Science.gov

Sample records for reservoir temperature

  1. 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

  2. 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.

  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. 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),

  10. 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

  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. 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.

  13. 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)

  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. 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.

  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. 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.

  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

    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.

  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

    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.

  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. 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.

  4. 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.

  5. 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

  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. 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…

  13. 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.

  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. 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.

  4. 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.

  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. 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

  10. 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

  11. 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

  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. 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

  18. 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.

  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. 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.

  1. 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.

  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. 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

  10. 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.

  11. 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.

  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. 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.

  17. 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

  18. 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

  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. 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.

  1. 21 CFR 868.5320 - Reservoir bag.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

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    Code of Federal Regulations, 2012 CFR

    2012-07-01

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