aggregate of 24 weeks at near-optimum aseismic injection conditions. This period of flow testing, which began on April 9, 1992, included several reservoir shut-ins due to equipment problems and an intervening lower-injection-rate Interim Flow Test lasting about 6 weeks. With the exceptions noted above, the majority of the flow testing for that period was conducted at an average injection rate of 7.2 l/s and at pressures up to 27.3 MPa. However, this high level of injection pressure has not produced any discernible reservoir microseismicity, indicating that we have been operating the reservoir at pressures below the threshold for fracture extension. The permeation loss from the boundaries of the reservoir at these elevated pressures has averaged about 0.7 l/s, a very low rate of water loss considering the very large volume of fractured rock (about 16x106 m³) comprising the pressure-stimulated reservoir region. Temperature logging across the 350-m production interval, centered at a depth of about 3500 m, indicates that there has been no measurable drop in the mixed-mean reservoir production temperature at the top of this interval since the time of our first temperature log in mid July. Most recently, we have conducted additional intermittent reservoir testing at higher levels of production backpressure during a period of reservoir pressure maintenance using a high-capacity rental triplex mud pump.

  16. Performance modeling of an integral, self-regulating cesium reservoir for the ATI-TFE

    SciTech Connect

    Thayer, K.L.; Ramalingam, M.L. ); Young, T.J. )

    1993-01-20

    This work covers the performance modeling of an integral metal-matrix cesium-graphite reservoir for operation in the Advanced Thermionic Initiative-Thermionic Fuel Element (ATI-TFE) converter configuration. The objectives of this task were to incorporate an intercalated cesium-graphite reservoir for the 3C[sub 24]Cs[r arrow]2C[sub 36]Cs+Cs[sub (g)] two phase equilibrium reaction into the emitter lead region of the ATI-TFE. A semi two-dimensional, cylindrical TFE computer model was used to obtain thermal and electrical converter output characteristics for various reservoir locations. The results of this study are distributions for the interelectrode voltage, output current density, and output power density as a function of axial position along the TFE emitter. This analysis was accomplished by identifying an optimum cesium pressure for three representative pins in the ATI driverless'' reactor core and determining the corresponding position of the graphite reservoir in the ATI-TFE lead region. The position for placement of the graphite reservoir was determined by performing a first-order heat transfer analysis of the TFE lead region to determine its temperature distribution. The results of this analysis indicate that for the graphite reservoirs investigated the 3C[sub 24]Cs[r arrow]2C[sub 36]Cs+Cs[sub (g)] equilibrium reaction reservoir is ideal for placement in the TFE emitter lead region. This reservoir can be directly coupled to the emitter, through conduction, to provide the desired cesium pressure for optimum performance. The cesium pressure corresponding to the optimum converter output performance was found to be 2.18 torr for the ATI core least power TFE, 2.92 torr for the average power TFE, and 4.93 torr for the maximum power TFE.

  17. Seasonal Evolution of Thermal Stratification of Two High Mountain Tropical Reservoirs

    NASA Astrophysics Data System (ADS)

    Arbelaez, A. C.; Román-Botero, R.; Gómez-Giraldo, A.; Toro, M.

    2014-12-01

    A research was conducted to identify the dominant basin scale and season evolution of the physical processes in Riogrande II and La Fe, two high mountain Andean tropical reservoirs (>2000 masl), of different size and form, located in the northwestern of Colombia, Southamerica. Eight field campaigns were conducted in each reservoir between 2010 and 2012. Temperature, conductivity and turbidity profiles were measured along the longitudinal axes with a CTD and inflow temperature was recorded continuously with thermistors. In addition, thermistor chains were deployed on the deepest zone of each reservoir, in 2011 in La Fe and in 2013 in Riogrande II. The heat surface fluxes were calculated based on weather measurements, using heat bulk-formulations. It was found that the seasonal variability of the thermal structure in both reservoirs was dominated mainly by changes in the inflows temperature, related to the hydrological cycle, and not by the solar radiation variability. The atmospheric net heat flux revealed low seasonal changes, with the larger variability due to cloud cover and wind speed variability associated to the passage of the Intertropical Convergence Zone. The effect of the net atmospheric flux was confined to the surface mixed layer, which thickness varied between 2 and 4 m by the effect of short wave radiation heating during the day and strong heat loss starting at mid afternoon and remaining through the night. The inflow temperature was inversely correlated to the discharge, so large inflows are also colder and denser than small inflows. The plumes from small inflows are intrusive and create an intermediate layer of young water while those of large inflows remain attached to the bottom and fill the reservoir from the bottom. This resulted in the thermal structure of both reservoirs developing a bimodal annual cycle that follows the bimodal distribution of the rainfall and river discharge. Due to the discharge related changing level of the intrusion of the

  18. Thermal and dissolved oxygen characteristics of a South Carolina cooling reservoir

    USGS Publications Warehouse

    Oliver, James L.; Hudson, Patrick L.

    1987-01-01

    Temperature and dissolved oxygen concentrations were measured monthly from January 1971 to December 1982 at 1-m depth intervals at 13 stations in Keowee Reservoir in order to characterize spatial and temporal changes associated with operation of the Oconee Nuclear Station. The reservoir water column was i to 4°C warmer in operational than in non-operational years. The thermo-dine was at depths of 5 to 15 m before the operation of Oconee Nuclear Station, but was always below the upper level of the intake (20 m) after the station was in full operation; this suggests that pumping by the Oconee Nuclear Station had depleted all available cool hypolimnetic water to this depth. As a result summer water temperatures at depths greater than 10 m were usually 10°C higher after plant operation began than before. By fall the reservoir was nearly homothemious to a depth of 27 m, where a thermocine developed. Seasonal temperature profiles varied with distance from the plant; a cool water plume was evident in spring and a warm water plume was present in the summer, fall, and winter. A cold water plume also developed in the northern section of the reservoir due to the operation of Jocassee Pumped Storage Station. Increases in the mean water temperature of the reservoir during operational periods were correlated with the generating output of the power plant. The annual heat load to the reservoir increased by one-third after plant operations began. The alteration of the thermal stratification of the receiving water during the summer also caused the dissolved oxygen to mix to greater depths.

  19. Geology, reservoir engineering and methane hydrate potential of the Walakpa Gas Field, North Slope, Alaska. Final report

    SciTech Connect

    Glenn, R.K.; Allen, W.W.

    1992-12-01

    The Walakpa Gas Field, located near the city of Barrow on Alaska`s North Slope, has been proven to be methane-bearing at depths of 2000--2550 feet below sea level. The producing formation is a laterally continuous, south-dipping, Lower Cretaceous shelf sandstone. The updip extent of the reservoir has not been determined by drilling, but probably extends to at least 1900 feet below sea level. Reservoir temperatures in the updip portion of the reservoir may be low enough to allow the presence of in situ methane hydrates. Reservoir net pay however, decreases to the north. Depths to the base of permafrost in the area average 940 feet. Drilling techniques and production configuration in the Walakpa field were designed to minimize formation damage to the reservoir sandstone and to eliminate methane hydrates formed during production. Drilling development of the Walakpa field was a sequential updip and lateral stepout from a previously drilled, structurally lower confirmation well. Reservoir temperature, pressure, and gas chemistry data from the development wells confirm that they have been drilled in the free-methane portion of the reservoir. Future studies in the Walakpa field are planned to determine whether or not a component of the methane production is due to the dissociation of updip in situ hydrates.

  20. A structurally complex and dynamic reservoir description for reservoir simulation, Kuparuk River Field, Alaska

    SciTech Connect

    Walsh, T.P.; Leander, M.H.; Wilcox, T.C.

    1995-08-01

    The Kupanuk River Field is a structurally complex giant oil field adjacent to the Prudhoe Bay Field on Alaska`s North Slope. Oil is reservoired within two Early Cretaceous shallow marine sandstone formations, separated stratigraphically by an erosionally truncated marine silt/shale. Subjected to several phases of tectonism, this highly compartmentalized reservoir has been developed on regular 160 acre direct line drive patterns. An integrated team of geoscientists and engineers from BP Exploration (Alaska) Inc. and ARCO Alaska Inc. is presently quantifying the benefits of infill drilling at Kuparuk, and identifying the best locations for well placement. The two primary reservoir characteristics believed to impact the effectiveness of infill drilling are large-scale reservoir heterogeneity, and reservoir comparmentation due to faulting. Multiple thin pay zones within the two reservoir intervals are isolated laterally by faults with magnitudes greater than pay zone thickness. A process and tools designed to construct and maintain a structurally complex reservoir description, shared by the geoscientists and reservoir engineers, are described. Cross-discipline integration is aided by the use of Tech*Logic`s IREX 3-D reservoir modeling and visualization application. The unique architecture of the IREX model allows for representation of very complex structural geometries, and facilitates iteration between reservoir description and simulation, along the seismic to simulation continuum. Modifications to the reservoir description are guided by well-level history matching within the constraints of all available geoscience information. The techniques described will be of particular interest to those working on reservoir description and simulation of structurally complex fields.

  1. Analyzing a hydrocarbon reservoir by determining the response of that reservoir to tidal forces

    SciTech Connect

    Graebner, P.

    1991-08-20

    This patent describes a method for determining a component of the response of a hydrocarbons reservoir to tidal forces. It comprises measuring a variable responsive to tidal forces within the reservoir over a measurement time period; determining a theoretical earth-tide for the reservoir over the measurement time period; and determining the component of the response to tidal forces by comparing the variable measurements and the theoretical earth-tide determinations.

  2. Assembling evidence for identifying reservoirs of infection

    USGS Publications Warehouse

    Mafalda, Viana; Rebecca, Mancy; Roman, Biek; Sarah, Cleaveland; Cross, Paul C.; James O, Lloyd-Smith; Daniel T, Haydon

    2014-01-01

    Many pathogens persist in multihost systems, making the identification of infection reservoirs crucial for devising effective interventions. Here, we present a conceptual framework for classifying patterns of incidence and prevalence, and review recent scientific advances that allow us to study and manage reservoirs simultaneously. We argue that interventions can have a crucial role in enriching our mechanistic understanding of how reservoirs function and should be embedded as quasi-experimental studies in adaptive management frameworks. Single approaches to the study of reservoirs are unlikely to generate conclusive insights whereas the formal integration of data and methodologies, involving interventions, pathogen genetics, and contemporary surveillance techniques, promises to open up new opportunities to advance understanding of complex multihost systems.

  3. Reservoir response to tidal and barometric effects

    SciTech Connect

    Hanson, J.M.

    1980-05-29

    Solid earth tidal strain and surface loading due to fluctuations in barometric pressure have the effect, although extremely minute, of dilating or contracting the effective pore volume in a porous reservoir. If a well intersects the formation, the change in pore pressure can be measured with sensitive quartz pressure gauges. Mathematical models of the relevant fluid dynamics of the well-reservoir system have been generated and tested against conventional well pumping results or core data at the Salton Sea Geothermal Field (SSGF), California and at the Raft River, Geothermal Field (RRGF), Idaho. Porosity-total compressibility product evaluation based on tidal strain response compares favorably with results based on conventional pumping techniques. Analysis of reservoir response to barometric loading using Auto Regressive Integrated Moving Average (ARIMA) stochastic modeling appears also to have potential use for the evaluation of reservoir parameters.

  4. Assembling evidence for identifying reservoirs of infection

    PubMed Central

    Viana, Mafalda; Mancy, Rebecca; Biek, Roman; Cleaveland, Sarah; Cross, Paul C.; Lloyd-Smith, James O.; Haydon, Daniel T.

    2014-01-01

    Many pathogens persist in multihost systems, making the identification of infection reservoirs crucial for devising effective interventions. Here, we present a conceptual framework for classifying patterns of incidence and prevalence, and review recent scientific advances that allow us to study and manage reservoirs simultaneously. We argue that interventions can have a crucial role in enriching our mechanistic understanding of how reservoirs function and should be embedded as quasi-experimental studies in adaptive management frameworks. Single approaches to the study of reservoirs are unlikely to generate conclusive insights whereas the formal integration of data and methodologies, involving interventions, pathogen genetics, and contemporary surveillance techniques, promises to open up new opportunities to advance understanding of complex multihost systems. PMID:24726345

  5. WATER QUALITY ASSESSMENT OF AMERICAN FALLS RESERVOIR

    EPA Science Inventory

    A water quality model was developed to support a TMDL for phosphorus related to phytoplankton growth in the reservoir. This report documents the conceptual model, available data, model evaluation, and simulation results.

  6. Models for naturally fractured, carbonate reservoir simulations

    SciTech Connect

    Tuncay, K.; Park, A.; Ozkan, G.; Zhan, X.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    This report outlines the need for new tools for the simulation of fractured carbonate reservoirs. Several problems are identified that call for the development of new reservoir simulation physical models and numerical techniques. These include: karst and vuggy media wherein Darcy`s and traditional multi-phase flow laws do not apply; the need for predicting the preproduction state of fracturing and stress so that the later response of effective stress-dependent reservoirs can be predicted; and methods for predicting the fracturing and collapse of vuggy and karst reservoirs in response to draw-down pressure created during production. Specific research directions for addressing each problem are outlined and preliminary results are noted.

  7. Fifteenth workshop on geothermal reservoir engineering: Proceedings

    SciTech Connect

    Not Available

    1990-01-01

    The Fifteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23--25, 1990. Major topics included: DOE's geothermal research and development program, well testing, field studies, geosciences, geysers, reinjection, tracers, geochemistry, and modeling.

  8. Reservoir parameter inversion based on weighted statistics

    NASA Astrophysics Data System (ADS)

    Gui, Jin-Yong; Gao, Jian-Hu; Yong, Xue-Shan; Li, Sheng-Jun; Liu, Bin-Yang; Zhao, Wan-Jin

    2015-12-01

    Variation of reservoir physical properties can cause changes in its elastic parameters. However, this is not a simple linear relation. Furthermore, the lack of observations, data overlap, noise interference, and idealized models increases the uncertainties of the inversion result. Thus, we propose an inversion method that is different from traditional statistical rock physics modeling. First, we use deterministic and stochastic rock physics models considering the uncertainties of elastic parameters obtained by prestack seismic inversion and introduce weighting coefficients to establish a weighted statistical relation between reservoir and elastic parameters. Second, based on the weighted statistical relation, we use Markov chain Monte Carlo simulations to generate the random joint distribution space of reservoir and elastic parameters that serves as a sample solution space of an objective function. Finally, we propose a fast solution criterion to maximize the posterior probability density and obtain reservoir parameters. The method has high efficiency and application potential.

  9. 33 CFR 211.81 - Reservoir areas.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Tennessee. (q) Dale Hollow Reservoir Area, Tennessee. (r) Lake Cumberland, Kentucky. (s) Fort Supply... McClellan-Kerr Navigation Project in Oklahoma, to Former Owners Authority: Secs. 211.101 to...

  10. Reservoir Greenhouse Gas Emissions at Russian HPP

    SciTech Connect

    Fedorov, M. P.; Elistratov, V. V.; Maslikov, V. I.; Sidorenko, G. I.; Chusov, A. N.; Atrashenok, V. P.; Molodtsov, D. V.; Savvichev, A. S.; Zinchenko, A. V.

    2015-05-15

    Studies of greenhouse-gas emissions from the surfaces of the world’s reservoirs, which has demonstrated ambiguity of assessments of the effect of reservoirs on greenhouse-gas emissions to the atmosphere, is analyzed. It is recommended that greenhouse- gas emissions from various reservoirs be assessed by the procedure “GHG Measurement Guidelines for Fresh Water Reservoirs” (2010) for the purpose of creating a data base with results of standardized measurements. Aprogram for research into greenhouse-gas emissions is being developed at the St. Petersburg Polytechnic University in conformity with the IHA procedure at the reservoirs impounded by the Sayano-Shushenskaya and Mainskaya HPP operated by the RusHydro Co.

  11. Measurement-feedback formalism meets information reservoirs

    NASA Astrophysics Data System (ADS)

    Shiraishi, Naoto; Matsumoto, Takumi; Sagawa, Takahiro

    2016-01-01

    There have been two distinct formalisms of thermodynamics of information: one is the measurement-feedback formalism, which concerns bipartite systems with measurement and feedback processes, and the other is the information reservoir formalism, which considers bit sequences as a thermodynamic fuel. In this paper, we derive a second-law-like inequality by applying the measurement-feedback formalism to information reservoirs, which provides a stronger bound of extractable work than any other known inequality in the same setup. In addition, we demonstrate that the Mandal-Jarzynski model, which is a prominent model of the information reservoir formalism, is equivalent to a model obtained by the contraction of a bipartite system with autonomous measurement and feedback. Our results provide a unified view on the measurement-feedback and the information-reservoir formalisms.

  12. Ecological assessment of a southeastern Brazil reservoir

    EPA Science Inventory

    Abstract: Reservoirs are artificial ecosystems with multiple functions having direct and indirect benefits to humans; however, they also cause ecological changes and influence the composition and structure of aquatic biota. Our objectives were to: (1) assess the environmen...

  13. Integration of reservoir simulation and geomechanics

    NASA Astrophysics Data System (ADS)

    Zhao, Nan

    Fluid production from tight and shale gas formations has increased significantly, and this unconventional portfolio of low-permeability reservoirs accounts for more than half of the gas produced in the United States. Stimulation and hydraulic fracturing are critical in making these systems productive, and hence it is important to understand the mechanics of the reservoir. When modeling fractured reservoirs using discrete-fracture network representation, the geomechanical effects are expected to have a significant impact on important reservoir characteristics. It has become more accepted that fracture growth, particularly in naturally fractured reservoirs with extremely low permeability, cannot be reliably represented by conventional planar representations. Characterizing the evolution of multiple, nonplanar, interconnected and possibly nonvertical hydraulic fractures requires hydraulic and mechanical characterization of the matrix, as well as existing latent or healed fracture networks. To solve these challenging problems, a reservoir simulator (Advanced Reactive Transport Simulator (ARTS)) capable of performing unconventional reservoir simulation is developed in this research work. A geomechanical model has been incorporated into the simulation framework with various coupling schemes and this model is used to understand the geomechanical effects in unconventional oil and gas recovery. This development allows ARTS to accept geomechanical information from external geomechanical simulators (soft coupling) or the solution of the geomechanical coupled problem (hard coupling). An iterative solution method of the flow and geomechanical equations has been used in implementing the hard coupling scheme. The hard coupling schemes were verified using one-dimensional and two-dimensional analytical solutions. The new reservoir simulator is applied to learn the influence of geomechanical impact on unconventional oil and gas production in a number of practical recovery scenarios

  14. Reservoir engineering of Wairakei geothermal field

    SciTech Connect

    Grant, Malcom A.

    1988-01-01

    Wairakei was the first liquid dominated geothermal field exploited for major power production. As such many decisions were taken on an ad-hoc or experimental basis. In retrospect the choice of Wairakei was fortunate : with extensive shallow high permeability and major recharge it is an easy field to exploit. This lecture describes the history of the field and the contribution of reservoir engineering to field management, and describes the reservoir as it is now understood.

  15. The LBL geothermal reservoir technology program

    SciTech Connect

    Lippmann, M.J.

    1991-03-01

    The main objective of the DOE/GD-funded Geothermal Reservoir Technology Program at Lawrence Berkeley Laboratory is the development and testing of new and improved methods and tools needed by industry in its effort to delineate, characterize, evaluate, and exploit hydrothermal systems for geothermal energy. This paper summarizes the recent and ongoing field, laboratory, and theoretical research activities being conducted as part of the Geothermal Reservoir Technology Program. 28 refs., 4 figs.

  16. Geophysical monitoring in a hydrocarbon reservoir

    NASA Astrophysics Data System (ADS)

    Caffagni, Enrico; Bokelmann, Goetz

    2016-04-01

    Extraction of hydrocarbons from reservoirs demands ever-increasing technological effort, and there is need for geophysical monitoring to better understand phenomena occurring within the reservoir. Significant deformation processes happen when man-made stimulation is performed, in combination with effects deriving from the existing natural conditions such as stress regime in situ or pre-existing fracturing. Keeping track of such changes in the reservoir is important, on one hand for improving recovery of hydrocarbons, and on the other hand to assure a safe and proper mode of operation. Monitoring becomes particularly important when hydraulic-fracturing (HF) is used, especially in the form of the much-discussed "fracking". HF is a sophisticated technique that is widely applied in low-porosity geological formations to enhance the production of natural hydrocarbons. In principle, similar HF techniques have been applied in Europe for a long time in conventional reservoirs, and they will probably be intensified in the near future; this suggests an increasing demand in technological development, also for updating and adapting the existing monitoring techniques in applied geophysics. We review currently available geophysical techniques for reservoir monitoring, which appear in the different fields of analysis in reservoirs. First, the properties of the hydrocarbon reservoir are identified; here we consider geophysical monitoring exclusively. The second step is to define the quantities that can be monitored, associated to the properties. We then describe the geophysical monitoring techniques including the oldest ones, namely those in practical usage from 40-50 years ago, and the most recent developments in technology, within distinct groups, according to the application field of analysis in reservoir. This work is performed as part of the FracRisk consortium (www.fracrisk.eu); this project, funded by the Horizon2020 research programme, aims at helping minimize the

  17. Reservoir Exploration/Testing by Elastomechanical Methods

    SciTech Connect

    Bodvarsson, Gunnar

    1980-12-18

    The purpose of this brief note is to present a preliminary evaluation of the potential of the elastomechanical methods in practical reservoir engineering and related areas. Assuming simple relevant situations, the strength of the field signals will be estimated and compared to other ground surface data such as gravity and D.C. electrical signals that are also of interest in reservoir monitoring. Because of greater difficulty in observing surface strain, we will limit our discussion to vertical ground displacement and tilt signals.

  18. Integrated management of multiple reservoir field developments

    SciTech Connect

    Lyons, S.L.; Chan, H.M.; Harper, J.L.; Boyett, B.A.; Dowson, P.R.; Bette, S.

    1995-10-01

    This paper consists of two sections. The authors first describe the coupling of a pipeline network model to a reservoir simulator and then the application of this new simulator to optimize the production strategy of two Mobil field developments. Mobil`s PEGASUS simulator is an integrated all purpose reservoir simulator that handles black-oil, compositional, faulted and naturally fractured reservoirs. The authors have extended the simulator to simultaneously model multiple reservoirs coupled with surface pipeline networks and processes. This allows them to account for the effects of geology, well placement, and surface production facilities on well deliverability in a fully integrated fashion. They have also developed a gas contract allocation system that takes the user-specified constraints, target rates and swing factors and automatically assigns rates to the individual wells of each reservoir. This algorithm calculates the overall deliverability and automatically reduces the user-specified target rates to meet the deliverability constraints. The algorithm and solution technique are described. This enhanced simulator has been applied to model a Mobil field development in the Southern Gas Basin, offshore United Kingdom, which consists of three separate gas reservoirs connected via a pipeline network. The simulator allowed the authors to accurately determine the impact on individual reservoir and total field performance by varying the development timing of these reservoirs. Several development scenarios are shown to illustrate the capabilities of PEGASUS. Another application of this technology is in the field developments in North Sumatra, Indonesia. Here the objective is to economically optimize the development of multiple fields to feed the PT Arun LNG facility. Consideration of a range of gas compositions, well productivity`s, and facilities constraints in an integrated fashion results in improved management of these assets. Model specifics are discussed.

  19. Horizontal sidetrack taps reservoir sweet spots''

    SciTech Connect

    Wible, J.R. )

    1994-02-21

    Cutting a window at 85[degree] deviation allowed a sidetrack to pass through the high-resistivity sections in a Gulf of Mexico reservoir. Results from logging-while-drilling (LWD) tools indicated the original horizontal bore dropped too low in the reservoir, possibly leading to a low productivity well. The subsequent sidetrack successfully delivered the desired well bore, and the increased productivity justified the efforts in cutting a window in the horizontal section.

  20. Application of integrated reservoir management and reservoir characterization to optimize infill drilling

    SciTech Connect

    1997-04-01

    This project has used a multi-disciplinary approach employing geology, geophysics, and engineering to conduct advanced reservoir characterization and management activities to design and implement an optimized infill drilling program at the North Robertson (Clearfork) Unit in Gaines County, Texas. The activities during the first Budget Period consisted of developing an integrated reservoir description from geological, engineering, and geostatistical studies, and using this description for reservoir flow simulation. Specific reservoir management activities were identified and tested. The geologically targeted infill drilling program currently being implemented is a result of this work. A significant contribution of this project is to demonstrate the use of cost-effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability shallow-shelf carbonate (SSC) reservoirs. The techniques that are outlined for the formulation of an integrated reservoir description apply to all oil and gas reservoirs, but are specifically tailored for use in the heterogeneous, low permeability carbonate reservoirs of West Texas.

  1. A reservoir operating method for riverine ecosystem protection, reservoir sedimentation control and water supply

    NASA Astrophysics Data System (ADS)

    Yin, Xin-An; Yang, Zhi-Feng; Petts, Geoffrey E.; Kondolf, G. Mathias

    2014-05-01

    Riverine ecosystem protection requires the maintenance of natural flow and sediment regimes downstream from dams. In reservoir management schedules this requirement should be integrated with sedimentation control and human water supply. However, traditional eco-friendly reservoir operating methods have usually only considered the natural flow regime. This paper seeks to develop a reservoir operating method that accounts for both the natural flow and sediment regimes as well as optimizing the water supply allocations. Herein, reservoir water level (RWL), sediment-occupied ratio of reservoir volume (SOR) and rate of change of SOR (RCSOR) are adopted as three triggers of a drawdown-flushing-based sediment management policy. Two different groups of reservoir operating rule curves (RORCs) are designed for sediment-flushing and non-sediment-flushing years, and the three triggers, RWL, SOR and RCSOR, are used to change the “static” RORCs to “dynamic” ones. The approach is applied to the Wangkuai Reservoir, China to test its effectiveness. This shows that the approach can improve the flexibility of reservoir operators to balance the reservoir management, water supply management and the flow and sediment needs of the downstream riverine ecosystem.

  2. Characterization of a deep geothermal reservoir in an active volcanic area

    NASA Astrophysics Data System (ADS)

    Brehme, M.; Kamah, Y.; Koestono, H.; Zimmermann, G.; Regenspurg, S.; Erbaş, K.; Wiegand, B.; Sauter, M.

    2012-04-01

    In this study an integrated methodological approach to characterize a complex deep geothermal reservoir located in an active volcanic setting in Indonesia is presented. The methods applied include hydraulic and hydrogeochemical (incl. isotope tracer) techniques to model groundwater flow, heat transport, and hydro-geochemical properties of the reservoir. 3D geological and hydraulic models of the area were constructed based on deep drill profiles, collected fluid and rock samples, and mapping of geological structures. First results show that the geothermal reservoir is composed of major geological units such as altered andesite, basalt, breccia, and tuff layers. Several tectonic faults crosscut the geological units into individual blocks and reservoirs and influence hydraulic pathways in multiple ways. Hot water and steam are produced by nine wells. Fluids are reinjected into the reservoir through one injection well. Currently, a geothermal plant produces 60 MWe from steam withdrawn. Temperatures of the geothermal system range between 250 and 350 °C (Koestono et al. 2010). Based on the chemical composition of fluids from the production wells (concentration of major ions and physicochemical parameters) at least two different hydro-geochemical reservoirs could be identified. The deep reservoir with a moderate pH of 5 is marked by total silica concentrations up to 350 mg/L and high chloride concentrations of 430 mg/L. For the shallow reservoir, highly acidic conditions with pH values of 2.9 are analysed for water, while steam shows pH values around 4. Furthermore, high chloride (1550 mg/L), total silica (460 mg/L), and sulphate concentrations (1600 mg/L) are characteristic for the shallow reservoir. According to Giggenbach (1988) and Nicholson (1993) the water can be classified into sulphate-rich waters and neutral chloride-waters. Sulphate-rich water is expected to occur near to the heat source while chloride-rich waters discharge near the outflow zone. Surface

  3. A paleolimnological investigation of historical environmental change in East Canyon Reservoir

    NASA Astrophysics Data System (ADS)

    Higby Halseth, Deanna Renee

    East Canyon Reservoir is located 32 km east of Salt Lake City, Utah, and serves as a resource for irrigation, culinary water, and recreation. This research used paleolimnology and historical records to investigate the impacts of multiple stressors, including land clearance, dam construction and enlargement, and climate warming on East Canyon Reservoir. Recently, blue green algal blooms, typically indicative of eutrophication, have been increasing at East Canyon Reservoir despite reductions of nutrients from point sources, so part of the impetus for this study was to understand the forcing mechanisms of these blooms. A multiproxy analysis of three sediment cores retrieved from the reservoir determined changes in nutrient concentrations and sediment composition over time. Percent organics, magnetic susceptibility, and diatom analyses of 210Pb dated cores were compared to measurements of temperature and precipitation as well as records of historical land use, which were determined using remote sensing. Percent organics and magnetic susceptibility showed changes related to dam construction and increased development. Fossil diatom assemblages indicated that East Canyon Reservoir had been eutrophic since origination; however, principal components analyses of the diatom data indicated that the canyon became more P-enriched following dam construction and increased development. Recent increases in Cyclotella diatoms indicate changes related to warming temperatures, and we speculate that this warming is also what is causing blue-green algal blooms to increase.

  4. Greenhouse Gas Emissions from U.S. Hydropower Reservoirs: FY2011 Annual Progress Report

    SciTech Connect

    Stewart, Arthur J; Mosher, Jennifer J; Mulholland, Patrick J; Fortner, Allison M; Phillips, Jana Randolph; Bevelhimer, Mark S

    2012-05-01

    The primary objective of this study is to quantify the net emissions of key greenhouse gases (GHG) - notably, CO{sub 2} and CH{sub 4} - from hydropower reservoirs in moist temperate areas within the U.S. The rationale for this objective is straightforward: if net emissions of GHG can be determined, it would be possible to directly compare hydropower to other power-producing methods on a carbon-emissions basis. Studies of GHG emissions from hydropower reservoirs elsewhere suggest that net emissions can be moderately high in tropical areas. In such areas, warm temperatures and relatively high supply rates of labile organic matter can encourage high rates of decomposition, which (depending upon local conditions) can result in elevated releases of CO{sub 2} and CH{sub 4}. CO{sub 2} and CH{sub 4} emissions also tend to be higher for younger reservoirs than for older reservoirs, because vegetation and labile soil organic matter that is inundated when a reservoir is created can continue to decompose for several years (Galy-Lacaux et al. 1997, Barros et al. 2011). Water bodies located in climatically cooler areas, such as in boreal forests, could be expected to have lower net emissions of CO{sub 2} and CH{sub 4} because their organic carbon supplies tend to be relatively recalcitrant to microbial action and because cooler water temperatures are less conducive to decomposition.

  5. Experiments on Sediment Trap Efficiency in Reservoirs

    NASA Astrophysics Data System (ADS)

    Toniolo, H. A.; Schultz, J.

    2003-12-01

    The results of experiments on sediment trap efficiency in reservoirs are presented. Five different outlet conditions were examined during the experiments. The goal of this research is to obtain the evolution of the trap efficiency in reservoirs as a function of the outlet position. Two different materials, coal slag and glass beads, were used in the experiments to simulate sand and silt in the reservoir. The specific gravities are 2.60 (coal slag) and 2.50 (glass beads). Sand is deposited in the delta region. Silt plunges in the foreset of the delta and forms a turbidity current. The downstream wall of the reservoir forces the turbidity current to undergo a submerged hydraulic jump. A muddy pond with a distinctive turbid-clear water interface is formed downstream of hydraulic jump. Part of the silt is trapped in the reservoir forming a bottomset. The silt that is not retained in the reservoir escapes through the outlet. The results, for this specific set of experiments, indicate the presence of an optimal outlet position for maximum venting capacity (minimum trap efficiency).

  6. Bathymetric contours of Breckenridge Reservoir, Quantico, Virginia

    USGS Publications Warehouse

    Wicklein, S.M.; Lotspeich, R.R.; Banks, R.B., III

    2012-01-01

    Breckenridge Reservoir, built in 1938, is fed by Chopawamsic Creek and South Branch Chopawamsic Creek. The Reservoir is a main source of drinking water for the U.S. Marine Corps (USMC) Base in Quantico, Virginia. The U.S. Geological Survey (USGS), in cooperation with the USMC, conducted a bathymetric survey of Breckenridge Reservoir in March 2009. The survey was conducted to provide the USMC Natural Resources and Environmental Affairs (NREA) with information regarding reservoir storage capacity and general bathymetric properties. The bathymetric survey can provide a baseline for future work on sediment loads and deposition rates for the reservoir. Bathymetric data were collected using a boat-mounted Wide Area Augmentation System (WAAS) differential global positioning system (DGPS), echo depth-sounding equipment, and computer software. Data were exported into a geographic information system (GIS) for mapping and calculating area and volume. Reservoir storage volume at the time of the survey was about 22,500,000 cubic feet (517 acre-feet) with a surface area of about 1,820,000 square feet (41.9 acres).

  7. Assessment of reservoir system variable forecasts

    NASA Astrophysics Data System (ADS)

    Kistenmacher, Martin; Georgakakos, Aris P.

    2015-05-01

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

  8. Characterization of CO2 reservoir rock in Switzerland

    NASA Astrophysics Data System (ADS)

    Fabbri, Stefano; Madonna, Claudio; Zappone, Alba

    2014-05-01

    Anthropogenic emissions of Carbon Dioxide (CO2) are one of the key drivers regarding global climate change (IPCC, 2007). Carbon Dioxide Capture and Storage (CCS) is one valuable technology to mitigate current climate change with an immediate impact. The IPCC special report on CCS predicted a potential capture range of 4.7 to 37.5 Gt of CO2 by 2050. Among several countries, Switzerland has started to investigate its potential for CO2 storage (Chevalier et al., 2010) and is currently performing research on the characterization of the most promising reservoir/seal rocks for CO2 sequestration. For Switzerland, the most feasible option is to store CO2 in saline aquifers, sealed by impermeable formations. One aquifer of regional scale in the Swiss Molasse Basin is a carbonate sequence consisting of reworked shallow marine limestones and accumulations of shell fragments. The upper part of the formation presents the most promising permeability values and storage properties. The storage potential has been estimated of 706 Mt of CO2, based on the specific ranking scheme proposed by Chevalier et al. 2010. In this study, key parameters such as porosity, permeability and acoustic velocities in compressional and shear mode have been measured in laboratory at pressures and temperatures simulating in situ conditions. Reservoir rock samples have been investigated. Permeability has been estimated before and after CO2 injection in supercritical state. The simulation of typical reservoir conditions allows us to go one step further towards a significant evaluation of the reservoir's true capacities for CO2 sequestration. It seems of major importance to notice that the permeability crucially depends on confining pressure, temperature and pore pressure conditions of the sample. Especially at in situ conditions with CO2 being at supercritical state, a substantial loss in permeability have to be taken into consideration when it comes to the calculation of potential injection rates. The

  9. Reservoir operation under variable climate: Case of Rozva Dam, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Ncube, S. P.; Makurira, H.; Kaseke, E.; Mhizha, A.

    The challenge of maintaining or improving the quality of rural livelihoods against the increasing threat of climate change (CC) and climate variability (CV) calls for the development of robust and tested systems, tools and procedures for the management of water resources. The research aimed at assessing reservoir operation under variable climate for Rozva Dam, a medium-sized reservoir in Zimbabwe. Rozva Dam is located in the Bikita District of Zimbabwe and has a full supply capacity of 2.8 Mm 3 at a maximum water level of 17.3 m. The research analysed 46 years of rainfall and temperature data to assess climate variability and or change. The CROPWAT model was used to estimate crop water requirements for the adjacent 80 hectare irrigation scheme. The WAFLEX model was applied to simulate the performance of the system under three scenarios: (1) existing demands and operational rules, (2) reduced water availability due to climate change, as predicted by the Ministry of Mines, but with increasing annual demands and (3) climate change situation coupled with change in irrigation technology. The results show a general decreasing linear trend for rainfall although the variance was not statistically significant at p = 0.05. A clearer cyclic pattern was observed for the decadal analysis. An increasing trend in both maximum and minimum temperature was observed although, again, these were not statistically significant with a Spearman’s rank correlation coefficient ( R sp) of below 0.5. The research used rainfall and temperature data as the basis for confirmation climate change and variability in the study area. Analyses show that the area is experiencing more of CV than CC. Modelling results show that the reservoir can satisfy current demands but will fail to cope under the forecasted increase in demand. The conclusions from the research are that the available water resources in the studied system are sufficient to satisfy the current demands. The predicted level of climate

  10. A finite element simulation system in reservoir engineering

    SciTech Connect

    Gu, Xiaozhong

    1996-03-01

    Reservoir engineering is performed to predict the future performance of a reservoir based on its current state and past performance and to explore other methods for increasing the recovery of hydrocarbons from a reservoir. Reservoir simulations are routinely used for these purposes. A reservoir simulator is a sophisticated computer program which solves a system of partial differential equations describing multiphase fluid flow (oil, water, and gas) in a porous reservoir rock. This document describes the use of a reservoir simulator version of BOAST which was developed by the National Institute for Petroleum and Energy Research in July, 1991.

  11. Recycling irrigation reservoir stratification and implications for crop health and production.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stratification is often assumed to only take place in deep water bodies. Recycling irrigation reservoirs often are shallow; however, they receive agricultural runoff containing elevated concentrations of nutrients and sediments. This study investigated the temperature, dissolved oxygen and pH charac...

  12. Controls on the Karaha-Telaga Bodas geothermal reservoir, Indonesia

    USGS Publications Warehouse

    Nemcok, M.; Moore, J.N.; Christensen, Carl; Allis, R.; Powell, T.; Murray, B.; Nash, G.

    2007-01-01

    Karaha-Telaga Bodas is a partially vapor-dominated, fracture-controlled geothermal system located adjacent to Galunggung Volcano in western Java, Indonesia. The geothermal system consists of: (1) a caprock, ranging from several hundred to 1600 m in thickness, and characterized by a steep, conductive temperature gradient and low permeability; (2) an underlying vapor-dominated zone that extends below sea level; and (3) a deep liquid-dominated zone with measured temperatures up to 353 ??C. Heat is provided by a tabular granodiorite stock encountered at about 3 km depth. A structural analysis of the geothermal system shows that the effective base of the reservoir is controlled either by the boundary between brittle and ductile deformational regimes or by the closure and collapse of fractures within volcanic rocks located above the brittle/ductile transition. The base of the caprock is determined by the distribution of initially low-permeability lithologies above the reservoir; the extent of pervasive clay alteration that has significantly reduced primary rock permeabilities; the distribution of secondary minerals deposited by descending waters; and, locally, by a downward change from a strike-slip to an extensional stress regime. Fluid-producing zones are controlled by both matrix and fracture permeabilities. High matrix permeabilities are associated with lacustrine, pyroclastic, and epiclastic deposits. Productive fractures are those showing the greatest tendency to slip and dilate under the present-day stress conditions. Although the reservoir appears to be in pressure communication across its length, fluid, and gas chemistries vary laterally, suggesting the presence of isolated convection cells. ?? 2006 CNR.

  13. Depletion modeling of liquid dominated geothermal reservoirs

    SciTech Connect

    Olsen, G.

    1984-06-01

    Depletion models for liquid-dominated geothermal reservoirs are derived and presented. The depletion models are divided into two categories: confined and unconfined. For both cases depletion models with no recharge (or influx), and depletion models including recharge, are used to match field data from the Svartsengi high temperature geothermal field in Iceland. The influx models included with the mass and energy balances are adopted from the petroleum engineering literature. The match to production data from Svartsengi is improved when influx was included. The Schilthuis steady-state influx gives a satisfactory match. The finite aquifer method of Fetkovitch, and the unsteady state method of Hurst gave reasonable answers, but not as good. The best match is obtained using Hurst simplified solution when lambda = 1.3 x 10{sup -4} m{sup -1}. From the match the cross-sectional area of the aquifer was calculated as 3.6 km{sup 2}. The drawdown was predicted using the Hurst simplified method, and compared with predicted drawdown from a boiling model and an empirical log-log model. A large difference between the models was obtained. The predicted drawdown using the Hurst simplified method falls between the other two. Injection has been considered by defining the net rate as being the production rate minus the injection rate. No thermal of transient effects were taken into account. Prediction using three different net rates shows that the pressure can be maintained using the Hurst simplified method if there is significant fluid reinjection. 32 refs., 44 figs., 2 tabs.

  14. The Potosi Reservoir Model 2013

    SciTech Connect

    Adushita, Yasmin; Smith, Valerie; Leetaru, Hannes

    2014-09-30

    As a part of a larger project co-funded by the United States Department of Energy (US DOE) to evaluate the potential of formations within the Cambro-Ordovician strata above the Mt. Simon as potential targets for carbon sequestration in the Illinois and Michigan Basins, the Illinois Clean Coal Institute (ICCI) requested Schlumberger to evaluate the potential injectivity and carbon dioxide (CO2) plume size of the Cambrian Potosi Formation. The evaluation of this formation was accomplished using wireline data, core data, pressure data, and seismic data from the US DOE-funded Illinois Basin–Decatur Project (IBDP) being conducted by the Midwest Geological Sequestration Consortium in Macon County, Illinois. In 2010, technical performance evaluations on the Cambrian Potosi Formation were performed through reservoir modeling. The data included formation tops from mud logs, well logs from the VW1 and the CCS1 wells, structural and stratigraphic formation from three dimensional (3D) seismic data, and field data from several waste water injection wells for Potosi Formation. Intention was for two million tons per annum (MTPA) of CO2 to be injected for 20 years. In the preceding, the 2010 Potosi heterogeneous model (referred to as the "Potosi Dynamic Model 2010" in this topical report) was re-run using a new injection scenario; 3.2 MTPA for 30 years. The extent of the Potosi Dynamic Model 2010, however, appeared too small for the new injection target. It was not sufficiently large enough to accommodate the evolution of the plume. The new model, Potosi Dynamic Model 2013a, was built by extending the Potosi Dynamic Model 2010 grid to 30 miles x 30 miles (48.3km x48.3km), while preserving all property modeling workflows and layering. This model was retained as the base case of Potosi Dynamic Model 2013a. The Potosi reservoir model was updated to take into account the new data from the verification well VW2 which was drilled in 2012. The new porosity and permeability modeling was

  15. Altering Reservoir Wettability to Improve Production from Single Wells

    SciTech Connect

    W. W. Weiss

    2006-09-30

    tests were conducted in an area of the field that has not met production expectations. The dataset on the 23 Phosphoria well surfactant soaks was updated. An analysis of the oil decline curves indicted that 4.5 lb of chemical produced a barrel of incremental oil. The AI analysis supports the adage 'good wells are the best candidates.' The generally better performance of surfactant in the high permeability core laboratory tests supports this observation. AI correlations were developed to predict the response to water-frac stimulations in a tight San Andres reservoir. The correlations maybe useful in the design of Cedar Creek Anticline surfactant soak treatments planned for next year. Nuclear Magnetic Resonance scans of dolomite cores to measure porosity and saturation during the high temperature laboratory work were acquired. The scans could not be correlated with physical measurement using either conventional or AI methods.

  16. Online interactive U.S. Reservoir Sedimentation Survey Database

    USGS Publications Warehouse

    Gray, J.B.; Bernard, J.M.; Schwarz, G.E.; Stewart, D.W.; Ray, K.T.

    2009-01-01

    In April 2009, the U.S. Geological Survey and the Natural Resources Conservation Service (prior to 1994, the Soil Conservation Service) created the Reservoir Sedimentation Survey Database (RESSED) and Web site, the most comprehensive compilation of data from reservoir bathymetric and dry basin surveys in the United States. RESSED data can be useful for a number of purposes, including calculating changes in reservoir storage characteristics, quantifying rates of sediment delivery to reservoirs, and estimating erosion rates in a reservoir's watershed.

  17. Producing Light Oil from a Frozen Reservoir: Reservoir and Fluid Characterization of Umiat Field, National Petroleum Reserve, Alaska

    SciTech Connect

    Hanks, Catherine

    2012-12-31

    compared to theoretical Umiat composition derived using the Pedersen method with original Umiat fluid properties published in the original reports. This comparison allowed estimation of the ‘lost’ light hydrocarbon fractions. An Umiat 'dead' oil sample then could be physically created by adding the lost light ends to the weatherized Umiat dead oil sample. This recreated sample was recombined with solution gas to create a 'pseudo-live' Umiat oil sample which was then used for experimental PVT and phase behavior studies to determine fluid properties over the range of reservoir pressures and temperatures. The phase behavior of the ‘pseudo-live’ oil was also simulated using the Peng- Robinson equations of state (EOS). The EOS model was tuned with measured experimental data to accurately simulate the differential liberation tests in order to obtain the necessary data for reservoir simulation studies, including bubble point pressure and oil viscosity. The bubble point pressure of the reconstructed Umiat oil is 345 psi, suggesting that maintenance of reservoir pressures above that pressure will be important for the any proposed production technique. A major part of predicting how the Umiat reservoir will perform is determining the relative permeability of oil in the presence of ice. Early in the project, UAF work on samples of the Umiat reservoir indicated that there is a significant reduction in the relatively permeability of oil in the presence of ice. However, it was not clear as to why this reduction occurred or where the ice resided. To explore this further, additional experimental and theoretical work was conducted. Core flood experiments were performed on two clean Berea sandstone cores under permafrost conditions to determine the relative permeability to oil (kro) over a temperature range of 23ºC to - 10ºC and for a range of connate water salinities. Both cores showed maximum reduction in relative permeability to oil when saturated with deionized water and less

  18. A coupled bubble plume-reservoir model for hypolimnetic oxygenation

    NASA Astrophysics Data System (ADS)

    Singleton, V. L.; Rueda, F. J.; Little, J. C.

    2010-12-01

    A model for a linear bubble plume used for hypolimnetic oxygenation was coupled with a three-dimensional hydrodynamic model to simulate the complex interaction between bubble plumes and the large-scale processes of transport and mixing. The coupled model accurately simulated the evolution of dissolved oxygen (DO) and temperature fields that occurred during two full-scale diffuser tests in a water supply reservoir. The prediction of asymmetric circulation cells laterally and longitudinally on both sides of the linear diffuser was due to the uneven reservoir bathymetry. Simulation of diffuser operation resulted in baroclinic pressure gradients, which caused vertical oscillations above the hypolimnion and contributed to distribution of plume detrainment upstream and downstream of the diffuser. On the basis of a first-order variance analysis, the largest source of uncertainty for both predicted DO and temperature was the model bathymetry, which accounted for about 90% of the overall uncertainty. Because the oxygen addition rate was 4 times the sediment oxygen uptake (SOU) rate, DO predictions were not sensitive to SOU. In addition to bathymetry, the momentum assigned to plume entrainment and detrainment is a significant source of uncertainty in the coupled model structure and appreciably affects the predicted intensity of mixing and lake circulation. For baseline runs, the entrainment and detrainment velocities were assumed to be half of the velocities through the flux face of the grid cells. Additional research on appropriate values of the plume detrainment momentum for the coupled model is required.

  19. Trachelomonas (Euglenophyta) from a eutrophic reservoir in Central Mexico.

    PubMed

    Solórzano, Gloria Garduño; Martinez, Maria Guadalupe Oliva; Vazquez, Alfonso Lugo; Garfias, Maria Berenit Mendoza; Zuñiga, Rafael Emiliano Quintanar; Conforti, Visitacion

    2011-07-01

    This study provides valuable information on the ultrastructure and environmental conditions of the Trachelomonas Ehr. (Euglenophyceae) genus in the Guadalupe Dam, a eutrophic reservoir located in the suburbs of Mexico City, which receives a considerable volume of wastewaters. Specimens were collected at surface level between November 2005 and May 2006. Using LM and SEM twelve taxa from phytoplankton were identified of which, 9 are new records for Mexico. The reservoir is warm monomictic, with basic pH values (7.4-10.1), a high concentration of chlorophyll a(18-101 microg l(-1), a permanent anoxic bottom, specific conductivity (K25) of 205 to 290 microS cm(-1), N-NO3, 0.19-1.2 mg l(-1) and P-PO4 0.22-1.6 mg l(-1). Water temperature was 15.6-23.0 degrees C. Most of the Trachelomonas species were found during the dry season, when concentrations of organic matter, nitrogen and phosphorus as well as the temperature were the highest. Higher species richness was also associated with the warmer months. This research contributes to increase our knowledge on Trachelomonas in Mexico and constitutes the first detailed description of lorica ultrastructure of 12 taxa that grow in a body of water with high concentration of nutrients and a moderate amount of mineral contents. PMID:22315825

  20. Development of luminescent bacteria as tracers for geological reservoir characterization

    SciTech Connect

    King, J.W.

    1991-10-01

    Bioluminescent cultures were acquired and tested for use as biological tracers for reservoir characterization by small independent oil companies. Initially these bacterial cultures were fastidious to work with, but when we finally determined their critical growth parameters simple test variations were developed that could be routinely accomplished. The intensity of their luminescence is easily distinguished by the human eye and requires no sophisticated technical knowledge or instrumentation. Cultures were received from culture banks and collected from marine environments. In our laboratory they were screened using the criteria of optimum growth and luminescence. Three stock cultures proved to grow profusely even when variations were made in nutrient additions, salts, and temperature. These three selected cultures were not inhibited when introduced to formations and formation waters and were not overgrown by other bacteria. Cultures isolated from the Gulf of Mexico were overgrown by indigenous bacteria and therefore, they were eliminated from further screening and adaption. Experiments were performed according to three major task descriptions: 1. Establish growth and luminescencing limitations of selected bacteria in various media, varying salt concentration and temperature. 2. Adapt cultures to formation waters. 3. Determine transport limitations of bioluminescent bacteria through representative reservoir cores. 19 refs., 5 figs., 7 tabs.

  1. Sensitivity of reservoir storage and outflow to climate change in a water-limited river basin

    NASA Astrophysics Data System (ADS)

    Zhao, G.; Gao, H.; Naz, B. S.; Kao, S. C.; Voisin, N.

    2015-12-01

    During the past several decades, numerous reservoirs have been built across the world for a variety of purposes such as flood control, irrigation, municipal water supplies, and hydropower. Consequently, streamflow timing and magnitude are altered significantly by reservoir operations. In addition, the hydrological cycle can be modified substantially by a changing climate. Therefore, a distributed hydrological model which has an embedded reservoir component is essential for representing these effects in future water management planning strategies. In this study, a multi-purpose reservoir module was integrated into the Distributed Hydrology Soil Vegetation Model (DHSVM). The DHSVM model was selected because of its high spatial and temporal resolution and because of its explicit representation of the physical processes. Prescribed operating rules, which are designed to reduce flood risk and enhance water supply reliability, were adopted in this module. The integrated model was tested over a water-limited basin (i.e. the central Brazos River Basin, Texas). Both the calibration and validation results suggest that the model performed robustly at daily, weekly, and monthly levels. Subsequently, the effect of climate sensitivity on reservoir storage and outflow was assessed by perturbing precipitation within a range from -30% to 30% and temperature from -2 °C to 2 °C. Results suggest that both variables are more sensitive to precipitation than temperature. However, there are more uncertainties associated with future precipitation than temperature. It was also found that the sensitivities vary significantly by season. Enabled with the new reservoir component, the DHSVM model provides a platform for projecting future water availability estimations under flow regulation, climate change, and land cover/land use changes. We expect this integrated model to be beneficial for sustainable water resources management.

  2. Geologic aspects of horizontal drilling in self-sourcing reservoirs

    SciTech Connect

    Illich, H.A. )

    1991-03-01

    Horizontal drilling techniques provide a way to exploit hydrocarbon reserves that are either noneconomic or only marginally economic using vertical drilling techniques. A significant fraction of these reserves is contained in reservoirs that are self-sourcing or in reservoirs that are closely associated with their resources. Most formations drilled as horizontal targets are self-sourcing. The Austin Chalk, Niobrara, Mesaverde, and Bakken are examples of horizontally drilled, self-sourcing reservoir systems. In formations like the Bakken or Austin Chalk, the close relationship between reservoir and source makes risks associated with migration and accumulation less important. Reservoirs of this kind can contain oil or gas and often have little or no associated water. They can be matrix-dominated reservoirs, dual-porosity reservoirs (Mesaverde), or fractured reservoirs (Austin Chalk, Bakken, and Niobrara). Fractured, self-sourcing reservoirs also can possess matrix characteristics that contribute increased recovery efficiency. Most reservoirs drilled horizontally possess matrix characteristics that contribute increased recovery efficiency. Most reservoirs drilled horizontally possess highly heterogeneous reservoir systems. Characterization of the style of reservoir heterogeneity in self-sourcing systems is important if the favorable properties of horizontally oriented bore holes are to be realized. Production data and rock mechanics considerations are important in horizontal drilling ventures. Examples of the use of these data for the purpose of defining reservoir characteristics are discussed. Knowledge of lateral changes in reservoir properties is essential if we are to recover known reserves efficiently.

  3. Architecture of collapsed-paleocave reservoirs

    SciTech Connect

    Loucks, R.G. ); Mescher, P. )

    1996-01-01

    It is important to investigate the architecture of collapsed-paleocave reservoirs at interwell scales in outcrops because reservoir heterogeneities cannot be adequately characterized by cores and log correlation sections. A 3000-foot long quarry wall of Ellenburger strata in central Texas displays the lithologic and pore network heterogeneities at typical well spacings (1300 to 2600 feet). The quarry wall exposes the transition from stratified host rock into a complex collapsed-paleocave system showing several developmental episodes. This paleocave system has over 2600 feet of laterally continuous chaotic breccias. The dimensions of these breccias are similar as to what is imaged by 3-D seismic over paleocave reservoirs. Collapsed-paleocave reservoirs are not single collapsed passages of tens of feet across, but are homogenized collapsed-cave systems hundreds to several thousand feet across. This concept of scale is very important because collapsed-paleocave systems offer larger exploration targets than individual cave passages. Collapsed-paleocave systems are complex because they are the homogenization of chaotic breccias and cave-sediment fill from passages, chambers, and shafts and of crackle breccias from roof- and wall-rock and pillars. Pore networks are associated with chaotic breakdown breccias, cave roof- and wall-crackle breccias, and/or clastic sediment fill. Strong heterogeneity within a collapsed paleocave system should be expected. Lateral and vertical changes in collapsed-paleocave-related facies have the strongest effect on reservoir heterogeneity and quality. Within individual facies there can be distinct reservoir quality variation, such as between the cave-sediment fill and associated blocks. Tectonic fractures, however, can interconnect the highly variable pore networks within a collapsed-paleocave reservoir.

  4. Architecture of collapsed-paleocave reservoirs

    SciTech Connect

    Loucks, R.G.; Mescher, P.

    1996-12-31

    It is important to investigate the architecture of collapsed-paleocave reservoirs at interwell scales in outcrops because reservoir heterogeneities cannot be adequately characterized by cores and log correlation sections. A 3000-foot long quarry wall of Ellenburger strata in central Texas displays the lithologic and pore network heterogeneities at typical well spacings (1300 to 2600 feet). The quarry wall exposes the transition from stratified host rock into a complex collapsed-paleocave system showing several developmental episodes. This paleocave system has over 2600 feet of laterally continuous chaotic breccias. The dimensions of these breccias are similar as to what is imaged by 3-D seismic over paleocave reservoirs. Collapsed-paleocave reservoirs are not single collapsed passages of tens of feet across, but are homogenized collapsed-cave systems hundreds to several thousand feet across. This concept of scale is very important because collapsed-paleocave systems offer larger exploration targets than individual cave passages. Collapsed-paleocave systems are complex because they are the homogenization of chaotic breccias and cave-sediment fill from passages, chambers, and shafts and of crackle breccias from roof- and wall-rock and pillars. Pore networks are associated with chaotic breakdown breccias, cave roof- and wall-crackle breccias, and/or clastic sediment fill. Strong heterogeneity within a collapsed paleocave system should be expected. Lateral and vertical changes in collapsed-paleocave-related facies have the strongest effect on reservoir heterogeneity and quality. Within individual facies there can be distinct reservoir quality variation, such as between the cave-sediment fill and associated blocks. Tectonic fractures, however, can interconnect the highly variable pore networks within a collapsed-paleocave reservoir.

  5. Pressure behavior of laterally composite reservoirs

    SciTech Connect

    Kuchuk, F.J.; Habashy, T.

    1997-03-01

    This paper presents a new general method for solving the pressure diffusion equation in laterally composite reservoirs, where rock and fluid properties may change laterally as a function of y in the x-y plane. Composite systems can be encountered as a result of many different types of depositional and tectonic processes. For example, meandering point bar reservoirs or reservoirs with edgewater encroachment are examples of such systems. The new solution method presented is based on the reflection-transmission concept of electromagnetics to solve fluid-flow problems in 3D nonhomogeneous reservoirs, where heterogeneity is in only one (y) direction. A general Green`s function for a point source in 3D laterally composite systems is developed by using the reflection-transmission method. The solutions in the Laplace transform domain are then developed from the Green`s function for the pressure behavior of specific composite reservoirs. The solution method can also be applied to many different types of wells, such as vertical, fractured, and horizontal in composite reservoirs. The pressure behavior of a few well-known laterally composite systems are investigated. It is shown that a network of partially communicating faults and fractures in porous medium can be modeled as composite systems. It is also shown that the existing solutions for a partially communicating fault are not valid when the fault permeability is substantially larger than the formation permeability. The derivative plots are presented for selected faulted, fractured, channel, and composite reservoirs as diagnostic tools for well-test interpretation. It is also shown that if the composite system`s permeability varies moderately in the x or y direction, it exhibits a homogeneous system behavior. However, it does not yield the system`s average permeability. Furthermore, the composite systems with distributed low-permeability zones behave as if the system has many two no-flow boundaries.

  6. PLANET TOPERS: Planets, Tracing the Transfer, Origin, Preservation, and Evolution of their ReservoirS

    NASA Astrophysics Data System (ADS)

    Dehant, V.; Asael, D.; Baland, R. M.; Baludikay, B. K.; Beghin, J.; Belza, J.; Beuthe, M.; Breuer, D.; Chernonozhkin, S.; Claeys, Ph.; Cornet, Y.; Cornet, L.; Coyette, A.; Debaille, V.; Delvigne, C.; Deproost, M. H.; De WInter, N.; Duchemin, C.; El Atrassi, F.; François, C.; De Keyser, J.; Gillmann, C.; Gloesener, E.; Goderis, S.; Hidaka, Y.; Höning, D.; Huber, M.; Hublet, G.; Javaux, E. J.; Karatekin, Ö.; Kodolanyi, J.; Revilla, L. Lobo; Maes, L.; Maggiolo, R.; Mattielli, N.; Maurice, M.; McKibbin, S.; Morschhauser, A.; Neumann, W.; Noack, L.; Pham, L. B. S.; Pittarello, L.; Plesa, A. C.; Rivoldini, A.; Robert, S.; Rosenblatt, P.; Spohn, T.; Storme, J.-Y.; Tosi, N.; Trinh, A.; Valdes, M.; Vandaele, A. C.; Vanhaecke, F.; Van Hoolst, T.; Van Roosbroek, N.; Wilquet, V.; Yseboodt, M.

    2016-06-01

    The Interuniversity Attraction Pole (IAP) `PLANET TOPERS' (Planets: Tracing the Transfer, Origin, Preservation, and Evolution of their Reservoirs) addresses the fundamental understanding of the thermal and compositional evolution of the different reservoirs of planetary bodies (core, mantle, crust, atmosphere, hydrosphere, cryosphere, and space) considering interactions and feedback mechanisms. Here we present the first results after 2 years of project work.

  7. AGRICULTURE RUNOFF AND RESERVOIR DRAWDOWN EFFECTS ON A 2760-HECTARE RESERVOIR

    EPA Science Inventory

    The 2760-hectare Big Eau Pleine Reservoir in Marathon County, Wisconsin has experienced frequent winter fish kills and summer algae blooms since its construction in 1937. A study of the reservoir and its 945 square kilometer watershed was conducted from 1974 to 1979 in an attempt...

  8. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    SciTech Connect

    Wiggins, Michael L.; Brown, Raymon L.; Civan, Frauk; Hughes, Richard G.

    2001-08-15

    Research continues on characterizing and modeling the behavior of naturally fractured reservoir systems. Work has progressed on developing techniques for estimating fracture properties from seismic and well log data, developing naturally fractured wellbore models, and developing a model to characterize the transfer of fluid from the matrix to the fracture system for use in the naturally fractured reservoir simulator.

  9. Application of integrated reservoir management and reservoir characterization to optimize infill drilling, Class II

    SciTech Connect

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

    2000-03-16

    The major purpose of this project was to demonstrate the use of cost effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability carbonate reservoirs such as the North Robertson (Clearfork) Unit.

  10. Application of integrated reservoir management and reservoir characterization to optimize infill drilling. [Quarterly] report, March 13, 1995--June 12, 1995

    SciTech Connect

    Pande, P.K.

    1995-06-12

    The primary objective of this project is to conduct a cost-shared geologically targeted infill drilling filed demonstration that will enhance the domestic producibility of shallow shelf carbonate reservoirs by demonstration and technology transfer of the advanced recovery technologies employed, application of integrated reservoir management and reservoir characterization. Progress reports are presented for this past quarter for the following tasks: management and administration; reservoir characterization and analysis; integrated reservoir management; and technology transfer.

  11. Deuterium in the outer solar system - Evidence for two distinct reservoirs

    NASA Technical Reports Server (NTRS)

    Owen, T.; Lutz, B. L.; De Bergh, C.

    1986-01-01

    A series of determinations of the CH3D/CH4 ratio in the atmospheres of Saturn, Titan, and Uranus has been completed. These results, coupled with the work of other investigators, suggest that the solar system contains at least two distinctly different primordial reservoirs of deuterium: that contained in gaseous hydrogen and that contained in the volatiles which have been maintained at low temperatures or isolated from hydrogen; for example, trapped in cold, solid material. Both of these reservoirs were established before the formation of the solar system.

  12. Seismic imaging of reservoir flow properties: Resolving waterinflux and reservoir permeability

    SciTech Connect

    Vasco, D.W.; Keers, Henk

    2006-11-27

    Methods for geophysical model assessment, in particuale thecomputation of model parameter resolution, indicate the value and thelimitations of time-lapse data in estimating reservoir flow properties. Atrajectory-based method for computing sensitivities provides an effectivemeans to compute model parameter resolutions. We examine the commonsituation in which water encroaches into a resrvoir from below, as due tothe upward movement of an oil-water contact. Using straight-forwardtechniques we find that, by inclusing reflections off the top and bottomof a reservoir tens of meters thick, we can infer reservoir permeabilitybased upon time-lapse data. We find that, for the caseof water influxfrom below, using multiple time-lapse 'snapshots' does not necessarilyimprove the resolution of reservoir permeability. An application totime-lapse data from the Norne field illustrates that we can resolve thepermeability near a producing well using reflections from threeinterfaces associated with the reservoir.

  13. Reservoir Characterization, Production Characteristics, and Research Needs for Fluvial/Alluvial Reservoirs in the United States

    SciTech Connect

    Cole, E.L.; Fowler, M.L.; Jackson, S.R.; Madden, M.P.; Raw-Schatzinger, V.; Salamy, S.P.; Sarathi, P.; Young, M.A.

    1999-04-28

    The Department of Energy's (DOE's) Oil Recovery Field Demonstration Program was initiated in 1992 to maximize the economically and environmentally sound recovery of oil from known domestic reservoirs and to preserve access to this resource. Cost-shared field demonstration projects are being initiated in geology defined reservoir classes which have been prioritized by their potential for incremental recovery and their risk of abandonment. This document defines the characteristics of the fifth geological reservoir class in the series, fluvial/alluvial reservoirs. The reservoirs of Class 5 include deposits of alluvial fans, braided streams, and meandering streams. Deposit morphologies vary as a complex function of climate and tectonics and are characterized by a high degree of heterogeneity to fluid flow as a result of extreme variations in water energy as the deposits formed.

  14. Preliminary Three-Dimensional Simulation of Sediment and Cesium Transport in the Ogi Dam Reservoir using FLESCOT – Task 6, Subtask 2

    SciTech Connect

    Onishi, Yasuo; Kurikami, Hiroshi; Yokuda, Satoru T.

    2014-03-28

    After the accident at the Fukushima Daiichi Nuclear Power Plant in March 2011, the Japan Atomic Energy Agency and the Pacific Northwest National Laboratory initiated a collaborative project on environmental restoration. In October 2013, the collaborative team started a task of three-dimensional modeling of sediment and cesium transport in the Fukushima environment using the FLESCOT (Flow, Energy, Salinity, Sediment Contaminant Transport) code. As the first trial, we applied it to the Ogi Dam Reservoir that is one of the reservoirs in the Japan Atomic Energy Agency’s (JAEA’s) investigation project. Three simulation cases under the following different temperature conditions were studied: • incoming rivers and the Ogi Dam Reservoir have the same water temperature • incoming rivers have lower water temperature than that of the reservoir • incoming rivers have higher water temperature than that of the reservoir. The preliminary simulations suggest that seasonal temperature changes influence the sediment and cesium transport. The preliminary results showed the following: • Suspended sand, and cesium adsorbed by sand, coming into the reservoirs from upstream rivers is deposited near the reservoir entrance. • Suspended silt, and cesium adsorbed by silt, is deposited farther in the reservoir. • Suspended clay, and cesium adsorbed by clay, travels the farthest into the reservoir. With sufficient time, the dissolved cesium reaches the downstream end of the reservoir. This preliminary modeling also suggests the possibility of a suitable dam operation to control the cesium migration farther downstream from the dam. JAEA has been sampling in the Ogi Dam Reservoir, but these data were not yet available for the current model calibration and validation for this reservoir. Nonetheless these preliminary FLESCOT modeling results were qualitatively valid and confirmed the applicability of the FLESCOT code to the Ogi Dam Reservoir, and in general to other reservoirs in

  15. Uncertainty quantification in fractured reservoir by considering geological deformation of reservoir and geomechanical accommodation of rocks

    NASA Astrophysics Data System (ADS)

    Shin, Y.; Jung, A.; Mukerji, T.

    2013-12-01

    Geological interpretations on structural deformation of a reservoir are uncertain. How the reservoir rocks have accommodated the deformational loading is also uncertain. The effects of these two on reservoir property modeling and uncertainty of reservoir responses is rarely investigated and used in reservoir forecasting. In this research, the effect of different scenarios on geological deformation history and modes of accommodation of rock deformation on reservoir flow response is investigated. To do that, we develop a geostatistical reservoir property modeling workflow which allows us to generate petrophysical properties (porosity & permeability) such that the properties are consistent with geological deformation. In this workflow, we restore the values of petrophysical properties from hard data into a restored condition using predefined transfer functions. We conduct geostatistical simulations to populate petrophysical properties using the restored property values in a restored grid. By using the inverse relation used to restore petrophysical values of hard data, we deform the simulated property values into a deformed grid with corresponding deformed values. Fracture sets are populated by considering both the populated petrophysical properties in a restored grid and the geomechanical condition derived from the deformation-restoration constraints. By using this workflow, we can compare and distinguish the effects of different modes of geological deformation on the uncertainty of reservoir flow responses. The uncertainty from different modes of accommodation is considered in the workflow by having different transfer relations when conducting restoration-deformation of the values of petrophysical properties. The proposed workflow is applied on a 3D synthetic fractured sandstone reservoir to see the impact on flow responses. Reservoir models from different scenario of deformation and the modes of accommodation for each deformation produce different characteristics on

  16. Experience in operating the Bratsk Reservoir

    SciTech Connect

    Nazarov, A.V.

    1984-04-01

    The Bratsk reservoir is the largest in the USSR and second largest in the world. Initially, the reservoir was expected to be filled by the end of 1966. However, the actual filling was not completed until September of 1967. During filling and in the first years of operation it was constantly necessary to deal with floating timber in order to ensure normal operation of the hydrostation, navigation safety, conditions for fishery, and fulfillment of the sanitary requirements. During seasonal variations of the reservoir level about 160 sq km of the shore zone was subjected to variable flooding and waterlogging. Maximum erosion occurred on expanded stretches, and within their limits on slopes composed of loam and sand deposits. Within the narrows, where the banks are composed mainly of hard and soft rocks and wave action is weak, erosion is negligible. Wind setup and setdown cause maximum denivellation of the water surface. The maximum increase of the level during setup reaches 232 cm and the maximum decrease during setdown is 24 cm. Seiche oscillations with various amplitudes and periods are observed on the reservoir surface. The main uses of the complex are hydropower, water transport, timber floating, water supply, and fishery. For the successful development of the shores of reservoirs it is necessary to select the construction sites with consideration of possible occurrence of karstic and landslide processes; the construction of heavy structures requires special karst-control measures. 3 references, 3 figures, 1 table.

  17. Integrated reservoir management doubles Nigerian field reserves

    SciTech Connect

    Akinlawon, Y.; Nwosu, T.; Satter, A.; Jespersen, R.

    1996-10-01

    An integrated alliance across disciplines, companies and countries enabled Texaco to conduct a comprehensive reservoir analysis of the North Apoi/Funiwa field in Nigeria. Recommendations implemented in 3 months doubled the book reserves of this mature field. The paper discusses the objectives, the integration of organizations, reservoir analysis, and conclusions. The conclusions made from the integrated study are: (1) 3-D seismic data dramatically improved reservoir description. (2) OOIP is considerably more than the booked values and reserves additions are substantial. (3) Significant value has been added to TOPCON`s assets as a result of teamwork and a multidisciplinary approach to evaluating the reservoirs and optimizing the scenarios for reservoir management. (4) Teamwork and integration of professionals, data, technology and tools was critical to the projects success. (5) The study set an example for effective and expeditious technology transfer and applications. (6) Partnering of TOPCON, DPR, NAPIMS, EPTD and SSI resulted in a quick cycle time and set an excellent example of integration and alliance.

  18. Eolian reservoir characteristics predicted from dune type

    SciTech Connect

    Kocurek, G.; Nielson, J.

    1985-02-01

    The nature of eolian-dune reservoirs is strongly influenced by stratification types (in decreasing order of quality: grain-flow, grain-fall, wind-ripple deposits) and their packaging by internal bounding surfaces. These are, in turn, a function of dune surface processes and migration behavior, allowing for predictive models of reservoir behavior. Migrating, simple crescentic dunes produce tabular bodies consisting mainly of grain-flow cross-strata, and form the best, most predictable reservoirs. Reservoir character improves as both original dune height and preserved set thickness increase, because fewer grain-fall deposits and a lower percentage of dune-apron deposits occur in the cross-strata, respectively. It is probable that many linear and star dunes migrate laterally, leaving a blanket of packages of wind ripple laminae reflecting deposition of broad, shifting aprons. This is distinct from models generated by freezing large portions of these dunes in place. Trailing margins of linear and star dunes are prone to reworking by sand-sheet processes that decrease potential reservoir quality. The occurrence of parabolic dunes isolated on vegetated sand sheets results in a core of grain-flow and grain-fall deposits surrounded by less permeable and porous deposits. Compound crescentic dunes, perhaps the most preservable dune type, may yield laterally (1) single sets of cross-strate, (2) compound sets derived from superimposed simple dunes, or (3) a complex of diverse sets derived from superimposed transverse and linear elements.

  19. Microseismic monitoring: a tool for reservoir characterization.

    NASA Astrophysics Data System (ADS)

    Shapiro, S. A.

    2011-12-01

    Characterization of fluid-transport properties of rocks is one of the most important, yet one of most challenging goals of reservoir geophysics. There are some fundamental difficulties related to using active seismic methods for estimating fluid mobility. However, it would be very attractive to have a possibility of exploring hydraulic properties of rocks using seismic methods because of their large penetration range and their high resolution. Microseismic monitoring of borehole fluid injections is exactly the tool to provide us with such a possibility. Stimulation of rocks by fluid injections belong to a standard development practice of hydrocarbon and geothermal reservoirs. Production of shale gas and of heavy oil, CO2 sequestrations, enhanced recovery of oil and of geothermal energy are branches that require broad applications of this technology. The fact that fluid injection causes seismicity has been well-established for several decades. Observations and data analyzes show that seismicity is triggered by different processes ranging from linear pore pressure diffusion to non-linear fluid impact onto rocks leading to their hydraulic fracturing and strong changes of their structure and permeability. Understanding and monitoring of fluid-induced seismicity is necessary for hydraulic characterization of reservoirs, for assessments of reservoir stimulation and for controlling related seismic hazard. This presentation provides an overview of several theoretical, numerical, laboratory and field studies of fluid-induced microseismicity, and it gives an introduction into the principles of seismicity-based reservoir characterization.

  20. Comparison of Gross Greenhouse Gas Fluxes from Hydroelectric Reservoirs in Brazil with Thermopower Generation

    NASA Astrophysics Data System (ADS)

    Rogerio, J. P.; Dos Santos, M. A.; Matvienko, B.; dos Santos, E.; Rocha, C. H.; Sikar, E.; Junior, A. M.

    2013-05-01

    Widespread interest in human impacts on the Earth has prompted much questioning in fields of concern to the general public. One of these issues is the extent of the impacts on the environment caused by hydro-based power generation, once viewed as a clean energy source. From the early 1990s onwards, papers and studies have been challenging this assumption through claims that hydroelectric dams also emit greenhouse gases, generated by the decomposition of biomass flooded by filling these reservoirs. Like as other freshwater bodies, hydroelectric reservoirs produce gases underwater by biology decomposition of organic matter. Some of these biogenic gases are effective in terms of Global Warming. The decomposition is mainly due by anaerobically regime, emitting methane (CH4), nitrogen (N2) and carbon dioxide (CO2). This paper compare results obtained from gross greenhouse fluxes in Brazilian hydropower reservoirs with thermo power plants using different types of fuels and technology. Measurements were carried in the Manso, Serra da Mesa, Corumbá, Itumbiara, Estreito, Furnas and Peixoto reservoirs, located in Cerrado biome and in Funil reservoir located at Atlantic forest biome with well defined climatologically regimes. Fluxes of carbon dioxide and methane in each of the reservoirs selected, whether through bubbles and/or diffusive exchange between water and atmosphere, were assessed by sampling. The intensity of emissions has a great variability and some environmental factors could be responsible for these variations. Factors that influence the emissions could be the water and air temperature, depth, wind velocity, sunlight, physical and chemical parameters of water, the composition of underwater biomass and the operational regime of the reservoir. Based in this calculations is possible to conclude that the large amount of hydro-power studied is better than thermopower source in terms of atmospheric greenhouse emissions. The comparisons between the reservoirs studied

  1. Time-Lapse inversion of EM Tomography data for polymer-injected hydrocarbon reservoirs

    NASA Astrophysics Data System (ADS)

    Cheon, Seiwook; Park, Chanho; Nam, Myung Jin; Son, Jeong-Sul

    2015-04-01

    Polymer flooding is a method to increase the production of hydrocarbon reservoir by injecting polymer solution into the reservoir. For a study on the monitoring fluid variation within the reservoir, we first make analysis on seismic- and electromagnetic (EM)- tomography responses for seismic and electrical-resistivity rock physics models (RPMs) of the reservoir considering polymer fluid. Constructing RPMs are dependent on not only geologic characteristics of reservoir but also reservoir parameters such as fluid-type, fluid saturation, pressure and temperature. When making RPM for monitoring analysis, we assume the geology does not changes while reservoir parameters change to affect responses of seismic and EM tomography data. Specifically when constructing electrical-resistivity RPM, we consider three different types of hydrocarbon reservoirs, which are clean sand, shaly sand, sand-shale lamination, while considering two different types of waters (fresh water and salt water) to make 2wt% polymer solution. To compute time lapse EM and seismic tomography responses for corresponding RPMs of polymer-injected reservoirs, we used 2.5D finite element EM modeling algorithm and staggered-grid finite difference elastic modeling algorithm, respectively. Comparison between sensitivities of seismic and EM tomography to polymer injection confirms that EM tomography is more sensitivity to the polymer injection. For the evaluation of the potential of EM tomography to monitor polymer flooding, this study subsequently develops an efficient time-lapse EM tomography inversion algorithm based on the 2.5D EM tomography modeling. Using the inversion algorithm, we inverted the time-lapse EM tomography data to construct true resistivity models of polymer-injected reservoirs and analyze differences between them. From the time-lapse inversion results, we can observe the differences in time lapse responses between using fresh water and salt water have been decreased in the inverted time

  2. Evaluation of Gas Production Potential of Hydrate Deposits in Alaska North Slope using Reservoir Simulations

    NASA Astrophysics Data System (ADS)

    Nandanwar, M.; Anderson, B. J.

    2015-12-01

    Over the past few decades, the recognition of the importance of gas hydrates as a potential energy resource has led to more and more exploration of gas hydrate as unconventional source of energy. In 2002, U.S. Geological Survey (USGS) started an assessment to conduct a geology-based analysis of the occurrences of gas hydrates within northern Alaska. As a result of this assessment, many potential gas hydrate prospects were identified in the eastern National Petroleum Reserve Alaska (NPRA) region of Alaska North Slope (ANS) with total gas in-place of about 2 trillion cubic feet. In absence of any field test, reservoir simulation is a powerful tool to predict the behavior of the hydrate reservoir and the amount of gas that can be technically recovered using best suitable gas recovery technique. This work focuses on the advanced evaluation of the gas production potential of hydrate accumulation in Sunlight Peak - one of the promising hydrate fields in eastern NPRA region using reservoir simulations approach, as a part of the USGS gas hydrate development Life Cycle Assessment program. The main objective of this work is to develop a field scale reservoir model that fully describes the production design and the response of hydrate field. Due to the insufficient data available for this field, the distribution of the reservoir properties (such as porosity, permeability and hydrate saturation) are approximated by correlating the data from Mount Elbert hydrate field to obtain a fully heterogeneous 3D reservoir model. CMG STARS is used as a simulation tool to model multiphase, multicomponent fluid flow and heat transfer in which an equilibrium model of hydrate dissociation was used. Production of the gas from the reservoir is carried out for a period of 30 years using depressurization gas recovery technique. The results in terms of gas and water rate profiles are obtained and the response of the reservoir to pressure and temperature changes due to depressurization and hydrate

  3. THMC Modeling of EGS Reservoirs -- Continuum through Discontinuum Representations. Capturing Reservoir Stimulation, Evolution and Induced Seismicity

    SciTech Connect

    Elsworth, Derek; Izadi, Ghazal; Gan, Quan; Fang, Yi; Taron, Josh; Sonnenthal, Eric

    2015-07-28

    This work has investigated the roles of effective stress induced by changes in fluid pressure, temperature and chemistry in contributing to the evolution of permeability and induced seismicity in geothermal reservoirs. This work has developed continuum models [1] to represent the progress or seismicity during both stimulation [2] and production [3]. These methods have been used to resolve anomalous observations of induced seismicity at the Newberry Volcano demonstration project [4] through the application of modeling and experimentation. Later work then focuses on the occurrence of late stage seismicity induced by thermal stresses [5] including the codifying of the timing and severity of such responses [6]. Furthermore, mechanistic linkages between observed seismicity and the evolution of permeability have been developed using data from the Newberry project [7] and benchmarked against field injection experiments. Finally, discontinuum models [8] incorporating the roles of discrete fracture networks have been applied to represent stimulation and then thermal recovery for new arrangements of geothermal wells incorporating the development of flow manifolds [9] in order to increase thermal output and longevity in EGS systems.

  4. Learned lessons from uncertainty assessment of monthly runoff using different methods to establish reservoir inflows

    NASA Astrophysics Data System (ADS)

    Domínguez, Efraín; Martínez, Juan; Caicedo, Fabian; Chavarro, John; Velasco, Andrés; Méndez, Zulma; Cardenas, Eder

    2015-04-01

    The time series of monthly runoff are critical information for the management of hydro-power reservoirs. This experience presents the learned lessons from the uncertainty assessment of reservoirs inflows for different hydro-power damps in Colombia. Rainfall-runoff models, water balance and hydrometry methods, with different data requirements, were used to establish the monthly runoff inflow to different hydro-power reservoirs. Second order uncertainty assessment was applied for uncertainty propagation from input data to model results, taking auto-correlation of runoff and meteorological data, in time and space, into account. Rainfall-runoff models of different complexity and water balance methods were applied using rainfall inputs averaged from interpolated fields, Thiessen polygons and from meteorological stations measurements. For temperature inputs, averaged DEM derived temperature fields and temperature station averages were used as well. The lowest uncertainty and best method's traceability were used as criteria to select the method to calculate monthly reservoir inflows. Findings show that hydrometric method is always preferable among others and that uncertainty for the rest of the methods heavily depends on the completness of the uncertainty assessment.

  5. Effect of Flow Rate of Side-Type Orifice Intake on Withdrawn Water Temperature

    PubMed Central

    Li, Guangning

    2014-01-01

    Side-type orifice intake is a type of selective withdrawal facility used in managing reservoirs to mitigate the negative effects of low-temperature water. Based on the temperature data of a thermal stratified reservoir in China, an experiment was conducted in flume to study the influence of intake flow rate on withdrawn water temperature with different temperature distributions. Results indicated that withdrawn water temperature changed with different flow rates. The temperature change was determined by the water temperature gradients above and below the intake, whereas the change trend of temperature depended on the difference between the water temperature gradient above and below the intake. We likewise proposed a new equation with which the withdrawn water temperature of a thermal stratified reservoir using a side-type orifice could be calculated. These findings could be directly applied to the design and operation of side-type orifice intake in thermal stratified reservoirs. PMID:25019100

  6. Carbon capture and storage reservoir properties from poroelastic inversion: A numerical evaluation

    NASA Astrophysics Data System (ADS)

    Lepore, Simone; Ghose, Ranajit

    2015-11-01

    We investigate the prospect of estimating carbon capture and storage (CCS) reservoir properties from P-wave intrinsic attenuation and velocity dispersion. Numerical analogues for two CCS reservoirs are examined: the Utsira saline formation at Sleipner (Norway) and the coal-bed methane basin at Atzbach-Schwanestadt (Austria). P-wave intrinsic dispersion curves in the field-seismic frequency band, obtained from theoretical studies based on simulation of oscillatory compressibility and shear tests upon representative rock samples, are considered as observed data. We carry out forward modelling using poroelasticity theories, making use of previously established empirical relations, pertinent to CCS reservoirs, to link pressure, temperature and CO2 saturation to other properties. To derive the reservoir properties, poroelastic inversions are performed through a global multiparameter optimization using simulated annealing. We find that the combination of attenuation and velocity dispersion in the error function helps significantly in eliminating the local minima and obtaining a stable result in inversion. This is because of the presence of convexity in the solution space when an integrated error function is minimized, which is governed by the underlying physics. The results show that, even in the presence of fairly large model discrepancies, the inversion provides reliable values for the reservoir properties, with the error being less than 10% for most of them. The estimated values of velocity and attenuation and their sensitivity to effective stress and CO2 saturation generally agree with the earlier experimental observation. Although developed and tested for numerical analogues of CCS reservoirs, the approach presented here can be adapted in order to predict key properties in a fluid-bearing porous reservoir, in general.

  7. Evaluating the variability in surface water reservoir planning characteristics during climate change impacts assessment

    NASA Astrophysics Data System (ADS)

    Soundharajan, Bankaru-Swamy; Adeloye, Adebayo J.; Remesan, Renji

    2016-07-01

    This study employed a Monte-Carlo simulation approach to characterise the uncertainties in climate change induced variations in storage requirements and performance (reliability (time- and volume-based), resilience, vulnerability and sustainability) of surface water reservoirs. 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 runoff scenarios. The resulting runoff ensembles were used to force simulation models of the behaviour of the reservoir to produce 'populations' of required reservoir storage capacity to meet demands, and the performance. Comparing these parameters between the current and the perturbed provided the population of climate change effects which was then analysed to determine the variability in the impacts. The methodology was applied to the Pong reservoir on the Beas River in northern India. The reservoir serves irrigation and hydropower needs and the hydrology of the catchment is highly influenced by Himalayan seasonal snow and glaciers, and Monsoon rainfall, both of which are predicted to change due to climate change. The results show that required reservoir capacity is highly variable with a coefficient of variation (CV) as high as 0.3 as the future climate becomes drier. Of the performance indices, the vulnerability recorded the highest variability (CV up to 0.5) while the volume-based reliability was the least variable. Such variabilities or uncertainties will, no doubt, complicate the development of climate change adaptation measures; however, knowledge of their sheer magnitudes as obtained in this study will help in the formulation of appropriate policy and technical interventions for sustaining and possibly enhancing

  8. Duck Valley Reservoirs Fish Stocking and Operation and Maintenance, 2006-2007 Annual Progress Report.

    SciTech Connect

    Sellman, Jake; Dykstra, Tim

    2009-05-11

    The Duck Valley Reservoirs Fish Stocking and Operations and Maintenance (DV Fisheries) project is an ongoing resident fish program that serves to partially mitigate the loss of anadromous fish that resulted from downstream construction of the hydropower system. The project's goals are to enhance subsistence fishing and educational opportunities for Tribal members of the Shoshone-Paiute Tribes and provide resident fishing opportunities for non-Tribal members. In addition to stocking rainbow trout (Oncorhynchus mykiss) in Mountain View, Lake Billy Shaw, and Sheep Creek Reservoirs, the program is also designed to maintain healthy aquatic conditions for fish growth and survival, to provide superior facilities with wilderness qualities to attract non-Tribal angler use, and to offer clear, consistent communication with the Tribal community about this project as well as outreach and education within the region and the local community. Tasks for this performance period are divided into operations and maintenance plus monitoring and evaluation. Operation and maintenance of the three reservoirs include fences, roads, dams and all reservoir structures, feeder canals, water troughs and stock ponds, educational signs, vehicles and equipment, and outhouses. Monitoring and evaluation activities included creel, gillnet, wildlife, and bird surveys, water quality and reservoir structures monitoring, native vegetation planting, photo point documentation, control of encroaching exotic vegetation, and community outreach and education. The three reservoirs are monitored in terms of water quality and fishery success. Sheep Creek Reservoir was very unproductive this year as a fishery. Fish morphometric and water quality data indicate that the turbidity is severely impacting trout survival. Lake Billy Shaw was very productive as a fishery and received good ratings from anglers. Mountain View was also productive and anglers reported a high number of quality sized fish. Water quality

  9. Temporal and spatial variation in relative abundance and length structure of salmonids in reservoirs: Implications for monitoring

    USGS Publications Warehouse

    Rhea, D.T.; Hubert, W.A.; Gangl, R.S.; Whaley, R.A.

    2005-01-01

    Spatial and temporal variations in salmonid catch per unit effort (C/f) may affect monitoring efforts in lakes and reservoirs. This study evaluated the spatial and temporal variation in gill-net C/f and length structure of captured salmonids in nearshore (???7.6-m bottom depth) and offshore (>7.6-m bottom depth) areas of two Wyoming reservoirs. Floating experimental gill nets were set as nearshore and offshore pairs at 24 locations in both reservoirs during each of four sampling periods (spring, early summer, late summer, and fall). Salmonid C/f was significantly higher in nearshore areas than in offshore areas during all periods in one reservoir and during all periods except spring in the other reservoir. Mean C/f of rainbow trout Oncorhynchus mykiss was not significantly different between nearshore and offshore areas when water temperatures were 10-13??C in both reservoirs. Length structure of salmonids differed significantly between nearshore and offshore locations and among periods in both reservoirs. These patterns should be considered in both the design and analysis phases of monitoring efforts that use floating experimental gill nets and other sampling gears. ?? Copyright by the American Fisheries Society 2005.

  10. Quantitative model of vapor dominated geothermal reservoirs as heat pipes in fractured porous rock

    SciTech Connect

    Pruess, K.

    1985-03-01

    We present a numerical model of vapor-dominated reservoirs which is based on the well-known conceptual model of White, Muffler, and Truesdell. Computer simulations show that upon heat recharge at the base, a single phase liquid-dominated geothermal reservoir in fractured rock with low matrix permeability will evolve into a two-phase reservoir with B.P.D. (boiling point-for-depth) pressure and temperature profiles. A rather limited discharge event through cracks in the caprock, involving loss of only a few percent of fluids in place, is sufficient to set the system off to evolve a vapor-dominated state. The attributes of this state are discussed, and some features requiring further clarification are identified. 26 refs., 5 figs.

  11. Dynamical Change of Quantum Fisher Information of Cavity-Reservoir Systems

    NASA Astrophysics Data System (ADS)

    Huang, Jiang; Xie, Qin

    2016-04-01

    We study the quantum Fisher information (QFI) dynamics of the phase parameter in the enlarged cavity-reservoir systems at zero temperature under two situations of large N limit and non-Markovian environment, respectively. We find an important relation that the total quantities of QFI of the cavity and reservoir are equal to unit during the dynamical evolution. The lost QFI of the cavity transfers to its corresponding reservoir with the same quantities simultaneously. Moreover, we also find that the detuning parameter and non-Markovian effect are two significant factors to affect the preservation of QFI. Supported by the National Natural Science Foundation of China under Grant No. 11374096 and the Natural Science Foundation of Guangdong Province under Grant No. 2015A030310354 and the Projection of Enhancing School with Innovation of Guangdong Ocean University under Grant Nos. GDOU2014050251 and GDOU2014050252

  12. Effects of adsorption and capillarity on injection in vapor-dominated geothermal reservoirs

    SciTech Connect

    Sta. Maria, R.B.; Horne, R.N.

    1996-04-10

    One major motivation for the study of the effects of adsorption in geothermal reservoirs is the phenomenon known as {open_quotes}The Geysers Paradox{close_quotes}. Data from The Geysers field suggest that some water must be stored in the reservoir in a condensed phase even though the prevailing reservoir pressure and temperature dictate superheated conditions. Physical adsorption of steam onto rocks and the thermodynamics of curved interfaces prevailing in the pore spaces of the rock matrix can explain the apparent paradox. These mechanisms make it possible for water and steam to coexist in conditions we normally refer to as {open_quotes}superheated{close_quotes} based on our concept of flat interface thermodynamics (e.g., the Steam Table).

  13. Gas filtration from an underground reservoir at a large initial pressure gradient

    NASA Astrophysics Data System (ADS)

    Miroshnichenko, T. P.; Lutsenko, N. A.; Levin, V. A.

    2015-09-01

    Gas filtration from an underground reservoir through a layer of a porous medium due to an instantaneous increase in the gas pressure in the reservoir is studied. The problem is considered in a one-dimensional formulation in the general case where the temperatures of the gas and the porous medium are different and unstable, and in the case of a high specific heat of the solid phase and a high interfacial heat-transfer rate. The dynamics of the gas flow at the inlet and outlet of the underground reservoir is analyzed, the time of unloading of the system is estimated as a function of the permeability of the porous medium. It is shown that, depending on the properties of the porous layer, two characteristic gas flow regimes are possible: a fast discharge regime and a slow regime which is determined mainly by barodiffusion.

  14. Geothermal reservoir engineering research at Stanford University. First annual report, October 1, 1980-September 30, 1981

    SciTech Connect

    Brigham, W.E.; Horne, R.N.; Kruger, P.; Miller, F.G.; Ramey, H.J. Jr.

    1981-09-01

    The work on energy extraction experiments concerns the efficiency with which the in-place heat and fluids can be produced. The work on noncondensable gas reservoir engineering covers both the completed and continuing work in these two interrelated research areas: radon emanation from the rock matrix of geothermal reservoirs, and radon and ammonia variations with time and space over geothermal reservoirs. Cooperative research programs with Italy and Mexico are described. The bench-scale experiments and well test analysis section covers both experimental and theoretical studies. The small core model continues to be used for the study of temperature effects on absolute permeability. The unconsolidated sand study was completed at the beginning of this contract period. The Appendices describe some of the Stanford Geothermal program activities that results in interactions with the geothermal community. These occur in the form of SGP Technical Reports, presentations at technical meetings and publications in the open literature.

  15. Shear-slip analysis in multiphase fluid-flow reservoir engineeringap plications using TOUGH-FLAC

    SciTech Connect

    Rutqvist, Jonny; Birkholzer, Jens; Cappa, Frederic; Oldenburg,Curt; Tsang, Chin-Fu

    2006-01-15

    This paper describes and demonstrates the use of the coupledTOUGH-FLAC simulator for geomechanical shear-slip (failure) analysis inmultiphase fluid-flow reservoir-engineering applications. Two approachesfor analyzing shear-slip are described, one using continuum stress-strainanalysis and another using discrete fault analysis. The use of shear-slipanalysis in TOUGH-FLAC is demonstrated on application examples related toCO2 sequestration and geothermal energy extraction. In the case of CO2sequestration, the shear-slip analysis is used to evaluate maximumsustainable CO2-injection pressure under increasing reservoir pressure,whereas in the case of geothermal energy extraction, the shear-slipanalysis is used to study induced seismicity during steam productionunder decreasing reservoir pressure and temperature.

  16. Simulating the effects of adsorption and capillary forces in geothermal reservoirs

    SciTech Connect

    Sta. Maria, Roman B.; Pingol, Alponso S.

    1996-01-24

    Until recently, geothermal reservoir simulators use flat interface thermodynamics to determine the thermodynamic state of the reservoir. Development of new simulators and the modification of existing ones has now incorporated the physics of curved interface thermodynamics. These simulators account for the effects of sorption and capillary forces. The simulators GSS and TETRAD were used to simulate the performance of a hypothetical vapordominated geothermal reservoir. GSS is a simulator specifically developed to account for adsorption by using adsorption isotherms. On the other hand, TETRAD is a commercial simulator that was modified to account for vapor pressure lowering by using capillary pressure relations. GSS and TETRAD yielded similar results. Thus, the two formulations being used to account for curved interface thermodynamics are practically equivalent. Areas for improvement of both GSS and TETRAD were identified. The hysteresis and temperature dependence of sorption and capillary properties are issues that are needed to be addressed.

  17. Reservoir characterization and enhanced oil recovery research

    SciTech Connect

    Lake, L.W.; Pope, G.A.; Schechter, R.S.

    1992-03-01

    The research in this annual report falls into three tasks each dealing with a different aspect of enhanced oil recovery. The first task strives to develop procedures for accurately modeling reservoirs for use as input to numerical simulation flow models. This action describes how we have used a detail characterization of an outcrop to provide insights into what features are important to fluid flow modeling. The second task deals with scaling-up and modeling chemical and solvent EOR processes. In a sense this task is the natural extension of task 1 and, in fact, one of the subtasks uses many of the same statistical procedures for insight into the effects of viscous fingering and heterogeneity. The final task involves surfactants and their interactions with carbon dioxide and reservoir minerals. This research deals primarily with phenomena observed when aqueous surfactant solutions are injected into oil reservoirs.

  18. Frameworks for amending reservoir water management

    USGS Publications Warehouse

    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.

  19. Mechanical Testing Development for Reservoir Forgings

    SciTech Connect

    Wenski, E.G.

    2000-05-22

    The goal of this project was to determine the machining techniques and testing capabilities required for mechanical property evaluation of commercially procured reservoir forgings. Due to the small size of these specific forgings, specialized methods are required to adequately machine and test these sub-miniature samples in accordance with the requirements of ASTM-E8 and ASTM-E9. At the time of project initiation, no capability existed at Federal Manufacturing & Technologies (FM&T) to verify the physical properties of these reservoirs as required on the drawing specifications. The project determined the sample definitions, machining processes, and testing procedures to verify the physical properties of the reservoir forgings; specifically, tensile strength, yield strength, reduction of area, and elongation. In addition, a compression test method was also developed to minimize sample preparation time and provide a more easily machined test sample while maintaining the physical validation of the forging.

  20. HIV-1 Reservoirs During Suppressive Therapy.

    PubMed

    Barton, Kirston; Winckelmann, Anni; Palmer, Sarah

    2016-05-01

    The introduction of antiretroviral therapy (ART) 20 years ago has dramatically reduced morbidity and mortality associated with HIV-1. Initially there was hope that ART would be curative, but it quickly became clear that even though ART was able to restore CD4(+) T cell counts and suppress viral loads below levels of detection, discontinuation of treatment resulted in a rapid rebound of infection. This is due to persistence of a small reservoir of latently infected cells with a long half-life, which necessitates life-long ART. Over the past few years, significant progress has been made in defining and characterizing the latent reservoir of HIV-1, and here we review how understanding the latent reservoir during suppressive therapy will lead to significant advances in curative approaches for HIV-1. PMID:26875617

  1. Operational trade-offs in reservoir control

    NASA Astrophysics Data System (ADS)

    Georgakakos, Aris P.

    1993-11-01

    Reservoir operation decisions require constant reevaluation in the face of conflicting objectives, varying hydrologic conditions, and frequent operational policy changes. Optimality is a relative concept very much dependent on the circumstances under which a decision is made. More than anything else, reservoir management authorities need the means to assess the impacts of various operational options. It is their responsibility to define what is desirable after a thorough evaluation of the existing circumstances. This article presents a model designed to generate operational trade-offs common among reservoir systems. The model avoids an all-encompassing problem formulation and distinguishes three operational modes (levels) corresponding to normal, drought, and flood operations. Each level addresses only relevant system elements and uses a static and a dynamic control module to optimize turbine performance within each planning period and temporally. The model is used for planning the operation of the Savannah River System.

  2. Wellbore stability analysis during the production of a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Alves, J.-L.; Coehlo, L.; Baud, P.; Guevara Junior, N.

    2009-04-01

    Carbonate reservoirs represent a major part of the world oil and gas reserves. During production, the extraction of hydrocarbons reduces pore pressure and thus causes an increase in the effective stress and mechanical compaction in the reservoir. The compactive deformation and failure may be spatially extensive or localized to the vicinity of the wellbore, but in either case the consequences can be economically severe involving surface subsidence, well failure and various production problems. The analysis of wellbore stability and more generally of deformation and failure in carbonate environments hinges upon a relevant constitutive modeling of carbonate rocks over a wide range of porosities. In this study, we performed a wellbore stability analysis for a lateral wellbore junction in three dimensions. The complex geometry for the wellbore junction was modeled with tetrahedral finite elements considering a rate independent elastic-plastic isotropic material that presented linear behavior during elastic strain and associated flow rule. A finite element model simulating drilling and production phases were done for field conditions from a deep water reservoir in Campos basin, offshore Brazil. In this context, several scenarios were studied considering true 3D orientation for both in situ stresses and geometry of the wellbore junction itself. We discussed the impact of constitutive modeling on the wellbore stability, based on new experimental data on two micritic porous carbonates. Series of conventional triaxial experiments were performed at room temperature in dry and wet conditions on samples of Comiso and Tavel limestones of respective porosity 17 and 16%. The wet samples were deformed in drained conditions with 10 MPa pore pressure. The initial yield stresses were identified as the critical stresses at the onset of shear-enhanced compaction, subsequent yield stresses were considered to depend on hardening given by the plastic volumetric strain. For both limestones

  3. Advances in our knowledge of biodegradation of hydrocarbons in reservoirs

    SciTech Connect

    Connan, J. )

    1993-09-01

    Biodegradation of hydrocarbons in reservoirs is a widespread phenomenon that is currently observed by petroleum organic geochemists in most sedimentary basins. This basic phenomenon is responsible for the occurrence of large, heavy oil deposits referred to as tar mats or tar belts. Biodegradation of crude oils takes place in reservoirs in which oil-eating bacteria may thrive. For this reason, effective and present biodegradation effects are not observed at subsurface temperatures higher than 70-80[degrees]C. Significant compositional changes, especially at a molecular level, still remain linked to the aerobic biodegradation of crude oils. Under favorable circumstances, both alkanes and aromatics are degraded, but when nutrients (N, P, O[sup 2]) are impoverished, aromatics seem to be preferentially removed. Biodegradation extends also to sulfur-bearing aromatics with a preferential removal of alkylated structures. Changes in molecular patterns are used to assess degrees of biodegradation in crude oils. The most bacterially resistant structures are polycyclic alkanes and aromatics. The in-reservoir biodegradation of hydrocarbons does not generate new hydrocarbons, e.g., 25-norhopanes as proposed by several authors. In fact, the selective removal of less resistant structures concentrates preexisting minor families that were not detected on the unaltered crude due to their low absolute concentration. Consequently, the molecular spectrum found in severely biodegraded oils may be considered as highly diagnostic of a part of the primary genetic spectrum of each oil. In outcrop samples, biodegradation is associated with other complementary phenomena such as photooxidation, oxidation, inspissation, evaporation, water washing, etc. Of particular importance are weathering effects linked to oxidation, which entail drastic compositional changes, with neogenesis of resins, asphaltenes, and even insoluble residue.

  4. Combined geophysical, geochemical and geological investigations of geothermal reservoir characteristics in Lower Saxony, Germany

    NASA Astrophysics Data System (ADS)

    Hahne, B.; Thomas, R.

    2012-04-01

    The North German basin provides a significant geothermal potential, although temperature gradients are moderate. However, deep drilling up to several thousand meters is required to reach temperatures high enough for efficient generation of geothermal heat and electric power. In these depths we have not much information yet about relevant physical properties like porosity or permeability of the rock formations. Therefore the costs of developing a geothermal reservoir and the risk of missing the optimum drilling location are high. The collaborative research association "Geothermal Energy and High Performance Drilling" (gebo) unites several universities and research institutes in Lower Saxony, Germany. It aims at a significant increase of economic efficiency by introducing innovative technology and high tech materials resisting temperatures up to 200 °C in the drilling process. Furthermore, a better understanding of the geothermal reservoir is essential. gebo is structured into four main fields: Drilling Technology, Materials, Technical Systems and Geosystem. Here, we show the combined work of the Geosystem group, which focuses on the exploration of geological fault zones as a potential geothermal reservoir as well as on modeling the stress field, heat transport, coupled thermo-hydro-mechanical processes, geochemical interactions and prediction of the long-term behavior of the reservoir. First results include combined seismic and geoelectric images of the Leinetalgraben fault system, a comparison of seismic images from P- and S-wave measurements, mechanical properties of North German rocks from field and laboratory measurements as well as from drill cores, seismological characterization of stimulated reservoirs, a thermodynamic "gebo" database for modeling hydrogeochemical processes in North German formation waters with high salinity and at high temperatures, stress models for specific sites in northern Germany, and modeling results of permeability and heat transport

  5. An Intelligent Systems Approach to Reservoir Characterization

    SciTech Connect

    Shahab D. Mohaghegh; Jaime Toro; Thomas H. Wilson; Emre Artun; Alejandro Sanchez; Sandeep Pyakurel

    2005-08-01

    Today, the major challenge in reservoir characterization is integrating data coming from different sources in varying scales, in order to obtain an accurate and high-resolution reservoir model. The role of seismic data in this integration is often limited to providing a structural model for the reservoir. Its relatively low resolution usually limits its further use. However, its areal coverage and availability suggest that it has the potential of providing valuable data for more detailed reservoir characterization studies through the process of seismic inversion. In this paper, a novel intelligent seismic inversion methodology is presented to achieve a desirable correlation between relatively low-frequency seismic signals, and the much higher frequency wireline-log data. Vertical seismic profile (VSP) is used as an intermediate step between the well logs and the surface seismic. A synthetic seismic model is developed by using real data and seismic interpretation. In the example presented here, the model represents the Atoka and Morrow formations, and the overlying Pennsylvanian sequence of the Buffalo Valley Field in New Mexico. Generalized regression neural network (GRNN) is used to build two independent correlation models between; (1) Surface seismic and VSP, (2) VSP and well logs. After generating virtual VSP's from the surface seismic, well logs are predicted by using the correlation between VSP and well logs. The values of the density log, which is a surrogate for reservoir porosity, are predicted for each seismic trace through the seismic line with a classification approach having a correlation coefficient of 0.81. The same methodology is then applied to real data taken from the Buffalo Valley Field, to predict inter-well gamma ray and neutron porosity logs through the seismic line of interest. The same procedure can be applied to a complete 3D seismic block to obtain 3D distributions of reservoir properties with less uncertainty than the geostatistical

  6. Characterization of Reservoir Heterogeneity from Surface Deformation

    NASA Astrophysics Data System (ADS)

    Maharramov, M.; Zoback, M. D.

    2015-12-01

    In our earlier work we resolved complex evolution of pressure fronts in a heavyoil reservoir undergoing cyclic steam stimulation. Our method was based onsolving a regularized inverse problem for inverting the pore pressure changefrom surface displacements. In this work we extend our method to recoversharp contrasts in induced reservoir pressure that may be due to permeabilitybarriers or hydraulically conductive faults. We demonstrate our method byinverting the pressure change from uplift observations for a synthetic modelof a heterogeneous reservoir undergoing fluid injection. Using the theory ofconstrained optimization, we invert values and locations of sharp pressurecontrasts from noisy measurements of surface deformation, and estimate thelocation of an impermeable boundary between reservoir compartments. In our synthetic model, two highly permeable reservoir compartmentsseparated by a nearly impermeable barrier (first panel) undergo fluid injec-tion. We simulate pressure evolution within the reservoir (second panel) andmodel surface deformation induced by the subsurface pressure change (thirdpanel), adding measurement noise to the result. We invert the noisy sur-face uplift measurements by solving a constrained optimization problem withTikhonov regularization (fourth panel). The result achieves a good inversionquality in areas of finite pressure change but provides only a rough estimatefor the barrier location. However, applying our new inversion technique with atotal-variation regularization that favors sharp model contrasts while penalizingoscillations, we achieve a more accurate approximation of the permeabilitybarrier as a level set of the inverted pressure field (fifth panel). Our new method provides a potentially useful tool for locating sharpsubsurface pressure contrasts from surface uplift observations. The methodcan be used in a variety of applications for identifying subsurface permeabil-ity heterogeneities (such as seals and hydraulically conductive

  7. Using Forecast Information in Reservoir Operation

    NASA Astrophysics Data System (ADS)

    Faber, B.

    2011-12-01

    Reservoir operation is a series of decisions made over time. We choose whether to release water for various downstream purposes, or store it for later use. We choose whether to detain high flows to protect downstream areas, or pass that flow to retain space to store imminent higher flows. These decisions are driven by current and future inflows to the reservoir, and yet those inflows are uncertain and extremely variable. Conceptually, more information provides opportunity for better decisions, and so information about future inflows can improve reservoir operations. However, uncertain information must be used carefully, with awareness of the uncertainty and the likely consequence of "wrong" decisions (i.e., those with consequences worse than decisions that might otherwise have been made.) The historical streamflow record offers one source of information on the range and timing of streamflows. Streamflow forecasting provides additional valuable information on coming reservoir inflows, both at short and longer time scales. For example, 5-day flow forecasts based on forecasted precipitation can inform rain-flood operations, while seasonal snowmelt forecasts can aid snowmelt-flood operation, reservoir refill, and seasonal allocation of water supply. Forecast information can aid our decision-making greatly, but too much reliance on an incorrect forecast can make operation worse. Informed use of forecasts requires an understanding of the expected range of the actual streamflow (the error distribution). Forecast products must therefore be provided with a description of skill and error distribution understood by the producers and users of that information. Using forecasts wisely, with an understanding of their uncertainty, is an important aspect of the operation of our nation's Federal reservoirs.

  8. Characterization of oil and gas reservoir heterogeneity

    SciTech Connect

    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.

  9. Seasonal Changes in Plankton Food Web Structure and Carbon Dioxide Flux from Southern California Reservoirs

    PubMed Central

    Adamczyk, Emily M.; Shurin, Jonathan B.

    2015-01-01

    Reservoirs around the world contribute to cycling of carbon dioxide (CO2) with the atmosphere, but there is little information on how ecosystem processes determine the absorption or emission of CO2. Reservoirs are the most prevalent freshwater systems in the arid southwest of North America, yet it is unclear whether they sequester or release CO2 and therefore how water impoundment impacts global carbon cycling. We sampled three reservoirs in San Diego, California, weekly for one year. We measured seasonal variation in the abundances of bacteria, phytoplankton, and zooplankton, as well as water chemistry (pH, nutrients, ions, dissolved organic carbon [DOC]), which were used to estimate partial pressure of CO2 (pCO2), and CO2 flux. We found that San Diego reservoirs are most often undersaturated with CO2 with respect to the atmosphere and are estimated to absorb on average 3.22 mmol C m-2 day-1. pCO2 was highest in the winter and lower in the summer, indicating seasonal shifts in the magnitudes of photosynthesis and respiration associated with day length, temperature and water inputs. Abundances of microbes (bacteria) peaked in the winter along with pCO2, while phytoplankton, nutrients, zooplankton and DOC were all unrelated to pCO2. Our data indicate that reservoirs of semi-arid environments may primarily function as carbon sinks, and that carbon flux varies seasonally but is unrelated to nutrient or DOC availability, or the abundances of phytoplankton or zooplankton. PMID:26473601

  10. Reliability, sensitivity, and uncertainty of reservoir performance under climate variability in basins with different hydrogeologic settings

    NASA Astrophysics Data System (ADS)

    Mateus, C.; Tullos, D.

    2014-12-01

    This study investigated how reservoir performance varied across different hydrogeologic settings and under plausible future climate scenarios. The study was conducted in the Santiam River basin, OR, USA, comparing the North Santiam basin (NSB), with high permeability and extensive groundwater storage, and the South Santiam basin (SSB), with low permeability, little groundwater storage, and rapid runoff response. We applied projections of future temperature and precipitation from global climate models to a rainfall-runoff model, coupled with a formal Bayesian uncertainty analysis, to project future inflow hydrographs as inputs to a reservoir operations model. The performance of reservoir operations was evaluated as the reliability in meeting flood management, spring and summer environmental flows, and hydropower generation objectives. Despite projected increases in winter flows and decreases in summer flows, results suggested little evidence of a response in reservoir operation performance to a warming climate, with the exception of summer flow targets in the SSB. Independent of climate impacts, historical prioritization of reservoir operations appeared to impact reliability, suggesting areas where operation performance may be improved. Results also highlighted how hydrologic uncertainty is likely to complicate planning for climate change in basins with substantial groundwater interactions.

  11. Spatial variation in the littoral vertebrate community of a reservoir relative to physical and biological gradients

    PubMed Central

    Soski, Jessica J.; Roosenburg, Willem M.

    2014-01-01

    Reservoirs possess gradients in conditions and resources along their long (deep-shallow) axis, but the response of littoral vertebrates (fish and turtles) to these gradients is poorly understood. We have quantified the littoral vertebrate communities throughout a small reservoir in Southeastern Ohio during July and August using traps, and related community composition to environmental variables using NMDS ordination. Ordination revealed that fish and turtles were broadly separated in ordination space, and three distinctly different environmental gradients were significantly associated with the underlying observed species abundances. Observed turtle abundance was explained by measurements of bathymetry, turbidity, and benthic resources, but none of these environmental variables were a reliable predictor of observed fish abundance. Temperature was a poor predictor of observed abundance for both fish and turtles independently, but when fish and turtles were considered together, it became apparent that there were cold areas of the reservoir where observed fish and turtle abundances were different than in other areas of the reservoir. These results suggest that the predictor (environmental) variables we used were appropriate for investigating turtle ecology in reservoirs, but that observed fish abundance is mediated by factors that were not modeled. The efficacy of using traps, the ecological implications of considering fish and turtles together as sympatric and potentially competing species, and directions for future study are discussed. PMID:25538870

  12. Seasonal Changes in Plankton Food Web Structure and Carbon Dioxide Flux from Southern California Reservoirs.

    PubMed

    Adamczyk, Emily M; Shurin, Jonathan B

    2015-01-01

    Reservoirs around the world contribute to cycling of carbon dioxide (CO2) with the atmosphere, but there is little information on how ecosystem processes determine the absorption or emission of CO2. Reservoirs are the most prevalent freshwater systems in the arid southwest of North America, yet it is unclear whether they sequester or release CO2 and therefore how water impoundment impacts global carbon cycling. We sampled three reservoirs in San Diego, California, weekly for one year. We measured seasonal variation in the abundances of bacteria, phytoplankton, and zooplankton, as well as water chemistry (pH, nutrients, ions, dissolved organic carbon [DOC]), which were used to estimate partial pressure of CO2 (pCO2), and CO2 flux. We found that San Diego reservoirs are most often undersaturated with CO2 with respect to the atmosphere and are estimated to absorb on average 3.22 mmol C m(-2) day(-1). pCO2 was highest in the winter and lower in the summer, indicating seasonal shifts in the magnitudes of photosynthesis and respiration associated with day length, temperature and water inputs. Abundances of microbes (bacteria) peaked in the winter along with pCO2, while phytoplankton, nutrients, zooplankton and DOC were all unrelated to pCO2. Our data indicate that reservoirs of semi-arid environments may primarily function as carbon sinks, and that carbon flux varies seasonally but is unrelated to nutrient or DOC availability, or the abundances of phytoplankton or zooplankton. PMID:26473601

  13. Oil industry first field trial of inter-well reservoir nanoagent tracers

    NASA Astrophysics Data System (ADS)

    Kanj, Mazen Y.; Kosynkin, Dmitry V.

    2015-05-01

    This short manuscript highlights the industry's first proven reservoir nanoagents' design and demonstrates a successful multi-well field trial using these agents. Our fundamental nanoparticles tracer template, A-Dots or Arab-D Dots, is intentionally geared towards the harsh but prolific Arab-D carbonate reservoir environment of 100+°C temperature, 150,000+ppm salinity, and an abundant presence of divalent ions in the connate water. Preliminary analyses confirmed nanoparticles' breakthrough at a producer nearly 500m from the injector at the reservoir level; thus, proving the tracer nanoparticles' mobility and transport capability. This is considered industry-first and a breakthrough achievement complementing earlier accomplishments in regard to the nanoagents' reservoir stability with the first successful single well test and ease of scale up with the synthesis of one metric ton of this material. The importance of this accomplishment is not in how sophisticated is the sensing functionalities of this design but rather in its stability, mobility, scalability, and field application potentials. This renders the concept of having active, reactive, and even communicative, in-situ reservoir nanoagents for underground sensing and intervention a well anticipated near-future reality.

  14. Improved scleroglucan for polymer flooding under harsh reservoir conditions

    SciTech Connect

    Rivenq, R.C.; Donche, A. )

    1992-02-01

    Polymer flooding is commonly used to improve water sweep efficiency in oil reserves. Successful application of this method, however, has been restricted to low-temperature reservoirs because suitable polymers are not available for harsh conditions. Scleroglucan, a polymer produced by fermentation that shows promising properties, forms solutions that are very viscous and highly resistant to shear. Viscosity is insensitive to both salts and pH and only slightly affected by temperature. To facilitate industrial development of scleroglucan polymer, improvements in the filterability of the solutions and better knowledge of their behavior in porous media are necessary. A high-quality scleroglucan was obtained by eliminating the impurities responsible for polymer aggregation. This allowed evaluation of the intrinsic properties of the polymer molecules. Complete elimination of impurities from the polymer solution led to a scleroglucan without any aggregation tendency and with a good filterability, particularly at high temperatures. The performance of this improved scleroglucan in porous media was evaluated by coreflood experiments in Berea cores at temperatures ranging from 30 to 90{degrees} C. Results provided in this paper showed low permeability reduction and a mobility reduction close to relative viscosity. Injection of successive slugs into a Berea core under anaerobic conditions indicated low polymer retention at high temperatures (30 {mu}g/g at 90{degrees} C).

  15. Dissolved-oxygen depletion and other effects of storing water in Flaming Gorge Reservoir, Wyoming and Utah

    USGS Publications Warehouse

    Bolke, E.L.

    1979-01-01

    The circulation of water in Flaming Gorge Reservoir is caused chiefly by insolation, inflow-outflow relationships, and wind, which is significant due to the geographical location of the reservoir. During 1970-75, there was little annual variation in the thickness, dissolved oxygen, and specific conductance of the hypolimnion near Flaming Gorge Dam. Depletion of dissolved oxygen occurred simultaneously in the bottom waters of both tributary arms in the upstream part of the reservoir and was due to reservoir stratification. Anaerobic conditions in the bottom water during summer stratification eventually results in a metalimnetie oxygen minimum in the reservoir. The depletion of flow in the river below Flaming Gorge Dam due to evaporation and bank storage in the reservoir for the 1983-75 period was 1,320 cubic hectometers, and the increase of dissolved-solids load in the river was 1,947,000 metric tens. The largest annual variations in dissolved-solids concentration in the river was about 800 milligrams per liter before closure of the dam and about 200 milligrams per liter after closure. The discharge weighted-average dissolved-solids concentration for the 5 years prior to closure was 888 milligrams per liter and 512 milligrams per liter after closure. The most significant changes in the individual dissolved-ion loads in the river during 1973-75 were the increase in sulfate (0.48 million metric tons), which was probably derived from the solution of gypsum, and the decrease in bicarbonate (0.39 million metric tons), which can be attributed to chemical precipitation. The maximum range in temperature in the Green River below the reservoir prior to closure of the dam in 1982 was from 0?C in winter to 21?C in summer. After closure until 1970 the temperature ranged from 2 ? to 12?C, but since 1970 the range has been from 4 ? to 9?C. During September 1975, a massive algal bloom was observed in the upstream part of the reservoir. The bloom covered approximately 16 kilometers

  16. How to Factor GCM Uncertainty in Assessing Changes to Reservoir Storage Capacity for Future (Warmer) Climates?

    NASA Astrophysics Data System (ADS)

    Woldemeskel, F. M.; Sharma, A.; Sivakumar, B.; Mehrotra, R.

    2013-12-01

    Whether or not the existing storage capacity of reservoirs is sufficient to meet future water demands is a question of great interest to water managers and policy makers. Among other factors, uncertainties in GCM projections make accurate estimation of future water availability and reservoir storage requirements extremely complicated. Projections of variables using GCMs (e.g. temperature, precipitation) are highly uncertain due to inaccuracies in the climate model structure, greenhouse gas emission scenarios, and initial conditions (or ensemble runs) used. The present study proposes a new method to quantify the uncertainties (or standard errors) of GCM projections and their influence on the estimation of reservoir storage. The GCM standard errors are estimated through the following four steps: (i) interpolating multiple GCM outputs to a common spatial grid; (ii) converting the interpolated GCM outputs to percentiles; (iii) estimating standard error for model, scenario, initial condition and total uncertainty for each percentile; and (iv) transforming standard error estimates to time series. By assuming an additive error model and conditioning on these standard errors, thousands of rainfall and temperature realizations are obtained for a selected GCM and scenario. The temperature realizations are used to estimate evaporation realizations, which are then used as input (together with rainfall) to rainfall-runoff model for estimating streamflow. Finally, the streamflow realizations are used to quantify reservoir storage requirements with its associated uncertainties using reservoir behavior analysis. The proposed method is tested for the case of the Warragamba dam reservoir system that supplies more than 80% of water to Sydney, Australia. The results suggest that uncertainties in reservoir storage capacity will be significantly large for the future period than that for the historical period. Comparison of the effects of rainfall and evaporation uncertainty suggests

  17. Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report

    SciTech Connect

    Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; Laurence C. Hull; George D. Redden

    2011-07-01

    The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat from the subsurface or to maintain pressures within the reservoir (e.g., Rose et al., 2001). As these injected fluids move along fractures, they acquire heat from the rock matrix and remove it from the reservoir as they are extracted to the surface. A consequence of such injection is the migration of a cold-fluid front through the reservoir (Figure 1) that could eventually reach the production well and result in the lowering of the temperature of the produced fluids (thermal breakthrough). Efficient operation of an EGS as well as conventional geothermal systems involving cold-fluid injection requires accurate and timely information about thermal depletion of the reservoir in response to operation. In particular, accurate predictions of the time to thermal breakthrough and subsequent rate of thermal drawdown are necessary for reservoir management, design of fracture stimulation and well drilling programs, and forecasting of economic return. A potential method for estimating migration of a cold front between an injection well and a production well is through application of reactive tracer tests, using chemical whose rate of degradation is dependent on the reservoir temperature between the two wells (e.g., Robinson 1985). With repeated tests, the rate of migration of the thermal front can be determined, and the time to thermal breakthrough calculated. While the basic theory behind the concept of thermal tracers has been understood for some time, effective application of the method has yet to be demonstrated. This report describes results of a study that used several methods to investigate application of reactive tracers to monitoring the thermal evolution of a geothermal reservoir. These methods included (1) mathematical investigation of the sensitivity of known and hypothetical reactive tracers, (2) laboratory testing of novel

  18. Reservoir processes and fluid origins in the Baca Geothermal System, Valles Caldera, New Mexico

    NASA Astrophysics Data System (ADS)

    Truesdell, Alfred H.; Janik, Cathy J.

    1986-02-01

    At the Baca geothermal field in the Valles caldera, New Mexico, 19 deep wells were drilled in an attempt to develop a 50-MWe (megawatts electric) power plant. The chemical and isotopic compositions of steam and water samples have been used to indicate uniquely the origin of reservoir fluids and natural reservoir processes. Two distinct reservoir fluids exist at Baca. These fluids originate from the same deep, high-temperature (335°C), saline (2500 mg/kg Cl) parent water but have had different histories during upflow. One fluid (from wells 4 and 13) is isotopically light, high in radiogenic noble gases, CO2 and HCO3, and low in Ca. It has a temperature of 290°-295°C and a reservoir chloride near 1900 mg/kg. This fluid resulted from rapid upward flow through 1.1- to 1.4-m.y.-old Bandelier Tuff reservoir rocks after long residence in pre-Bandelier (>7 m.y.) sediments and Precambrian basement rocks and 25% dilution with high-altitude cold groundwater from Redondo Peak. The other water (from wells 15, 19, and 24) moved slowly through the Bandelier Tuff and cooled conductively (with minor steam loss for well 19) from 335°C to 280°-260°C. Apparently, short residence in old basement rocks has left this water with low radiogenic gases. Conductive cooling without mixing has kept the original chloride and relatively heavy isotope composition of the deep water. The recharge to the deep parent water is not well understood but may be from lower elevation precipitation outside the Valles caldera area. Gases are in equilibrium in all-liquid reservoir fluids at near reservoir temperatures, and the concentrations of atmospheric gases are similar to those of air-saturated water, indicating little boiling and steam loss. All water, solutes, and gases in the reservoir fluids originate from air-saturated meteoric recharge water, watermineral reactions, and rock leaching, with the possible exception of excess 3He that must have an ultimate mantle source. This gas could originate

  19. Sediment transport capacity as an objective of reservoir operations

    USGS Publications Warehouse

    Milhous, Robert T.

    1998-01-01

    A sediment transport capacity index was developed as a part of a program to develop methods of flushing flow analysis. The index can be used to develop reservoir operation strategies that consider the movement of sediment as one of the reservoir management goals. The sedimentation transport capacity index determines the instream flow for the maintenance of the substrate below a reservoir in a condition needed by a desirable ecosystem. It can also be used in investigating the impacts of reservoir on the river channel downstream of the reservoir. The method allows a reservoir operator the flexibility of meeting the streamflow needs with a mix of streamflows.

  20. Reservoir compartmentalization assessed with fluid compositional data

    SciTech Connect

    Smalley, P.C.; England, W.A. . Alliance R D Centre)

    1994-08-01

    Fluid composition is a valuable addition to the battery of static'' data available during reservoir appraisal that can be used to predict the dynamic behavior of the reservoir later in field life. This is because fluid data are not truly static; natural fluid mixing is a dynamic process that occurs over a long (geologic) time scale. Oil compositional differences, especially those that parallel changes in density, should be mixed rapidly by convection; their preservation indicates barriers to fluid flow. Water variations, now measurable on conventional core samples by use of residual salt analysis (RSA), help identify barriers to vertical fluid flow in oil and water legs.