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1

Pressure transient analysis for naturally fractured reservoirs  

Science Conference Proceedings (OSTI)

New ideas are presented for the interpretation of pressure transient tests for wells in naturally fractured reservoirs. This work is based on the transient matrix flow model formulated by de Swaan. The differences between this model and the Warren and Root model occur during the transition flow period. It is demonstrated that the behavior of a naturally fractured reservoir can be correlated by using three dimensionless parameters. It is established that regardless of matrix geometry the transition period might exhibit a straight line whose slope is equal to half the slope of the classical parallel semilog straight lines, provided the transient matrix linear flow is present. In addition, information is provided on the estimation of fracture area per unit matrix volume or matrix parameters from the transition period semilog straight line. It is shown that matrix geometry might be identified when pressure data are smooth. Field examples are included to illustrate the application and the validity of the theoretical results of this study.

Cinco-ley, H.; Samaniego, F.V.

1982-09-01T23:59:59.000Z

2

Adequate description of heavy oil viscosities and a method to assess optimal steam cyclic periods for thermal reservoir simulation  

E-Print Network (OSTI)

A global steady increase of energy consumption coupled with the decline of conventional oil resources points to a more aggressive exploitation of heavy oil. Heavy oil is a major source of energy in this century with a worldwide base reserve exceeding 2.5 trillion barrels. Management decisions and production strategies from thermal oil recovery processes are frequently based on reservoir simulation. A proper description of the physical properties, particularly oil viscosity, is essential in performing reliable modeling studies of fluid flow in the reservoir. We simulated cyclic steam injections on the highly viscous Hamaca oil, with a viscosity of over 10,000 cp at ambient temperature, and the production was drastically impacted by up to an order of magnitude when using improper mixing rules to describe the oil viscosity. This thesis demonstrates the importance of these mixing rules and alerts reservoir engineers to the significance of using different options simulators have built in their platforms to describe the viscosity of heavy oils. Log linear and power mixing rules do not provide enough flexibility to describe the viscosity of extra heavy oil with temperature. A recently implemented mixing rule in a commercial simulator has been studied providing satisfactory results. However, the methodology requires substantial interventions, and cannot be automatically updated. We provide guidelines to improve it and suggest more flexible mixing rules that could easily be implemented in commercial simulators. We also provide a methodology to determine the adequate time for each one of the periods in cyclic steam injection: injection, soaking and production. There is a lot of speculation in this matter and one of the objectives of this thesis is to better understand and provide guidelines to optimize oil production using proper lengths in each one of these periods. We have found that the production and injection periods should be similar in time length. Nevertheless, the production period should not be less than the injection period. On the other hand, the soaking period should be as short as possible because it is unproductive time in terms of field oil production for the well and therefore it translates into a negative cash flow for a company.

Mago, Alonso Luis

2003-05-01T23:59:59.000Z

3

The Impact of Uncertain Centrifuge Capillary Pressure on Reservoir Simulation  

Science Conference Proceedings (OSTI)

The capillary pressure in a reservoir determines the saturation distribution, and hence the total in situ volumes of fluids (oil/water/gas). The accurate knowledge of the capillary pressure distribution is one of the primary factors that may be decisive ... Keywords: Volterra, Voronoi cells, capillary pressure, centrifuge, ill-posed, inverse, linear integral equation, measured data, stochastic algorithm, synthetic data, uncertainty

Sam Subbey; Mike Christie; Malcolm Sambridge

2005-02-01T23:59:59.000Z

4

Transient pressure analysis in composite reservoirs  

Science Conference Proceedings (OSTI)

The problem of fluid flow in a radially composite reservoir is discussed. Recently published was the most general analytic solution available thus far. That analytic solution is analyzed, and the results are presented. The solution is dependent upon the following dimensionless parameters (if well-bore storage and skin effect are neglected): (1) dimensionless time based on the discontinuity radius, (2) the dimensionless discontinuity radius, (3) the mobility ratio, and (4) the diffusivity ratio. The range of parameters used in generating the results include dimensionless radius time of 0.01 t

Tang, R.W.K.; Brigham, W.E.

1982-08-01T23:59:59.000Z

5

THE IMPACT OF UNCERTAIN CENTRIFUGE CAPILLARY PRESSURE ON RESERVOIR SIMULATION  

E-Print Network (OSTI)

THE IMPACT OF UNCERTAIN CENTRIFUGE CAPILLARY PRESSURE ON RESERVOIR SIMULATION SAM SUBBEY, MIKE distribution, and hence the total in situ volumes of fluids (oil/water/gas). The accurate knowledge estimation of hydrocarbon reserves. The centrifuge procedure provides laboratory data, which can be inverted

Sambridge, Malcolm

6

Permeability prediction and drainage capillary pressure simulation in sandstone reservoirs  

E-Print Network (OSTI)

Knowledge of reservoir porosity, permeability, and capillary pressure is essential to exploration and production of hydrocarbons. Although porosity can be interpreted fairly accurately from well logs, permeability and capillary pressure must be measured from core. Estimating permeability and capillary pressure from well logs would be valuable where cores are unavailable. This study is to correlate permeability with porosity to predict permeability and capillary pressures. Relationships between permeability to porosity can be complicated by diagenetic processes like compaction, cementation, dissolution, and occurrence of clay minerals. These diagenetic alterations can reduce total porosity, and more importantly, reduce effective porosity available for fluid flow. To better predict permeability, effective porosity needs to be estimated. A general equation is proposed to estimate effective porosity. Permeability is predicted from effective porosity by empirical and theoretical equations. A new capillary pressure model is proposed. It is based on previous study, and largely empirical. It is tested with over 200 samples covering a wide range of lithology (clean sandstone, shaly sandstone, and carbonates dominated by intergranular pores). Parameters in this model include: interfacial tension, contact angle, shape factor, porosity, permeability, irreducible water saturation, and displacement pressure. These parameters can be measured from routine core analysis, estimated from well log, and assumed. An empirical equation is proposed to calculate displacement pressure from porosity and permeability. The new capillary-pressure model is applied to evaluate sealing capacity of seals, calculate transition zone thickness and saturation above free water level in reservoirs. Good results are achieved through integration of well log data, production data, core, and geological concepts.

Wu, Tao

2004-12-01T23:59:59.000Z

7

A triple-continuum pressure-transient model for a naturally fractured vuggy reservoir  

E-Print Network (OSTI)

reservoir. The fraction of oil reserves in a vuggy fracturedcontribute to oil and gas reserves and production [Kossackreserves estimation. Field Examples Pressure transient data from two oil-

2007-01-01T23:59:59.000Z

8

Comparison of pressure ransient response in intensely and sparsely fractured reservoirs  

DOE Green Energy (OSTI)

A comprehensive analytical model is presented to study the pressure transient behavior of a naturally fractured reservoir with a continuous matrix block size distribution. Geologically realistic probability density functions of matrix block size are used to represent reservoirs of varying fracture intensity and uniformity. Transient interporosity flow is assumed and interporosity skin is incorporated. Drawdown and interference pressure transient tests are investigated. The results show distinctions in the pressure response from intensely and sparsely fractured reservoirs in the absence of interporosity skin. Also, uniformly and nonuniformly fractured reservoirs exhibit distinct responses, irrespective of the degree of fracture intensity. The pressure response in a nonuniformly fractured reservoir with large block size variability, approaches a nonfractured (homogeneous) reservoir response. Type curves are developed to estimate matrix block size variability and the degree of fracture intensity from drawdown and interference well tests.

Johns, R.T.

1989-01-01T23:59:59.000Z

9

Comparison of pressure transient response in intensely and sparsely fractured reservoirs  

DOE Green Energy (OSTI)

A comprehensive analytical model is presented to study the pressure transient behavior of a naturally fractured reservoir with a continuous matrix block size distribution. Geologically realistic probability density functions of matrix block size are used to represent reservoirs of varying fracture intensity and uniformity. Transient interporosity flow is assumed and interporosity skin is incorporated. Drawdown and interference pressure transient tests are investigated. The results show distinctions in the pressure response from intensely and sparsely fractured reservoirs in the absence of interporosity skin. Also, uniformly and nonuniformly fractured reservoirs exhibit distinct responses, irrespective of the degree of fracture intensity. The pressure response in a nonuniformly fractured reservoir with large block size variability, approaches a nonfractured (homogeneous) reservoir response. Type curves are developed to estimate matrix block size variability and the degree of fracture intensity from drawdown and interference well tests.

Johns, R.T.

1989-04-01T23:59:59.000Z

10

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

DOE Green Energy (OSTI)

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.

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

1983-03-01T23:59:59.000Z

11

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

Science Conference Proceedings (OSTI)

Despite declining production rates, existing reservoirs in the United States contain vast volumes of remaining oil that is not being effectively recovered. This oil resource constitutes a huge target for the development and application of modern, cost-effective technologies for producing oil. Chief among the barriers to the recovery of this oil are the high costs of designing and implementing conventional advanced recovery technologies in these mature, in many cases pressure-depleted, reservoirs. An additional, increasingly significant barrier is the lack of vital technical expertise necessary for the application of these technologies. This lack of expertise is especially notable among the small operators and independents that operate many of these mature, yet oil-rich, reservoirs. We addressed these barriers to more effective oil recovery by developing, testing, applying, and documenting an innovative technology that can be used by even the smallest operator to significantly increase the flow of oil from mature U.S. reservoirs. The Bureau of Economic Geology and Goldrus Producing Company assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The Permian Basin, the largest oil-bearing basin in North America, contains more than 70 billion barrels of remaining oil in place and is an ideal venue to validate this technology. We have demonstrated the potential of HPAI for oil-recovery improvement in preliminary laboratory tests and a reservoir pilot project. To more completely test the technology, this project emphasized detailed characterization of reservoir properties, which were integrated to access the effectiveness and economics of HPAI. The characterization phase of the project utilized geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. The successful development of HPAI technology has tremendous potential for increasing the flow of oil from deep carbonate reservoirs in the Permian Basin, a target resource that can be conservatively estimated at more than 1.5 billion barrels. Successful implementation in the field chosen for demonstration, for example, could result in the recovery of more than 34 million barrels of oil that will not otherwise be produced. Geological and petrophysical analysis of available data at Barnhart field reveals the following important observations: (1) the Barnhart Ellenburger reservoir is similar to most other Ellenburger reservoirs in terms of depositional facies, diagenesis, and petrophysical attributes; (2) the reservoir is characterized by low to moderate matrix porosity much like most other Ellenburger reservoirs in the Permian Basin; (3) karst processes (cave formation, infill, and collapse) have substantially altered stratigraphic architecture and reservoir properties; (4) porosity and permeability increase with depth and may be associated with the degree of karst-related diagenesis; (5) tectonic fractures overprint the reservoir, improving overall connectivity; (6) oil-saturation profiles show that the oil-water contact (OWC) is as much as 125 ft lower than previous estimations; (7) production history and trends suggest that this reservoir is very similar to other solution-gas-drive reservoirs in the Permian Basin; and (8) reservoir simulation study showed that the Barnhart reservoir is a good candidate for HPAI and that application of horizontal-well technology can improve ultimate resource recovery from the reservoir.

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

2006-09-30T23:59:59.000Z

12

REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR  

SciTech Connect

The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plant that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration are being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the US.

Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olsen; Deanna Combs; Dhiraj Dembla; Leonel Gomez

2003-06-01T23:59:59.000Z

13

Pressure transient analysis of fractured wells in shale reservoirs.  

E-Print Network (OSTI)

??In this study, an unconventional reservoir simulator is developed, which is based on a general black-oil simulator "MSFLOW". We incorporate several non-linear flow mechanisms (Klinkenberg… (more)

Wang, Cong

2013-01-01T23:59:59.000Z

14

Designing cyclic pressure pulsing in naturally fractured reservoirs using an inverse looking recurrent neural network  

Science Conference Proceedings (OSTI)

In this paper, an inverse looking approach is presented to efficiently design cyclic pressure pulsing (huff 'n' puff) with N"2 and CO"2, which is an effective improved oil recovery method in naturally fractured reservoirs. A numerical flow simulation ... Keywords: Big Andy Field, CO2, Cyclic pressure pulsing, Huff 'n' puff, N2, Recurrent neural networks

E. Artun; T. Ertekin; R. Watson; B. Miller

2012-01-01T23:59:59.000Z

15

REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR  

SciTech Connect

The Bureau of Economic Geology (BEG) and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology (BEG) and the Department of Petroleum and Geosystems Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data were to be generated during the demonstration phase to improve the accuracy of the reservoir model. The demonstration phase has been delayed by Goldrus because of funding problems. Since the first of the year, Goldrus has been active in searching for partners to help finance the project. To this end it has commissioned several small consulting studies to technically support its effort to secure a partner. After financial support is obtained, the demonstration phase of the project will proceed. Since just after the beginning of the year, BEG has curtailed project activities and spending of DOE funds except for the continued support of one engineering student. This student has now completed his work and has written a thesis describing his research (titled ''Stimulating enhanced oil recovery (EOR) by high-pressure air injection (HPAI) in west Texas light oil reservoir''). We plan to recommence our work on the project as soon as the operator obtains necessary funding to carry out the demonstration phase of the project. In order to complete all activities specified in the proposal, it will be necessary to request an extension of the project from the originally defined completion date. We are confident that Goldrus will obtain the necessary funding to continue and that we can complete the project if an extension is granted. We strongly believe that the results of this study will provide the impetus for a new approach to enhanced oil recovery in the Permian Basin and elsewhere in the United States.

Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olson; Deanna Combs; Dhiraj Dembla

2004-06-01T23:59:59.000Z

16

REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR  

SciTech Connect

The field operator, Goldrus Producing Company, has been unable to secure funding needed to continue the field demonstration phase of the project. Accordingly, we have temporarily halted all project activities until necessary funding is obtained. Goldrus felt confident that funds could be acquired by third quarter 2005 at which time it would have been necessary to request a project extension to complete the originally designed study. A project extension was granted but it appears Goldrus will have difficulty securing funds. We Bureau of Economic Geology are investigating a new approach on how to fulfill our initial objectives of promoting high-pressure air injection of Ellenburger reservoirs.

Robert Loucks; Stephen C. Ruppel

2006-02-01T23:59:59.000Z

17

Critically pressured free-gas reservoirs below gas-hydrate  

E-Print Network (OSTI)

; importantly, no observed gas column thickness significantly exceeds the calculated critical value (Fig. 3 complete gas evacuation3,24 . A Received 16 June; accepted 5 November 2003; doi:10.1038/nature02172. 1.............................................................. Critically pressured free-gas

Holbrook, W. Steven

18

Pressure testing of a high temperature naturally fractured reservoir  

DOE Green Energy (OSTI)

Los Alamos National Laboratory has conducted a number of pumping and flow-through tests at the Hot Dry Rock (HDR) test site at Fenton Hill, New Mexico. These tests consisted of injecting fresh water at controlled rates up to 12 BPM (32 l/s) and surface pressures up to 7000 psi (48 MPa) into the HDR formation at depths from 10,000 to 13,180 feet (3050 to 4000 m). The formation is a naturally fractured granite at temperatures of about 250/sup 0/C. The matrix porosity is <1% and permeability is on the order of 1 nD. Hence most of the injected fluid is believed to move through fractures. There has been no evidence of fracture breakdown phenomena, and hence it is believed that preexisting joints in the formation are opened by fluid injection. Water losses during pumping are significant, most likely resulting from flow into secondary fractures intersecting the main fluid conducting paths. The pressure-time response observed in these tests can be interpreted in terms of non-isothermal, fracture-dominated flow. As the fluid pressure increases from small values to those comparable to fracturing pressures, the formation response changes from linear fracture flow to the highly nonlinear situation where fracture lift-off occurs. A numerical heat and mass flow model was used to match the observed pressure response. Good matches were obtained for pressure buildup and shut-in data by assigning pressure dependent fracture and leak-off permeabilities. 12 refs., 5 figs., 2 tabs.

Kelkar, S.M.; Zyvoloski, G.A.; Dash, Z.V.

1986-01-01T23:59:59.000Z

19

Constant-pressure production in solution-gas-drive reservoirs; Transient flow  

SciTech Connect

This paper presents procedures to obtain reservoir parameters from constant-pressure drawdown data in solution-gas-drive reservoirs. A novel procedure to determine the mechanical skin factor is introduced. Examples, including a field case, illustrate the use of this procedure. An estimate of the drainage area can be obtained with the derivative of rate data. A theoretical basis for analyzing data by the pressure-squared, p{sup 2}, approach is presented; this procedure permits the approximate determination of sandface effective permeabilities in the transient flow period. For damaged wells, it is possible to obtain rough estimates of the size of the skin zone and the ratio of reservoir/skin-zone permeability when early transient data are available. The expression of the appropriate dimensionless rate in terms of physical properties for solution-gas-drive systems is presented. Finally, this paper presents a procedure to obtain an estimate of the change in sandface saturation during the transient flow period.

Camacho, R.G. (National Univ. of Mexico/PEMEX (MX))

1991-06-01T23:59:59.000Z

20

REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR  

SciTech Connect

The Bureau of Economic Geology (BEG) and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology (BEG) and the Department of Petroleum and Geosystems Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data were to be generated during the demonstration phase to improve the accuracy of the reservoir model. The demonstration phase has been delayed by Goldrus because of funding problems. Since the first of the year, Goldrus has been active in searching for partners to help finance the project. After financial support is obtained, the demonstration phase of the project will proceed. Since just after the beginning of the year, BEG has curtailed project activities and spending of DOE funds except for the continued support of one engineering student. This student has now completed his work and his thesis was reported on in the last semi-annual report. We plan to recommence our work on the project as soon as the operator obtains necessary funding to carry out the demonstration phase of the project. In order to complete all activities specified in the proposal, we requested and received an extension of the project to September 30, 2005. We are confident that Goldrus will obtain the necessary funding to continue and that we can complete the project by the end of the extension data. We strongly believe that the results of this study will provide the impetus for a new approach to enhanced oil recovery in the Permian Basin and elsewhere in the United States.

Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olson

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR  

SciTech Connect

The Bureau of Economic Geology and Goldrus Producing Company have assembled a multidisciplinary team of geoscientists and engineers to evaluate the applicability of high-pressure air injection (HPAI) in revitalizing a nearly abandoned carbonate reservoir in the Permian Basin of West Texas. The characterization phase of the project is utilizing geoscientists and petroleum engineers from the Bureau of Economic Geology and the Department of Petroleum Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. This model will be used to define a field deployment plan that Goldrus, a small independent oil company, will implement by drilling both vertical and horizontal wells during the demonstration phase of the project. Additional reservoir data are being gathered during the demonstration phase to improve the accuracy of the reservoir model. The results of the demonstration will being closely monitored to provide a basis for improving the design of the HPAI field deployment plan. The results of the reservoir characterization field demonstration and monitoring program will be documented and widely disseminated to facilitate adoption of this technology by oil operators in the Permian Basin and elsewhere in the U.S.

Robert Loucks; Steve Ruppel; Julia Gale; Jon Holder; Jon Olsen; Deanna Combs; Dhiraj Dembla; Leonel Gomez

2003-12-10T23:59:59.000Z

22

Low-pressure reservoir drilled with air/N[sub 2] in a closed system  

Science Conference Proceedings (OSTI)

Ignition tests on simulated produced fluids helped determine the ideal air/nitrogen mixture for an underbalanced drilling operation that used a closed surface system to process return fluids. The low-pressure, heavy-oil target reservoir required underbalanced drilling to minimize formation damage. Underbalanced or near-balanced drilling can improve production from pressure-depleted reservoirs by reducing the chance of formation damage from drilling fluid losses. Underbalanced drilling technology currently available includes the use of gas injection through parasite strings or through drilling tubulars. No one (to the author's knowledge) has combined concentric-string commingled gas injection with through-drilling-tubular commingled gas injection. The paper describes lab work, test results, surface returns, downhole design, operations, and field results.

Teichrob, R.R. (Husky Oil Operations Ltd., Calgary, Alberta (Canada))

1994-03-21T23:59:59.000Z

23

Pressure analysis of the hydromechanical fracture behaviour in stimulated tight sedimentary geothermal reservoirs  

E-Print Network (OSTI)

in jointed and layered rocks in geothermal fields.of Volcanology and Geothermal Research 116, 257- 278.fracturing in a sedimentary geothermal reservoir: Results

Wessling, S.

2009-01-01T23:59:59.000Z

24

Effects of pressure drawdown and recovery on the Cerro Prieto beta reservoir in the CP-III area  

DOE Green Energy (OSTI)

The production characteristics of wells in the northwestern Cerro Prieto III area changed greatly when the Cp-III power plant went on line in 1986. Fluid extraction in the field more than doubled and reservoir-wide boiling started immediately, greatly increasing the enthalpy of produced fluids. Some well fluids showed a decrease in chloride due to adiabatic steam condensation in the well and separator, and others were enriched in chloride due to boiling. As reservoir drawdown increased, entrance of cooler and more dilute groundwaters into the reservoir became evident (i.e., condensation stopped, and there was a decrease in enthalpy and chloride in produced fluids). Although some groundwater inflow was from the leaky western margin of the reservoir, the majority is in the northeast, inferred to be local and downward, possibly through more permeable zones associated with the normal fault H. This natural recharge and some reinjection have slowed and possibly reversed pressure drawdown throughout CP-III. Enthalpy has decreased and liquid saturation has increased as the steam-rich zone in the upper part of the reservoir has either disappeared or become thinner.

Truesdell, A.H. [Truesdell (Alfred H.), Menlo Park, CA (United States); Lippmann, M.J. [Lawrence Berkeley National Lab., CA (United States)

1998-02-01T23:59:59.000Z

25

Dependence of waterflood remaining oil saturation on relative permeability, capillary pressure, and reservoir parameters in mixed-wet turbidite sands  

SciTech Connect

The dependence of waterflood oil recovery on relative permeability, capillary pressure, and reservoir parameters was investigated by numerical simulation. The relative permeability and capillary pressure curves were based on laboratory measurements on unconsolidated sands. The water-wet case is based on the assumption that the system is water-wet and measurements were made with refined oil. The mixed-wet case assumed that the system is mixed-wet and restored-state measurements were made with crude oil. The reservoir model was a prototype turbidite sand with a range of thickness and permeability values. The economic oil recovery was based on an economic limit water cut of 50%. The remaining oil saturation (ROS) in the swept region for the water-wet cases was close to the residual oil saturation. The ROS of the mixed-wet cases ranged from low values near the residual oil saturation to far above the residual oil saturation. It is dependent on the reservoir parameters that govern (1) the vertical film surface drainage of oil by gravity, (2) accumulation of a high oil saturation and thus a high relative permeability under the caprock, and (3) up-dip migration of the oil that accumulated under the caprock. The dependence on the reservoir parameters can be summarized by dimensionless groups. There is a dimensionless time for the vertical displacement of oil by gravity. The accumulation of a high oil saturation under the caprock is dependent on the ratio of the capillary transition zone and the sand thickness. The updip migration is dependent on a combination of the gravity number and the endpoint mobility ratio.

Hirasaki, G.J. [Rice Univ., Houston, TX (United States)

1996-05-01T23:59:59.000Z

26

Characterization of gas condensate reservoirs using pressure transient and production data - Santa Barbara Field, Monagas, Venezuela  

E-Print Network (OSTI)

This thesis presents a field case history of the integrated analysis and interpretation developed using all of the available petrophysical, production, and well test data from the condensate zone of Block A, Santa Barbara Field (Monagas, Venezuela). The reservoir units in Santa Barbara Field present substantial structural and fluid complexity, which, in turn, presents broad challenges for assessment and optimization of well performance behavior. Approximately 60 well tests have been performed in the gas condensate sections within Santa Barbara Field, and the analysis and interpretation of this data suggests the existence of condensate banking and layered reservoir behavior, as well as "well interference" effects. We demonstrate and discuss analysis and interpretation techniques that can be utilized for wells that exhibit condensate banking, layered reservoir behavior, and well interference effects (where all of these phenomena are observed in the well performance data taken from Block A in Santa Barbara Field). We have established that the layered reservoir model (no crossflow), coupled with the model for a two-zone radial composite reservoir, is an appropriate reservoir model for the analysis and interpretation of well performance data (i.e., well test and production data) taken from wells in Santa Barbara Field. It is of particular importance to note our success in using the "well interference" approach to analyze and interpret well test data taken from several wells in Santa Barbara Field. While it is premature to make broad conclusions, it can be noted that well interference effects (interference between production wells) could be (and probably is) a major influence on the production performance of Santa Barbara Field. In addition, our well test analysis approach corroborates the use of the Correa and Ramey (variable rate) plotting function for the analysis of drillstem test (DST) data. In summary, we are able to use our integrated analysis developed for Block A (Santa Barbara Field) estimate areal distributions of "flow" properties (porosity, effective permeability, and skin factor), as well as "volumetric" properties (original gas-in-place, gas reserves, and reservoir drainage area (all on a "per-well" basis)).

Medina Tarrazzi, Trina Mercedes

2003-01-01T23:59:59.000Z

27

THE EFFECT OF PRESSURE ON OXIDATION KINETICS OF TAR FROM A TARMAT RESERVOIR  

E-Print Network (OSTI)

, the pressure differential across the tarmat could build up to a level that might cause the tar seal to beak). The pipe was #12;sealed at both ends by flanges and copper O-rings. A 1.6-mm OD, stainless steel tube. About 20 g of clean sand were placed on top of the mixture to help preheat and distribute air flow

Abu-Khamsin, Sidqi

28

Analytic study of geothermal reservoir pressure response to cold water reinjection  

DOE Green Energy (OSTI)

Derivation of the governing equation, including temperature effects, is given where the permeability-viscosity ratio is assumed to be an arbitrary function of r{sup 2}t. This function is represented by a Fermi-Dirac function, whose parameters are determined based upon physical considerations. The solution for the pressure change is analytic except for the final step, where a numerical integration is called for. The results and implications of the calculations are discussed. Summary and concluding remarks are presented.

Tsang, Y.W.; Tsang, C.F.

1978-11-01T23:59:59.000Z

29

Laboratory tests to evaluate and study formation damage with low-density drill-in fluids (LDDIF) for horizontal well completions in low pressure and depleted reservoirs  

E-Print Network (OSTI)

The increasing number of open hole horizontal well completions in low-pressure and depleted reservoirs requires the use of non-damaging low-density drill-in fluids (LDDIF) to avoid formation damage and realize optimum well productivity. To address this need we have formulated new LDDIFS with specific density lower than 1.0 sg (8.34 ppg) specifically to drill and complete low pressure and depleted reservoirs with minimum formation damage and maximum production. These materials exhibit typical drilling fluid characteristics, allowing the well to be safely drilled (0 required well depth but also perform as completion fluids, lessening formation damage to a greater extent than fluids with greater density and higher wellbore pressures. The new LDDIF incorporates low-density hollow glass spheres (HGS) to allow near-balanced drilling in low pressure and depleted reservoirs. The LDDIF uses potassium chloride (KCI) brine as the base fluid because of its low density and inhibition of clay hydration and employs low concentrations of the HGS so that fluid rheology is not altered. We have conducted extensive laboratory testing to compare performance of the HGS LDDIF with that of conventional horizontal well DIFs. Experiments consisted of permeability regain tests on unconsolidated sands with sand control screens. Test variables included temperature, concentration of drill solids cleanup technique and HGS concentration. Test results have shown that the new fluids are up to 50% easier to remove from the wellbore formation faces and provide higher productivity than higher density fluids. Such results indicate that higher well productivity from wells with less impairment would offset any added costs of HGS additives in the fluids.

Chen, Guoqiang

2002-01-01T23:59:59.000Z

30

Analysis of the dynamics of saturation and pressure close to the wellbore for condensate reservoirs as a tool to optimize liquid production  

E-Print Network (OSTI)

Gas condensate reservoirs often exhibit a rapid decline in production with depletion. During early production, liquid dropout accumulates in the near wellbore area and this liquid dropout reduces the effective permeability to gas and thereby the well and field productivity. Our primary goal in this research is to understand the dynamics of condensate banking in the near well region of retrograde gases. We propose a relationship that can be used in determining gas oil ratios and near the wellbore saturation. The tasks accomplished in this study of gas condensate reservoir behavior include: Development of a generalized relationship, that allows us to estimate the gas-oil- ratio (GOR) and the effect condensate banking close to production wells. This simple relationship allows us to estimate GOR and condensate banking at any time by using basic data such as saturation pressure, field pressure, gas injection rates, and gas production rates. We recognize and acknowledge that further work is required in testing and improving this relation. We suggest the addition of molecular weights (or specific gravity) of the reservoir fluid to improve the correlative relationship. Comparison of field performance under a variety of production scenarios including natural depletion, gas cycling, water injection, and, the injection of different gases (methane, nitrogen and carbon dioxide). We provide a discussion of the effects of different production schemes upon saturation profiles and saturation histories, as well as the influence of various production-injection schemes on well and field productivity. We also include an analysis of the compositional changes driven by injection and the influence of these changes on reservoir performance.

Guerra Camargo, Andrea M

2001-01-01T23:59:59.000Z

31

Adequate NQA-1 Suppliers | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Adequate NQA-1 Suppliers Adequate NQA-1 Suppliers Scope of Project Milestone Task 2.6: Request the procedures used for qualifying nuclear grade suppliers from each major EM...

32

Reinjection into geothermal reservoirs  

DOE Green Energy (OSTI)

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)

Bodvarsson, G.S.; Stefansson, V.

1987-08-01T23:59:59.000Z

33

Reservoir Modeling for Production Management  

DOE Green Energy (OSTI)

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.

Brown, Donald W.

1989-03-21T23:59:59.000Z

34

Reservoir compaction loads on casings and liners  

Science Conference Proceedings (OSTI)

Pressure drawdown due to production from a reservoir causes compaction of the reservoir formation which induces axial and radial loads on the wellbore. Reservoir compaction loads increase during the production life of a well, and are greater for deviated wells. Presented here are casing and liner loads at initial and final pressure drawdowns for a particular reservoir and at well deviation angles of 0 to 45 degrees.

Wooley, G.R.; Prachner, W.

1984-09-01T23:59:59.000Z

35

Asbestos/NESHAP adequately wet guidance  

SciTech Connect

The Asbestos NESHAP requires facility owners and/or operators involved in demolition and renovation activities to control emissions of particulate asbestos to the outside air because no safe concentration of airborne asbestos has ever been established. The primary method used to control asbestos emissions is to adequately wet the Asbestos Containing Material (ACM) with a wetting agent prior to, during and after demolition/renovation activities. The purpose of the document is to provide guidance to asbestos inspectors and the regulated community on how to determine if friable ACM is adequately wet as required by the Asbestos NESHAP.

Shafer, R.; Throwe, S.; Salgado, O.; Garlow, C.; Hoerath, E.

1990-12-01T23:59:59.000Z

36

-Injection Technology -Geothermal Reservoir Engineering  

E-Print Network (OSTI)

.A. Hsieh 1e$ Pressure Buildup Monitoring of the Krafla Geothermal Field, . . . . . . . . 1'1 Xceland - 0 Initial Chemical and Reservoir Conditions at Lo6 Azufres Wellhead Power Plant Startup - P. Kruger, LSGP-TR-92 - Injection Technology - Geothermal Reservoir Engineering Research at Stanford Principal

Stanford University

37

Modeling well performance in compartmentalized gas reservoirs  

E-Print Network (OSTI)

Predicting the performance of wells in compartmentalized reservoirs can be quite challenging to most conventional reservoir engineering tools. The purpose of this research is to develop a Compartmentalized Gas Depletion Model that applies not only to conventional consolidated reservoirs (with constant formation compressibility) but also to unconsolidated reservoirs (with variable formation compressibility) by including geomechanics, permeability deterioration and compartmentalization to estimate the OGIP and performance characteristics of each compartment in such reservoirs given production data. A geomechanics model was developed using available correlation in the industry to estimate variable pore volume compressibility, reservoir compaction and permeability reduction. The geomechanics calculations were combined with gas material balance equation and pseudo-steady state equation and the model was used to predict well performance. Simulated production data from a conventional gas Simulator was used for consolidated reservoir cases while synthetic data (generated by the model using known parameters) was used for unconsolidated reservoir cases. In both cases, the Compartmentalized Depletion Model was used to analyze data, and estimate the OGIP and Jg of each compartment in a compartmentalized gas reservoir and predict the subsequent reservoir performance. The analysis was done by history-matching gas rate with the model using an optimization technique. The model gave satisfactory results with both consolidated and unconsolidated reservoirs for single and multiple reservoir layers. It was demonstrated that for unconsolidated reservoirs, reduction in permeability and reservoir compaction could be very significant especially for unconsolidated gas reservoirs with large pay thickness and large depletion pressure.

Yusuf, Nurudeen

2007-12-01T23:59:59.000Z

38

Nonisothermal injection tests in fractured reservoirs  

DOE Green Energy (OSTI)

The paper extends the analysis of nonisothermal pressure transient data to fractured reservoirs. Two cases are considered: reservoirs with predominantly horzontal fractures and reservoirs with predominantly vertical fractures. Effects of conductive heat transfer between the fractures and the rock matrix are modeled, and the resulting pressure transients evaluated. Thermal conduction tends to retard the movement of the thermal front in the fractures, which significantly affects the pressure transient data. The purpose of the numerical simulation studies is to provide methods for analyzing nonisothermal injection/falloff data for fractured reservoirs.

Cox, B.L.; Bodvarsson, G.S.

1985-01-01T23:59:59.000Z

39

Fracture characterization of multilayered reservoirs  

Science Conference Proceedings (OSTI)

Fracture treatment optimization techniques have been developed using Long-Spaced-Digital-Sonic (LSDS) log, pumpin-flowback, mini-frac, and downhole treating pressure data. These analysis techniques have been successfully applied in massive hydraulic fracturing (MHF) of ''tight gas'' wells. Massive hydraulic fracture stimulations have been used to make many tight gas reservoirs commercially attractive. However, studies have shown that short highly conductive fractures are optimum for the successful stimulation of wells in moderate permeability reservoirs. As a result, the ability to design and place optimal fractures in these reservoirs is critical. This paper illustrates the application of fracture analysis techniques to a moderate permeability multi-layered reservoir. These techniques were used to identify large zonal variations in rock properties and pore pressure which result from the complex geology. The inclusion of geologic factors in fracture treatment design allowed the placement of short highly conductive fractures which were used to improve injectivity and vertical sweep, and therefore, ultimate recovery.

Britt, L.K.; Larsen, M.J.

1986-01-01T23:59:59.000Z

40

Fractured reservoir characterization through injection, falloff, and flowback tests  

SciTech Connect

This paper presents the development of a multiphase pressure-transient-analysis technique for naturally fractured reservoirs and the analysis of a series of field tests performed to evaluate the water injection potential and the reservoir characteristics of a naturally fractured reservoir. These included step-rate, water-injectivity, pressure-falloff, and flowback tests. Through these tests, a description of the reservoir was obtained.

Peng, C.P.; Singh, P.K. (Amoco Production Co., Tulsa, OK (United States)); Halvorsen, H. (Amoco Norway Oil Co., Stavanger (NO)); York, S.D. (Amoco Production Co., Houston, TX (United States))

1992-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Modelling the propagation of turbid density inflows into a stratified lake: Daecheong Reservoir, Korea  

Science Conference Proceedings (OSTI)

Many reservoirs and associated downstream ecosystems located in the Asian monsoon climate region are under increased pressure from the long-term negative effects of turbid flood runoff. Despite the ubiquitous use of turbidity (C"T) as a barometer of ... Keywords: Daecheong Reservoir, ELCOM-CAEDYM, Real-time reservoir management, Reservoir density flow, Stratified reservoir, Turbidity modelling

S. W. Chung; M. R. Hipsey; J. Imberger

2009-12-01T23:59:59.000Z

42

A reservoir management strategy for multilayered reservoirs in eastern Venezuela  

E-Print Network (OSTI)

A reservoir management strategy has been developed for a field located in eastern Venezuela. The field contains deep, high pressure, multilayer reservoirs. A thorough formation evaluation was accomplished using the log data, core data, PVT data, geologic data, well completion data and the production data. A reservoir simulation model was built to forecast reservoir performance for a variety of exploitation and well completion strategies. Reserve forecasts have been made using the reservoir model. The methodology applied in this research consists of eight tasks: 1) build a data base with existing data, 2) analyze the log and core data, 3) analyze the pressure and production data, 4) analyze the PVT data, 5) analyze the hydraulic fracture treatments, 6) build the reservoir model, 7) determine the possible reservoir management strategies, and 8) perform economic evaluations for the management strategies. While much of the data for the field studied was supplied by PDVSA, we did not receive all of the data we requested. For example, no pressure buildup data were available. When necessary, we used correlations to determine values for reservoir data that we were not supplied. In this research four formations were studied and characterized, determining porosity and permeability values. Also, fracture treatments were analyzed and a reservoir model was developed. Runs for black oil and volatile oil were performed. The results show that the upper zones are the most prospective areas, but fracture treatments must be performed to reduce the damage on the sand face. Lower formations (Cretaceous) have a lower permeability value, but high OOIP that justify performing fracture treatments and completing this zone. Economics were developed to support this conclusion. Optimum well spacing was calculated showing that 960 acres is the optimum well spacing, but also that 640 acres can be maintained for all the reservoirs and dual completions can be performed, first hydraulic fracturing and completing the Cretaceous formation, and then, completing any upper zone. Reservoir simulation results show that up to 31% of OOIP may be incrementally recovered by hydraulic fracturing the Cretaceous formation and 10 or less from the upper zones.

Espinel Diaz, Arnaldo Leopoldo

1998-01-01T23:59:59.000Z

43

An Updated Conceptual Model Of The Los Humeros Geothermal Reservoir  

Open Energy Info (EERE)

Humeros Geothermal Reservoir Humeros Geothermal Reservoir (Mexico) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: An Updated Conceptual Model Of The Los Humeros Geothermal Reservoir (Mexico) Details Activities (0) Areas (0) Regions (0) Abstract: An analysis of production and reservoir engineering data of 42 wells from the Los Humeros geothermal field (Mexico) allowed obtaining the pressure and temperature profiles for the unperturbed reservoir fluids and developing 1-D and 2-D models for the reservoir. Results showed the existence of at least two reservoirs in the system: a relatively shallow liquid-dominant reservoir located between 1025 and 1600 m above sea level (a.s.l.) the pressure profile of which corresponds to a 300-330°C boiling water column and a deeper low-liquid-saturation reservoir located between

44

Two-dimensional simulation of the Raft River geothermal reservoir...  

Open Energy Info (EERE)

and wells. (SINDA-3G program) Details Activities (1) Areas (1) Regions (0) Abstract: Computer models describing both the transient reservoir pressure behavior and the time...

45

Stanford Geothermal Program, reservoir and injection technology  

DOE Green Energy (OSTI)

This annual report of the Stanford Geothermal Program presents major projects in reservoir and injection technology. The four include: (1) an application of the boundary element method to front tracking and pressure transient testing; (2) determination of fracture aperture, a multi-tracer approach; (3) an analysis of tracer and thermal transients during reinjection; and, (4) pressure transient modeling of a non-uniformly fractured reservoir. (BN)

Horne, R.; Ramey, H.J. Jr.; Miller, F.G.; Brigham, W.E.; Kruger, P.

1988-12-01T23:59:59.000Z

46

Reservoir response to tidal and barometric effects  

DOE Green Energy (OSTI)

Solid earth tidal strain and surface loading due to fluctuations in barometric pressure have the effect, although extremely minute, of dilating or contracting the effective pore volume in a porous reservoir. If a well intersects the formation, the change in pore pressure can be measured with sensitive quartz pressure gauges. Mathematical models of the relevant fluid dynamics of the well-reservoir system have been generated and tested against conventional well pumping results or core data at the Salton Sea Geothermal Field (SSGF), California and at the Raft River, Geothermal Field (RRGF), Idaho. Porosity-total compressibility product evaluation based on tidal strain response compares favorably with results based on conventional pumping techniques. Analysis of reservoir response to barometric loading using Auto Regressive Integrated Moving Average (ARIMA) stochastic modeling appears also to have potential use for the evaluation of reservoir parameters.

Hanson, J.M.

1980-05-29T23:59:59.000Z

47

Determining the Adequate Level of Distributed Generation Penetration...  

NLE Websites -- All DOE Office Websites (Extended Search)

Determining the Adequate Level of Distributed Generation Penetration in Future Grids Speaker(s): Johan Driesen Date: March 18, 2004 - 12:00pm Location: Bldg. 90 Seminar HostPoint...

48

Adsorption of water vapor on reservoir rocks  

DOE Green Energy (OSTI)

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

Not Available

1993-07-01T23:59:59.000Z

49

Dispersivity as an oil reservoir rock characteristic  

Science Conference Proceedings (OSTI)

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

Menzie, D.E.; Dutta, S.

1989-12-01T23:59:59.000Z

50

Status of Norris Reservoir  

DOE Green Energy (OSTI)

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.

Not Available

1990-09-01T23:59:59.000Z

51

Integrated reservoir study of the 8 reservoir of the Green Canyon 18 field  

E-Print Network (OSTI)

The move into deeper waters in the Gulf of Mexico has produced new opportunities for petroleum production, but it also has produced new challenges as different reservoir problems are encountered. This integrated reservoir characterization effort has provided useful information about the behavior and characteristics of a typical unconsolidated, overpressured, fine-grained, turbidite reservoir, which constitutes the majority of the reservoirs present in the Outer Continental Shelf of the Gulf of Mexico. Reservoirs in the Green Canyon 18 (GC 18) field constitute part of a turbidite package with reservoir quality typically increasing with depth. Characterization of the relatively shallow 8 reservoir had hitherto been hindered by the difficulty in resolving its complex architecture and stratigraphy. Furthermore, the combination of its unconsolidated rock matrix and abnormal pore pressure has resulted in severe production-induced compaction. The reservoir's complex geology had previously obfuscated the delineation of its hydrocarbon accumulation and determination of its different resource volumes. Geological and architectural alterations caused by post-accumulation salt tectonic activities had previously undermined the determination of the reservoir's active drive mechanisms and their chronology. Seismic interpretation has provided the reservoir geometry and topography. The reservoir stratigraphy has been defined using log, core and seismic data. With well data as pilot points, the spatial distribution of the reservoir properties has been defined using geostatistics. The resulting geological model was used to construct a dynamic flow model that matched historical production and pressure data.. The reservoir's pressure and production behavior indicates a dominant compaction drive mechanism. The results of this work show that the reservoir performance is influenced not only by the available drive energy, but also by the spatial distribution of the different facies relative to well locations. The study has delineated the hydrocarbon bearing reservoir, quantified the different resource categories as STOIIP/GIIP = 19.8/26.2 mmstb/Bscf, ultimate recovery = 9.92/16.01 mmstb/Bscf, and reserves (as of 9/2001) = 1.74/5.99 mmstb/Bscf of oil and gas, respectively. There does not appear to be significant benefit to infill drilling or enhanced recovery operations.

Aniekwena, Anthony Udegbunam

2003-08-01T23:59:59.000Z

52

A Thermoelastic Hydraulic Fracture Design Tool for Geothermal Reservoir Development  

DOE Green Energy (OSTI)

Geothermal energy is recovered by circulating water through heat exchange areas within a hot rock mass. Geothermal reservoir rock masses generally consist of igneous and metamorphic rocks that have low matrix permeability. Therefore, cracks and fractures play a significant role in extraction of geothermal energy by providing the major pathways for fluid flow and heat exchange. Thus, knowledge of conditions leading to formation of fractures and fracture networks is of paramount importance. Furthermore, in the absence of natural fractures or adequate connectivity, artificial fracture are created in the reservoir using hydraulic fracturing. At times, the practice aims to create a number of parallel fractures connecting a pair of wells. Multiple fractures are preferred because of the large size necessary when using only a single fracture. Although the basic idea is rather simple, hydraulic fracturing is a complex process involving interactions of high pressure fluid injections with a stressed hot rock mass, mechanical interaction of induced fractures with existing natural fractures, and the spatial and temporal variations of in-situ stress. As a result it is necessary to develop tools that can be used to study these interactions as an integral part of a comprehensive approach to geothermal reservoir development, particularly enhanced geothermal systems. In response to this need we have set out to develop advanced thermo-mechanical models for design of artificial fractures and rock fracture research in geothermal reservoirs. These models consider the significant hydraulic and thermo-mechanical processes and their interaction with the in-situ stress state. Wellbore failure and fracture initiation is studied using a model that fully couples poro-mechanical and thermo-mechanical effects. The fracture propagation model is based on a complex variable and regular displacement discontinuity formulations. In the complex variable approach the displacement discontinuities are defined from the numerical solution of a complex hypersingular integral equation written for a given fracture configuration and loading. The fracture propagation studies include modeling interaction of induced fractures with existing discontinuities such as faults and joints. In addition to the fracture propagation studies, two- and three-dimensional heat extraction solution algorithms have been developed and used to estimate heat extraction and the variations of the reservoir stress with cooling. The numerical models have been developed in a user-friendly environment to create a tool for improving fracture design and investigating single or multiple fracture propagation in rock.

Ahmad Ghassemi

2003-06-30T23:59:59.000Z

53

Data quality enhancement in oil reservoir operations : an application of IPMAP  

E-Print Network (OSTI)

This thesis presents a study of data quality enhancement opportunities in upstream oil and gas industry. Information Product MAP (IPMAP) methodology is used in reservoir pressure and reservoir simulation data, to propose ...

Lin, Paul Hong-Yi

2012-01-01T23:59:59.000Z

54

Comparing non-adequate test suites using coverage criteria  

Science Conference Proceedings (OSTI)

A fundamental question in software testing research is how to compare test suites, often as a means for comparing test-generation techniques. Researchers frequently compare test suites by measuring their coverage. A coverage criterion C provides a set ... Keywords: Coverage criteria, non-adequate test suites

Milos Gligoric, Alex Groce, Chaoqiang Zhang, Rohan Sharma, Mohammad Amin Alipour, Darko Marinov

2013-07-01T23:59:59.000Z

55

Status of Wheeler Reservoir  

DOE Green Energy (OSTI)

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.

Not Available

1990-09-01T23:59:59.000Z

56

Status of Cherokee Reservoir  

DOE Green Energy (OSTI)

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.

Not Available

1990-08-01T23:59:59.000Z

57

Feasibility of optimizing recovery and reserves from a mature and geological complex multiple turbidite offshore California reservoir through the drilling and completion of a trilateral horizontal well. Annual report, September 1, 1995--December 31, 1996  

Science Conference Proceedings (OSTI)

The main objective of this project is to devise an effective re-development strategy to combat producibility problems related to the Repetto turbidite sequences of the Carpinteria Field. The lack of adequate reservoir characterization, high-water cut production, and scaling problems have in the past contributed to the field`s low productivity. To improve productivity and enhance recoverable reserves, the following specific goals were proposed: develop an integrated database of all existing data from work done by the former ownership group; expand reservoir drainage and reduce sand problems through horizontal well drilling and completion; operate and validate reservoir`s conceptual model by incorporating new data from the proposed trilateral well; and transfer methodologies employed in geologic modeling and drilling multilateral wells to other operators with similar reservoirs. A computer based data retrieval system was developed to convert hard copy documents containing production, well completion and well log data into easily accessible on-line format. To ascertain the geological framework of the reservoir, a thorough geological modeling and subsurface mapping of the Carpinteria field was developed. The model is now used to examine the continuity of the sands, characteristics of the sub-zones, nature of water influx and transition intervals in individual major sands. The geological model was then supplemented with a reservoir engineering study of spatial distribution of voidage in individual layers using the production statistics and pressure surveys. Efforts are continuing in selection of optimal location for drilling and completion of probing wells to obtain new data about reservoir pressure, in-situ saturation and merits of drilling a series of horizontal wells.

Coombs, S.; Edwards, E.; Fleckenstein, W.; Ershaghi, I.; Sobbi, F.; Coombs, S.

1998-07-01T23:59:59.000Z

58

Pressure transient method for front tracking  

DOE Green Energy (OSTI)

A pressure transient technique for tracking the advance of cold water fronts during water flooding and goethermal injection operations has been developed. The technique is based on the concept that the steady state pressure buildup in the reservoir region inside the front can be calculated by a fluid skin factor. By analyzing successive pressure falloff tests, the advance of the front in the reservoir can be monitored. The validity of the methods is demonstrated by application to three numerically simulated data sets, a nonisothermal step-rate injection test, a series of pressure falloffs in a multilayered reservoir, and a series of pressure falloff tests in a water flooded oil reservoir.

Benson, S.M.; Bodvarsson, G.S.

1983-08-01T23:59:59.000Z

59

Decline curve derivative analysis for homogeneous and composite reservoirs  

DOE Green Energy (OSTI)

In this study, the rate decline and rate decline derivatives of a constant pressure well are presented for infinite, constant pressure outer boundary, and closed outer boundary homogeneous reservoirs. A rate derivative type curve is provided for these cases as well. The effects of the dimensionless reservoir exterior radius are discussed. Rate decline and rate decline derivatives of a constant pressure well in an infinite composite reservoir are also presented. For composite reservoirs, the effects of mobility ratios and discontinuity distance on both rate decline and rate decline derivatives are presented. Type curves for dimensionless wellbore flow rate derivatives for infinite composite reservoirs are provided. A new correlating group for the derivative type curve is provided, and is different than the correlating group for the rate type curve presented in the past. Finally, an analysis method that comprises type curve and derivative type curve matching to determine the dimensionless variables is proposed and demonstrated with a simulated example.

Demski, J.A.

1987-06-01T23:59:59.000Z

60

Field Demonstration of Horizontal Infill Drilling Using Cost-effective Integrated Reservoir Modeling--Mississippian Carbonates, Central Kansas  

Science Conference Proceedings (OSTI)

Mississippian carbonate reservoirs have produced in excess of 1 billion barrels of oil in Kansas accounting for over 16% of the state's production. With declining production from other age reservoirs, the contribution of Mississippian reservoirs to Kansas's oil production has risen to 43% as of 2004. However, solution-enhanced features such as vertical shale intervals extending from the karst erosional surface at the top introduce complexities/compartmentalizations in Mississippian carbonate reservoirs. Coupled with this, strong water drives charge many of these reservoirs resulting in limited drainage from vertical wells due to high water cuts after an initial period of low water production. Moreover, most of these fields are operated by small independent operators without access to the knowledge bank of modern research in field characterization and exploitation/development practices. Thus, despite increasing importance of Mississippian fields to Kansas production, these fields are beset with low recovery factors and high abandonment rates leaving significant resources in the ground. Worldwide, horizontal infill wells have been successful in draining compartmentalized reservoirs with limited pressure depletion. The intent of this project was to demonstrate the application of horizontal wells to successfully exploit the remaining potential in mature Mississippian fields of the mid-continent. However, it is of critical importance that for horizontal wells to be economically successful, they must be selectively targeted. This project demonstrated the application of initial and secondary screening methods, based on publicly available data, to quickly shortlist fields in a target area for detailed studies to evaluate their potential to infill horizontal well applications. Advanced decline curve analyses were used to estimate missing well-level production data and to verify if the well produced under unchanging bottom-hole conditions--two commonly occurring data constraints afflicting mature Mississippian fields. A publicly accessible databank of representative petrophysical properties and relationships was developed to overcome the paucity of such data that is critical to modeling the storage and flow in these reservoirs. Studies in 3 Mississippian fields demonstrated that traditional reservoir models built by integrating log, core, DST, and production data from existing wells on 40-acre spacings are unable to delineate karst-induced compartments, thus making 3D-seismic data critical to characterize these fields. Special attribute analyses on 3D data were shown to delineate reservoir compartments and predict those with pay porosities. Further testing of these techniques is required to validate their applicability in other Mississippian reservoirs. This study shows that detailed reservoir characterization and simulation on geomodels developed by integrating wireline log, core, petrophysical, production and pressure, and 3D-seismic data enables better evaluation of a candidate field for horizontal infill applications. In addition to reservoir compartmentalization, two factors were found to control the economic viability of a horizontal infill well in a mature Mississippian field: (a) adequate reservoir pressure support, and (b) an average well spacing greater than 40-acres.

Saibal Bhattacharya

2005-08-31T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Determining the Adequate Level of Distributed Generation Penetration in  

NLE Websites -- All DOE Office Websites (Extended Search)

Determining the Adequate Level of Distributed Generation Penetration in Determining the Adequate Level of Distributed Generation Penetration in Future Grids Speaker(s): Johan Driesen Date: March 18, 2004 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Kristina LaCommare In this talk, Johan will discuss the technical barriers met while deploying distributed generation (DG) technology in the grid. These are related to voltage quality, reliability, stability of the grid, but also safety, environmental and economic issues are important. Eventually, the question 'how far can you go ?' is addressed. The range from small-scale local DG such as photovoltaics to large-scale (off-shore) wind farms are dealt with, each with their specific issues. The talk is illustrated with examples from research projects at the KULeuven financied by national and European

62

Hydrothermal Reservoirs | Open Energy Information  

Open Energy Info (EERE)

Hydrothermal Reservoirs Hydrothermal Reservoirs Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Hydrothermal Reservoirs Dictionary.png Hydrothermal Reservoir: Hydrothermal Reservoirs are underground zones of porous rock containing hot water and steam, and can be naturally occurring or human-made. Other definitions:Wikipedia Reegle Natural, shallow hydrothermal reservoirs naturally occurring hot water reservoirs, typically found at depths of less than 5 km below the Earth's surface where there is heat, water and a permeable material (permeability in rock formations results from fractures, joints, pores, etc.). Often, hydrothermal reservoirs have an overlying layer that bounds the reservoir and also serves as a thermal insulator, allowing greater heat retention. If hydrothermal reservoirs

63

Hot Dry Rock Geothermal Reservoir Testing- 1978 To 1980 | Open Energy  

Open Energy Info (EERE)

Dry Rock Geothermal Reservoir Testing- 1978 To 1980 Dry Rock Geothermal Reservoir Testing- 1978 To 1980 Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Hot Dry Rock Geothermal Reservoir Testing- 1978 To 1980 Details Activities (3) Areas (1) Regions (0) Abstract: The Phase I Hot Dry Rock Geothermal Energy reservoirs at the Fenton Hill field site grew continuously during Run Segments 2 through 5 (January 1978 to December 1980). Reservoir growth was caused not only by pressurization and hydraulic fracturing, but also by heat-extraction and thermal-contraction effects. Reservoir heat-transfer area grew from 8000 to 50,000 m2 and reservoir fracture volume grew from 11 to 266 m3. Despite this reservoir growth, the water loss rate increased only 30%, under similar pressure environments. For comparable temperature and pressure

64

Hot dry rock geothermal reservoir testing: 1978 to 1980  

DOE Green Energy (OSTI)

Experimental results and re-evaluation of the Phase I Hot Dry Rock Geothermal Energy reservoirs at the Fenton Hill field site are summarized. This report traces reservoir growth as demonstrated during Run Segments 2 through 5 (January 1978 to December 1980). Reservoir growth was caused not only by pressurization and hydraulic fracturing, but also by heat extraction and thermal contraction effects. Reservoir heat-transfer area grew from 8000 to 50,000 m/sup 2/ and reservoir fracture volume grew from 11 to 266 m/sup 3/. Despite this reservoir growth, the water loss rate increased only 30%, under similar pressure environments. For comparable temperature and pressure conditions, the flow impedance (a measure of the resistance to circulation of water through the reservoir) remained essentially unchanged, and if reproduced in the Phase II reservoir under development, could result in self pumping. Geochemical and seismic hazards have been nonexistent in the Phase I reservoirs. The produced water is relatively low in total dissolved solids and shows little tendency for corrosion or scaling. The largest microearthquake associated with heat extraction measures less than -1 on the extrapolated Richter scale.

Dash, Z.V.; Murphy, H.D.; Cremer, G.M. (eds.)

1981-11-01T23:59:59.000Z

65

Analysis of the Development of Messoyakha Gas Field: A Commercial Gas Hydrate Reservoir  

E-Print Network (OSTI)

Natural gas is an important energy source that contributes up to 25% of the total US energy reserves (DOE 2011). An increase in natural gas demand spurs further development of unconventional resources, including methane hydrate (Rajnauth 2012). Natural gas from methane hydrate has the potential to play a major role in ensuring adequate future energy supplies in the US. The worldwide volume of gas in the hydrate state has been estimated to be approximately 1.5 x 10^16 m^3 (Makogon 1984). More than 230 gas-hydrate deposits have been discovered globally. Several production technologies have been tested; however, the development of the Messoyakha field in the west Siberian basin is the only successful commercial gas-hydrate field to date. Although the presence of gas hydrates in the Messoyakha field was not a certainty, this current study determined the undeniable presence of gas hydrates in the reservoir. This study uses four models of the Messoyakha field structure and reservoir conditions and examines them based on the available geologic and engineering data. CMG STARS and IMEX software packages were used to calculate gas production from a hydrate-bearing formation on a field scale. Results of this analysis confirm the presence of gas hydrates in the Messoyakha field and also determine the volume of hydrates in place. The cumulative production from the field on January 1, 2012 is 12.9 x 10^9 m^3, and it was determined in this study that 5.4 x 10^9 m^3 was obtained from hydrates. The important issue of pressure-support mechanisms in developing a gas hydrate reservoir was also addressed in this study. Pressure-support mechanisms were investigated using different evaluation methods such as the use of gas-injection well patterns and gas/water injection using isothermal and non-isothermal simulators. Several aquifer models were examined. Simulation results showed that pressure support due to aquifer activity was not possible. Furthermore, it was shown that the water obtained from hydrates was not produced and remained in the reservoir. Results obtained from the aquifer models were confirmed by the actual water production from the field. It was shown that water from hydrates is a very strong pressure-support mechanism. Water not only remained in the reservoir, but it formed a thick water-saturated layer between the free-gas and gas-hydrate zone. Finally, thermodynamic behavior of gas hydrate decomposition was studied. Possible areas of hydrate preservation were determined. It was shown that the central top portion of the field preserved most of hydrates due to temperature reduction of hydrate decomposition.

Omelchenko, Roman 1987-

2012-12-01T23:59:59.000Z

66

Horizontal Well Placement Optimization in Gas Reservoirs Using Genetic Algorithms  

E-Print Network (OSTI)

Horizontal well placement determination within a reservoir is a significant and difficult step in the reservoir development process. Determining the optimal well location is a complex problem involving many factors including geological considerations, reservoir and fluid properties, economic costs, lateral direction, and technical ability. The most thorough approach to this problem is that of an exhaustive search, in which a simulation is run for every conceivable well position in the reservoir. Although thorough and accurate, this approach is typically not used in real world applications due to the time constraints from the excessive number of simulations. This project suggests the use of a genetic algorithm applied to the horizontal well placement problem in a gas reservoir to reduce the required number of simulations. This research aims to first determine if well placement optimization is even necessary in a gas reservoir, and if so, to determine the benefit of optimization. Performance of the genetic algorithm was analyzed through five different case scenarios, one involving a vertical well and four involving horizontal wells. The genetic algorithm approach is used to evaluate the effect of well placement in heterogeneous and anisotropic reservoirs on reservoir recovery. The wells are constrained by surface gas rate and bottom-hole pressure for each case. This project's main new contribution is its application of using genetic algorithms to study the effect of well placement optimization in gas reservoirs. Two fundamental questions have been answered in this research. First, does well placement in a gas reservoir affect the reservoir performance? If so, what is an efficient method to find the optimal well location based on reservoir performance? The research provides evidence that well placement optimization is an important criterion during the reservoir development phase of a horizontal-well project in gas reservoirs, but it is less significant to vertical wells in a homogeneous reservoir. It is also shown that genetic algorithms are an extremely efficient and robust tool to find the optimal location.

Gibbs, Trevor Howard

2010-05-01T23:59:59.000Z

67

Research to understand and predict geopressured reservoir characteristics with confidence  

DOE Green Energy (OSTI)

The Department of Energy's Geopressured Geothermal Program has sponsored a series of geoscience studies to resolve key uncertainties in the performance of geopressured reservoirs. The priority areas for research include improving the ability to predict reservoir size and flow capabilities, understanding the role of oil and gas in reservoir depletion and evaluating mechanisms for reservoir pressure maintenance. Long-term production from the Gladys McCall well has provided the basis for most of the current research efforts. The well was shut-in on October 29, 1987, for pressure recovery after producing over 27 million barrels of brine with associated gas. Geologic investigations are evaluating various mechanisms for pressure maintenance in this reservoir, including recharge from adjacent reservoirs or along growth faults, shale dewatering, and laterally overlapping and connected sandstone layers. Compaction studies using shale and sandstone core samples have provided data on the relationship between rock compression and reservoir pressure decline and the correlation to changes in porosity and permeability. The studies support the use of a porosity-coupled reservoir simulation model which has provided an excellent match to the well's production history. 10 refs., 3 figs.

Stiger, S.G.; Prestwich, S.M.

1988-01-01T23:59:59.000Z

68

Geothermal reservoir technology  

DOE Green Energy (OSTI)

A status report on Lawrence Berkeley Laboratory's Reservoir Technology projects under DOE's Hydrothermal Research Subprogram is presented. During FY 1985 significant accomplishments were made in developing and evaluating methods for (1) describing geothermal systems and processes; (2) predicting reservoir changes; (3) mapping faults and fractures; and (4) field data analysis. In addition, LBL assisted DOE in establishing the research needs of the geothermal industry in the area of Reservoir Technology. 15 refs., 5 figs.

Lippmann, M.J.

1985-09-01T23:59:59.000Z

69

Numerical simulation of water injection into vapor-dominated reservoirs  

DOE Green Energy (OSTI)

Water injection into vapor-dominated reservoirs is a means of condensate disposal, as well as a reservoir management tool for enhancing energy recovery and reservoir life. We review different approaches to modeling the complex fluid and heat flow processes during injection into vapor-dominated systems. Vapor pressure lowering, grid orientation effects, and physical dispersion of injection plumes from reservoir heterogeneity are important considerations for a realistic modeling of injection effects. An example of detailed three-dimensional modeling of injection experiments at The Geysers is given.

Pruess, K.

1995-01-01T23:59:59.000Z

70

The Ahuachapan geothermal field, El Salvador: Reservoir analysis  

DOE Green Energy (OSTI)

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)

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

1989-08-01T23:59:59.000Z

71

An Updated Conceptual Model Of The Los Humeros Geothermal Reservoir...  

Open Energy Info (EERE)

sea level (a.s.l.) the pressure profile of which corresponds to a 300-330C boiling water column and a deeper low-liquid-saturation reservoir located between 850 and 100 m...

72

Geothermal Reservoir Dynamics - TOUGHREACT  

E-Print Network (OSTI)

Swelling in a Fractured Geothermal Reservoir, presented atTHC) Modeling Based on Geothermal Field Data, Geothermics,and Silica Scaling in Geothermal Production-Injection Wells

2005-01-01T23:59:59.000Z

73

Numerical studies of gravity effects in two-phase reservoirs  

DOE Green Energy (OSTI)

Numerical studies are performed to investigate the effects of localized feed zones on the pressure transients in two-phase reservoirs. It is shown that gravity effects can significantly affect the pressure transients, because of the large difference in the density of liquid water and vapor. Pressure transients for shallow and deep feed zones and the resulting fluid flow patterns are discussed.

Bodvarsson, G.S.; Cox, B.L.

1986-06-01T23:59:59.000Z

74

Stanford Geothermal Program, reservoir and injection technology. Fourth annual report  

DOE Green Energy (OSTI)

This annual report of the Stanford Geothermal Program presents major projects in reservoir and injection technology. The four include: (1) an application of the boundary element method to front tracking and pressure transient testing; (2) determination of fracture aperture, a multi-tracer approach; (3) an analysis of tracer and thermal transients during reinjection; and, (4) pressure transient modeling of a non-uniformly fractured reservoir. (BN)

Horne, R.; Ramey, H.J. Jr.; Miller, F.G.; Brigham, W.E.; Kruger, P.

1988-12-01T23:59:59.000Z

75

HDR reservoir flow impedance and potentials for impedance reduction  

DOE Green Energy (OSTI)

The data from flow tests which employed two different production zones in a well at Fenton Hill indicates the flow impedance of a wellbore zone damaged by rapid depressurization was altered, possibly by pressure spallation, which appears to have mechanically propped the joint apertures of outlet flow paths intersecting the altered wellbore. The rapid depressurization and subsequent flow test data derived from the damaged well has led to the hypothesis that pressure spallation and the resultant mechanical propping of outlet flow paths reduced the outlet flow impedance of the damaged wellbore. Furthermore, transient pressure data shows the largest pressure drop between the injection and production wellheads occurs near the production wellbore, so lowering the outlet impedance by increasing the apertures of outlet flow paths will have the greatest effect on reducing the overall reservoir impedance. Fenton Hill data also reveals that increasing the overall reservoir pressure dilates the apertures of flow paths, which likewise serves to reduce the reservoir impedance. Data suggests that either pressure dilating the wellbore connected joints with high production wellhead pressure, or mechanically propping open the outlet flow paths will increase the near-wellbore permeability. Finally, a new method for calculating and comparing near-wellbore outlet impedances has been developed. Further modeling, experimentation, and engineered reservoir modifications, such as pressure dilation and mechanical propping, hold considerable potential for significantly improving the productivity of HDR reservoirs.

DuTeau, R.; Brown, D.

1993-06-01T23:59:59.000Z

76

HDR reservoir flow impedance and potentials for impedance reduction  

DOE Green Energy (OSTI)

The data from flow tests which employed two different production zones in a well at Fenton Hill indicates the flow impedance of a wellbore zone damaged by rapid depressurization was altered, possibly by pressure spallation, which appears to have mechanically propped the joint apertures of outlet flow paths intersecting the altered wellbore. The rapid depressurization and subsequent flow test data derived from the damaged well has led to the hypothesis that pressure spallation and the resultant mechanical propping of outlet flow paths reduced the outlet flow impedance of the damaged wellbore. Furthermore, transient pressure data shows the largest pressure drop between the injection and production wellheads occurs near the production wellbore, so lowering the outlet impedance by increasing the apertures of outlet flow paths will have the greatest effect on reducing the overall reservoir impedance. Fenton Hill data also reveals that increasing the overall reservoir pressure dilates the apertures of flow paths, which likewise serves to reduce the reservoir impedance. Data suggests that either pressure dilating the wellbore connected joints with high production wellhead pressure, or mechanically propping open the outlet flow paths will increase the near-wellbore permeability. Finally, a new method for calculating and comparing near-wellbore outlet impedances has been developed. Further modeling, experimentation, and engineered reservoir modifications, such as pressure dilation and mechanical propping, hold considerable potential for significantly improving the productivity of HDR reservoirs.

DuTeau, R.; Brown, D.

1993-01-01T23:59:59.000Z

77

Geysers reservoir studies  

DOE Green Energy (OSTI)

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.

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

1993-04-01T23:59:59.000Z

78

Structural Reliability: Assessing the Condition and Reliability of Casing in Compacting Reservoirs  

E-Print Network (OSTI)

Casing has a higher risk of failure in a compacting reservoir than in a typical reservoir. Casing fails when reservoir compaction induces compression and shear stresses onto it. They compact as reservoir pressure depletes during production. High compaction reservoirs typically are composed of unconsolidated, overpressured rocks such as chalk, diatomite, and sandstone. Pore pressure depletion increases effective stress, which is the rock matrix stress pushing upward against overburden pressure. Effective stress may exceed rock compressive strength, inducing compaction. Wells in compacting reservoirs risk high failure and deformation rates. This project introduces the concept of structural reliability to quantify casing failure risks in compacting reservoirs. This research developed probabilistic models for casing capacities using current design methods and a reservoir compaction load using finite-element model simulations. Probabilistic models were used in creating two limit-states functions to predict casing failure: axial yielding and buckling failures. A limit-state function describes the casing condition as the casing experiences a reservoir compaction load. The limit state function is the input in component and system analyses for casing fragility and conditional probability of casing failure. Fragilities can predict casing probability of failure as reservoir pressure is depleting. Sensitivity and importance analyses are also performed to determine the importance of parameters affecting the casing reliability. Applying the knowledge produced from this research to casing design methods can improve design reliabilities and forecast the risk of casing failure in compacting reservoirs.

Chantose, Prasongsit

2011-12-01T23:59:59.000Z

79

ENSURING ADEQUATE SAFETY WHEN USING HYDROGEN AS A FUEL  

DOE Green Energy (OSTI)

Demonstration projects using hydrogen as a fuel are becoming very common. Often these projects rely on project-specific risk evaluations to support project safety decisions. This is necessary because regulations, codes, and standards (hereafter referred to as standards) are just being developed. This paper will review some of the approaches being used in these evolving standards, and techniques which demonstration projects can implement to bridge the gap between current requirements and stakeholder desires. Many of the evolving standards for hydrogen-fuel use performance-based language, which establishes minimum performance and safety objectives, as compared with prescriptive-based language that prescribes specific design solutions. This is being done for several reasons including: (1) concern that establishing specific design solutions too early will stifle invention, (2) sparse performance data necessary to support selection of design approaches, and (3) a risk-adverse public which is unwilling to accept losses that were incurred in developing previous prescriptive design standards. The evolving standards often contain words such as: ''The manufacturer shall implement the measures and provide the information necessary to minimize the risk of endangering a person's safety or health''. This typically implies that the manufacturer or project manager must produce and document an acceptable level of risk. If accomplished using comprehensive and systematic process the demonstration project risk assessment can ease the transition to widespread commercialization. An approach to adequately evaluate and document the safety risk will be presented.

Coutts, D

2007-01-22T23:59:59.000Z

80

Prediction of reservoir compaction and surface subsidence  

SciTech Connect

A new loading-rate-dependent compaction model for unconsolidated clastic reservoirs is presented that considerably improves the accuracy of predicting reservoir rock compaction and surface subsidence resulting from pressure depletion in oil and gas fields. The model has been developed on the basis of extensive laboratory studies and can be derived from a theory relating compaction to time-dependent intergranular friction. The procedure for calculating reservoir compaction from laboratory measurements with the new model is outlined. Both field and laboratory compaction behaviors appear to be described by one single normalized, nonlinear compaction curve. With the new model, the large discrepancies usually observed between predictions based on linear compaction models and actual (nonlinear) field behavior can be explained.

De Waal, J.A.; Smits, R.M.M.

1988-06-01T23:59:59.000Z

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81

Shale Reservoir Characterization | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Oil & Gas » Shale Gas » Shale Reservoir Oil & Gas » Shale Gas » Shale Reservoir Characterization Shale Reservoir Characterization Geologist examining the base of the Marcellus Shale at an outcrop near Bedford, PA. Geologist examining the base of the Marcellus Shale at an outcrop near Bedford, PA. Gas-producing shales are predominantly composed of consolidated clay-sized particles with a high organic content. High subsurface pressures and temperatures convert the organic matter to oil and gas, which may migrate to conventional petroleum traps and also remains within the shale. However, the clay content severely limits gas and fluid flow within the shales. It is, therefore, necessary to understand the mineral and organic content, occurrence of natural fractures, thermal maturity, shale volumes, porosity

82

Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report  

SciTech Connect

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.

Kelkar, M.

1995-02-01T23:59:59.000Z

83

Reservoir Protection (Oklahoma)  

Energy.gov (U.S. Department of Energy (DOE))

The Oklahoma Water Resource Board has the authority to make rules for the control of sanitation on all property located within any reservoir or drainage basin. The Board works with the Department...

84

Geology and Reservoir Simulation  

NLE Websites -- All DOE Office Websites (Extended Search)

Service: 1-800-553-7681 Geology and Reservoir Simulation Background Natural gas from shale is becoming ever more recognized as an abundant and economically viable fuel in the...

85

Gas network model allows full reservoir coupling  

Science Conference Proceedings (OSTI)

The gas-network flow model (Gasnet) developed for and added to an existing Qatar General Petroleum Corp. (OGPC) in-house reservoir simulator, allows improved modeling of the interaction among the reservoir, wells, and pipeline networks. Gasnet is a three-phase model that is modified to handle gas-condensate systems. The numerical solution is based on a control volume scheme that uses the concept of cells and junctions, whereby pressure and phase densities are defined in cells, while phase flows are defined at junction links. The model features common numerical equations for the reservoir, the well, and the pipeline components and an efficient state-variable solution method in which all primary variables including phase flows are solved directly. Both steady-state and transient flow events can be simulated with the same tool. Three test cases show how the model runs. One case simulates flow redistribution in a simple two-branch gas network. The second simulates a horizontal gas well in a waterflooded gas reservoir. The third involves an export gas pipeline coupled to a producing reservoir.

Methnani, M.M. [Qatar General Petroleum Corp., Doha (Qatar)

1998-02-23T23:59:59.000Z

86

Session: Reservoir Technology  

DOE Green Energy (OSTI)

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

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

1992-01-01T23:59:59.000Z

87

Physical processes of subsidence in geothermal reservoirs  

DOE Green Energy (OSTI)

The objectives of this project were to acquire core and fluid from producing geothermal reservoirs (East Mesa, United States, and Cerro Prieto, Mexico); to test specimens of this core for their short-term and long-term (creep) compaction response; and to develop a compaction constitutive model that would allow future analysis of reservoir compaction and a surface subsidence. A total of approximately two hundred feet of core was obtained from eleven wells in the two geothermal fields. Depths and porosities ranged from 3500 to 11,000 feet and 15 to 40 percent, respectively. Several samples of geothermal fluids were also obtained. After geologically and geochemically describing the materials obtained, selected specimens were tested for their response to the pressures and temperatures of the geothermal environment and to simulated changes in those conditions that would be caused by production. Short-term tests (for example, tests for compressibility extending over a time interval of an hour or less in the laboratory) indicated that these sedimentary materials behaved normally with respect to the expected behavior of reservoir sandstones of these depths and porosities. Compressibilities were of the order 1 x 10/sup 6/ psi. Long-term tests, extending up to several weeks in duration, indicated that pore pressure reduction, simulating reservoir production, tended to cause creep compaction at an initial rate of about 1 x 10/sup -7/ percent porosity reduction per second.

Schatz, J.F.

1982-06-01T23:59:59.000Z

88

Method of using in situ porosity measurements to place an upper bound on geothermal reservoir compaction  

DOE Green Energy (OSTI)

Placing an upper bound on reservoir compaction requires placing a lower bound on the reservoir effective compaction modulus. Porosity-depth data can be used to find that lower-bound modulus in a young sedimentary basin. Well-log and sample porosity data from a geothermal field in the Imperial Valley, CA, give a lower-bound modulus of 7.7 x 10{sup 3} psi. This modulus is used with pressure drops calculated for a reservoir to determine an upper bound on reservoir compaction. The effects of partial reinjection and aquifer leakage on upper-bound subsidence estimated from the compaction are illustrated for a hypothetical reservoir and well array.

Schatz, J.F.; Kasameyer, P.W.; Cheney, J.A.

1979-01-03T23:59:59.000Z

89

GEOTHERMAL RESERVOIR SIMULATIONS WITH SHAFT79  

E-Print Network (OSTI)

that well blocks must geothermal reservoir s·tudies, paperof Califomia. LBL-10066 GEOTHERMAL RESERVOIR SIMULATIONSbe presented at the Fifth Geothermal Reservoir Engineering

Pruess, Karsten

2012-01-01T23:59:59.000Z

90

REAL-TIME TRACER MONITORING OF RESERVOIR STIMULATION PROCEDURES  

SciTech Connect

Ongoing Phase 2 work comprises the development and field-testing of a real-time reservoir stimulation diagnostic system. Phase 3 work commenced in June 2001, and involved conducting research, development and field-testing of real-time enhanced dual-fluid stimulation processes. Experimental field-testing to date includes three well tests. Application of these real-time stimulation processes and diagnostic technologies has been technically successful with commercial production from the ''marginal'' reservoirs in the first two well tests. The third well test proved downhole-mixing is an efficient process for acid stimulation of a carbonate reservoir that produced oil and gas with 2200 psi bottomhole reservoir pressure, however, subsequent shut-in pressure testing indicated the reservoir was characterized by low-permeability. Realtimezone continues to seek patent protection in foreign markets to the benefit of both RTZ and NETL. Realtimezone and the NETL have licensed the United States patented to Halliburton Energy Services (HES). Ongoing Phase 2 and Phase 3 field-testing continues to confirm applications of both real-time technologies, from well testing conducted over the last 12-month work period and including well test scheduled for year-end of 2002. Technical data transfer to industry is ongoing via Internet tech-transfer, public presentations and industry publications. Final Phase 3 test work will be focused on further field-testing the innovational process of blending stimulation fluids downhole. This system provides a number of advantages in comparison to older industry fracturing techniques and allows the operator to control reservoir fracture propagation and concentrations of proppant placed in the reservoir, in real-time. Another observed advantage is that lower friction pressures result, which results in lower pump treating pressures and safer reservoir hydraulic fracturing jobs.

George Scott III

2002-08-01T23:59:59.000Z

91

Modeling of reservoir compaction and surface subsidence at South Belridge  

SciTech Connect

Finite-element models of depletion-induced reservoir compaction and surface subsidence have been calibrated with observed subsidence, locations of surface fissures, and regions of subsurface casing damage at South Belridge and used predictively for the evaluation of alternative reservoir-development plans. Pressure maintenance through diatomite waterflooding appears to be a beneficial means of minimizing additional subsidence and fissuring as well as reducing axial-compressive-type casing damage.

Hansen, K.S. [Shell Western E and P Inc., Houston, TX (United States); Chan, C.K. [Shell Oil Co., Houston, TX (United States); Prats, M.

1995-08-01T23:59:59.000Z

92

Feasibility of waterflooding Soku E7000 gas-condensate reservoir  

E-Print Network (OSTI)

We performed a simple 3D compositional reservoir simulation study to examine the possibility of waterflooding the Soku E7 gas-condensate reservoir. This study shows that water injection results in higher condensate recovery than natural depletion. To achieve this recovery, the reservoir should return to natural depletion after four years of water injection, before water invades the producing wells. Factors that affect the effectiveness of water injection in this reservoir include aquifer strength, reservoir property distribution, timing of the start of injection, and intra-reservoir shale thickness and continuity. Sensitivity analyses used to quantify the effects of these factors on condensate recovery indicate the need to acquire more production, pressure and log data to reduce the present large uncertainty on aquifer strength before proceeding on waterflooding this reservoir. The study also shows that the injection scheme should be implemented as soon as possible to avoid further loss of condensate recovery. The result of this study is applicable to other gas condensate reservoirs in the Niger delta with similar depositional environments.

Ajayi, Arashi

2002-01-01T23:59:59.000Z

93

Real natural gas reservoir data Vs. natural gas reservoir models  

Science Conference Proceedings (OSTI)

The gas reservoir per se model is an exceedingly simple model of a natural gas reservoir designed to develop the physical relationship between ultimate recovery and rate(s) of withdrawal for production regulation policy assessment. To be responsive, ...

Ellis A. Monash; John Lohrenz

1979-03-01T23:59:59.000Z

94

Evolution of the Cerro Prieto reservoirs under exploitation  

DOE Green Energy (OSTI)

The Cerro Prieto Geothermal field of Baja California (Mexico) has been under commercial production to generate electricity since 1973. Over the years, the large amount of Geothermal fluids extracted (at present about 12,000 tons per hour) to supply steam to the power plants has resulted in a reduction of pressures, changes in reservoir processes, and increased flow of cooler groundwater into the geothermal system. The groundwater recharging the reservoir moves horizontally through permeable layers, as well as vertically through permeable fault zones. In addition, the supply of deep hot waters has continued unabated, and perhaps has increased as reservoir pressure decreased. Since 1989, this natural fluid recharge has been supplemented by injection which presently amounts to about 20% of the fluid produced. Changes in the chemical and physical characteristics of the reservoir fluids due to the drop in pressures and the inflow of cooler groundwaters and injectate have been detected on the basis of wellhead data. These changes point to reservoir processes like local boiling, phase segregation, steam condensation, mixing and dilution. Finally, the study identified areas where fluids are entering the reservoir, as well as indicated their source (i.e. natural Groundwater recharge versus injectate) and established the controlling geologic structures.

Truesdell, A.H.; Lippmann, M.J. [Lawrence Berkeley National Lab., CA (United States); Puente, H.G. [Comision Federal de Electricidad, Mexicali (Mexico)

1997-07-01T23:59:59.000Z

95

Study of Water Reinjection on the Kamojang Geothermal Reservoir Performance, Indonesia  

DOE Green Energy (OSTI)

A reservoir simulation model study was developed to investigate effects of water reinjection into the performance of Kamojang geothermal field. Several cases including the existing injection wells and rates, the effect of injection rates, location and depth of proposed injection wells were run to study the temperature, pressure and fluid distribution in the reservoir and its effect into the reservoir and production performance for 30 years of prediction. The results show that the reservoir pressure and temperature drops are very small (4 bar and 5 C, respectively) at the end of the prediction time; therefore, the production target of 140 MW for 30 years can still be accomplished.

Darwis, R.S.; Tampubolon, T.; Simatupang, R.; Asdassah, D.

1995-01-01T23:59:59.000Z

96

Analysis of reservoir performance and forecasting for the eastern area of the C-2 Reservoir, Lake Maracaibo, Venezuela  

E-Print Network (OSTI)

This research developed a numerical simulation based on the latest reservoir description to evaluate the feasibility of new infill wells to maximize the recovery specifically in the eastern region of the reservoir operated by Petroleos de Venezuela S.A. (PDVSA). This research provides a full-field numerical simulation that predicts performance and aids in planning future development with infill wells for a reservoir located at the south of Block V, Lamar in Lake Maracaibo. The simulation is especially promising for the eastern region, which has the current highest oil production behavior. The final model achieved an acceptable history match for pressure and fluids for the entire reservoir, especially for the eastern area. On the basis of this model and an opportunity index, the best six infill wells should be located in the eastern area of the reservoir, which would increased the cumulated production in 44.5 MMSTB. This work is important because it provides the first numerical simulation for the entire reservoir that considers the new geological model developed during reservoir description. Furthermore, it provides PDVSA with a powerful tool for planning and reservoir management decisions, especially in the eastern area of the reservoir. Predictions resulting from this area show an important increment in the final reservoir recovery over the base case, production depletion under current conditions without any change. On the basis of these results, I strongly recommend starting a new infill drilling campaign in the eastern area as indicated by the simulation results to increase the oil rate reservoir productions and to improve total ultimate recovery.

Urdaneta Anez, Jackeline C

2001-01-01T23:59:59.000Z

97

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

Science Conference Proceedings (OSTI)

Advanced reservoir characterization techniques are being used at the Nash Draw Brushy Canyon Pool project to develop reservoir management strategies for optimizing oil recovery from this Delaware reservoir. The reservoir characterization, geologic modeling, 3-D seismic interpretation, and simulation studies have provided a detailed model of the Brushy Canyon zones. This model was used to predict the success of different reservoir management scenarios and to aid in determining the most favorable combination of targeted drilling, pressure maintenance, well stimulation, and well spacing to improve recovery from this reservoir.

Murphy, M.B.

1999-02-01T23:59:59.000Z

98

A critical evaluation of the deviation time method to calculate discontinuity radias from well tests in composite reservoirs  

SciTech Connect

Reservoirs with a fluid bank, or a burning front, reservoirs with a reduced or an increased permeability region around the wellbore, and geothermal reservoirs are often modeled as composite reservoirs. Reservoirs with a fluid bank include reservoirs undergoing waterflood, chemical flood, polymer flood, CO/sub 2/ flood, and steam injection. Eight well tests reported in the literature exhibiting composite reservoir behavior have been analyzed using the deviation time method. The dimensionless deviation times obtained from pressure and pressure derivative responses for a well in a composite reservoir are used for analyzing the well tests. Analysis shows the estimate of discontinuity radius to be sensitive to both the real and the dimensionless deviation times used. The estimate discontinuity radius from the deviation time method may represent a lower bound for discontinuity radius, if the swept region is not cylindrical. Also, obtaining an accurate deviation time for small mobility contrasts may be difficult.

Ambastha, A.K.; Ramey, H.J., Jr. (Stanford Univ., CA (USA))

1988-01-01T23:59:59.000Z

99

Reservoir Fracturing in the Geysers Hydrothermal System: Fact or Fallacy?  

DOE Green Energy (OSTI)

Proper application of proven worldwide fracture determination analyses adequately aids in the detection and enhanced exploitation of reservoir fractures in The Geysers steam field. Obsolete, superficial ideas concerning fracturing in this resource have guided various malformed judgements of the actual elusive trends. Utilizing regional/local tectonics with theoretical rack mechanics and drilling statistics, offers the most favorable method of fracture comprehension. Exploitation philosophies should favor lateral drilling trends along local tensional components and under specific profound drainage/faulting manifestations to enhance high productivities. Drill core observations demonstrate various degrees of fracture filling, brecciation, strain responses, and rock fracture properties, giving the most favorable impression of subsurface reservoir conditions. Considerably more work utilizing current fracturing principles and geologic thought is required to adequately comprehend and economically exploit this huge complex resource.

Hebein, Jeffrey J.

1986-01-21T23:59:59.000Z

100

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

SciTech Connect

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

Howrie, I.; Dauben, D.

1994-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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We encourage you to perform a real-time search of NLEBeta
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101

Reservoir response to tidal and barometric effects | Open Energy  

Open Energy Info (EERE)

to tidal and barometric effects to tidal and barometric effects Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Reservoir response to tidal and barometric effects Details Activities (2) Areas (2) Regions (0) Abstract: Solid earth tidal strain and surface loading due to fluctuations in barometric pressure have the effect, although extremely minute, of dilating or contracting the effective pore volume in a porous reservoir. If a well intersects the formation, the change in pore pressure can be measured with sensitive quartz pressure gauges. Mathematical models of the relevant fluid dynamics of the well-reservoir system have been generated and tested against conventional well pumping results or core data at the Salton Sea Geothermal Field (SSGF), California and at the Raft River,

102

Fracture network modeling of a Hot Dry Rock geothermal reservoir  

DOE Green Energy (OSTI)

Fluid flow and tracer transport in a fractured Hot Dry Rock (HDR) geothermal reservoir are modeled using fracture network modeling techniques. The steady state pressure and flow fields are solved for a two-dimensional, interconnected network of fractures with no-flow outer boundaries and constant-pressure source and sink points to simulate wellbore-fracture intersections. The tracer response is simulated by particle tracking, which follows the progress of a representative sample of individual tracer molecules traveling through the network. Solute retardation due to matrix diffusion and sorption is handled easily with these particle tracking methods. Matrix diffusion is shown to have an important effect in many fractured geothermal reservoirs, including those in crystalline formations of relatively low matrix porosity. Pressure drop and tracer behavior are matched for a fractured HDR reservoir tested at Fenton Hill, NM.

Robinson, B.A.

1988-01-01T23:59:59.000Z

103

Measurement requirements and methods for geothermal reservoir system parameters: an appraisal  

DOE Green Energy (OSTI)

One of the key needs in the advancement of geothermal energy is the availability of adequate measurements to aid the reservoir and production engineer in the development and operation of geothermal reservoirs, wells and the overall process plant. This report documents the geothermal parameters and their measurement requirements and provides an appraisal of measurement methods and instruments capable of meeting the requirements together with recommendations on identified deficiencies.

Lamers, M.D.

1979-08-01T23:59:59.000Z

104

Well Productivity in Gas-Condensate and Volatile Oil Reservoirs:  

E-Print Network (OSTI)

Wells in gas condensate reservoirs usually exhibit complex behaviours due to condensate deposit as the bottomhole pressure drops below the dew point. The formation of this liquid saturation can lead to a severe loss of well productivity and therefore lower gas recovery. A similar behaviour is observed in volatile oil reservoirs below the bubble point. Understanding these behaviours and extracting values of controlling parameters is necessary to evaluate well potential and design effective programmes to improve productivity. The Centre of Petroleum Studies at Imperial College London has been involved in research in these areas since 1997, sponsored mainly by consortia of oil companies. Results from this work have already greatly improved the understanding of well behaviour in gas condensate and volatile oil reservoirs and the ability to interpret well tests in such reservoirs. Work to-date has focused on vertical and horizontal wells in sandstone reservoirs. Much work remains to understand the behaviours of fractured wells and wells in naturally fractured reservoirs. The objective of this proposal is to complete the work performed to-date in sandstone reservoirs and to extend it to new well and reservoir characteristics, in order to develop a better understanding of near-wellbore effects in gas condensate and volatile oil reservoirs from well testing, and to use this understanding to develop new methods for predicting and improving well productivity in such reservoirs. The work will be performed by staff, MSc and PhD students from the Centre for Petroleum Studies at Imperial College, with input and guidance from industry partners.

Prof A. C. Gringarten

2004-01-01T23:59:59.000Z

105

Rock compressibility, compaction, and subsidence in a high-porosity Chalk Reservoir  

SciTech Connect

A case study of the North Sea Valhall chalk reservoir demonstrates the significant impact that rock compressibility can have on field performance. Porosity reduction, reservoir interval compaction, and seabed subsidence have been observed in conjunction with reservoir pressure depletion. Full-diameter samples from a recently cut core of the unconsolidated high-porosity chalk were subjected to a series of uniaxial-strain experiments to determine compaction and PV compressibility. The laboratory measurements were corrected to field stress rates and pressure, and porosity-dependent rock-compressibility curves were developed. The uniaxial compaction data were used both in a reservoir model to recognize the significant additional reservoir energy resulting from the lithic drive of large-scale rock compaction and in a subsidence model to predict the impact of reservoir depletion on seabed displacements.

Ruddy, I. (Amoco Norway Oil Co. (US)); Andersen, M.A.; Pattillo, P.D.; Bishiawi, M. (Amoco Production Co., Tulsa, OK (USA)); Foged, N. (Danish Geotechnical Inst. (US))

1989-07-01T23:59:59.000Z

106

History match simulation of Serrazzano geothermal reservoir  

DOE Green Energy (OSTI)

The simulator SHAFT79 of Lawrence Berkeley Laboratory has been applied to field-wide distributed parameter simulation of the vapor-dominated geothermal reservoir at Serrazzano, Italy. Using a three-dimensional geologically accurate mesh and detailed flow rate data from 19 producing wells, a period of 15.5 years (from 1959 to 1975) has been simulated. The reservoir model used is based on field measurements of temperatures and pressures, laboratory data for core samples, and available geological and hydrological information. The main parameters determined (adjusted) during development of the simulation are permeabilities and much of the initial conditions. Simulated patterns of pressure decline show semi-quantitative agreement with field observations. The simulation suggests that there is cold water recharge and/or incomplete heat transfer from he rock due to fractures in the margins of the reservoir, and some steam flowing to the main well field originates from deep fractures rather than from boiling in the two-phase zones modeled. Simulation methodology and ambiguity of parameter determination is discussed.

Pruess, K.; Weres, O.; Schroeder, R.; Marconcini, R.; Neri, G.

1980-08-01T23:59:59.000Z

107

Guntong field: Development and management of a multiple-reservoir offshore waterflood  

SciTech Connect

The Guntong field, the largest waterflood field in offshore peninsular Malaysia, with an oil-in-place (OIP) of about 200 million m{sup 3}, has been producing since 1985. The field contains 13 stacked reservoirs with small gas caps and limited aquifer support. This paper describes some of the significant reservoir, geologic, and facility challenges faced during development and management of this complex reservoir system. A combination of five-spot and peripheral waterflood patterns was selected to provide the required areal coverage, and reservoirs were commingled into two operational groups. Key reservoir management strategies to maximize performance include determination of optimum target reservoir pressures, use of a PC-based program to guide production and injection targets, and meeting pattern-balancing and capacity-enhancement programs. The response to the reservoir management efforts has been favorable, with an all-time-high production rate of 14,000 m{sup 3}/d recorded in 1994.

Chik, A.N.; Selamat, S.; Elias, M.R.; White, J.P.; Wakatake, M.T.

1996-12-01T23:59:59.000Z

108

Reservoir studies of the Seltjarnarnes geothermal field, Iceland  

DOE Green Energy (OSTI)

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.

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

1986-10-01T23:59:59.000Z

109

Determining the 3-D fracture structure in the Geysers geothermal reservoir  

DOE Green Energy (OSTI)

The bulk of the steam at the Geysers geothermal field is produced from fractures in a relatively impermeable graywacke massif which has been heated by an underlying felsite intrusion. The largest of these fractures are steeply dipping right lateral strike-slip faults which are subparallel to the NW striking Collayomi and Mercuryville faults which form the NE and SW boundaries of the known reservoir. Where the graywacke source rock outcrops at the surface it is highly sheared and fractured over a wide range of scale lengths. Boreholes drilled into the reservoir rock encounter distinct ''steam entries'' at which the well head pressure jumps from a few to more than one hundred psi. This observation that steam is produced from a relatively small number of major fractures has persuaded some analysts to use the Warren and Root (1963) dual porosity model for reservoir simulation purposes. The largest fractures in this model are arranged in a regular 3-D array which partitions the reservoir into cubic ''matrix'' blocks. The net storage and transport contribution of all the smaller fractures in the reservoir are lumped into average values for the porosity and permeability of these matrix blocks which then feed the large fractures. Recent improvements of this model largely focus on a more accurate representation of the transport from matrix to fractures (e.g. Pruess et al., 1983; Ziminerman et al., 1992), but the basic geometry is rarely questioned. However, it has long been recognized that steam entries often occur in clusters separated by large intervals of unproductive rock (Thomas et al., 1981). Such clustering of fixtures at all scale lengths is one characteristic of self-similar distributions in which the fracture distribution is scale-independent. Recent studies of the geometry of fracture networks both in the laboratory and in the field are finding that such patterns are self-similar and can be best described using fractal geometry. Theoretical simulations of fracture development in heterogeneous media also produce fractal patterns. However, a physical interpretation of the mechanics which produce the observed fractal geometry remains an active area of current research. Two hypotheses for the physical cause of self-similarity are the Laplacian growth of fractures in a self-organized critical stress field, and the evolution of percolation clusters in a random medium. Each predicts a different, fractal dimension. The more important questions from a reservoir engineering point of view are: (1) is the network of fractures in the Geysers reservoir fractal and if so over what range of fracture sizes is the self-similarity observed and what is its fractal dimension, and (2) do the conventional dual porosity numerical simulation schemes provide an adequate description of flow and heat mining at the Geysers? Other papers in this volume by Acuna, Ershaghi, and Yortsos (1992) and Mukhopodhyoy and Sahimi (1992) address the second question. The primary objective of this paper is to try to answer the first. Toward this goal we have mapped fracture patterns in surface exposures of the graywacke source rock at the outcrop scale (meters), at the road-cut scale (tens of meters) and at the regional scale (kilometers). We have also examined cores collected at depth from the graywacke reservoir rocks, and analyzed drilling logs making use of the pattern of steam entries as well as the fluctuations in drilling rate.

Sammis, Charles G.; Linji An; Iraj Ershaghi

1992-01-01T23:59:59.000Z

110

Coupled reservoir-geomechanical analysis of CO2 injection and ground deformations at In Salah, Algeria  

SciTech Connect

In Salah Gas Project in Algeria has been injecting 0.5-1 million tonnes CO{sub 2} per year over the past five years into a water-filled strata at a depth of about 1,800 to 1,900 m. Unlike most CO{sub 2} storage sites, the permeability of the storage formation is relatively low and comparatively thin with a thickness of about 20 m. To ensure adequate CO{sub 2} flow-rates across the low-permeability sand-face, the In Salah Gas Project decided to use long-reach (about 1 to 1.5 km) horizontal injection wells. In an ongoing research project we use field data and coupled reservoir-geomechanical numerical modeling to assess the effectiveness of this approach and to investigate monitoring techniques to evaluate the performance of a CO{sub 2}-injection operation in relatively low permeability formations. Among the field data used are ground surface deformations evaluated from recently acquired satellite-based inferrometry (InSAR). The InSAR data shows a surface uplift on the order of 5 mm per year above active CO{sub 2} injection wells and the uplift pattern extends several km from the injection wells. In this paper we use the observed surface uplift to constrain our coupled reservoir-geomechanical model and conduct sensitivity studies to investigate potential causes and mechanisms of the observed uplift. The results of our analysis indicates that most of the observed uplift magnitude can be explained by pressure-induced, poro-elastic expansion of the 20 m thick injection zone, but there could also be a significant contribution from pressure-induced deformations within a 100 m thick zone of shaly sands immediately above the injection zone.

Rutqvist, J.; Vasco, D.W.; Myer, L.

2009-11-01T23:59:59.000Z

111

Core Analysis for the Development and Constraint of Physical Models of Geothermal Reservoirs  

DOE Green Energy (OSTI)

Effective reservoir exploration, characterization, and engineering require a fundamental understanding of the geophysical properties of reservoir rocks and fracture systems. Even in the best of circumstances, spatial variability in porosity, fracture density, salinity, saturation, tectonic stress, fluid pressures, and lithology can all potentially produce and/or contribute to geophysical anomalies. As a result, serious uniqueness problems frequently occur when interpreting assumptions based on a knowledge base founded in validated rock physics models of reservoir material.

Greg N. Boitnott

2003-12-14T23:59:59.000Z

112

Status of Blue Ridge Reservoir  

DOE Green Energy (OSTI)

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.

Not Available

1990-09-01T23:59:59.000Z

113

Improved recovery from Gulf of Mexico reservoirs  

Science Conference Proceedings (OSTI)

The Gulf of Mexico Basin offers the greatest near-term potential for reducing the future decline in domestic oil and gas production. The Basin is less mature than productive on-shore areas, large unexplored areas remain, and there is great potential for reducing bypassed oil in known fields. Much of the remaining oil in the offshore is trapped in formations that are extremely complex due to intrusions Of salt domes. Recently, however, significant innovations have been made in seismic processing and reservoir simulation. In addition, significant advances have been made in deviated and horizontal drilling technologies. Effective application of these technologies along with improved integrated resource management methods offer opportunities to significantly increase Gulf of Mexico production, delay platform abandonments, and preserve access to a substantial remaining oil target for both exploratory drilling and advanced recovery processes. On February 18, 1992, Louisiana State University (the Prime Contractor) with two technical subcontractors, BDNL Inc. and ICF, Inc., began a research program to estimate the potential oil and gas reserve additions that could result from the application of advanced secondary and enhanced oil recovery technologies and the exploitation of undeveloped and attic oil zones in the Gulf of Mexico oil fields that are related to piercement salt dornes. This project is a one year continuation of this research and will continue work in reservoir description, extraction processes, and technology transfer. Detailed data will be collected for two previously studied reservoirs: a South Marsh Island reservoir operated by Taylor Energy and a South Pelto reservoir operated by Mobil. This data will include reprocessed 2-D seismic data, newly acquired 3-D data, fluid data, fluid samples, pressure data, well test data, well logs, and core data/samples. Geologic data is being compiled; extraction research has not begun.

Schenewerk, P.

1995-07-30T23:59:59.000Z

114

Application of stress corrosion to geothermal reservoirs  

DOE Green Energy (OSTI)

There are several alternative equations which describe slow crack growth by stress corrosion. Presently available data suggest that an alternative form may be preferable to the form which is most often used, but the issue cannot be clearly decided. Presently available stress corrosion data on glasses and ceramics suggest that rocks in a proposed geothermal reservoir will crack readily over long time periods, thus seriously limiting the operation of this type of power source. However, in situ hydrofracturing measurements together with a theoretical treatment suggest that such a reservoir will contain a relatively high pressure over a long period of time without further cracking. Further experimentation is desirable to measure directly the critical stresses for crack growth rates on the order of 10/sup -7/ m/sec.

Demarest, H.H. Jr.

1975-10-01T23:59:59.000Z

115

Hot dry rock Phase II reservoir engineering  

DOE Green Energy (OSTI)

Early attempts to hydraulically fracture and connect two wells drilled at the Hot Dry Rock site at Fenton Hill in New Mexico failed. Microearthquakes triggered by hydraulic fracturing indicated that the fracture zones grew in unexpected directions. Consequently one of the wells was sidetracked at a depth of 2.9 km; was redrilled into the zones of most intense microseismic activity; and a flow connection was achieved. Hydraulic communication was improved by supplemental fracturing using recently developed high temperature and high pressure open hole packers. Preliminary testing indicates a reservoir with stimulated joint volume which already surpasses that attained in the earlier phase I reservoir after several years of development. 12 refs., 6 figs.

Murphy, H.D.

1985-01-01T23:59:59.000Z

116

Hydrologic Properties of the Dixie Valley, Nevada, Geothermal Reservoir  

Open Energy Info (EERE)

Hydrologic Properties of the Dixie Valley, Nevada, Geothermal Reservoir Hydrologic Properties of the Dixie Valley, Nevada, Geothermal Reservoir from Well-Test Analyses Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Hydrologic Properties of the Dixie Valley, Nevada, Geothermal Reservoir from Well-Test Analyses Abstract Temperature, pressure, and spinner (TPS) logs have been recorded in several wells from the Dixie Valley Geothermal Reservoir in west central Nevada. A variety of well-test analyses has been performed with these data to quantify the hydrologic properties of this fault-dominated geothermal resource. Four complementary analytical techniques were employed, their individual application depending upon availability and quality of data and validity of scientific assumptions. In some instances, redundancy in

117

Reservoir characteristics in Uinta basin gas wells. Final report, September 1, 1978-January 31, 1980  

SciTech Connect

Volumes of 29 lenticular tight gas sandstone reservoirs in the Uinta Basin, Utah have been approximated from long-term pressure buildups on 6 wells. Average reservoir volume was interpreted to be about 240,000 ft/sup 3/ per ft of net pay. Outcrop reservoir geometry studies indicate an average reservoir volume (without any reservoir interconnection assumed) of about 30% less than the average based upon production analysis. Therefore, some reservoir interconnection may exist. Results of this study are consistent with the Knutson lenticular reservoir model in which average reservoir width is 22 times the gross sand thickness, length is 10 times the width, and reservoir interconnection is a function of the sand fraction in the productive interval. Apparent reservoir permeabilities, assuming radial flow, range from .009 to .052 millidarcies and actual sandstone matrix permeabilities are interpreted to range from .06 to .21 millidarcies. Fracture half lengths are interpreted to be about 0.1 ft/bbl of fluid with an average proppant load of 1.2 to 1.7 lb/gal at injection rates of 18 to 24 BPM and injection pressures of 2,500 to 4,600 psi for each 100 ft of gross sand in the fracced interval.

Boardman, C.R.; Knutson, C.F.

1979-11-27T23:59:59.000Z

118

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

Science Conference Proceedings (OSTI)

The Paradox Basin of Utah, Colorado, and Arizona contains nearly 100 small oil fields producing from shallow-shelf carbonate buildups or mounds within the Desert Creek zone of the Pennsylvanian (Desmoinesian) Paradox Formation. These fields typically have one to four wells with primary production ranging from 700,000 to 2,000,000 barrels (111,300-318,000 m{sup 3}) of oil per field at a 15 to 20 percent recovery rate. Five fields in southeastern Utah were evaluated for waterflood or carbon-dioxide (CO{sub 2})-miscible flood projects based upon geological characterization and reservoir modeling. Geological characterization on a local scale focused on reservoir heterogeneity, quality, and lateral continuity as well as possible compartmentalization within each of the five project fields. The Desert Creek zone includes three generalized facies belts: (1) open-marine, (2) shallow-shelf and shelf-margin, and (3) intra-shelf, salinity-restricted facies. These deposits have modern analogs near the coasts of the Bahamas, Florida, and Australia, respectively, and outcrop analogs along the San Juan River of southeastern Utah. The analogs display reservoir heterogeneity, flow barriers and baffles, and lithofacies geometry observed in the fields; thus, these properties were incorporated in the reservoir simulation models. Productive carbonate buildups consist of three types: (1) phylloid algal, (2) coralline algal, and (3) bryozoan. Phylloid-algal buildups have a mound-core interval and a supra-mound interval. Hydrocarbons are stratigraphically trapped in porous and permeable lithotypes within the mound-core intervals of the lower part of the buildups and the more heterogeneous supramound intervals. To adequately represent the observed spatial heterogeneities in reservoir properties, the phylloid-algal bafflestones of the mound-core interval and the dolomites of the overlying supra-mound interval were subdivided into ten architecturally distinct lithotypes, each of which exhibits a characteristic set of reservoir properties obtained from outcrop analogs, cores, and geophysical logs. The Anasazi and Runway fields were selected for geostatistical modeling and reservoir compositional simulations. Models and simulations incorporated variations in carbonate lithotypes, porosity, and permeability to accurately predict reservoir responses. History matches tied previous production and reservoir pressure histories so that future reservoir performances could be confidently predicted. The simulation studies showed that despite most of the production being from the mound-core intervals, there were no corresponding decreases in the oil in place in these intervals. This behavior indicates gravity drainage of oil from the supra-mound intervals into the lower mound-core intervals from which the producing wells' major share of production arises. The key to increasing ultimate recovery from these fields (and similar fields in the basin) is to design either waterflood or CO{sub 2}-miscible flood projects capable of forcing oil from high-storage-capacity but low-recovery supra-mound units into the high-recovery mound-core units. Simulation of Anasazi field shows that a CO{sub 2} flood is technically superior to a waterflood and economically feasible. For Anasazi field, an optimized CO{sub 2} flood is predicted to recover a total 4.21 million barrels (0.67 million m3) of oil representing in excess of 89 percent of the original oil in place. For Runway field, the best CO{sub 2} flood is predicted to recover a total of 2.4 million barrels (0.38 million m3) of oil representing 71 percent of the original oil in place. If the CO{sub 2} flood performed as predicted, it is a financially robust process for increasing the reserves in the many small fields in the Paradox Basin. The results can be applied to other fields in the Rocky Mountain region, the Michigan and Illinois Basins, and the Midcontinent.

Thomas C. Chidsey, Jr.

2002-11-01T23:59:59.000Z

119

Summary of hot dry rock geothermal reservoir testing 1978 to 1980  

DOE Green Energy (OSTI)

Experimental results and re-evaluation of the Phase I Hot Dry Rock Geothermal Energy reservoirs at the Fenton Hill field site are summarized. Reservoir growth is traced. Reservoir growth was caused not only by pressurization and hydraulic fracturing, but also by heat extraction and thermal contraction effects. Reservoir heat-transfer area grew from 8000 to 50,000 m/sup 2/ and reservoir fracture volume grew from 11 to 266/sup 3/m. Despite this reservoir growth, the water loss rate increased only 30%, under similar pressure environments. For comparable temperature and pressure conditions, the flow impedance (a measure of the resistance to circulation of water through the reservoir) remained essentially unchanged, and if reproduced in the Phase II reservoir under development, could result in self pumping. Geochemical and seismic hazards have been nonexistent in the Phase I reservoirs. The produced water is relatively low in total dissolved solids and shows little tendency for corrosion or scaling. The largest microearthquake associated with heat extraction measures less than -1 on the extrapolated Richter scale.

Dash, Z.V.; Murphy, H.D. (eds.)

1981-01-01T23:59:59.000Z

120

Alternate operating strategies for Hot Dry Rock geothermal reservoirs  

DOE Green Energy (OSTI)

Flow testing and heat extraction experiments in prototype Hot Dry Rock (HDR) geothermal reservoirs have uncovered several challenges which must be addressed before commercialization of the technology is possible. Foremost among these is the creation of a reservoir which simultaneously possesses high permeability pathways and a large volume of fractured rock. The current concept of heat extraction -- a steady state circulation system with fluid pumping from the injection well to a single, low pressure production well -- may limit our ability to create heat extraction systems which meet these goals. A single injection well feeding two production wells producing fluid at moderate pressures is shown to be a potentially superior way to extract heat. Cyclic production is also demonstrated to have potential as a method for sweeping fluid through a larger volume of rock, thereby inhibiting flow channeling and increasing reservoir lifetime. 10 refs., 4 figs., 2 tabs.

Robinson, B.A.

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Developing hot dry rock reservoirs with inflatable open hole packers  

DOE Green Energy (OSTI)

An open hole packer system was designed for high pressure injection operations in high temperature wells at the Fenton Hill, Hot Dry Rock (HDR) Geothermal Site. The packer runs were required to verify that the HDR reservoir fractures had been penetrated during the drilling of well EE-3A. They were also used to stimulate fractures connecting EE-3A to the reservoir and to conduct two massive hydraulic fracture treatments at the bottom of EE-3A. An attempt to use a modified packer design as a temporary well completion system was not successful but with modification the system may prove to be an important HDR completion technique. The eleven packer runs have demonstrated that formation testing, stimulation and HDR reservoir development can now be conducted with an open hole inflatable packer operating over large temperature ranges and high differential pressures.

Dreesen, D.S.; Miller, J.R.; Nicholson, R.W.

1987-01-01T23:59:59.000Z

122

What is the Cost of an Adequate Vermont High School Education?.  

E-Print Network (OSTI)

??Access to an adequate education has been widely considered an undeniable right since Chief Justice Warren stated in his landmark decision that “Today, education is… (more)

Rucker, Frank D.

2010-01-01T23:59:59.000Z

123

Characterization of Roabiba Sandstones Reservoir in Bintuni Field, Papua, Indonesia  

E-Print Network (OSTI)

Bintuni Field has two Middle Jurassic gas reservoirs, Upper and Lower Roabiba Sandstone reservoirs, with the estimated reserve from eight appraisal drilled wells of 6.08 tcf. The field has not been producing commercially. The main gas reservoir is the Upper Roabiba Sandstone. It was deposited in a tidal-dominated shoreface delta and consists of a moderately sorted, fine to medium grain, quartzarenite with average porosity of 12% and average permeability of 250 md. Lower Roabiba Sandstone was deposited in estuarine channel and marsh and consists of lower fine to lower coarse grained quartzarenites with average porosity of 12% and permeability 215 md. This study is considered necessary since the field is considered to be a giant field and there are a limited number of studies on the Roabiba Sandstones reservoir specifically in Bintuni Field that have been published. The purpose of this study was to develop geological and petrophysical analysis that will identify reservoir quality and distribution of best, intermediate, and poor reservoir zones by characterizing distribution of porosity-permeability values in lithofacies and mercury injection capillary pressure. The methods to characterize the reservoir included core-based lithofacies determination, well logs analysis, and mercury injection capillary pressure analysis. As a result from core descriptions, three main units of lithofacies could be identified. Lithofacies massive sandstones (ms), slightly bioturbated sandstones (sb1), and crosslaminated sandstones (xls) have the highest average permeability (>100 md) and porosity (>10%). Petrophysical properties from core data show that porosity varies only slightly regardless of lithofacies characteristic whereas permeability variations are greater and correspond closely with the lithofacies. When grouped according to the dominant pore throat dimension, distinct collections or grouping of rocks and their associated lithofacies were observed. Winland plot was engaged to do clustering of rock types since Winland R35 pore port sizes represent "cut off values" for good and bad flow unit quality. The analyses of porositypermeability plots were confirmed with the Winland plot that the best reservoir rock (rock type 1) consists of lithofacies ms, xls, and sb1. From this development, four petrophysical rock types were defined and characterized. Rock type 1 (the best reservoir rock) consists of lithofacies ms, xls, and sb1. Therefore, associated lithofacies in rock type 1 may be used as a pore-proxy rock property for the determination of best reservoir rock and corresponding flow units at the reservoir scale.

Vera, Riene

2009-12-01T23:59:59.000Z

124

Geothermal reservoir management  

DOE Green Energy (OSTI)

The optimal management of a hot water geothermal reservoir was considered. The physical system investigated includes a three-dimensional aquifer from which hot water is pumped and circulated through a heat exchanger. Heat removed from the geothermal fluid is transferred to a building complex or other facility for space heating. After passing through the heat exchanger, the (now cooled) geothermal fluid is reinjected into the aquifer. This cools the reservoir at a rate predicted by an expression relating pumping rate, time, and production hole temperature. The economic model proposed in the study maximizes discounted value of energy transferred across the heat exchanger minus the discounted cost of wells, equipment, and pumping energy. The real value of energy is assumed to increase at r percent per year. A major decision variable is the production or pumping rate (which is constant over the project life). Other decision variables in this optimization are production timing, reinjection temperature, and the economic life of the reservoir at the selected pumping rate. Results show that waiting time to production and production life increases as r increases and decreases as the discount rate increases. Production rate decreases as r increases and increases as the discount rate increases. The optimal injection temperature is very close to the temperature of the steam produced on the other side of the heat exchanger, and is virtually independent of r and the discount rate. Sensitivity of the decision variables to geohydrological parameters was also investigated. Initial aquifer temperature and permeability have a major influence on these variables, although aquifer porosity is of less importance. A penalty was considered for production delay after the lease is granted.

Scherer, C.R.; Golabi, K.

1978-02-01T23:59:59.000Z

125

Gas injection techniques for condensate recovery and remediation of liquid banking in gas-condensate reservoirs.  

E-Print Network (OSTI)

??In gas-condensate reservoirs, gas productivity declines due to the increasing accumulation of liquids in the near wellbore region as the bottom-hole pressure declines below the… (more)

Hwang, Jongsoo

2011-01-01T23:59:59.000Z

126

Three-phase immiscible displacement in heterogeneous petroleum reservoirs  

Science Conference Proceedings (OSTI)

We describe a fractional-step numerical procedure for the simulation of immiscible three-phase flow in heterogeneous porous media that takes into account capillary pressure and apply it to indicate the existence of a so-called "transitional" wave in ... Keywords: central difference scheme, heterogeneous reservoirs, mixed finite elements, operator splitting, three-phase flow

E. Abreu; J. Douglas, Jr.; F. Furtado; D. Marchesin; F. Pereira

2006-11-01T23:59:59.000Z

127

Development of Surrogate Reservoir Models (SRM) For Fast Track  

E-Print Network (OSTI)

for integrated Reservoir Management Time Scale: Seconds, Minutes, Hours Time Scale: Days, Months, .... #12;3 SPE. Single Run = 10 Hours on 12 CPUs. Water Injection for Pressure Maintenance. #12;5 SPE 99667 Shahab D involved: 5. Such results bounds to be much more reliable and therefore, more acceptable to the management

Mohaghegh, Shahab

128

Advanced reservoir simulation using soft computing  

Science Conference Proceedings (OSTI)

Reservoir simulation is a challenging problem for the oil and gas industry. A correctly calibrated reservoir simulator provides an effective tool for reservoir evaluation that can be used to obtain essential reservoir information. A long-standing problem ... Keywords: fuzzy control, history matching, parallel processing, reservoir simulation

G. Janoski; F.-S. Li; M. Pietrzyk; A. H. Sung; S.-H. Chang; R. B. Grigg

2000-06-01T23:59:59.000Z

129

NFFLOW: A reservoir simulator incorporating explicit fractures (SPE 153890)  

SciTech Connect

NFFLOW is a research code that quickly and inexpensively simulates flow in moderately fractured reservoirs. It explicitly recognizes fractures separately from rock matrix. In NFFLOW fracture flow is proportional to the pressure gradient along the fracture, and flow in the rock matrix is determined by Darcy’s Law. The two flow mechanisms are coupled through the pressure gradient between a fracture and its adjacent rock matrix. Presented is a promising change to NFFLOW that allows for flow across a rock matrix block.

Boyle, E.J.; Sams, W.N.

2012-01-01T23:59:59.000Z

130

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

Science Conference Proceedings (OSTI)

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

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

1996-04-30T23:59:59.000Z

131

Session 4: Geothermal Reservoir Definition  

DOE Green Energy (OSTI)

The study of geothermal reservoir behavior is presently in a state of change brought about by the discovery that reservoir heterogeneity--fractures in particular--is responsible for large scale effects during production. On the other hand, some parts of a reservoir, or some portions of its behavior. may be unaffected by fractures and behave, instead, as if the reservoir were a homogeneous porous medium. Drilling has for many years been guided by geologists prospecting for fractures (which have been recognized as the source of production), but until recently reservoir engineers have not studied the behavior of fractured systems under production. In the last three years research efforts, funded by the Department of Energy and others, have made significant progress in the study of fractures. The investigations into simulation of fracture flow, tracer analysis of fractured systems, and well test analysis of double porosity reservoirs are all advancing. However, presently we are at something of a conceptual impasse in defining a reservoir as fractured or porous. It seems likely that future directions will not continue to attempt to distinguish two separate reservoir types, but will focus instead on defining behavior types. That is, certain aspects of reservoir behavior may be considered to be generally of the porous medium type (for example, field wide decline), while others may be more frequently fracture type (for example, breakthrough of reinjected water). In short, our overall view of geothermal reservoir definition is becoming a little more complex, thereby better accommodating the complexities of the reservoirs themselves. Recent research results already enable us to understand some previously contradictory results, and recognition of the difficulties is encouraging for future progress in the correct direction.

Horne, Roland N.

1983-12-01T23:59:59.000Z

132

A dual-porosity reservoir model with a nonlinear coupling term  

DOE Green Energy (OSTI)

Since their introduction by Barenblatt et al. (1960), double-porosity models have been widely used for simulating flow in fractured reservoirs, such as geothermal reservoirs. In a dual-porosity system, the matrix blocks provide most of the storage of the reservoir, whereas the fractures provide the global transmissivity. Initially, most work on dual-porosity models emphasized the development of analytical solutions to idealized reservoir problems. Increasingly, the dual-porosity approach is being implemented by numerical reservoir simulators. Accurate numerical simulation of a dual-porosity problem often requires a prohibitively large number of computational cells in order to resolve the transient pressure gradients in the matrix blocks. We discuss a new dual-porosity model that utilizes a nonlinear differential equation to approximate the fracture/matrix interactions, When implemented into a numerical simulator, it eliminates the need to discretize the matrix blocks, and thereby allows more efficient simulation of reservoir problems.

Zimmerman, R.W.; Chen, G.; Hadgu, T.; Bodvarsson, G.S.

1992-09-01T23:59:59.000Z

133

Two-dimensional simulation of the Raft River geothermal reservoir and  

Open Energy Info (EERE)

dimensional simulation of the Raft River geothermal reservoir and dimensional simulation of the Raft River geothermal reservoir and wells. (SINDA-3G program) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Two-dimensional simulation of the Raft River geothermal reservoir and wells. (SINDA-3G program) Details Activities (1) Areas (1) Regions (0) Abstract: Computer models describing both the transient reservoir pressure behavior and the time dependent temperature response of the wells at the Raft River, Idaho, Geothermal Resource were developed. A horizontal, two-dimensional, finite-difference model for calculating pressure effects was constructed to simulate reservoir performance. Vertical, two-dimensional, finite-difference, axisymmetric models for each of the three existing wells at Raft River were also constructed to describe the

134

Carbon sequestration in natural gas reservoirs: Enhanced gas recovery and natural gas storage  

SciTech Connect

Natural gas reservoirs are obvious targets for carbon sequestration by direct carbon dioxide (CO{sub 2}) injection by virtue of their proven record of gas production and integrity against gas escape. Carbon sequestration in depleted natural gas reservoirs can be coupled with enhanced gas production by injecting CO{sub 2} into the reservoir as it is being produced, a process called Carbon Sequestration with Enhanced Gas Recovery (CSEGR). In this process, supercritical CO{sub 2} is injected deep in the reservoir while methane (CH{sub 4}) is produced at wells some distance away. The active injection of CO{sub 2} causes repressurization and CH{sub 4} displacement to allow the control and enhancement of gas recovery relative to water-drive or depletion-drive reservoir operations. Carbon dioxide undergoes a large change in density as CO{sub 2} gas passes through the critical pressure at temperatures near the critical temperature. This feature makes CO{sub 2} a potentially effective cushion gas for gas storage reservoirs. Thus at the end of the CSEGR process when the reservoir is filled with CO{sub 2}, additional benefit of the reservoir may be obtained through its operation as a natural gas storage reservoir. In this paper, we present discussion and simulation results from TOUGH2/EOS7C of gas mixture property prediction, gas injection, repressurization, migration, and mixing processes that occur in gas reservoirs under active CO{sub 2} injection.

Oldenburg, Curtis M.

2003-04-08T23:59:59.000Z

135

Cesium reservoir and interconnective components. Final test report: TFE Verification Program  

Science Conference Proceedings (OSTI)

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

Not Available

1994-03-01T23:59:59.000Z

136

Improved Upscaling & Well Placement Strategies for Tight Gas Reservoir Simulation and Management  

E-Print Network (OSTI)

Tight gas reservoirs provide almost one quarter of the current U.S. domestic gas production, with significant projected increases in the next several decades in both the U.S. and abroad. These reservoirs constitute an important play type, with opportunities for improved reservoir simulation & management, such as simulation model design, well placement. Our work develops robust and efficient strategies for improved tight gas reservoir simulation and management. Reservoir simulation models are usually acquired by upscaling the detailed 3D geologic models. Earlier studies of flow simulation have developed layer-based coarse reservoir simulation models, from the more detailed 3D geologic models. However, the layer-based approach cannot capture the essential sand and flow. We introduce and utilize the diffusive time of flight to understand the pressure continuity within the fluvial sands, and develop novel adaptive reservoir simulation grids to preserve the continuity of the reservoir sands. Combined with the high resolution transmissibility based upscaling of flow properties, and well index based upscaling of the well connections, we can build accurate simulation models with at least one order magnitude simulation speed up, but the predicted recoveries are almost indistinguishable from those of the geologic models. General practice of well placement usually requires reservoir simulation to predict the dynamic reservoir response. Numerous well placement scenarios require many reservoir simulation runs, which may have significant CPU demands. We propose a novel simulation-free screening approach to generate a quality map, based on a combination of static and dynamic reservoir properties. The geologic uncertainty is taken into consideration through an uncertainty map form the spatial connectivity analysis and variograms. Combining the quality map and uncertainty map, good infill well locations and drilling sequence can be determined for improved reservoir management. We apply this workflow to design the infill well drilling sequence and explore the impact of subsurface also, for a large-scale tight gas reservoir. Also, we evaluated an improved pressure approximation method, through the comparison with the leading order high frequency term of the asymptotic solution. The proposed pressure solution can better predict the heterogeneous reservoir depletion behavior, thus provide good opportunities for tight gas reservoir management.

Zhou, Yijie

2013-08-01T23:59:59.000Z

137

Reservoir management using streamline simulation  

E-Print Network (OSTI)

Geostatistical techniques can generate fine-scale description of reservoir properties that honor a variety of available data. The differences among multiple geostatistical realizations indicate the presence of uncertainty due to the lack of information and sparsity of data. Quantifying this uncertainty in terms of reservoir performance forecast poses a major reservoir management challenge. One solution to this problem is flow simulation of a large number of these plausible reservoir descriptions. However, this approach is not feasible in practice because of the computational costs associated with multiple detailed flow simulations. Other major reservoir management challenges include the determination of the swept and unswept areas at a particular time of interest in the life of a reservoir. Until now, sweep efficiency correlations have generally been limited to homogeneous 2-D cases. Calculating volumetric sweep efficiency in a 3-D heterogeneous reservoir is difficult due to the inherent complexity of multiple layers and arbitrary well configurations. Identifying the swept and unswept areas is primarily important for making a decision on the infill locations. Most of the mature reservoirs all over the world are under waterflood. Managing a waterflood requires an understanding of how injection wells displace oil to producing wells. By quantifying the fluid movements, the displacement process can be actively managed. Areas that are not being swept can be developed, and inefficiencies, such as water cycling, can be removed. Conventional simulation provides general answers to almost all of these problems, however time constraint prohibits using a detailed model to capture complexities for each well. Three dimensional streamline simulation can meet most of these reservoir management challenges. Moreover use of fast streamline-based simulation technique offers significant potential in terms of computational efficiency. Its high performance simulation speed makes it well suited for describing flow characteristics for high resolution reservoir models and can be used on a routine basis to make effective and efficient reservoir management decisions. In this research, we extend the capability of streamline simulation as an efficient tool for reservoir management purposes. We show its application in terms of swept volume calculations, ranking of stochastic reservoir models, pattern rate allocation and reservoir performance forecasting under uncertainty.

Choudhary, Manoj Kumar

2000-01-01T23:59:59.000Z

138

Tertiary carbonate reservoirs in Indonesia  

Science Conference Proceedings (OSTI)

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.

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

1981-01-01T23:59:59.000Z

139

Water resources review: Ocoee reservoirs, 1990  

DOE Green Energy (OSTI)

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.

Cox, J.P.

1990-08-01T23:59:59.000Z

140

NETL: Discrete Fracture Reservoir Simulation Software  

NLE Websites -- All DOE Office Websites (Extended Search)

Discrete Fracture Reservoir Simulation FRACGENNFFLOW Shale Gas Flow Simulation Shale Gas Flow Simulation FRACGENNFFLOW, a fractured reservoir modeling software developed by the...

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
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141

ANNOTATED RESEARCH BIBLIOGRAPHY FOR GEOTHERMAL RESERVOIR ENGINEERING  

E-Print Network (OSTI)

Bibliography Definition of Geothermal Reservoir EngineeringDevelopment of Geothermal Reservoir Engineering. * 1.4 DataF i r s t Geopressured Geothermal Energy Conference. Austin,

Sudo!, G.A

2012-01-01T23:59:59.000Z

142

Data requirements and acquisition for reservoir characterization  

Science Conference Proceedings (OSTI)

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.

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

1993-03-01T23:59:59.000Z

143

Coal bed methane reservoir simulation studies.  

E-Print Network (OSTI)

??The purpose of this study is to perform simulation studies for a specific coal bed methane reservoir. First, the theory and reservoir engineering aspects of… (more)

Karimi, Kaveh

2005-01-01T23:59:59.000Z

144

Greenhouse gas cycling in experimental boreal reservoirs.  

E-Print Network (OSTI)

??Hydroelectric reservoirs account for 59% of the installed electricity generating capacity in Canada and 26% in Ontario. Reservoirs also provide irrigation capacity, drinking water, and… (more)

Venkiteswaran, Jason James

2009-01-01T23:59:59.000Z

145

ANALYSIS OF PRODUCTION DECLINE IN GEOTHERMAL RESERVOIRS  

E-Print Network (OSTI)

Petroleum Reservoirs. Geothermal Reservoirs IV. DATA1970, Superheating of Geothermal Steam, Proc. of the U.N.the Development & Utilization of Geothermal Resources, Pisa.

Zais, E.J.; Bodvarsson, G.

2008-01-01T23:59:59.000Z

146

Reservoir description through pulse testing in a mature field  

SciTech Connect

Pulse testing was used in the Fortescue field to clarify reservoir geometries and fluid communication pathways. The high communication levels demonstrated in the test data required a nonstandard analysis of the pressure responses. In addition, proper attention to test planning, data acquisition, and data processing allowed valuable insights into reservoir limits. Most of the structural implications derived from the pulse tests have been supported subsequently by a recent 3D seismic survey of the area. The results and insights gained from these tests are being incorporated into a full-field simulation model of the Fortescue field, which is an integral part of a continuing depletion field study.

Braisted, D.M.; Spengler, R.M. (Esso Australia Ltd., Sydney (Australia)); Youie, R.A.

1993-06-01T23:59:59.000Z

147

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

Science Conference Proceedings (OSTI)

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 survivability issues. Our findings indicate that packaging represents the most significant technical challenge associated with application of sensors in the downhole environment for long periods (5+ years) of time. These issues are described in detail within the report. The impact of successful reservoir monitoring programs and coincident improved reservoir management is measured by the production of additional oil and gas volumes from existing reservoirs, revitalization of nearly depleted reservoirs, possible re-establishment of already abandoned reservoirs, and improved economics for all cases. Smart Well monitoring provides the means to understand how a reservoir process is developing and to provide active reservoir management. At the same time it also provides data for developing high-fidelity simulation models. This work has been a joint effort with Sandia National Laboratories and UT-Austin's Bureau of Economic Geology, Department of Petroleum and Geosystems Engineering, and the Institute of Computational and Engineering Mathematics.

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

2006-11-01T23:59:59.000Z

148

Reservoir response to injection in the Southeast Geysers  

DOE Green Energy (OSTI)

A 20 megawatt (MW) increase in steam flow potential resulted within five months of the start-up of new injection wells in the Southeast Geysers. Flow rate increases were observed in 25 wells offset to the injectors, C-11 and 956A-1. This increased flowrate was sustained during nine months of continuous injection with no measurable decrease in offset well temperature until C-11 was shut-in due to wellbore bridging. The responding steam wells are located in an area of reduced reservoir steam pressure known as the Low Pressure Area (LPA). The cause of the flowrate increases was twofold (1) an increase in static reservoir pressure and (2) a decrease in interwell communication. Thermodynamic and microseismic evidence suggests that most of the water is boiling near the injector and migrating to offset wells located ''down'' the static pressure gradient. However, wells showing the largest increase in steam flowrate are not located at the heart of the pressure sink. This indicates that localized fracture distribution controls the preferred path of fluid migration from the injection well. A decrease in non-condensible gas concentrations was also observed in certain wells producing injection derived steam within the LPA. The LPA project has proven that steam suppliers can work together and benefit economically from joint efforts with the goal of optimizing the use of heat from The Geysers reservoir. The sharing of costs and information led directly to the success of the project and introduces a new era of increased cooperation at The Geysers.

Enedy, Steve; Enedy, Kathy; Maney, John

1991-01-01T23:59:59.000Z

149

TEXAS A&M UNIVERSITY Reservoir Geophysics Program  

E-Print Network (OSTI)

includes applications to clastic reservoirs, heavy oil reservoirs, gas/oil shale, gas hydrates. Basic

150

Evaluating salience metrics for the context-adequate realization of discourse referents  

Science Conference Proceedings (OSTI)

We describe the application of a framework for salience metrics and linguistic variability with respect to the contextually adequate choice of referring expressions and grammatical roles: Where multiple meaning-equivalent candidate realizations are available ...

Christian Chiarcos

2011-09-01T23:59:59.000Z

151

Evolution of Risk Management at NASA in the Context of Achieving Adequate  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Evolution of Risk Management at NASA in the Context of Achieving Evolution of Risk Management at NASA in the Context of Achieving Adequate Safety Evolution of Risk Management at NASA in the Context of Achieving Adequate Safety September 20, 2012 Presenter: Homayoon Dezfuli, Ph.D. NASA Technical Fellow for System Safety Office of Safety and Mission Assurance NASA Headquarters Topics Covered: Historical Perspective on NASA Risk Management (RM) * RM Approach After 2008 * Future Direction of RM at NASA - The Concept of "Adequate Safety" - The Issue of Risk Analysis Completeness (Rationale for Future Trends in RM) Summary 2 Acknowledgment Evolution of Risk Management at NASA in the Context of Achieving Adequate Safety More Documents & Publications DOE Standard on Development and Use of Probabilistic Risk Assessment in DOE

152

Using multi-layer models to forecast gas flow rates in tight gas reservoirs  

E-Print Network (OSTI)

The petroleum industry commonly uses single-layer models to characterize and forecast long-term production in tight gas reservoir systems. However, most tight gas reservoirs are layered systems where the permeability and porosity of each layer can vary significantly, often over several orders of magnitude. In addition, the drainage areas of each of the layers can be substantially different. Due to the complexity of such reservoirs, the analysis of pressure and production history using single-layer analyses techniques provide incorrect estimates of permeability, fracture conductivity, drainage area, and fracture half-length. These erroneous values of reservoir properties also provide the reservoir engineer with misleading values of forecasted gas recovery. The main objectives of this research project are: (1) to demonstrate the typical errors that can occur in reservoir properties when single-layer modeling methods are used to history match production data from typical layered tight gas reservoirs, and (2) to use the single-layer match to demonstrate the error that can occur when forecasting long-term gas production for such complex gas reservoirs. A finite-difference reservoir simulator was used to simulate gas production from various layered tight gas reservoirs. These synthetic production data were analyzed using single-layer models to determine reservoir properties. The estimated reservoir properties obtained from the history matches were then used to forecast ten years of cumulative gas production and to find the accuracy of gas reserves estimated for tight gas reservoirs when a single-layer model is used for the analysis. Based on the results obtained in this work, I conclude that the accuracy in reservoir properties and future gas flow rates in layered tight gas reservoirs when analyzed using a single-layer model is a function of the degree of variability in permeability within the layers and the availability of production data to be analyzed. In cases where there is an idea that the reservoir presents a large variability in ��k�, using a multi-layer model to analyze the production data will provide the reservoir engineer with more accurate estimates of long-term production recovery and reservoir properties.

Jerez Vera, Sergio Armando

2006-12-01T23:59:59.000Z

153

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

DOE Patents (OSTI)

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.

Kamath, Krishna

1984-08-14T23:59:59.000Z

154

Alternate Methods in Reservoir Simulation  

Science Conference Proceedings (OSTI)

As time progresses, more and more oil fields and reservoirs are reaching maturity; consequently, secondary and tertiary methods of oil recovery have become increasingly important in the petroleum industry. This significance has added to the industry's ...

Guadalupe I. Janoski; Andrew H. Sung

2001-05-01T23:59:59.000Z

155

Integrated Reservoir Characterization: Offshore Louisiana, Grand Isle Blocks 32 & 33  

E-Print Network (OSTI)

This thesis integrated geology, geophysics, and petroleum engineering data to build a detailed reservoir characterization models for three gas pay sands in the Grand Isle 33 & 43 fields, offshore Louisiana. The reservoirs are Late Miocene in age and include the upper (PM), middle (QH), and lower (RD) sands. The reservoir models address the stratigraphy of the upper (PM) sand and help delineate the lower (RD) reservoir. In addition, this research addresses the partially depleted QH-2 reservoir compartment. The detailed models were constructed by integrating seismic, well log, and production data. These detailed models can help locate recoverable oil and gas that has been left behind. The upper PM model further delineated that the PM sand has several areas that are shaled-out effectively creating a flow barrier within reservoir compartments. Due to the barrier in the PM-1 reservoir compartment, an area of potentially recoverable hydrocarbons remains. In Grand Isle 33, the middle QH sand was partially depleted in the QH-2 reservoir compartment by a series of development wells. Bottom hole pressure data from wells in Grand Isle 32 & 33 reveal that the two QH fault compartments are in communication across a leaking fault. Production wells in the QH-1 compartment produced reserves from the QH-2 compartment. The lower RD sand model helped further delineate the reservoir in the RD-2 compartment and show that this compartment has been depleted. The RD model also shows the possible presence of remaining recoverable hydrocarbons in the RD-1 compartment. It is estimated that about 6.7 billion cubic feet of gas might remain within this reservoir waiting to be recovered. A seismic amplitude anomaly response from the QH and RD sands is interpreted to be a lithologic indicator rather than the presence of hydrocarbons. Amplitude response from the PM level appears to be below the resolution of the seismic data. A synthetic seismogram model was generated to represent the PM and surrounding sands. This model shows that by increasing the frequency of the seismic data from 20 Hz to a dominant frequency of 30 Hz that the PM and surrounding sands could be seismically resolvable. Also the PM-1 compartment has possible recoverable hydrocarbons of 1.5 billion cubic feet of gas remaining.

Casey, Michael Chase

2011-05-01T23:59:59.000Z

156

Geothermal Reservoir Dynamics - TOUGHREACT  

DOE Green Energy (OSTI)

This project has been active for several years and has focused on developing, enhancing and applying mathematical modeling capabilities for fractured geothermal systems. The emphasis of our work has recently shifted towards enhanced geothermal systems (EGS) and hot dry rock (HDR), and FY05 is the first year that the DOE-AOP actually lists this project under Enhanced Geothermal Systems. Our overall purpose is to develop new engineering tools and a better understanding of the coupling between fluid flow, heat transfer, chemical reactions, and rock-mechanical deformation, to demonstrate new EGS technology through field applications, and to make technical information and computer programs available for field applications. The objectives of this project are to: (1) Improve fundamental understanding and engineering methods for geothermal systems, primarily focusing on EGS and HDR systems and on critical issues in geothermal systems that are difficult to produce. (2) Improve techniques for characterizing reservoir conditions and processes through new modeling and monitoring techniques based on ''active'' tracers and coupled processes. (3) Improve techniques for targeting injection towards specific engineering objectives, including maintaining and controlling injectivity, controlling non-condensable and corrosive gases, avoiding scale formation, and optimizing energy recovery. Seek opportunities for field testing and applying new technologies, and work with industrial partners and other research organizations.

Pruess, Karsten; Xu, Tianfu; Shan, Chao; Zhang, Yingqi; Wu,Yu-Shu; Sonnenthal, Eric; Spycher, Nicolas; Rutqvist, Jonny; Zhang,Guoxiang; Kennedy, Mack

2005-03-15T23:59:59.000Z

157

Shale Oil Production Performance from a Stimulated Reservoir Volume  

E-Print Network (OSTI)

The horizontal well with multiple transverse fractures has proven to be an effective strategy for shale gas reservoir exploitation. Some operators are successfully producing shale oil using the same strategy. Due to its higher viscosity and eventual 2-phase flow conditions when the formation pressure drops below the oil bubble point pressure, shale oil is likely to be limited to lower recovery efficiency than shale gas. However, the recently discovered Eagle Ford shale formations is significantly over pressured, and initial formation pressure is well above the bubble point pressure in the oil window. This, coupled with successful hydraulic fracturing methodologies, is leading to commercial wells. This study evaluates the recovery potential for oil produced both above and below the bubble point pressure from very low permeability unconventional shale oil formations. We explain how the Eagle Ford shale is different from other shales such as the Barnett and others. Although, Eagle Ford shale produces oil, condensate and dry gas in different areas, our study focuses in the oil window of the Eagle Ford shale. We used the logarithmically gridded locally refined gridding scheme to properly model the flow in the hydraulic fracture, the flow from the fracture to the matrix and the flow in the matrix. The steep pressure and saturation changes near the hydraulic fractures are captured using this gridding scheme. We compare the modeled production of shale oil from the very low permeability reservoir to conventional reservoir flow behavior. We show how production behavior and recovery of oil from the low permeability shale formation is a function of the rock properties, formation fluid properties and the fracturing operations. The sensitivity studies illustrate the important parameters affecting shale oil production performance from the stimulated reservoir volume. The parameters studied in our work includes fracture spacing, fracture half-length, rock compressibility, critical gas saturation (for 2 phase flow below the bubble point of oil), flowing bottom-hole pressure, hydraulic fracture conductivity, and matrix permeability. The sensitivity studies show that placing fractures closely, increasing the fracture half-length, making higher conductive fractures leads to higher recovery of oil. Also, the thesis stresses the need to carry out the core analysis and other reservoir studies to capture the important rock and fluid parameters like the rock permeability and the critical gas saturation.

Chaudhary, Anish Singh

2011-08-01T23:59:59.000Z

158

Fluid and heat flow in gas-rich geothermal reservoirs  

DOE Green Energy (OSTI)

Numerical-simulation techniques are used to study the effects of noncondensible gases (CO/sub 2/) on geothermal reservoir behavior in the natural state and during exploitation. It is shown that the presence of CO/sub 2/ has large effects on the thermodynamic conditions of a reservoir in the natural state, especially on temperature distributions and phase compositions. The gas will expand two-phase zones and increase gas saturations to enable flow of CO/sub 2/ through the system. During exploitation, the early pressure drop is primarily due to degassing of the system. This process can cause a very rapid initial pressure drop, on the order of tens of bars, depending upon the initial partial pressure of CO/sub 2/. The following gas content from wells can provide information on in-place gas saturations and relative permeability curves that apply at a given geothermal resource. Site-specific studies are made for the gas-rich two-phase reservoir at the Ohaki geothermal field in New Zealand. A simple lumped-parameter model and a vertical column model are applied to the field data. The results obtained agree well with the natural thermodynamic state of the Ohaki field (pressure and temperature profiles) and a partial pressure of 15 to 25 bars is calculated in the primary reservoirs. The models also agree reasonably well with field data obtained during exploitation of the field. The treatment of thermophysical properties of H/sub 2/O-CO/sub 2/ mixtures for different phase compositions is summarized.

O'Sullivan, M.J.; Bodvarsson, G.S.; Pruess, K.; Blakeley, M.R.

1983-07-01T23:59:59.000Z

159

Chickamauga reservoir embayment study - 1990  

DOE Green Energy (OSTI)

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.

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

1992-12-01T23:59:59.000Z

160

Reservoir simulation studies: Wairakei Geothermal Field, New Zealand. Final report  

DOE Green Energy (OSTI)

Numerical reservoir simulation techniques were used to perform a history-match of the Wairakei geothermal system in New Zealand. First, a one-dimensional (vertical) model was chosen; realistic stratigraphy was incorporated and the known production history was imposed. The effects of surface and deep recharge were included. Good matches were obtained, both for the reservoir pressure decline history and changes in average discharge enthalpy with time. Next, multidimensional effects were incorporated by treating with a two-dimensional vertical section. Again, good history matches were obtained, although computed late-time discharge enthalpies were slightly high. It is believed that this disparity arises from inherently three-dimensional effects. Predictive calculations using the two-dimensional model suggest that continued future production will cause little additional reservoir pressure drop, but that thermal degradation will occur. Finally, ground subsidence data at Wairakei was examined. It was concluded that traditional elastic pore-collapse models based on classical soil-mechanics concepts are inadequate to explain the observed surface deformation. It is speculated that the measured subsidence may be due to structural effects such as aseismic slippage of a buried reservoir boundary fault.

Pritchett, J.W.; Rice, L.F.; Garg, S.K.

1980-01-01T23:59:59.000Z

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161

Interdisciplinary study of reservoir compartments. Annual technical report  

SciTech Connect

This DOE research project was established to document the integrated team approach for solving reservoir engineering problems. The goal will be to provide tools and approaches that can be used to detect reservoir compartments, reach a better reserve estimate, and improve profits early in the life of a field. Field selection consumed nearly the first four months of the project. The choice was the Hambert Field area which is the field area being studied. During the remainder of the year, a significant portion of the data was gathered and entered into a data base. Cores have been described, log analysis performed on over 100 wells, and regional mapping and correlation of sedimentary packages completed. Compressional (P) and shear (S) wave velocity data was measured on 8 core plugs at various conditions and lithologies. The analysis of the 3D seismic data has been started and supports the interpretation that the structural component will be a significant factor for reservoir compartmentalization in this reservoir. The experimental permeability work completed includes the pressure decay profile permeability measurements on the cores. Relationships of porosity and permeability with net confining stress were developed. Core relative permeability measurements were also completed during the year. Additional experimental measurements completed include Young`s Modulus, Shear Modulus, Poisson`s ratio, and the bulk compressibility as a function of the effective stress. Preliminary engineering analysis of the pressure build-up data from two wells supports the conclusion that sealing faults may act as barriers to flow.

Van Kirk, C.W.

1994-10-28T23:59:59.000Z

162

Rock Physics Based Determination of Reservoir Microstructure for Reservoir Characterization  

E-Print Network (OSTI)

One of the most important, but often ignored, factors affecting the transport and the seismic properties of hydrocarbon reservoir is pore shape. Transport properties depend on the dimensions, geometry, and distribution of pores and cracks. Knowledge of pore shape distribution is needed to explain the often-encountered complex interrelationship between seismic parameters (e.g. seismic velocity) and the independent physical properties (e.g. porosity) of hydrocarbon reservoirs. However, our knowledge of reservoir pore shape distribution is very limited. This dissertation employs a pore structure parameter via a rock physics model to characterize mean reservoir pore shape. The parameter was used to develop a new physical concept of critical clay content in the context of pore compressibility as a function of pore aspect ratio for a better understanding of seismic velocity as a function of porosity. This study makes use of well log dataset from offshore Norway and from North Viking Graben in the North Sea. In the studied North Sea reservoir, porosity and measured horizontal permeability was found to increase with increasing pore aspect ratio (PAR). PAR is relatively constant at 0.23 for volumes of clay (V_cl) less than 32% with a significant decrease to 0.04 for V_cl above 32%. The point of inflexion at 32% in the PAR –V_cl plane is defined as the critical clay volume. Much of the scatters in the compressional velocity-porosity cross-plots are observed where V_cl is above this critical value. For clay content higher than the critical value, Hertz-Mindlin (HM) contact theory over-predicts compressional velocity (V_p) by about 69%. This was reduced to 4% when PAR distribution was accounted for in the original HM formulation. The pore structure parameter was also used to study a fractured carbonate reservoir in the Sichuan basin, China. Using the parameter, the reservoir interval can be distinguished from those with no fracture. The former has a pore structure parameter value that is ? 3.8 whereas it was < 3.8 for the latter. This finding was consistent with the result of fracture analysis, which was based on FMI image. The results from this dissertation will find application in reservoir characterization as the industry target more complex, deeper, and unconventional reservoirs.

Adesokan, Hamid 1976-

2013-05-01T23:59:59.000Z

163

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

Science Conference Proceedings (OSTI)

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.

None

1998-01-01T23:59:59.000Z

164

Interaction of cold-water aquifers with exploited reservoirs of the Cerro Prieto geothermal system  

DOE Green Energy (OSTI)

Cerro Prieto geothermal reservoirs tend to exhibit good hydraulic communication with adjacent cool groundwater aquifers. Under natural state conditions the hot fluids mix with the surrounding colder waters along the margins of the geothermal system, or discharge to shallow levels by flowing up fault L. In response to exploitation reservoir pressures decrease, leading to changes in the fluid flow pattern in the system and to groundwater influx. The various Cerro Prieto reservoirs have responded differently to production, showing localized near-well or generalized boiling, depending on their access to cool-water recharge. Significant cooling by dilution with groundwater has only been observed in wells located near the edges of the field. In general, entry of cool water at Cerro Prieto is beneficial because it tends to maintain reservoir pressures, restrict boiling, and lengthen the life and productivity of wells. 15 refs., 10 figs., 1 tab.

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

1990-04-01T23:59:59.000Z

165

Convolution analysis of surge pressure data  

Science Conference Proceedings (OSTI)

Pressure data from underbalanced perforating or back-surge perforation washing are analyzed by convolution analysis. The method presented allows closed-chamber test evaluation of reservoir transmissivity and wellbore skin by a straight-line graph analogous to a Horner plot. As a well-test analysis method, the closed-chamber test avoids surface pressure buildup, which often prohibits conventional drillstem testing.

Simmons, J.F. (Shell Development Co., Houston, TX (US))

1990-01-01T23:59:59.000Z

166

Reservoir technology research at LBL addressing geysers issues  

DOE Green Energy (OSTI)

The Geothermal Technology Division of the Department of Energy is redirecting a significant part of its Reservoir Technology funding to study problems now being experienced at The Geysers. These include excessive pressure drawdown and associated decline in well flow rates, corrosion due to high chloride concentration in the produced steam and high concentration of noncondensible gases in some parts of the field. Lawrence Berkeley Laboratory (LBL) is addressing some of these problems through field, laboratory and theoretical studies. 11 refs., 6 figs.

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

1990-04-01T23:59:59.000Z

167

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

SciTech Connect

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

P. K. Pande

1998-10-29T23:59:59.000Z

168

Rate-decline Relations for Unconventional Reservoirs and Development of Parametric Correlations for Estimation of Reservoir Properties  

E-Print Network (OSTI)

Time-rate analysis and time-rate-pressure analysis methods are available to estimate reserves and study flow performance of wells in unconventional gas reservoirs. However, these tools are often incorrectly used or the analysis can become difficult because of the complex nature of the reservoir system. Conventional methods (e.g., Arps' time-rate relations) are often used incorrectly to estimate reserves from such reservoirs. It was only recently that a serious study was conducted to outline the limitations of these relations and to set guidelines for their correct application. New time-rate relations, particularly the Duong and logistic growth model, were introduced to estimate reserves and forecast production from unconventional reservoirs. These new models are being used with limited understanding of their characteristics and limitations. Moreover, well performance analyses using analytical/semi-analytical solutions (time-rate-pressure) are often complicated from non-uniqueness that arises when estimating well/formation properties. In this work, we present a detailed study of the Duong model and logistic growth model to investigate the behaviors and limitations of these models when analyzing production data from unconventional reservoirs. We consider production data generated from numerical simulation cases and data obtained from unconventional gas reservoirs to study the quality of match to specific flow regimes and compare accuracy of the reserve estimates. We use the power-law exponential model (PLE), which has been shown to model transient, transition and boundary-dominated flow regimes reliably, as a benchmark to study performance of Duong and logistic growth models. Moreover, we use the "continuous EUR" approach to compare these models during reserve estimation. Finally, we develop four new time-rate relations, based on characteristics of the time-rate data on diagnostic plots. Using diagnostic plots we show that the new time-rate relations provide a quality match to the production data across all flow regimes, leading to a reliable reserve estimate. In a preliminary study, we integrated time-rate model parameters with fundamental reservoir properties (i.e., fracture conductivity (Fc) and 30 year EUR (EUR30yr)), by studying 15 numerical simulation cases to yield parametric correlations. We have demonstrated a methodology to integrate time-rate model parameters and reservoir properties. This method avoids the non-uniqueness issues often associated with model-based production data analysis. This study provides theoretical basis for further demonstration of the methodology using field cases.

Askabe, Yohanes 1985-

2012-12-01T23:59:59.000Z

169

Artificial geothermal reservoirs in hot volcanic rock  

SciTech Connect

S>Some recent results from the Los Alamos program in which hydraulic fracturing is used for the recovery of geothermal energy are discussed. The location is about 4 kilometers west and south of the ring fault of the enormous Jemez Caldera in the northcentral part of New Mexico. It is shown that geothermal energy may be extracted from hot rock that does not contain circulating hot water or steam and is relatively impermeable. A fluid is pumped at high pressure into an isolated section of a wellbore. If the well is cased the pipe in this pressurized region is perforated as it is in the petroleum industry, so that the pressure may be applied to the rock, cracking it. A second well is drilled a few hundred feet away from the first. Cold water is injected through the first pipe, circulates through the crack, and hot water returns to the surface through the second pipe. Results are described and circumstances are discussed under which artiflcial geothermal reservoirs might be created in the basaltic rock of Hawaii. (MCW)

Aamodt, R.L.

1974-02-08T23:59:59.000Z

170

Underwater robots require adequate guidance and control to perform useful tasks. Visual  

E-Print Network (OSTI)

Abstract Underwater robots require adequate guidance and control to perform useful tasks. Visual trained by reinforcement learn- ing our aim is to enable an underwater robot to hold station on a reef technologies for underwater exploration and obser- vation. Our objectives are to enable underwater robots

171

Polynomial time learning of some multiple context-free languages with a minimally adequate teacher  

Science Conference Proceedings (OSTI)

We present an algorithm for the inference of some Multiple Context-Free Grammars from Membership and Equivalence Queries, using the Minimally Adequate Teacher model of Angluin. This is an extension of the congruence based methods for learning some Context-Free ...

Ryo Yoshinaka; Alexander Clark

2010-08-01T23:59:59.000Z

172

STATUS OF GEOTHERMAL RESERVOIR ENGINEERING MANAGEMENT PROGRAM ("GREMP") -DECEMBER, 1979  

E-Print Network (OSTI)

the characteristics of a geothermal reservoir: Items 2, 6,new data important to geothermal reservoir engineering prac-forecast performance of the geothermal reservoir and bore

Howard, J. H.

2012-01-01T23:59:59.000Z

173

A STOCHASTIC METHOD FOR MODELING FLUID DISPLACEMENT IN PETROLEUM RESERVOIRS  

E-Print Network (OSTI)

FLUID DISPLACEMENT IN PETROLEUM RESERVOIRS C. Anderson andFLUID DISPLACEMENT IN PETROLEUM RESERVOIRS C. Anderson andachieve optimal recovery of petroleum from a reservoir, it

Anderson, C.

2011-01-01T23:59:59.000Z

174

Water coning in porous media reservoirs for compressed air energy storage  

DOE Green Energy (OSTI)

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

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

1981-06-01T23:59:59.000Z

175

Adsorption of water vapor on reservoir rocks. First quarterly report, January--March 1993  

DOE Green Energy (OSTI)

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

Not Available

1993-07-01T23:59:59.000Z

176

Blackfoot Reservoir Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

Blackfoot Reservoir Geothermal Area Blackfoot Reservoir Geothermal Area (Redirected from Blackfoot Reservoir Area) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermal Resource Area: Blackfoot Reservoir Geothermal Area Contents 1 Area Overview 2 History and Infrastructure 3 Regulatory and Environmental Issues 4 Exploration History 5 Well Field Description 6 Geology of the Area 7 Geofluid Geochemistry 8 NEPA-Related Analyses (0) 9 Exploration Activities (3) 10 References Area Overview Geothermal Area Profile Location: Idaho Exploration Region: Northern Basin and Range Geothermal Region GEA Development Phase: 2008 USGS Resource Estimate Mean Reservoir Temp: Estimated Reservoir Volume: Mean Capacity: Click "Edit With Form" above to add content History and Infrastructure Operating Power Plants: 0

177

Modeling of Geothermal Reservoirs: Fundamental Processes, Computer  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » Modeling of Geothermal Reservoirs: Fundamental Processes, Computer Simulation and Field Applications Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Modeling of Geothermal Reservoirs: Fundamental Processes, Computer Simulation and Field Applications Abstract This article attempts to critically evaluate the present state of the art of geothermal reservoir simulation. Methodological aspects of geothermal reservoir modeling are briefly reviewed, with special emphasis on flow in fractured media. We then examine some applications of numerical simulation to studies of reservoir dynamics, well test design and analysis, and modeling of specific fields. Tangible impacts of reservoir simulation

178

Reservoir technology research at Lawrence Berkeley Laboratory  

DOE Green Energy (OSTI)

The research being carried out at LBL as part of DOE/GTD's Reservoir Technology Program includes field, theoretical and modeling activities. The purpose is to develop, improve and validate methods and instrumentation to: (1) determine geothermal reservoir parameters, (2) detect and characterize reservoir fractures and boundaries, and (3) identify and evaluate the importance of reservoir processes. The ultimate objective of this work is to advance the state-of-the-art for characterizing geothermal reservoirs and evaluating their productive capacity and longevity under commercial exploitation. LBL's FY1986 accomplishments, FY1987 progress to date, and possible future activities under DOE's Reservoir Technology Program are discussed.

Lippmann, M.J.

1987-04-01T23:59:59.000Z

179

Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs  

Science Conference Proceedings (OSTI)

This document reports progress of this research effort in identifying relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. These dependencies are investigated by identifying the main transport mechanisms at the pore scale that should affect fluids flow at the reservoir scale. A critical review of commercial reservoir simulators, used to predict tight sand gas reservoir, revealed that many are poor when used to model fluid flow through tight reservoirs. Conventional simulators ignore altogether or model incorrectly certain phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization. We studied the effect of Knudsen's number in Klinkenberg's equation and evaluated the effect of different flow regimes on Klinkenberg's parameter b. We developed a model capable of explaining the pressure dependence of this parameter that has been experimentally observed, but not explained in the conventional formalisms. We demonstrated the relevance of this, so far ignored effect, in tight sands reservoir modeling. A 2-D numerical simulator based on equations that capture the above mentioned phenomena was developed. Dynamic implications of new equations are comprehensively discussed in our work and their relative contribution to the flow rate is evaluated. We performed several simulation sensitivity studies that evidenced that, in general terms, our formalism should be implemented in order to get more reliable tight sands gas reservoirs' predictions.

Maria Cecilia Bravo

2006-06-30T23:59:59.000Z

180

The effective approach for predicting viscosity of saturated and undersaturated reservoir oil  

E-Print Network (OSTI)

Predicting reservoir oil viscosity with numerical correlation equations using field-measured variables is widely used in the petroleum industry. Most published correlation equations, however, have never profoundly realized the genuine relationship between the reservoir oil viscosity and other field-measured parameters. Using the proposed systematic strategy is an effective solution for achieving a high performance correlation equation of reservoir oil viscosity. The proposed strategy begins with creating a large database of pressure-volumetemperature (PVT) reports and screening all possible erroneous data. The relationship between the oil viscosity and other field-measured parameters is intensively analyzed by using theoretical and empirical approaches to determine the influential parameters for correlating reservoir oil viscosity equations. The alternating conditional expectation (ACE) algorithm is applied for correlating saturated and undersaturated oil viscosity equations. The precision of field-measured PVT data is inspected by a data reconciliation technique in order to clarify the correctness of oil viscosity correlations. Finally, the performance of the proposed oil viscosity correlation equations is represented in terms of statistical error analysis functions. The result of this study shows that reservoir oil density turns out to be the most effective parameter for correlating both saturated and undersaturated reservoir oil viscosity equations. Expected errors in laboratory-measured oil viscosity are the main factors that degrade the efficiency of oil viscosity correlation equations. The proposed correlation equations provide a reasonable estimate of reservoir oil viscosity; and their superior performance is more reliable than that of published correlation equations at any reservoir conditions.

Kulchanyavivat, Sawin

2005-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Tailored ramp-loading via shock release of stepped-density reservoirs  

Science Conference Proceedings (OSTI)

The concept of a gradient piston drive has been extended from that of a single component reservoir, such as a high explosive, to that of a multi-component reservoir that utilizes low density foams and large shocks to achieve high pressures ({approx}3.5 mbar) and controlled pressure vs. time profiles on a driven sample. Simulated and experimental drives shaped through the use of multiple component (including carbonized resorcinol formaldehyde and SiO{sub 2} foam) reservoirs are compared. Individual density layers in a multiple component reservoir are shown to correlate with velocity features in the measured drive which enables the ability to tune a pressure drive by adjusting the components of the reservoir. Pre-shot simulations are shown to be in rough agreement with the data, but post-shot simulations involving the use of simulated plasma drives were needed to achieve an exact match. Results from a multiple component reservoir shot ({approx}3.5 mbar) at the National Ignition Facility are shown.

Prisbrey, Shon T.; Park, Hye-Sook; Remington, Bruce A.; Cavallo, Robert; May, Mark; Pollaine, Stephen M.; Rudd, Robert; Maddox, Brian; Comley, Andrew; Fried, Larry; Blobaum, Kerri; Wallace, Russ; Wilson, Mike; Swift, David; Satcher, Joe; Kalantar, Dan; Perry, Ted [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Giraldez, Emilio; Farrell, Michael; Nikroo, Abbas [General Atomics, San Diego, California 92186 (United States)

2012-05-15T23:59:59.000Z

182

Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs  

Science Conference Proceedings (OSTI)

This document reports progress of this research effort in identifying possible relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. Based on a critical review of the available literature, a better understanding of the main weaknesses of the current state of the art of modeling and simulation for tight sand reservoirs has been reached. Progress has been made in the development and implementation of a simple reservoir simulator that is still able to overcome some of the deficiencies detected. The simulator will be used to quantify the impact of microscopic phenomena in the macroscopic behavior of tight sand gas reservoirs. Phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization are being considered as part of this study. To date, the adequate modeling of gas slippage in porous media has been determined to be of great relevance in order to explain unexpected fluid flow behavior in tight sand reservoirs.

Maria Cecilia Bravo; Mariano Gurfinkel

2005-06-30T23:59:59.000Z

183

Developing a tight gas sand advisor for completion and stimulation in tight gas reservoirs worldwide  

E-Print Network (OSTI)

As the demand for energy worldwide increases, the oil and gas industry will need to increase recovery from unconventional gas reservoirs (UGR). UGRs include Tight Gas Sand (TGS), coalbed methane and gas shales. To economically produce UGRs, one must have adequate product price and one must use the most current technology. TGS reservoirs require stimulation as a part of the completion, so improvement of completion practices is very important. We did a thorough literature review to extract knowledge and experience about completion and stimulation technologies used in TGS reservoirs. We developed the principal design and two modules of a computer program called Tight Gas Sand Advisor (TGS Advisor), which can be used to assist engineers in making decisions while completing and stimulating TGS reservoirs. The modules include Perforation Selection and Proppant Selection. Based on input well/reservoir parameters these subroutines provide unambiguous recommendations concerning which perforation strategy(s) and what proppant(s) are applicable for a given well. The most crucial parameters from completion best-practices analyses and consultations with experts are built into TGS Advisor's logic, which mimics human expert's decision-making process. TGS Advisor's recommended procedures for successful completions will facilitate TGS development and improve economical performance of TGS reservoirs.

Bogatchev, Kirill Y

2007-12-01T23:59:59.000Z

184

Developing a tight gas sand advisor for completion and stimulation in tight gas reservoirs worldwide  

E-Print Network (OSTI)

As the demand for energy worldwide increases, the oil and gas industry will need to increase recovery from unconventional gas reservoirs (UGR). UGRs include Tight Gas Sand (TGS), coalbed methane and gas shales. To economically produce UGRs, one must have adequate product price and one must use the most current technology. TGS reservoirs require stimulation as a part of the completion, so improvement of completion practices is very important. We did a thorough literature review to extract knowledge and experience about completion and stimulation technologies used in TGS reservoirs. We developed the principal design and two modules of a computer program called Tight Gas Sand Advisor (TGS Advisor), which can be used to assist engineers in making decisions while completing and stimulating TGS reservoirs. The modules include Perforation Selection and Proppant Selection. Based on input well/reservoir parameters these subroutines provide unambiguous recommendations concerning which perforation strategy(s) and what proppant(s) are applicable for a given well. The most crucial parameters from completion best-practices analyses and consultations with experts are built into TGS Advisor’s logic, which mimics human expert’s decision-making process. TGS Advisor’s recommended procedures for successful completions will facilitate TGS development and improve economical performance of TGS reservoirs.

Bogatchev, Kirill Y.

2007-12-01T23:59:59.000Z

185

Geotechnical studies of geothermal reservoirs  

DOE Green Energy (OSTI)

It is proposed to delineate the important factors in the geothermal environment that will affect drilling. The geologic environment of the particular areas of interest are described, including rock types, geologic structure, and other important parameters that help describe the reservoir and overlying cap rock. The geologic environment and reservoir characteristics of several geothermal areas were studied, and drill bits were obtained from most of the areas. The geothermal areas studied are: (1) Geysers, California, (2) Imperial Valley, California, (3) Roosevelt Hot Springs, Utah, (4) Bacca Ranch, Valle Grande, New Mexico, (5) Jemez Caldera, New Mexico, (6) Raft River, Idaho, and (7) Marysville, Montona. (MHR)

Pratt, H.R.; Simonson, E.R.

1976-01-01T23:59:59.000Z

186

Optimization Online - Managing Hydroelectric Reservoirs over an ...  

E-Print Network (OSTI)

Jul 7, 2013 ... Managing Hydroelectric Reservoirs over an Extended Planning Horizon using a Benders Decomposition Algorithm Exploiting a Memory Loss ...

187

Prevention of Reservoir Interior Discoloration  

SciTech Connect

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.

Arnold, K.F.

2001-04-03T23:59:59.000Z

188

HIGH TEMPERATURE GEOTHERMAL RESERVOIR ENGINEERING  

E-Print Network (OSTI)

on the Cerro P r i e t o Geothermal F i e l d , Mexicali,e C e r r o P r i e t o Geothermal F i e l d , Baja C a l i1979 HIGH TEMPERATURE GEOTHERMAL RESERVOIR ENGINEERING R.

Schroeder, R.C.

2009-01-01T23:59:59.000Z

189

Shear-slip analysis in multiphase fluid-flow reservoir engineeringap plications using TOUGH-FLAC  

DOE Green Energy (OSTI)

This paper describes and demonstrates the use of the coupledTOUGH-FLAC simulator for geomechanical shear-slip (failure) analysis inmultiphase fluid-flow reservoir-engineering applications. Two approachesfor analyzing shear-slip are described, one using continuum stress-strainanalysis and another using discrete fault analysis. The use of shear-slipanalysis in TOUGH-FLAC is demonstrated on application examples related toCO2 sequestration and geothermal energy extraction. In the case of CO2sequestration, the shear-slip analysis is used to evaluate maximumsustainable CO2-injection pressure under increasing reservoir pressure,whereas in the case of geothermal energy extraction, the shear-slipanalysis is used to study induced seismicity during steam productionunder decreasing reservoir pressure and temperature.

Rutqvist, Jonny; Birkholzer, Jens; Cappa, Frederic; Oldenburg,Curt; Tsang, Chin-Fu

2006-01-15T23:59:59.000Z

190

Nutrient transport model in CHAHNIMEH manmade reservoirs  

Science Conference Proceedings (OSTI)

A Model for predicting nutrient transport to CHAHNIMEH reservoir is developed in this paper. Nitrogen and phosphorous have been simulated as the important parameters in evaluating water quality in the reservoir. Solar radiation and wind flow are considered ... Keywords: CHAHNIMEH, modeling, nutrient, reservoir, transport, water movement

Seyyed Ahmad Mirbagheri; Seyyed Arman Hashemi Monfared

2008-08-01T23:59:59.000Z

191

Tenth workshop on geothermal reservoir engineering: proceedings  

DOE Green Energy (OSTI)

The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

Not Available

1985-01-22T23:59:59.000Z

192

Eutrophication modelling of reservoirs in Taiwan  

Science Conference Proceedings (OSTI)

Two reservoirs in Taiwan were modeled to simulate the hydrodynamics and water quality in the water column. The modelling effort was supported with data collected in the field for a 2-year period for both reservoirs. Spatial and temporal distributions ... Keywords: CE-QUAL-W2, Reservoir Eutrophication Modelling, Water quality

Jan-Tai Kuo; Wu-Seng Lung; Chou-Ping Yang; Wen-Cheng Liu; Ming-Der Yang; Tai-Shan Tang

2006-06-01T23:59:59.000Z

193

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

SciTech Connect

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

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

2001-08-07T23:59:59.000Z

194

Sixth workshop on geothermal reservoir engineering: Proceedings  

SciTech Connect

INTRODUCTION TO THE PROCEEDINGS OF THE SIXTH GEOTHERMAL RESERVOIR ENGINEERING WORKSHOP, STANFORD GEOTHERMAL PROGRAM Henry J. Ramey, Jr., and Paul Kruger Co-Principal Investigators Ian G. Donaldson Program Manager Stanford Geothermal Program The Sixth Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 16, 1980. As with previous Workshops the attendance was around 100 with a significant participation from countries other than the United States (18 attendees from 6 countries). In addition, there were a number of papers from foreign contributors not able to attend. Because of the success of all the earlier workshops there was only one format change, a new scheduling of Tuesday to Thursday rather than the earlier Wednesday through Friday. This change was in general considered for the better and will be retained for the Seventh Workshop. Papers were presented on two and a half of the three days, the panel session, this year on the numerical modeling intercomparison study sponsored by the Department of Energy, being held on the second afternoon. This panel discussion is described in a separate Stanford Geothermal Program Report (SGP-TR42). This year there was a shift in subject of the papers. There was a reduction in the number of papers offered on pressure transients and well testing and an introduction of several new subjects. After overviews by Bob Gray of the Department of Energy and Jack Howard of Lawrence Berkeley Laboratory, we had papers on field development, geopressured systems, production engineering, well testing, modeling, reservoir physics, reservoir chemistry, and risk analysis. A total of 51 papers were contributed and are printed in these Proceedings. It was, however, necessary to restrict the presentations and not all papers printed were presented. Although the content of the Workshop has changed over the years, the format to date has proved to be satisfactory. The objectives of the Workshop, the bringing together of researchers, engineers and managers involved in geothermal reservoir study and development and the provision of a forum for the prompt and open reporting of progress and for the exchange of ideas, continue to be met . Active discussion by the majority of the participants is apparent both in and outside the workshop arena. The Workshop Proceedings now contain some of the most highly cited geothermal literature. Unfortunately, the popularity of the Workshop for the presentation and exchange of ideas does have some less welcome side effects. The major one is the developing necessity for a limitation of the number of papers that are actually presented. We will continue to include all offered papers in the Summaries and Proceedings. As in the recent past, this sixth Workshop was supported by a grant from the Department of Energy. This grant is now made directly to Stanford as part of the support for the Stanford Geothermal Program (Contract No. DE-AT03-80SF11459). We are certain that all participants join us in our appreciation of this continuing support. Thanks are also due to all those individuals who helped in so many ways: The members of the program committee who had to work so hard to keep the program to a manageable size - George Frye (Aminoil USA), Paul G. Atkinson (Union Oil Company). Michael L. Sorey (U.S.G.S.), Frank G. Miller (Stanford Geothermal Program), and Roland N. Horne (Stanford Geothermal Program). The session chairmen who contributed so much to the organization and operation of the technical sessions - George Frye (Aminoil USA), Phillip H. Messer (Union Oil Company), Leland L. Mink (Department of Energy), Manuel Nathenson (U.S.G.S.), Gunnar Bodvarsson (Oregon State University), Mohindar S. Gulati (Union Oil Company), George F. Pinder (Princeton University), Paul A. Witherspoon (Lawrence Berkeley Laboratory), Frank G. Miller (Stanford Geothermal Program) and Michael J. O'Sullivan (Lawrence Berkeley Laboratory). The many people who assisted behind the scenes, making sure that everything was prepared and organized - in particular we would like

Ramey, H.J. Jr.; Kruger, P. (eds.)

1980-12-18T23:59:59.000Z

195

Sixth workshop on geothermal reservoir engineering: Proceedings  

DOE Green Energy (OSTI)

INTRODUCTION TO THE PROCEEDINGS OF THE SIXTH GEOTHERMAL RESERVOIR ENGINEERING WORKSHOP, STANFORD GEOTHERMAL PROGRAM Henry J. Ramey, Jr., and Paul Kruger Co-Principal Investigators Ian G. Donaldson Program Manager Stanford Geothermal Program The Sixth Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 16, 1980. As with previous Workshops the attendance was around 100 with a significant participation from countries other than the United States (18 attendees from 6 countries). In addition, there were a number of papers from foreign contributors not able to attend. Because of the success of all the earlier workshops there was only one format change, a new scheduling of Tuesday to Thursday rather than the earlier Wednesday through Friday. This change was in general considered for the better and will be retained for the Seventh Workshop. Papers were presented on two and a half of the three days, the panel session, this year on the numerical modeling intercomparison study sponsored by the Department of Energy, being held on the second afternoon. This panel discussion is described in a separate Stanford Geothermal Program Report (SGP-TR42). This year there was a shift in subject of the papers. There was a reduction in the number of papers offered on pressure transients and well testing and an introduction of several new subjects. After overviews by Bob Gray of the Department of Energy and Jack Howard of Lawrence Berkeley Laboratory, we had papers on field development, geopressured systems, production engineering, well testing, modeling, reservoir physics, reservoir chemistry, and risk analysis. A total of 51 papers were contributed and are printed in these Proceedings. It was, however, necessary to restrict the presentations and not all papers printed were presented. Although the content of the Workshop has changed over the years, the format to date has proved to be satisfactory. The objectives of the Workshop, the bringing together of researchers, engineers and managers involved in geothermal reservoir study and development and the provision of a forum for the prompt and open reporting of progress and for the exchange of ideas, continue to be met . Active discussion by the majority of the participants is apparent both in and outside the workshop arena. The Workshop Proceedings now contain some of the most highly cited geothermal literature. Unfortunately, the popularity of the Workshop for the presentation and exchange of ideas does have some less welcome side effects. The major one is the developing necessity for a limitation of the number of papers that are actually presented. We will continue to include all offered papers in the Summaries and Proceedings. As in the recent past, this sixth Workshop was supported by a grant from the Department of Energy. This grant is now made directly to Stanford as part of the support for the Stanford Geothermal Program (Contract No. DE-AT03-80SF11459). We are certain that all participants join us in our appreciation of this continuing support. Thanks are also due to all those individuals who helped in so many ways: The members of the program committee who had to work so hard to keep the program to a manageable size - George Frye (Aminoil USA), Paul G. Atkinson (Union Oil Company). Michael L. Sorey (U.S.G.S.), Frank G. Miller (Stanford Geothermal Program), and Roland N. Horne (Stanford Geothermal Program). The session chairmen who contributed so much to the organization and operation of the technical sessions - George Frye (Aminoil USA), Phillip H. Messer (Union Oil Company), Leland L. Mink (Department of Energy), Manuel Nathenson (U.S.G.S.), Gunnar Bodvarsson (Oregon State University), Mohindar S. Gulati (Union Oil Company), George F. Pinder (Princeton University), Paul A. Witherspoon (Lawrence Berkeley Laboratory), Frank G. Miller (Stanford Geothermal Program) and Michael J. O'Sullivan (Lawrence Berkeley Laboratory). The many people who assisted behind the scenes, making sure that everything was prepared and organized - in particular we would like to t

Ramey, H.J. Jr.; Kruger, P. (eds.)

1980-12-18T23:59:59.000Z

196

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

SciTech Connect

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

Not Available

1991-10-01T23:59:59.000Z

197

A discrete fracture model for a hot dry rock geothermal reservoir  

DOE Green Energy (OSTI)

Modeling results are presented for the Fenton Hill Phase II reservoir using a two-dimensional steady state simulator of fluid flow and solute transport in fractured porous media. Fluid flow and tracer response data are simulated using a fracture flow model in which the fracture apertures are string functions of pressure. The model is used to match the available steady state data of pressure drop versus flow rate and the tracer data. Various schemes for improving reservoir performance, such as high backpressure, chemical etching, stimulation using a viscous fluid, and the drilling of a second production wellbore, are then examined. 15 refs., 7 figs., 4 tabs.

Robinson, B.A.

1989-01-01T23:59:59.000Z

198

Blackfoot Reservoir Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

Blackfoot Reservoir Geothermal Area Blackfoot Reservoir Geothermal Area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermal Resource Area: Blackfoot Reservoir Geothermal Area Contents 1 Area Overview 2 History and Infrastructure 3 Regulatory and Environmental Issues 4 Exploration History 5 Well Field Description 6 Geology of the Area 7 Geofluid Geochemistry 8 NEPA-Related Analyses (0) 9 Exploration Activities (3) 10 References Area Overview Geothermal Area Profile Location: Idaho Exploration Region: Northern Basin and Range Geothermal Region GEA Development Phase: 2008 USGS Resource Estimate Mean Reservoir Temp: Estimated Reservoir Volume: Mean Capacity: Click "Edit With Form" above to add content History and Infrastructure Operating Power Plants: 0 No geothermal plants listed.

199

4. International reservoir characterization technical conference  

Science Conference Proceedings (OSTI)

This volume contains the Proceedings of the Fourth International Reservoir Characterization Technical Conference held March 2-4, 1997 in Houston, Texas. The theme for the conference was Advances in Reservoir Characterization for Effective Reservoir Management. On March 2, 1997, the DOE Class Workshop kicked off with tutorials by Dr. Steve Begg (BP Exploration) and Dr. Ganesh Thakur (Chevron). Tutorial presentations are not included in these Proceedings but may be available from the authors. The conference consisted of the following topics: data acquisition; reservoir modeling; scaling reservoir properties; and managing uncertainty. Selected papers have been processed separately for inclusion in the Energy Science and Technology database.

NONE

1997-04-01T23:59:59.000Z

200

Geothermal reservoir at Tatapani Geothermal field, Surguja district, Madhya Pradesh, IN  

SciTech Connect

The Tatapani Geothermal field, located on the Son-Narmada mega lineament is one of the most intense geothermal manifestation, with hot spring temperature of 98°c. in Central India. 21 Exploratory and thermal gradient boreholes followed by 5 production wells for proposed 300 KWe binary cycle power plant, have revealed specific reservoir parameters of shallow geothermal reservoir of 110°c in upper 350 m of geothermal system and their possible continuation to deeper reservoir of anticipated temperature of 160 ± 10°c. Testing of five production wells done by Oil and Natural Gas Corporation concurrently with drilling at different depths and also on completion of drilling, have established feeder zones of thermal water at depth of 175-200 m, 280-300 m, maximum temperature of 112.5°c and bottom hole pressure of 42 kg/cm˛. Further interpretation of temperature and pressure profiles, injection test, well head discharges and chemical analysis data has revealed thermal characteristics of individual production wells and overall configuration of .thermal production zones with their permeability, temperature, and discharge characteristics in the shallow thermal reservoir area. Well testing data and interpretation of reservoir parameters therefrom, for upper 350 m part of geothermal system and possible model of deeper geothermal reservoir at Tatapani have been presented in the paper.

Pitale, U.L.; Sarolkar, P.B.; Rawat, H.S.; Shukia, S.N.

1996-01-24T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Design and life-cycle considerations for unconventional-reservoir wells  

Science Conference Proceedings (OSTI)

This paper provides an overview of design and life-cycle considerations for certain unconventional-reservoir wells. An overview of unconventional-reservoir definitions is provided. Well design and life-cycle considerations are addressed from three aspects: upfront reservoir development, initial well completion, and well-life and long-term considerations. Upfront-reservoir-development issues discussed include well spacing, well orientation, reservoir stress orientations, and tubular metallurgy. Initial-well-completion issues include maximum treatment pressures and rates, treatment diversion, treatment staging, flowback and cleanup, and dewatering needs. Well-life and long-term discussions include liquid loading, corrosion, refracturing and associated fracture reorientation, and the cost of abandonment. These design considerations are evaluated with case studies for five unconventional-reservoir types: shale gas (Barnett shale), tight gas (Jonah feld), tight oil (Bakken play), coalbed methane (CBM) (San Juan basin), and tight heavy oil (Lost Hills field). In evaluating the life cycle and design of unconventional-reservoir wells, 'one size' does not fit all and valuable knowledge and a shortening of the learning curve can be achieved for new developments by studying similar, more-mature fields.

Miskimins, J.L. [Colorado School of Mines, Golden, CO (United States)

2009-05-15T23:59:59.000Z

202

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

SciTech Connect

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.

Bhat, Suniti Kumar; Kovscek, Anthony R.

1999-08-09T23:59:59.000Z

203

1995 verification flow testing of the HDR reservoir at Fenton Hill, New Mexico  

Science Conference Proceedings (OSTI)

Recent flow testing of the Fenton Hill HDR reservoir has demonstrated that engineered geothermal systems can be shut-in for extended periods of d= with apparently no adverse effects. However, when this particular reservoir at Venton Hill was shut-in for 2 years in a pressurized condition, natural convection within the open-jointed reservoir region appears to have leveled out the preexisting temperature gradient so that the gradient has now approached a condition more typical of liquid-dominated hydrothermal reservoirs which air invariably almost isothermal due to natural convection. As a result of the sudden flow impedance reduction that led to an almost 50% increase in Production flow new the end of the Second Phase of the LTFR in May 1993, we were uncertain as to the state of the reservoir after being shut-in for 2 years. The flow performance observed during the current testing was found to be intermediate between that at-the end of the Second Phase of the LTFT and that following, the subsequent sudden flow increase, implying that whatever caused the sudden reduction in impedance in the first place is probably somehow associated with the cooldown of the reservoir near the injection interval, since temperature recovery at the surfaces of the surrounding open joints is the most obvious phenomenon expected to occur over time within the reservoir.

Brown, D.

1995-01-01T23:59:59.000Z

204

Laboratory experiments simulating fire flooding through a fractured reservoir  

SciTech Connect

Low-permeability heavy-oil reservoirs are considered to be poor prospects for in-situ-combustion recovery methods. The low-permeability, high-viscosity heavy oils, combined, make air injection through the formation insufficient to support combustion in the formation. The objective of this research is to show results obtained through burn tests on whole cores and fractured cores relating these results to heavy-oil reservoirs. These tests were performed to determine the technical feasibility of recovering heavy oil by the in-situ-combustion process from reservoirs which are shallow and contain no reservoir energy. These tests were conducted on cores obtained from a heavy-oil reservoir near Bartlett, Kansas. The tests were performed in a thin-walled core holder with a built-in heater to start combustion. Air was measured and injected through the heater and into the core. The produced fluids (oil and water) were obtained and measured and the resulting effluent gas was measured and analyzed on a chromatograph to determine the constituents of the produced gas. The injected air pressure was determined and temperature logs were plotted during the entire test. It was determined from the results of the tests on competent cores that 78 percent of the oil was removed from the cores as a result of the in-situ-combustion process on competent cores while 16 percent was used as fuel for combustion. The results from the tests on fractured cores show that 33 percent of the oil was removed from the cores as a result of the in-situ-combustion process while 45 percent was used as fuel for combustion. The results from the tests on fractured cores held apart by propping agents show that 16 percent of the oil was removed from the cores as a result of the in-situ-combustion process, while 38 percent was used as fuel to support combustion. 46 figures, 56 tables.

Miller, J.S.; Jones, R.

1983-04-01T23:59:59.000Z

205

Hot Dry Rock Geothermal Reservoir Model Development at Los Alamos  

DOE Green Energy (OSTI)

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

Robinson, Bruce A.; Birdsell, Stephen A.

1989-03-21T23:59:59.000Z

206

Hot Dry Rock geothermal reservoir model development at Los Alamos  

DOE Green Energy (OSTI)

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

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

1989-01-01T23:59:59.000Z

207

Numerical modeling of water injection into vapor-dominatedgeothermal reservoirs  

SciTech Connect

Water injection has been recognized as a powerful techniquefor enhancing energy recovery from vapor-dominated geothermal systemssuch as The Geysers. In addition to increasing reservoir pressures,production well flow rates, and long-term sustainability of steamproduction, injection has also been shown to reduce concentrations ofnon-condensible gases (NCGs) in produced steam. The latter effectimproves energy conversion efficiency and reduces corrosion problems inwellbores and surface lines.This report reviews thermodynamic andhydrogeologic conditions and mechanisms that play an important role inreservoir response to water injection. An existing general-purposereservoir simulator has been enhanced to allow modeling of injectioneffects in heterogeneous fractured reservoirs in three dimensions,including effects of non-condensible gases of different solubility.Illustrative applications demonstrate fluid flow and heat transfermechanisms that are considered crucial for developing approaches to insitu abatement of NCGs.

Pruess, Karsten

2006-11-06T23:59:59.000Z

208

EXPERIMENTAL VERIFICATION OF THE LOAD-FOLLOWING POTENTIAL OF A HOT DRY ROCK GEOTHERMAL RESERVOIR  

E-Print Network (OSTI)

Figure 1. Transient Shut-in Pressure Profiles for the Injection and Production Wells. Conversely, when. During this entire period of cyclic production, the pressure at the injection well was maintained experience. The control system on the injection well worked adequately until the 4-hour pulsed flow period

209

Geothermal Reservoir Engineering Research. Fourth annual report, October 1, 1983-September 30, 1984  

DOE Green Energy (OSTI)

Reservoir definition research consisted of well test analysis and bench-scale experiments. Well testing included both single-well pressure drawdown and buildup testing, and multiple-well interference testing. The development of new well testing methods continued to receive major emphasis during the year. Work included a project on multiphase compressibility, including the thermal content of the rock. Several projects on double-porosity systems were completed, and work was done on relative-permeability. Heat extraction from rock will determine the long-term response of geothermal reservoirs to development. The work in this task area involved a combination of physical and mathematical modeling of heat extraction from fractured geothermal reservoirs. International cooperative research dealt with adsorption of water on reservoir cores, the planning of tracer surveys, and an injection and tracer test in the Los Azufres fields. 32 refs.

Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.

1984-09-01T23:59:59.000Z

210

Geothermal reservoir engineering, second workshop summaries, December 1-3, 1976  

DOE Green Energy (OSTI)

Workshop proceedings included the following: (1) During the Overview Session some papers, among others, discussed 'Geothermal Reservoir Engineering Research' and 'Geothermal Reservoir Engineering in Industry'; (2) Session I, Reservoir Physics, included papers on 'Steam Zone Temperature Gradients at the Geysers' and 'Water Influx in a Steam Producing Well'; (3) Session II, Well Testing, included papers on 'Borehole Geophysics in Geothermal Wells--Problems and Progress' and 'Herber-Pressure Interference Study'; (4) Session III, Field Development, included papers on 'A Reservoir Engineering Study of the East Mesa KGRA' and 'Determining the Optimal Rate of Geothermal Energy Extraction'; (5) Session IV, Well Stimulation, included papers on 'Fluid Flow Through a Large Vertical Crack in the Earth's Crust' and 'Explosive Stimulation of Geothermal Wells'; and (6) Session V, Modeling, included papers on 'Steam Transport in Porous Media' and 'Large-Scale Geothermal Field Parameters and Convection Theory.'

Kruger, P.; Ramey, H.J. Jr.

1976-12-01T23:59:59.000Z

211

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

DOE Green Energy (OSTI)

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

Garg, S.K. [S-Cubed, La Jolla, CA (United States); Combs, J. [Geo Hills Associates, Los Altos Hills, CA (United States)

1993-06-01T23:59:59.000Z

212

Reservoir engineering studies of small low-temperature hydrothermal systems in Iceland  

SciTech Connect

Geothermal energy provides more than one third of the energy consumed in Iceland. Its primary use is for space heating and most of the 28 public hitaveitur (district heating services) in Iceland utilize small low-temperature geothermal fields that have a natural heat output of only a few 100 kW{sub t} to a few MW{sub t}. All of these small reservoirs respond to production by declining pressure and some by declining temperature. During the 1980's the emphasis in geothermal research in Iceland shifted from exploration to reservoir engineering. The reservoir engineering work carried out concurrent with the exploitation of these small fields includes: testing of individual wells, field wide tests, monitoring the response of reservoirs to long-term production and simple modeling.

Axelsson, Gudni

1991-01-01T23:59:59.000Z

213

Geomechanical Development of Fractured Reservoirs During Gas Production  

E-Print Network (OSTI)

Within fractured reservoirs, such as tight gas reservoir, coupled processes between matrix deformation and fluid flow are very important for predicting reservoir behavior, pore pressure evolution and fracture closure. To study the coupling between gas desorption and rock matrix/fracture deformation, a poroelastic constitutive relation is developed and used for deformation of gas shale. Local continuity equation of dry gas model is developed by considering the mass conservation of gas, including both free and absorbed phases. The absorbed gas content and the sorption-induced volumetric strain are described through a Langmiur-type equation. A general porosity model that differs from other empirical correlations in the literature is developed and utilized in a finite element model to coupled gas diffusion and rock mass deformation. The dual permeability method (DPM) is implemented into the Finite Element Model (FEM) to investigate fracture deformation and closure and its impact on gas flow in naturally fractured reservoir. Within the framework of DPM, the fractured reservoir is treated as dual continuum. Two independent but overlapping meshes (or elements) are used to represent these kinds of reservoirs: one is the matrix elements used for deformation and fluid flow within matrix domain; while the other is the fracture element simulating the fluid flow only through the fractures. Both matrix and fractures are assumed to be permeable and can accomodate fluid transported. A quasi steady-state function is used to quantify the flow that is transferred between rock mass and fractures. By implementing the idea of equivalent fracture permeability and shape-factor within the transfer function into DPM, the fracture geometry and orientation are numerically considered and the complexity of the problem is well reduced. Both the normal deformation and shear dilation of fractures are considered and the stress-dependent fracture aperture can be updated in time. Further, a non-linear numerical model is constructed by implementing a poroviscoelastic model into the dual permeability (DPM)-finite element model (FEM) to investigate the coupled time-dependent viscoelastic deformation, fracture network evolution and compressible fluid flow in gas shale reservoir. The viscoelastic effect is addressed in both deviatoric and symmetric effective stresses to emphasize the effect of shear strain localization on fracture shear dilation. The new mechanical model is first verified with an analytical solution in a simple wellbore creep problem and then compared with the poroelastic solution in both wellbore and field cases.

Huang, Jian

2013-05-01T23:59:59.000Z

214

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

Science Conference Proceedings (OSTI)

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

Not Available

1992-11-01T23:59:59.000Z

215

An integrated study of the reservoir performance in the Area Central Norte (ACN) region of the Tordillo Field (Argentina)  

E-Print Network (OSTI)

The Tordillo Field is located within the San Jorge Basin of southern Argentina. The field is located within a small, dominantly extension basin, and is operated by Tecpetrol S.A., a domestic private oil company. The field produces from the El TreboL Comodoro Rivadavia, and Mina El Carmen Formations and is estimated to contain approximately 1,800 MMSTB of in-place oil. The Area Central Norte (ACN) region is a designated portion of the TordiHo Field in which a pilot waterflood was initiated in September 1993. There are immediate plans for expanding the pilot waterflood, and therefore, it is imperative that we evaluate the reservoir properties, as well as the reservoir production potential in order to design the most effective field development plan. Our integrated study of reservoir performance in the ACN pilot area, combining the geological, engineering, and reservoir performance data, is utilized to characterize the reservoir and to develop an appropriate reservoir management plan. This study win be used to determine the feasibility of expanding secondary recovery efforts throughout the Tordiflo Field by developing a reservoir description that includes the reservoir structure, rock and fluid properties, and the performance potential of the reservoir. The main focus of this work is to evaluate primary and secondary well performance in a highly stratified sequence of oil producing sands. In this study, we use rigorous methods to analyze and interpret production rate, injection rate, and pressure data from oil and water injection wells using decline type curves and estimated ultimate recovery (EUR) analysis. These methods are shown to yield excellent results for a variety of field conditions, without regard to the structure of the reservoir (shape and size), or the reservoir drive mechanism(s). Results of these analyses include the following: eservo rties: 0 Fonnation permeability, k łSkin factor, s, for near-well damage or stimulation In-pplace fluid volumes: łOriginal oil-in-place, N ł Reservoir drainage area, A łMovable oil at current conditions, Np,,,,,, We examined the available core and modem well log data to develop an understanding for the petrophysical (k and 0) properties of the reservoir. These results will help us determine if reservoir performance is directly influenced by the geologic structure and flow characteristics of the reservoir. By combing the geological, petrophysical, and reservoir performance data in this manner, we are able to develop an integrated reservoir description for future developments as well as production optimization.

Tuvio, Raul

1997-01-01T23:59:59.000Z

216

Modeling and Analysis of Reservoir Response to Stimulation by Water Injection  

E-Print Network (OSTI)

The distributions of pore pressure and stresses around a fracture are of interest in conventional hydraulic fracturing operations, fracturing during water-flooding of petroleum reservoirs, shale gas, and injection/extraction operations in a geothermal reservoir. During the operations, the pore pressure will increase with fluid injection into the fracture and leak off to surround the formation. The pore pressure increase will induce the stress variations around the fracture surface. This can cause the slip of weakness planes in the formation and cause the variation of the permeability in the reservoir. Therefore, the investigation on the pore pressure and stress variations around a hydraulic fracture in petroleum and geothermal reservoirs has practical applications. The stress and pore pressure fields around a fracture are affected by: poroelastic, thermoelastic phenomena as well as by fracture opening under the combined action of applied pressure and in-situ stress. In our study, we built up two models. One is a model (WFPSD model) of water-flood induced fracturing from a single well in an infinite reservoir. WFPSD model calculates the length of a water flood fracture and the extent of the cooled and flooded zones. The second model (FracJStim model) calculates the stress and pore pressure distribution around a fracture of a given length under the action of applied internal pressure and in-situ stresses as well as their variation due to cooling and pore pressure changes. In our FracJStim model, the Structural Permeability Diagram is used to estimate the required additional pore pressure to reactivate the joints in the rock formations of the reservoir. By estimating the failed reservoir volume and comparing with the actual stimulated reservoir volume, the enhanced reservoir permeability in the stimulated zone can be estimated. In our research, the traditional two dimensional hydraulic fracturing propagation models are reviewed, the propagation and recession of a poroelastic PKN hydraulic fracturing model are studied, and the pore pressure and stress distributions around a hydraulically induced fracture are calculated and plotted at a specific time. The pore pressure and stress distributions are used to estimate the failure potentials of the joints in rock formations around the hydraulic fracture. The joint slips and rock failure result in permeability change which can be calculated under certain conditions. As a case study and verification step, the failure of rock mass around a hydraulic fracture for the stimulation of Barnett Shale is considered. With the simulations using our models, the pore pressure and poro-induced stresses around a hydraulic fracture are elliptically distributed near the fracture. From the case study on Barnett Shale, the required additional pore pressure is about 0.06 psi/ft. With the given treatment pressure, the enhanced permeability after the stimulation of hydraulic fracture is calculated and plotted. And the results can be verified by previous work by Palmer, Moschovidis and Cameron in 2007.

Ge, Jun

2009-12-01T23:59:59.000Z

217

Storage capacity in hot dry rock reservoirs  

DOE Patents (OSTI)

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

Brown, D.W.

1997-11-11T23:59:59.000Z

218

Exploration, Drilling and Development Operations in the Bottle Rock Area of the Geysers Steam Field, With New Geologic Insights and Models Defining Reservoir Parameters  

Science Conference Proceedings (OSTI)

MCR Geothermal Corporation pioneered successful exploratiory drilling the Bottle Rock area of the Geysers Steam Field in 1976. The wellfield is characterized by a deep reservoir with varied flowrates, temperatures, pressures, and stem chemistries being quite acceptable. More detailed reservoir engineering tests will follow as production commences.

Hebein, Jeffrey J.

1983-12-15T23:59:59.000Z

219

IMPROVING CO2 EFFICIENCY FOR RECOVERING OIL IN HETEROGENEOUS RESERVOIRS  

Science Conference Proceedings (OSTI)

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

Reid B. Grigg

2003-10-31T23:59:59.000Z

220

Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs  

SciTech Connect

During this last period of the ''Seismic Evaluation of Hydrocarbon Saturation in Deep-Water Reservoirs'' project (Grant/Cooperative Agreement DE-FC26-02NT15342), we finalized integration of rock physics, well log analysis, seismic processing, and forward modeling techniques. Most of the last quarter was spent combining the results from the principal investigators and come to some final conclusions about the project. Also much of the effort was directed towards technology transfer through the Direct Hydrocarbon Indicators mini-symposium at UH and through publications. As a result we have: (1) Tested a new method to directly invert reservoir properties, water saturation, Sw, and porosity from seismic AVO attributes; (2) Constrained the seismic response based on fluid and rock property correlations; (3) Reprocessed seismic data from Ursa field; (4) Compared thin layer property distributions and averaging on AVO response; (5) Related pressures and sorting effects on porosity and their influence on DHI's; (6) Examined and compared gas saturation effects for deep and shallow reservoirs; (7) Performed forward modeling using geobodies from deepwater outcrops; (8) Documented velocities for deepwater sediments; (9) Continued incorporating outcrop descriptive models in seismic forward models; (10) Held an open DHI symposium to present the final results of the project; (11) Relations between Sw, porosity, and AVO attributes; (12) Models of Complex, Layered Reservoirs; and (14) Technology transfer Several factors can contribute to limit our ability to extract accurate hydrocarbon saturations in deep water environments. Rock and fluid properties are one factor, since, for example, hydrocarbon properties will be considerably different with great depths (high pressure) when compared to shallow properties. Significant over pressure, on the other hand will make the rocks behave as if they were shallower. In addition to the physical properties, the scale and tuning will alter our hydrocarbon indicators. Gas saturated reservoirs change reflection amplitudes significantly. The goal for the final project period was to systematically combine and document these various effects for use in deep water exploration and transfer this knowledge as clearly and effectively as possible.

Michael Batzle

2006-04-30T23:59:59.000Z

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221

Two-dimensional simulation of the Raft River geothermal reservoir and wells. [SINDA-3G program  

DOE Green Energy (OSTI)

Computer models describing both the transient reservoir pressure behavior and the time dependent temperature response of the wells at the Raft River, Idaho, Geothermal Resource were developed. A horizontal, two-dimensional, finite-difference model for calculating pressure effects was constructed to simulate reservoir performance. Vertical, two-dimensional, finite-difference, axisymmetric models for each of the three existing wells at Raft River were also constructed to describe the transient temperature and hydraulic behavior in the vicinity of the wells. All modeling was done with the use of the thermal hydraulics computer program SINDA-3G. The models are solved simultaneously with one input deck so that reservoir-well interaction may occur. The model predicted results agree favorably with the test data.

Kettenacker, W.C.

1977-03-01T23:59:59.000Z

222

Pressure oscillations caused by momentum on shut in of a high rate well in a fractured formation  

DOE Green Energy (OSTI)

Pressure transient testing techniques are an important part of reservoir and production testing procedures. These techniques are frequently used to determine practical information about underground reservoirs such as the permeability, porosity, liquid content, reservoir and liquid discontinuities and other related data. This information is valuable in helping to analyze, improve and forecast reservoir performance. This report is concerned with developing models for pressure transient well testing in high permeability, high flow rate, naturally fractured reservoirs. In the present work, a study was made of the effects of liquid inertia in the fractures and the wellbore on the pressure response obtained during a well test. The effects of turbulent flow and multi-phase flow effects such as gravitational segregation or anisotropic porous media effects were not considered. The scope of the study was limited to studying inertial effects on the pressure response of a fractured reservoir.

Bhatnagar, S.

1989-06-01T23:59:59.000Z

223

PROCEEDINGS, Thirty-Fifth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, February 1-3, 2010  

E-Print Network (OSTI)

and is in a 250-260 °C range. Under reservoir temperature and pressure conditions the geothermal fluid plant to 15 MWe (GB1+GB2) and was put into service in 2003. The consequent increase in geothermal fluid the geothermal fluid supplied to GB1. Over this period, the well-head pressures were monitored for each well

Stanford University

224

Geothermal reservoir well stimulation program. Final program summary report  

DOE Green Energy (OSTI)

Eight field experiments and the associated theoretical and laboratory work performed to develop the stimulation technology are described. A discussion of the pre-stimulation and post-stimulation data and their evaluation is provided for each experiment. Overall results have shown that stimulation is viable where adequate reservoirs are penetrated by wells encountering formation damage or locally tight formation zones. Seven of the eight stimulation experiments were at least technically successful in stimulating the wells. The two fracture treatments in East Mesa 58-30 more than doubled the producing rate of the previously marginal producer. The two fracture treatments at Raft River and the two at Baca were all successful in obtaining significant production from previously nonproductive intervals. However, these treatments failed to establish commercial production due to deficiencies in either fluid temperature or reservoir transmissivity. The Beowawe chemical stimulation treatment appears to have significantly improved the well's injectivity, but production data were not obtained because of well mechanical problems. The acid etching treatment in the well at the Geysers did not have any material effect on producing rate. Evaluations of the field experiments to date have suggested improvements in treatment design and treatment interval selection which offer substantial encouragement for future stimulation work.

Not Available

1984-01-01T23:59:59.000Z

225

Stimulation and reservoir engineering of geothermal resources. Second annual report, July 1, 1978-September 30, 1979  

DOE Green Energy (OSTI)

Individual projects are grouped under four main areas of study: energy extraction, bench-scale flow experiments, radon tracer techniques, and well test analysis. The energy extraction experiments concern the efficiency with which the in-place heat and fluids can be produced in the most economical manner. The bench-scale flow experiments cover the results of three models used to examine the properties of flow through porous media at elevated temperature and pressures. Random tracer techniques describe accelerated efforts to field test several geothermal reservoirs by both transient and transect test procedures. The well test analysis section describes several new developments: analysis of earth-tide effects, pressure transient analysis of multilayered systems, interference testing with storage and skin effects, determination of steam-water relative permeability from wellhead data, well test analysis for wells produced at constant pressure, the parallelepiped model, slug test DST analysis, and pressure transient behavior in naturally fractured reservoirs. (MHR)

Kruger, P.; Ramey, H.J. Jr.

1979-09-01T23:59:59.000Z

226

A virtual company concept for reservoir management  

SciTech Connect

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

Martin, F.D. [Dave Martin and Associates, Inc. (United States); Kendall, R.P.; Whitney, E.M. [Los Alamos National Lab., NM (United States)

1998-12-31T23:59:59.000Z

227

Producing Light Oil from a Frozen Reservoir: Reservoir and Fluid Characterization of Umiat Field, National Petroleum Reserve, Alaska  

Science Conference Proceedings (OSTI)

Umiat oil field is a light oil in a shallow, frozen reservoir in the Brooks Range foothills of northern Alaska with estimated oil-in-place of over 1 billion barrels. Umiat field was discovered in the 1940’s but was never considered viable because it is shallow, in the permafrost, and far from any transportation infrastructure. The advent of modern drilling and production techniques has made Umiat and similar fields in northern Alaska attractive exploration and production targets. Since 2008 UAF has been working with Renaissance Alaska Inc. and, more recently, Linc Energy, to develop a more robust reservoir model that can be combined with rock and fluid property data to simulate potential production techniques. This work will be used to by Linc Energy as they prepare to drill up to 5 horizontal wells during the 2012-2013 drilling season. This new work identified three potential reservoir horizons within the Cretaceous Nanushuk Formation: the Upper and Lower Grandstand sands, and the overlying Ninuluk sand, with the Lower Grandstand considered the primary target. Seals are provided by thick interlayered shales. Reserve estimates for the Lower Grandstand alone range from 739 million barrels to 2437 million barrels, with an average of 1527 million bbls. Reservoir simulations predict that cold gas injection from a wagon-wheel pattern of multilateral injectors and producers located on 5 drill sites on the crest of the structure will yield 12-15% recovery, with actual recovery depending upon the injection pressure used, the actual Kv/Kh encountered, and other geologic factors. Key to understanding the flow behavior of the Umiat reservoir is determining the permeability structure of the sands. Sandstones of the Cretaceous Nanushuk Formation consist of mixed shoreface and deltaic sandstones and mudstones. A core-based study of the sedimentary facies of these sands combined with outcrop observations identified six distinct facies associations with distinctive permeability trends. The Lower Grandstand sand consists of two coarsening-upward shoreface sands sequences while the Upper Grandstand consists of a single coarsening-upward shoreface sand. Each of the shoreface sands shows a distinctive permeability profile with high horizontal permeability at the top getting progressively poorer towards the base of the sand. In contrast, deltaic sandstones in the overlying Ninuluk are more permeable at the base of the sands, with decreasing permeability towards the sand top. These trends impart a strong permeability anisotropy to the reservoir and are being incorporated into the reservoir model. These observations also suggest that horizontal wells should target the upper part of the major sands. Natural fractures may superimpose another permeability pattern on the Umiat reservoir that need to be accounted for in both the simulation and in drilling. Examination of legacy core from Umiat field indicate that fractures are present in the subsurface, but don't provide information on their orientation and density. Nearby surface exposures of folds in similar stratigraphy indicate there are at least three possible fracture sets: an early, N/S striking set that may predate folding and two sets possibly related to folding: an EW striking set of extension fractures that are parallel to the fold axes and a set of conjugate shear fractures oriented NE and NW. Analysis of fracture spacing suggests that these natural fractures are fairly widely spaced (25-59 cm depending upon the fracture set), but could provide improved reservoir permeability in horizontal legs drilled perpendicular to the open fracture set. The phase behavior of the Umiat fluid needed to be well understood in order for the reservoir simulation to be accurate. However, only a small amount of Umiat oil was available; this oil was collected in the 1940’s and was severely weathered. The composition of this ‘dead’ Umiat fluid was characterized by gas chromatography. This analysis was then compared to theoretical Umiat composition derived using the Pedersen method with original Umiat

Hanks, Catherine

2012-12-31T23:59:59.000Z

228

A study to assess the value of post-stack seismic amplitude data in forecasting fluid production from a Gulf-of-Mexico reservoir  

E-Print Network (OSTI)

from a Gulf-of-Mexico reservoir Maika GambĂşs-Ordaz, Carlos Torres-VerdĂ­n The University of Texas in the Gulf of Mexico. The availability of measured time records of fluid production and pressure depletion

Torres-VerdĂ­n, Carlos

229

Slimholes for geothermal reservoir evaluation - An overview  

DOE Green Energy (OSTI)

The topics covered in this session include: slimhole testing and data acquisition, theoretical and numerical models for slimholes, and an overview of the analysis of slimhole data acquired by the Japanese. The fundamental issues discussed are concerned with assessing the efficacy of slimhole testing for the evaluation of geothermal reservoirs. the term reservoir evaluation is here taken to mean the assessment of the potential of the geothermal reservoir for the profitable production of electrical power. As an introduction to the subsequent presentations and discussions, a brief summary of the more important aspects of the use of slimholes in reservoir evaluation is given.

Hickox, C.E.

1996-08-01T23:59:59.000Z

230

Mapping Diffuse Seismicity for Geothermal Reservoir Management...  

Open Energy Info (EERE)

Facebook icon Twitter icon Mapping Diffuse Seismicity for Geothermal Reservoir Management with Matched Field Processing Geothermal Lab Call Project Jump to: navigation,...

231

Injecting Carbon Dioxide into Unconventional Storage Reservoirs...  

NLE Websites -- All DOE Office Websites (Extended Search)

will also be investigated with a targeted CO 2 injection test into a depleted shale gas well. Different reservoir models will be used before, during, and after injection...

232

Naturally fractured tight gas reservoir detection optimization  

SciTech Connect

Research continued on methods to detect naturally fractured tight gas reservoirs. This report discusses 3D-3C seismic acquisition and 3D P-wave alternate processing.

NONE

1995-12-31T23:59:59.000Z

233

Safety of Dams and Reservoirs Act (Nebraska)  

Energy.gov (U.S. Department of Energy (DOE))

This act regulates dams and associated reservoirs to protect health and public safety and minimize adverse consequences associated with potential dam failure. The act describes the responsibilities...

234

Storage capacity in hot dry rock reservoirs  

DOE Patents (OSTI)

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

Brown, Donald W. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

235

A Bayesian petrophysical decision support system for estimation of reservoir compositions  

Science Conference Proceedings (OSTI)

The exploration for oil and gas requires real-time petrophysical expertise to interpret measurement data acquired in boreholes and to recommend further steps. High time pressure and the far reaching nature of these decisions, as well as the limited opportunity ... Keywords: Bayesian inference, Decision support, Hybrid Monte Carlo, Oil and gas industry, Petrophysics, Reservoir estimation

Willem Burgers; Wim Wiegerinck; Bert Kappen; Mirano Spalburg

2010-12-01T23:59:59.000Z

236

SEISMIC AND ROCK PHYSICS DIAGNOSTICS OF MULTISCALE RESERVOIR TEXTURES  

Science Conference Proceedings (OSTI)

As part of our study on ''Relationships between seismic properties and rock microstructure'', we have (1) Studied relationships between velocity and permeability. (2) Used independent experimental methods to measure the elastic moduli of clay minerals as functions of pressure and saturation. (3) Applied different statistical methods for characterizing heterogeneity and textures from scanning acoustic microscope (SAM) images of shale microstructures. (4) Analyzed the directional dependence of velocity and attenuation in different reservoir rocks (5) Compared Vp measured under hydrostatic and non-hydrostatic stress conditions in sands. (6) Studied stratification as a source of intrinsic anisotropy in sediments using Vp and statistical methods for characterizing textures in sands.

Gary Mavko

2003-10-01T23:59:59.000Z

237

Injection in basin and range-type reservoirs: the Raft River experience  

DOE Green Energy (OSTI)

Injection testing at the Raft River KGRA has yielded some interesting results which can be useful in planning injection systems in Basin and Range type reservoirs. Because of inhomogeneities and possible fracturing in basin fill sediment, rapid pressure response to injection has been observed in one shallow monitor well, but not others. In some monitor wells in the injection field, pressure drops are observed during injection suggesting plastic deformation of the sediments. Seismicity, however, has not accompanied these observed water level changes.

Petty, S.; Spencer, S.

1981-01-01T23:59:59.000Z

238

Advanced Oil Recovery Technologies for Improved Recovery From Slope Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico  

Science Conference Proceedings (OSTI)

The overall goal of this project is to demonstrate that an advanced development drilling and pressure maintenance program based on advanced reservoir management methods can significantly improve oil recovery. The plan included developing a control area using standard reservoir management techniques and comparing its performance to an area developed using advanced methods. A key goal is to transfer advanced methodologies to oil and gas producers in the Permian Basin and elsewhere, and throughout the US oil and gas industry.

Mark B. Murphy

1998-01-30T23:59:59.000Z

239

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

Science Conference Proceedings (OSTI)

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

Clarkson, Christopher R [ORNL

2011-01-01T23:59:59.000Z

240

ADVANCED OIL RECOVERY TECHNOLOGIES FOR IMPROVED RECOVERY FROM SLOPE BASIN CLASTIC RESERVOIRS, NASH DRAW BRUSHY CANYON POOL, EDDY COUNTY, NM  

SciTech Connect

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

Mark B. Murphy

2004-01-31T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

ADVANCED OIL RECOVERY TECHNOLOGIES FOR IMPROVED RECOVERY FROM SLOPE BASIN CLASTIC RESERVOIRS, NASH DRAW BRUSHY CANYON POOL, EDDY COUNTY, NM  

SciTech Connect

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

Mark B. Murphy

2003-10-31T23:59:59.000Z

242

ADVANCED OIL RECOVERY TECHNOLOGIES FOR IMPROVED RECOVERY FROM SLOPE BASIN CLASTIC RESERVOIRS, NASH DRAW BRUSHY CANYON POOL, EDDY COUNTY, NM  

SciTech Connect

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

Mark B. Murphy

2002-12-31T23:59:59.000Z

243

ADVANCED OIL RECOVERY TECHNOLOGIES FOR IMPROVED RECOVERY FROM SLOPE BASIN CLASTIC RESERVOIRS, NASH DRAW BRUSHY CANYON POOL, EDDY COUNTY, NM  

Science Conference Proceedings (OSTI)

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

Mark B. Murphy

2003-07-30T23:59:59.000Z

244

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

Science Conference Proceedings (OSTI)

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

Koerner, Roy; Clarke, Don; Walker, Scott

1999-11-09T23:59:59.000Z

245

ADVANCED TECHNIQUES FOR RESERVOIR SIMULATION AND MODELING OF NONCONVENTIONAL WELLS  

Science Conference Proceedings (OSTI)

Nonconventional wells, which include horizontal, deviated, multilateral and ''smart'' wells, offer great potential for the efficient management of oil and gas reservoirs. These wells are able to contact larger regions of the reservoir than conventional wells and can also be used to target isolated hydrocarbon accumulations. The use of nonconventional wells instrumented with downhole inflow control devices allows for even greater flexibility in production. Because nonconventional wells can be very expensive to drill, complete and instrument, it is important to be able to optimize their deployment, which requires the accurate prediction of their performance. However, predictions of nonconventional well performance are often inaccurate. This is likely due to inadequacies in some of the reservoir engineering and reservoir simulation tools used to model and optimize nonconventional well performance. A number of new issues arise in the modeling and optimization of nonconventional wells. For example, the optimal use of downhole inflow control devices has not been addressed for practical problems. In addition, the impact of geological and engineering uncertainty (e.g., valve reliability) has not been previously considered. In order to model and optimize nonconventional wells in different settings, it is essential that the tools be implemented into a general reservoir simulator. This simulator must be sufficiently general and robust and must in addition be linked to a sophisticated well model. Our research under this five year project addressed all of the key areas indicated above. The overall project was divided into three main categories: (1) advanced reservoir simulation techniques for modeling nonconventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and for coupling the well to the simulator (which includes the accurate calculation of well index and the modeling of multiphase flow in the wellbore); and (3) accurate approaches to account for the effects of reservoir heterogeneity and for the optimization of nonconventional well deployment. An overview of our progress in each of these main areas is as follows. A general purpose object-oriented research simulator (GPRS) was developed under this project. The GPRS code is managed using modern software management techniques and has been deployed to many companies and research institutions. The simulator includes general black-oil and compositional modeling modules. The formulation is general in that it allows for the selection of a wide variety of primary and secondary variables and accommodates varying degrees of solution implicitness. Specifically, we developed and implemented an IMPSAT procedure (implicit in pressure and saturation, explicit in all other variables) for compositional modeling as well as an adaptive implicit procedure. Both of these capabilities allow for efficiency gains through selective implicitness. The code treats cell connections through a general connection list, which allows it to accommodate both structured and unstructured grids. The GPRS code was written to be easily extendable so new modeling techniques can be readily incorporated. Along these lines, we developed a new dual porosity module compatible with the GPRS framework, as well as a new discrete fracture model applicable for fractured or faulted reservoirs. Both of these methods display substantial advantages over previous implementations. Further, we assessed the performance of different preconditioners in an attempt to improve the efficiency of the linear solver. As a result of this investigation, substantial improvements in solver performance were achieved.

Louis J. Durlofsky; Khalid Aziz

2004-08-20T23:59:59.000Z

246

Effects of confining pressure, pore pressure and temperature on absolute permeability. SUPRI TR-27  

SciTech Connect

This study investigates absolute permeability of consolidated sandstone and unconsolidated sand cores to distilled water as a function of the confining pressure on the core, the pore pressure of the flowing fluid and the temperature of the system. Since permeability measurements are usually made in the laboratory under conditions very different from those in the reservoir, it is important to know the effect of various parameters on the measured value of permeability. All studies on the effect of confining pressure on absolute permeability have found that when the confining pressure is increased, the permeability is reduced. The studies on the effect of temperature have shown much less consistency. This work contradicts the past Stanford studies by finding no effect of temperature on the absolute permeability of unconsolidated sand or sandstones to distilled water. The probable causes of the past errors are discussed. It has been found that inaccurate measurement of temperature at ambient conditions and non-equilibrium of temperature in the core can lead to a fictitious permeability reduction with temperature increase. The results of this study on the effect of confining pressure and pore pressure support the theory that as confining pressure is increased or pore pressure decreased, the permeability is reduced. The effects of confining pressure and pore pressure changes on absolute permeability are given explicitly so that measurements made under one set of confining pressure/pore pressure conditions in the laboratory can be extrapolated to conditions more representative of the reservoir.

Gobran, B.D.; Ramey, H.J. Jr.; Brigham, W.E.

1981-10-01T23:59:59.000Z

247

Impact of injection on reservoir performance in the NCPA steam field at The Geysers  

SciTech Connect

A managed injection program implemented by the NCPA in The Southeast Geysers reservoir continues to positively impact reservoir performance. Injection effects are determined by the application of geochemical and geophysical techniques to track the movement of injectate. This information, when integrated with reservoir pressure, flowrate, and thermodynamic data, is used to quantify the overall performance and efficiency of the injection program. Data analysis indicates that injected water is boiling near the injection wells, without deeper migration, and is recovered as superheated steam from nearby production wells. Injection derived steam (IDS) currently accounts for 25 to 35 percent of total production in the NCPA steamfield. Most importantly, 80 to 100% of the injectate is flashing and being recovered as steam. The amount of IDS has increased since 1988 due to both a change in injection strategy and a drying out of the reservoir. However, significant areas of the reservoir still remain relatively unaffected by injection because of the limited amount of injectate presently available. That the reservoir has been positively impacted in the injection areas is evidenced by a decrease in the rate of pressure decline from 1989 through 1992. Correspondingly, there has been a reduction in the rate of steam flow decline in the areas' production wells. Conversely, little evidence of reservoir cooling or thermal breakthrough is shown even in areas where IDS accounts for 80 percent or more of production. Finally, since injection water is a relatively low-gas source of steam, noncondensible gas concentrations have been reduced in some steam wells located within the injection dominated areas.

Enedy, S.L.; Smith, J.L.; Yarter, R.E.; Jones, S.M.; Cavote, P.E.

1993-01-28T23:59:59.000Z

248

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

SciTech Connect

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

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

1997-04-10T23:59:59.000Z

249

River Flow Forecasting for Reservoir management through Neural Networks  

Science Conference Proceedings (OSTI)

In utilities using a mixture of hydroelectric and nonhydroelectric power, the economics of the hydroelectric plants depend upon the reservoir height and the inflow into the reservoir for several months into the future. Accurate forecasts of reservoir ...

Meuser Valenca; Teresa Ludermir; Anelle Valenca

2005-12-01T23:59:59.000Z

250

Unsteady Flow Model for Fractured Gas Reservoirs  

Science Conference Proceedings (OSTI)

Developing low permeability reservoirs is currently a big challenge to the industry. Because low permeability reservoirs are of low quality and are easily damaged, production from a single well is low, and there is unlikely to be any primary recovery. ... Keywords: Low permeability, Fractured well, Orthogonal transformation, Unsteady, Productivity

Li Yongming; Zhao Jinzhou; Gong Yang; Yao Fengsheng; Jiang Youshi

2010-12-01T23:59:59.000Z

251

Water resources review: Wheeler Reservoir, 1990  

DOE Green Energy (OSTI)

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

Wallus, R.; Cox, J.P.

1990-09-01T23:59:59.000Z

252

Geothermal reservoir insurance study. Final report  

DOE Green Energy (OSTI)

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

Not Available

1981-10-09T23:59:59.000Z

253

Measuring Frac-pack Conductivity at Reservoir Temperature and High Closure Stress  

E-Print Network (OSTI)

Ultra-deepwater reservoirs are important non-conventional reservoirs that hold the potential to produce billions of barrels of hydrocarbons but present major challenges. Hydraulic fracturing or frac-packing high permeability reservoirs is different from the conventional hydraulic fracturing technology used in low permeability formations. While the main purpose of the conventional technique is to create a long, highly conductive path, frac-packing on the other hand is used predominantly to get past near wellbore formation damage, control sand production and reduce near wellbore pressure drop. Ultra-deepwater reservoirs are usually high temperature and high pressure with high permeabilities. Frac-packing these types of wells requires short fractures packed with high proppant concentrations. Understanding the behavior of the fracture fluid and proppant is critical to pump such a job successfully and to ensure long term productivity from the fracture. A series of laboratory experiments have been conducted to research the different problems resulting from high temperature and pressure which negatively affect conductivity. Unlike conventional long-term conductivity measurements, we placed the proppant into the fracture and pumped fracture fluid through it and then measured conductivity by pumping oil to represent true reservoir conditions. Proppant performance and fracture fluids clean-up during production were examined. High strength proppant is ideal for deep fracture stimulations and in this study different proppant loadings at different stresses were tested to measure the impact of crushing and embedment on conductivity. The preliminary test results indicated that oil at reservoir conditions does improve clean-up of fracture fluid left back in the proppant pack. Increasing the proppant concentration in the fracture showed higher conductivity values even at high closure stress. The increase in effective closure stress with high temperature yielded significant loss in conductivity values as compared to those obtained from industry tests.

Fernandes, Preston X.

2009-08-01T23:59:59.000Z

254

Reservoir characterization of the Upper and Lower Repetto reservoirs of the Santa Clara field-federal waters, offshore California  

E-Print Network (OSTI)

This thesis presents the characterization of the Upper and Lower Repetto reservoirs of the Santa Clara field, which lies seven miles offshore of Ventura County, California. The approaches that we adopted for this reservoir characterization are based on the analysis of field production data. These reservoir characterization approaches include: The application of the Fetkovich/McCray decline type curve to estimate original oil-in-place, drainage area, flow capacity, and a skin factor for each well. This approach requires converting the field production data for each well to dimensionless decline flowrate, dimensionless rate integral, and dimensionless rate integral-derivative functions. These functions are then simultaneously plotted against dimensionless decline time so that a unique match of these plots can be obtained using the Fetkovich/McCray decline type curve (in this research, data conversion and type curve matching are performed using a software package). The analysis of plots of reciprocal production rate versus material balance time to estimate "movable" or recoverable oil reserves. This new material balance approach is used in conjunction with a semi-analytical method of graphical analysis (pressure drop normalized rate versus cumulative oil production), which also provides estimates of recoverable oil reserves. Together, these plotting techniques provide good estimates of the estimated ultimate recovery for each well. Our approaches for the analysis of field production data allow us to provide recovery factors for each well (using our estimates of original oil-in-place and estimated ultimate recovery). Furthermore, we were able to generate maps of original oil-in-place, estimated ultimate recovery, flow capacity, and permeability for both the Upper and Lower Repetto reservoirs.

Roco, Craig Emmitt

2000-01-01T23:59:59.000Z

255

Numerical Simulation of Injectivity Effects of Mineral Scaling and Clay Swelling in a Fractured Geothermal Reservoir  

DOE Green Energy (OSTI)

A major concern in the development of hot dry rock (HDR) and hot fractured rock (HFR) reservoirs is achieving and maintaining adequate injectivity, while avoiding the development of preferential short-circuiting flow paths such as those caused by thermally-induced stress cracking. Past analyses of HDR and HFR reservoirs have tended to focus primarily on the coupling between hydrology (flow), heat transfer, and rock mechanics. Recent studies suggest that rock-fluid interactions and associated mineral dissolution and precipitation effects could have a major impact on the long-term performance of HFR reservoirs. The present paper uses recent European studies as a starting point to explore chemically-induced effects of fluid circulation in HFR systems. We examine ways in which the chemical composition of reinjected waters can be modified to improve reservoir performance by maintaining or even enhancing injectivity. Chemical manipulations considered here include pH modification and dilution with fresh water. We performed coupled thermo-hydrologic-chemical simulations in which the fractured medium was represented by a one-dimensional MINC model (multiple interacting continua), using the non-isothermal multi-phase reactive geochemical transport code TOUGHREACT. Results indicate that modifying the injection water chemistry can enhance mineral dissolution and reduce clay swelling. Chemical interactions between rocks and fluids will change a HFR reservoir over time, with some changes favorable and others not. A detailed, quantitative understanding of processes and mechanisms can suggest chemical methods for reservoir management, which may be employed to improve the performance of the geothermal system.

Xu, Tianfu; Pruess, Karsten

2004-05-10T23:59:59.000Z

256

Characterization of oil and gas reservoir heterogeneity  

SciTech Connect

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.

Sharma, G.D.

1992-01-01T23:59:59.000Z

257

Characterization of oil and gas reservoir heterogeneity  

SciTech Connect

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.

Sharma, G.D.

1991-01-01T23:59:59.000Z

258

Characterization of oil and gas reservoir heterogeneity  

SciTech Connect

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.

Sharma, G.D.

1992-01-01T23:59:59.000Z

259

Evaluating reservoir production strategies in miscible and immiscible gas-injection projects  

E-Print Network (OSTI)

Miscible gas injection processes could be among the most widely used enhanced oil recovery processes. Successful design and implementation of a miscible gas injection project depends upon the accurate determination of the minimum miscibility pressure (MMP) and other factors such as reservoir and fluid characterization. The MMP indicates the lowest pressure at which the displacement process becomes multicontact miscible. The experimental methods available for determining MMP are both costly and time consuming. Therefore, the use of correlations that prove to be reliable for a wide range of fluid types would likely be considered acceptable for preliminary screening studies. This work includes a comparative and critical evaluation of MMP correlations and thermodynamic models using an equation of state by PVTsim software. Application of gas injection usually entails substantial risk because of the technological sophistication and financial requirements to initiate the project. More detailed, comprehensive reservoir engineering and project monitoring are necessary for typical miscible flood projects than for other recovery methods. This project evaluated effects of important factors such as injection pressure, vertical-to-horizontal permeability ratio, well completion, relative permeability, and permeability stratification on the recovery efficiency from the reservoir for both miscible and immiscible displacements. A three-dimensional, three-phase, Peng-Robinson equation of state (PR-EOS) compositional simulator based on the implicit-pressure explicit-saturation (IMPES) technique was used to determine the sensitivity of miscible or immiscible oil recovery to suitable ranges of these reservoir parameters. Most of the MMP correlations evaluated in this study have proven not to consider the effect of fluid composition properly. In most cases, EOS-based models are more conservative in predicting MMP values. If screening methods identify a reservoir as a candidate for a miscible injection project, experimental MMP measurements should be conducted for specific gas-injection purposes. Simulation results indicated that injection pressure was a key parameter that influences oil recovery to a high degree. MMP appears to be the optimum injection pressure since the incremental oil recovery at pressures above the MMP is negligible and at pressures below the MMP recovery is substantially lower. Stratification, injection-well completion pattern, and vertical-to-horizontal permeability ratios could also affect the recovery efficiency of the reservoir in a variety of ways discussed in this work.

Farzad, Iman

2004-08-01T23:59:59.000Z

260

Monitoring downhole pressures and flow rates critical for underbalanced drilling  

Science Conference Proceedings (OSTI)

True underbalanced drilling, and not just flow drilling, requires thorough engineering and monitoring of downhole pressures and flow rates to ensure the formations are drilled without formation damage. Underbalanced drilling involves intentionally manipulating the bottom hole circulating pressure so that it is less than static reservoir pressure. This underbalanced pressure condition allows reservoir fluids to enter the well bore while drilling continues, preventing fluid loss and many causes of formation damage. Applied correctly, this technology can address problems of formation damage, lost circulation, and poor penetration rates. Another important benefit of drilling underbalanced is the ability to investigate the reservoir in real time. The paper discusses the reasons for under balanced drilling, creating underbalance, well site engineering, fluids handling, rotating flow divertor injection gas, survey techniques, data acquisition, operations, maintaining under-balance, routine drilling, rate of penetration, misconceptions, and economics.

Butler, S.D.; Rashid, A.U.; Teichrob, R.R. [Flow Drilling Engineering Ltd., Calgary, Alberta (Canada)

1996-09-16T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Utah Natural Gas, Wet After Lease Separation New Reservoir Discoveries...  

U.S. Energy Information Administration (EIA) Indexed Site

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Utah Natural Gas, Wet After Lease Separation New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0...

262

Utah Coalbed Methane Proved Reserves New Reservoir Discoveries...  

U.S. Energy Information Administration (EIA) Indexed Site

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Utah Coalbed Methane Proved Reserves New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1...

263

Utah Nonassociated Natural Gas, Reserves in Nonproducing Reservoirs...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs, Wet (Billion Cubic Feet) Utah Nonassociated Natural Gas, Reserves in Nonproducing Reservoirs, Wet (Billion Cubic Feet) Decade Year-0 Year-1...

264

A New Method for Treating Wells in Reservoir Simulation.  

E-Print Network (OSTI)

??A new method for formulating finite difference equations for reservoir simulation has been developed. It can be applied throughout the entire simulated reservoir or to… (more)

Gessel, Gregory M 1980-

2007-01-01T23:59:59.000Z

265

Louisiana--North Crude Oil Reserves in Nonproducing Reservoirs...  

Annual Energy Outlook 2012 (EIA)

Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Louisiana--North Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3...

266

The Influence of Reservoir Heterogeneity on Geothermal Fluid...  

NLE Websites -- All DOE Office Websites (Extended Search)

Alliance for Sustainable Energy, LLC. THE INFLUENCE OF RESERVOIR HETEROGENEITY ON GEOTHERMAL FLUID AND METHANE RECOVERY FROM A GEOPRESSURED GEOTHERMAL RESERVOIR Ariel Esposito...

267

EIA - Natural Gas Pipeline Network - Salt Cavern Storage Reservoir...  

U.S. Energy Information Administration (EIA) Indexed Site

Salt Cavern Underground Natural Gas Storage Reservoir Configuration Salt Cavern Underground Natural Gas Storage Reservoir Configuration Source: PB Energy Storage Services Inc....

268

Wyoming Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Wyoming Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

269

Illinois Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Illinois Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

270

Arkansas Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Arkansas Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

271

Florida Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Florida Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

272

Montana Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Montana Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

273

Kentucky Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Kentucky Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

274

Michigan Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Michigan Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

275

Pennsylvania Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Pennsylvania Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

276

Oklahoma Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Oklahoma Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

277

Colorado Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Colorado Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

278

Louisiana--South Onshore Crude Oil Reserves in Nonproducing Reservoirs...  

U.S. Energy Information Administration (EIA) Indexed Site

Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Louisiana--South Onshore Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2...

279

Effect of matrix shrinkage on permeability of coalbed methane reservoirs .  

E-Print Network (OSTI)

??The dynamic nature of coalbed methane reservoir permeability makes the continuous modeling of the flow process difficult. Knowledge of conventional reservoir modeling is of little… (more)

Tandon, Rohit, 1966-

1991-01-01T23:59:59.000Z

280

Borehole geophysics evaluation of the Raft River geothermal reservoir...  

Open Energy Info (EERE)

reservoir, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Borehole geophysics evaluation of the Raft River geothermal reservoir, Idaho Details...

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

California Federal Offshore Dry Natural Gas New Reservoir Discoveries...  

U.S. Energy Information Administration (EIA) Indexed Site

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) California Federal Offshore Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0...

282

Statistical study of seismicity associated with geothermal reservoirs...  

Open Energy Info (EERE)

reservoirs in California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Statistical study of seismicity associated with geothermal reservoirs in California...

283

Lower 48 States Crude Oil Reserves in Nonproducing Reservoirs...  

Gasoline and Diesel Fuel Update (EIA)

Reserves in Nonproducing Reservoirs (Million Barrels) Lower 48 States Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4...

284

Miscellaneous States Crude Oil Reserves in Nonproducing Reservoirs...  

Annual Energy Outlook 2012 (EIA)

Reserves in Nonproducing Reservoirs (Million Barrels) Miscellaneous States Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4...

285

New Mexico - East Dry Natural Gas New Reservoir Discoveries in...  

U.S. Energy Information Administration (EIA) Indexed Site

Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) New Mexico - East Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade...

286

New Mexico - West Dry Natural Gas New Reservoir Discoveries in...  

U.S. Energy Information Administration (EIA) Indexed Site

Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) New Mexico - West Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade...

287

Texas--State Offshore Crude Oil Reserves in Nonproducing Reservoirs...  

Annual Energy Outlook 2012 (EIA)

Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Texas--State Offshore Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2...

288

Boiling and condensation processes in the Cerro Prieto beta reservoir under exploitation  

DOE Green Energy (OSTI)

The deep Cerro Prieto (Baja California, Mexico) beta reservoir is offset vertically by the southwest-northeast trending, normal H fault. Under exploitation pressures in the upthrown block have decreased strongly resulting in boiling and high-enthalpy production fluids. Significant differences in fluid chemical and isotopic compositions are observed in the two parts of the reservoir and particularly in an anomalous zone associated with the H fault. These differences result from intense boiling and adiabatic steam condensation, as well as from leakage of overlying cooler water along the fault.

Truesdell, A. (Truesdell (Alfred), Menlo Park, CA (United States)); Manon, A.; Quijano, L. (Comision Federal de Electricidad, Morelia (Mexico)); Coplen, T. (Geological Survey, Reston, VA (United States)); Lippmann, M. (Lawrence Berkeley Lab., CA (United States))

1992-01-01T23:59:59.000Z

289

Secondary recovery of gas from Gulf Coast reservoirs  

SciTech Connect

Studies funded by the Gas Research Institute have provided insight into the investment decisions of a small operator engaged in SGR from an abandoned Frio sandstone reservoir in Galveston County, Texas. Favorable gas-brine ratios were obtained by rapid brine production using gas lift. The lowered reservoir pressure allowed imbibition-trapped gas bubbles to expand and merge, forming a mobile phase which greatly improved recovery. Brine was disposed by environmentally benign reinjection into a shallower, unconsolidated sand unit, although the disposal formation suffered permeability damage due to iron hydroxides in the brine. Brine solids were reduced by keeping oxygen out of the surface plumbing and performing gas-brine separation in several steps inside pressurized vessels. Periodic backflowing of the disposal well dislodged the damaged surface layer of the unconsolidated disposal sand, which was then removed from the hole by swabbing, exposing a fresh formation surface to the brine. This work has shown that the technical problems involved in secondary gas recovery can be overcome by using relatively simple solutions in line with the budget constraints of a small operator. Because secondary gas production occurs in known fields located near major gathering systems and transmission lines, it is expected to supply a significant portion of future domestic natural gas.

Soeder, D.J.; Randolph, P.L.

1989-03-01T23:59:59.000Z

290

Review of the geothermal reservoir well stimulation program  

SciTech Connect

The overall program and the four experimental fracture stimulation treatments completed to date are described. The GRWSP is organized into two phases. Phase I consists of studies (literature and theoretical), laboratory investigations, and numerical work. Phase II will include the planning, execution and evaluation of six well stimulation treatments which utilize the technology developed in Phase I. Two stimulation experiments were performed at the Raft River, Idaho, Known Geothermal Resource Area (KGRA) in late-1979. This is a naturally fractured, hard rock reservoir with a relatively low geothermal resource temperature (300/sup 0/F). A conventional planar hydraulic fracture job was performed in Well RRGP-5 and a Kiel dendritic (or reverse flow) technique was utilized in Well RRGP-4. In mid-1980, two stimulation experiments were performed at the East Mesa, California, KGRA. The stimulation of Well 58-30 provided the first geothermal well fracturing experience in a moderate temperature (350/sup 0/F/sup +/) reservoir with matrix type rock properties. The two treatments consisted of a conventional hydraulic fracture of a deep, low permeability zone and a minifrac Kiel treatment of a shallow, high permeability zone in the same well. The stimulation experiment results to date were evaluated using short-term production tests, conventional pressure transient analysis, interference pressure data, chemical and radioactive tracers, borehole acoustic televiewer surveys, and numerical models.

Campbell, D.A.; Hanold, R.J.; Sinclair, A.R.; Vetter, O.J.

1981-01-01T23:59:59.000Z

291

Analysis of injection tests in liquid-dominated geothermal reservoirs  

DOE Green Energy (OSTI)

The objective was to develop procedures for analyzing nonisothermal injection test data during the early phases of injection. In particular, methods for determining the permeability-thickness of the formation, skin factor of the well and tracking the movement of the thermal front have been developed. The techniques developed for interpreting injection pressure transients are closely akin to conventional groundwater and petroleum techniques for evaluating these parameters. The approach taken was to numerically simulate injection with a variety of temperatures, reservoir parameters and flowrates, in order to determine the characteristic responses due to nonisothermal injection. Two characteristic responses were identified: moving front dominated behavior and composite reservoir behavior. Analysis procedures for calculating the permeability-thickness of the formation and the skin factor of the well have been developed for each of these cases. In order to interpret the composite reservior behavior, a new concept has been developed; that of a ''fluid skin factor'', which accounts for the steady-state pressure buildup due to the region inside the thermal front. Based on this same concept, a procedure for tracking the movement of the thermal front has been established. The results also identify the dangers of not accounting the nonisothermal effects when analyzing injection test data. Both the permeability-thickness and skin factor of the well can be grossly miscalculated if the effects of the cold-region around the well are not taken into consideration. 47 refs., 30 figs., 14 tabs.

Benson, S.M.

1984-12-01T23:59:59.000Z

292

Description of the three-dimensional two-phase simulator shaft78 for use in geothermal reservoir studies  

DOE Green Energy (OSTI)

The algorithm of SHAFT78 is based on mass and energy-balance equations for two-phase flow in a porous medium. The basic differential equations are converted into integrated finite-difference form. This allows regular and irregular reservoir shapes to be handled with the same ease. The equations are solved semi-implicitly for discrete time steps. The present version of SHAFT78 treats the coupling between mass and energy flow in a noniterative way. Special provisions are made to compute phase transitions with high accuracy. The program was verified by computing a number of sample problems that previously had been investigated by other authors. Model studies reveal that two-phase geothermal reservoirs are capable of a great variety of pressure responses upon production. It is shown that the standard technique of estimating reserves by extrapolating a plot of p/Z vs cumulative production is not applicable to two-phase geothermal reservoirs. A bulk model (lumped parameters) was developed for a two-phase reservoir that admits an analytical solution for pressure decline upon production. From this it is concluded that in many cases pressure will be a linear function of cumulative production, with the slope allowing an estimate of total reservoir volume. Reserve assessment requires knowledge of average porosity and vapor saturation, which cannot be obtained from pressure decline curves.

Pruess, K.; Zerzan, J.M.; Schroeder, R.C.; Witherspoon, P.A.

1979-01-01T23:59:59.000Z

293

THE NATURAL THERMODYNAMIC STATE OF THE FLUIDS IN THE LOS AZUFRES GEOTHERMAL RESERVOIR  

DOE Green Energy (OSTI)

We have devised a simple method to assess the natural thermodynamic state of two-phase reservoirs. This is usually a complex task. The method is based on inferring sandface flowing pressures and enthalpies from production output (deliverability) curves, and then extrapolating to shutin conditions in the pressure-enthalpy plane. The method was applied to data from 10 wells of the Los Azufres geothermal field. Comparison of the results with measured pressures and temperatures showed that the method is reliable. We present detailed thermodynamic properties of the unperturbed reservoir fluid in the neighborhood of the wells studied, in tabular form. Moreover, we present a match to these results with a very simple model that allows reasonable estimates of natural thermodynamic conditions as functions of height above sea level. The present results have important implications for the assessment of the fluid reserves, which are suggested to be greater than previously thought.

Iglesias, E.R.; Arellano, V.M.; Gardias, A.

1985-01-22T23:59:59.000Z

294

Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies  

SciTech Connect

The project involves improving thermal recovery techniques in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. using advanced reservoir characterization and thermal production technologies. The existing steamflood in the Tar zone of Fault Block (FB) II-A has been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the existing steam drive area to improve thermal efficiency. (7) Installing a 2100 foot insulated, subsurface harbor channel crossing to supply steam to an island location. (8) Test a novel alkaline steam completion technique to control well sanding problems and fluid entry profiles. (9) Advanced reservoir management through computer-aided access to production and geologic data to integrate reservoir characterization, engineering, monitoring, and evaluation.

Scott Hara

1998-03-03T23:59:59.000Z

295

Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies  

SciTech Connect

The project involves improving thermal recovery techniques in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. using advanced reservoir characterization and thermal production technologies. The existing steamflood in the Tar zone of Fault Block (FB) II-A has been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the existing steam drive area to improve thermal efficiency. (7) Installing a 2100 foot insulated, subsurface harbor channel crossing to supply steam to an island location. (8) Test a novel alkaline steam completion technique to control well sanding problems and fluid entry profiles. (9) Advanced reservoir management through computer-aided access to production and geologic data to integrate reservoir characterization, engineering, monitoring, and evaluation. Summary of Technical Progress

Scott Hara

1997-08-08T23:59:59.000Z

296

Increasing Heavy Oil Reservers in the Wilmington Oil field Through Advanced Reservoir Characterization and Thermal Production Technologies  

SciTech Connect

The project involves improving thermal recovery techniques in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. using advanced reservoir characterization and thermal production technologies. The existing steamflood in the Tar zone of Fault Block (FB) 11-A has been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the existing steam drive area to improve thermal efficiency. (7) Installing a 2100 foot insulated, subsurface harbor channel crossing to supply steam to an island location. (8) Test a novel alkaline steam completion technique to control well sanding problems and fluid entry profiles. (9) Advanced reservoir management through computer-aided access to production and geologic data to integrate reservoir characterization, engineering, monitoring, and evaluation.

Hara, Scott [Tidelands Oil Production Co., Long Beach, CA (United States)

1997-05-05T23:59:59.000Z

297

Integrated reservoir characterization for the Mazari oil field, Pakistan  

E-Print Network (OSTI)

This thesis describes a field study performed on the Mazari oil field located in Sind province, Pakistan. We used an integrated reservoir characterization technique to incorporate the geological, petrophysical, and reservoir performance data to interpret historical reservoir performance, to assess and refine reservoir management activities, and to make plans for future reservoir developments. We used a modified approach to characterize within the mappable geological facies. Our approach is based on the Kozeny-Carmen equation and uses the concept of mean hydraulic radius. As part of our objective to characterize the reservoir, we tabulated reservoir characteristics for each hydraulic flow unit, and we presented estimates of in-place reserves. We evaluated reservoir performance potential using the production history, well tests and cased-hole well log surveys. Suggestions for reservoir management activities in conjunction with the evaluation of the reservoir performance are discussed in detail. Finally, we give recommendations for activities in reservoir development particularly infill drilling considerations and secondary recovery efforts.

Ashraf, Ejaz

1994-01-01T23:59:59.000Z

298

Optimizing reservoir management through fracture modeling  

DOE Green Energy (OSTI)

Fracture flow will become increasingly important to optimal reservoir management as exploration of geothermal reservoirs continues and as injection of spent fluid increases. The Department of Energy conducts research focused on locating and characterizing fractures, modeling the effects of fractures on movement of fluid, solutes, and heat throughout a reservoir, and determining the effects of injection on long-term reservoir production characteristics in order to increase the ability to predict with greater certainty the long-term performance of geothermal reservoirs. Improvements in interpreting and modeling geophysical techniques such as gravity, self potential, and aeromagnetics are yielding new information for the delineation of active major conduits for fluid flow. Vertical seismic profiling and cross-borehole electromagnetic techniques also show promise for delineating fracture zones. DOE funds several efforts for simulating geothermal reservoirs. Lawrence Berkeley Laboratory has adopted a continuum treatment for reservoirs with a fracture component. Idaho National Engineering Laboratory has developed simulation techniques which utilize discrete fractures and interchange of fluid between permeable matrix and fractures. Results of these research projects will be presented to industry through publications and appropriate public meetings. 9 refs.

Renner, J.L.

1988-01-01T23:59:59.000Z

299

Depletion modeling of liquid dominated geothermal reservoirs  

DOE Green Energy (OSTI)

Depletion models for liquid-dominated geothermal reservoirs are derived and presented. The depletion models are divided into two categories: confined and unconfined. For both cases depletion models with no recharge (or influx), and depletion models including recharge, are used to match field data from the Svartsengi high temperature geothermal field in Iceland. The influx models included with the mass and energy balances are adopted from the petroleum engineering literature. The match to production data from Svartsengi is improved when influx was included. The Schilthuis steady-state influx gives a satisfactory match. The finite aquifer method of Fetkovitch, and the unsteady state method of Hurst gave reasonable answers, but not as good. The best match is obtained using Hurst simplified solution when lambda = 1.3 x 10{sup -4} m{sup -1}. From the match the cross-sectional area of the aquifer was calculated as 3.6 km{sup 2}. The drawdown was predicted using the Hurst simplified method, and compared with predicted drawdown from a boiling model and an empirical log-log model. A large difference between the models was obtained. The predicted drawdown using the Hurst simplified method falls between the other two. Injection has been considered by defining the net rate as being the production rate minus the injection rate. No thermal of transient effects were taken into account. Prediction using three different net rates shows that the pressure can be maintained using the Hurst simplified method if there is significant fluid reinjection. 32 refs., 44 figs., 2 tabs.

Olsen, G.

1984-06-01T23:59:59.000Z

300

An Integrated Study of the Grayburg/San Andres Reservoir, Foster and South Cowden Fields, Ector County, Texas, Class II  

SciTech Connect

The objectives of the project were to: (1) Thoroughly understand the 60-year history of the field. (2) Develop a reservoir description using geology and 3D seismic. (3) Isolate the upper Grayburg in wells producing from multiple intervals to stop cross flow. (4) Re-align and optimize the upper Grayburg waterflood. (5) Determine well condition, identify re-frac candidates, evaluate the effectiveness of well work and obtain bottom hole pressure data for simulation utilizing pressure transient testing field wide. (6) Quantitatively integrate all the data to guide the field operations, including identification of new well locations utilizing reservoir simulation.

Trentham, Robert C.; Weinbrandt, Richard; Robinson, William C.; Widner, Kevin

2001-05-03T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

PROCESSING AND INTERPRETATION OF PRESSURE TRANSIENT DATA FROM PERMANENT DOWNHOLE GAUGES  

E-Print Network (OSTI)

reservoir pa- rameters, monitor reservoir conditions, develop recovery schemes, and forecast future well) to monitor the well performance in real time. This continuous monitoring enables engineers to observe ongoing complexities, since the pressure data are not mea- sured under well-designed conditions as in the conventional

302

The Performance of Fractured Horizontal Well in Tight Gas Reservoir  

E-Print Network (OSTI)

Horizontal wells have been used to increase reservoir recovery, especially in unconventional reservoirs, and hydraulic fracturing has been applied to further extend the contact with the reservoir to increase the efficiency of development. In the past, many models, analytical or numerical, were developed to describe the flow behavior in horizontal wells with fractures. Source solution is one of the analytical/semi-analytical approaches. To solve fractured well problems, source methods were advanced from point sources to volumetric source, and pressure change inside fractures was considered in the volumetric source method. This study aims at developing a method that can predict horizontal well performance and the model can also be applied to horizontal wells with multiple fractures in complex natural fracture networks. The method solves the problem by superposing a series of slab sources under transient or pseudosteady-state flow conditions. The principle of the method comprises the calculation of semi-analytical response of a rectilinear reservoir with closed outer boundaries. A statistically assigned fracture network is used in the study to represent natural fractures based on the spacing between fractures and fracture geometry. The multiple dominating hydraulic fractures are then added to the natural fracture system to build the physical model of the problem. Each of the hydraulic fractures is connected to the horizontal wellbore, and the natural fractures are connected to the hydraulic fractures through the network description. Each fracture, natural or hydraulically induced, is treated as a series of slab sources. The analytical solution of superposed slab sources provides the base of the approach, and the overall flow from each fracture and the effect between the fractures are modeled by applying superposition principle to all of the fractures. It is assumed that hydraulic fractures are the main fractures that connect with the wellbore and the natural fractures are branching fractures which only connect with the main fractures. The fluid inside of the branch fractures flows into the main fractures, and the fluid of the main fracture from both the reservoir and the branch fractures flows to the wellbore. Predicting well performance in a complex fracture network system is extremely challenged. The statistical nature of natural fracture networks changes the flow characteristic from that of a single linear fracture. Simply using the single fracture model for individual fracture, and then adding the flow from each fracture for the network could introduce significant error. This study provides a semi-analytical approach to estimate well performance in a complex fracture network system.

Lin, Jiajing

2011-12-01T23:59:59.000Z

303

Evaluation of testing and reservoir parameters in geothermal wells at Raft  

Open Energy Info (EERE)

testing and reservoir parameters in geothermal wells at Raft testing and reservoir parameters in geothermal wells at Raft River and Boise, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Evaluation of testing and reservoir parameters in geothermal wells at Raft River and Boise, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: Evaluating the Raft River and Boise, Idaho, resources by pump and injection tests require information on the geology, geochemistry, surficial and borehole geophysics, and well construction and development methods. Nonideal test conditions and a complex hydrogeologic system prevent the use of idealized mathematical models for data evaluation in a one-phase fluid system. An empirical approach is successfully used since it was observed that all valid pump and injection well pressure data for constant discharge

304

Effects of non-condensible gases on fluid recovery in fractured geothermal reservoirs  

DOE Green Energy (OSTI)

Numerical simulations are performed in order to investigate the effects of noncondensible gases (CO/sub 2/) on fluid recovery and matrix depletion in fractured geothermal reservoirs. The model used is that of a well producing at a constant bottomhole pressure from a two-phase fractured reservoir. The results obtained have received a complex fracture-matrix interaction due to the thermodynamics of H/sub 2/O-CO/sub 2/ mixtures. Although the matrix initially contributes fluids (liquid and gas) to the fractures, later on, the flow directions reverse and the fractures backflow fluids into the matrix. The amount of backflow depends primarily upon the flowing gas saturation in the fractures; the lower the flowing gas saturation in the fractures the more backflow. It is shown that the recoverable fluid reserves depend strongly on the amount of CO/sub 2/ present in the reservoir system.

Bodvarsson, G.S.; Gaulke, S.

1986-02-01T23:59:59.000Z

305

Quantitative model of vapor dominated geothermal reservoirs as heat pipes in fractured porous rock  

DOE Green Energy (OSTI)

We present a numerical model of vapor-dominated reservoirs which is based on the well-known conceptual model of White, Muffler, and Truesdell. Computer simulations show that upon heat recharge at the base, a single phase liquid-dominated geothermal reservoir in fractured rock with low matrix permeability will evolve into a two-phase reservoir with B.P.D. (boiling point-for-depth) pressure and temperature profiles. A rather limited discharge event through cracks in the caprock, involving loss of only a few percent of fluids in place, is sufficient to set the system off to evolve a vapor-dominated state. The attributes of this state are discussed, and some features requiring further clarification are identified. 26 refs., 5 figs.

Pruess, K.

1985-03-01T23:59:59.000Z

306

Reservoir evaluation tests on RRGE 1 and RRGE 2, Raft River Geothermal Project, Idaho  

DOE Green Energy (OSTI)

Results of the production and interference tests conducted on the geothermal wells RRGE 1 and RRGE 2 in Raft River Valley, Idaho during September--November, 1975 are presented. In all, three tests were conducted, two of them being short-duration production tests and one, a long duration interference test. In addition to providing estimates on the permeability and storage parameters of the geothermal reservoir, the tests also indicated the possible existence of barrier boundaries. The data collected during the tests also indicated that the reservoir pressure varies systematically in response to the changes in the Earth's gravitational field caused by the passage of the sun and the moon. Overall, the results of the tests indicate that the geothermal reservoir in southern Raft River valley is fairly extensive and significantly permeable and merits further exploration.

Narasimhan, T.N.; Witherspoon, P.A.

1977-05-01T23:59:59.000Z

307

Simulation of fracture fluid cleanup and its effect on long-term recovery in tight gas reservoirs  

E-Print Network (OSTI)

In the coming decades, the world will require additional supplies of natural gas to meet the demand for energy. Tight gas reservoirs can be defined as reservoirs where the formation permeability is so low (flowback procedures, production strategy, and reservoir conditions. Residual polymer in the fracture can reduce the effective fracture permeability and porosity, reduce the effective fracture half-length, and limit the well productivity. Our ability to mathematically model the fundamental physical processes governing fluid recovery in hydraulic fractures in the past has been limited. In this research, fracture fluid damage mechanisms have been investigated, and mathematical models and computer codes have been developed to better characterize the cleanup process. The codes have been linked to a 3D, 3-phase simulator to model and quantify the fracture fluid cleanup process and its effect on long-term gas production performances. Then, a comprehensive systematic simulation study has been carried out by varying formation permeability, reservoir pressure, fracture length, fracture conductivity, yield stress, and pressure drawdown. On the basis of simulation results and analyses, new ways to improve fracture fluid cleanup have been provided. This new progress help engineers better understand fracture fluid cleanup, improve fracture treatment design, and increase gas recovery from tight sand reservoirs, which can be extremely important as more tight gas reservoirs are developed around the world.

Wang, Yilin

2008-12-01T23:59:59.000Z

308

Reservoir compaction of the Belridge Diatomite and surface subsidence, south Belridge field, Kern County, California  

SciTech Connect

Surface subsidence due to reservoir compaction during production has been observed in many large oil fields. Subsidence is most obvious in coastal and offshore fields where inundation by the sea occurs. Well-known examples are Wilmington field in California and Ekofisk field in the North Sea. In South Belridge field, the Belridge Diatomite member of the late Miocene Reef Ridge Shale has proven prone to compaction during production. The reservoir, a high-porosity, low-permeability, highly compressive rock composed largely of diatomite and mudstone, is about 1,000 ft thick and lies at an average depth of 1,600 ft. Within the Belridge Diatomite, reservoir compaction due to withdrawal of oil and water in Sec. 12, T28S, R20E, MDB and M, was noticed after casing failures in producing wells began occurring and tension cracks, enlarged by hydrocompaction after a heavy rainstorm were observed. Surface subsidence in Sec. 12 has been monitored since April 1987, through the surveying of benchmark monuments. The average annualized subsidence rate during 1987 was {minus}1.86 ft/yr, {minus}0.92 ft/yr during 1988, and {minus}0.65 ft/yr during 1989; the estimated peak subsidence rate reached {minus}7.50 ft/yr in July 1985, after 1.5 yrs of production from the Belridge Diatomite reservoir. Since production from the Belridge Diatomite reservoir commenced in February 1984, the surface of the 160-ac producing area has subsided about 12.5 ft. This equates to an estimated reservoir compaction of 30 ft in the Belridge Diatomite and an average loss of reservoir porosity of 2.4% from 55.2 to 52.8%. Injection of water for reservoir pressure maintenance in the Belridge diatomite began in June 1987, and has been effective in mitigating subsidence to current rates and repressurizing the reservoir to near-initial pressure. An added benefit of water injection has been improved recovery of oil from the Belridge Diatomite by waterflood.

Bowersox, J.R.; Shore, R.A. (Mission Resources, Inc., Bakersfield, CA (USA))

1990-05-01T23:59:59.000Z

309

Geomechanical modeling of reservoir compaction, surface subsidence, and casing damage at the Belridge diatomite field  

Science Conference Proceedings (OSTI)

Geologic, and historical well failure, production, and injection data were analyzed to guide development of three-dimensional geomechanical models of the Belridge diatomite field, California. The central premise of the numerical simulations is that spatial gradients in pore pressure induced by production and injection in a low permeability reservoir may perturb the local stresses and cause subsurface deformation sufficient to result in well failure. Time-dependent reservoir pressure fields that were calculated from three-dimensional black oil reservoir simulations were coupled uni-directionally to three-dimensional non-linear finite element geomechanical simulations. The reservoir models included nearly 100,000 gridblocks (100--200 wells), and covered nearly 20 years of production and injection. The geomechanical models were meshed from structure maps and contained more than 300,000 nodal points. Shear strain localization along weak bedding planes that causes casing dog-legs in the field was accommodated in the model by contact surfaces located immediately above the reservoir and at two locations in the overburden. The geomechanical simulations are validated by comparison of the predicted surface subsidence with field measurements, and by comparison of predicted deformation with observed casing damage. Additionally, simulations performed for two independently developed areas at South Belridge, Sections 33 and 29, corroborate their different well failure histories. The simulations suggest the three types of casing damage observed, and show that although water injection has mitigated surface subsidence, it can, under some circumstances, increase the lateral gradients in effective stress, that in turn can accelerate subsurface horizontal motions. Geomechanical simulation is an important reservoir management tool that can be used to identify optimal operating policies to mitigate casing damage for existing field developments, and applied to incorporate the effect of well failure potential in economic analyses of alternative infilling and development options.

FREDRICH,JOANNE T.; DEITRICK,G.L.; ARGUELLO JR.,JOSE G.; DEROUFFIGNAC,E.P.

2000-05-01T23:59:59.000Z

310

A structurally complex and dynamic reservoir description for reservoir simulation, Kuparuk River Field, Alaska  

SciTech Connect

The Kupanuk River Field is a structurally complex giant oil field adjacent to the Prudhoe Bay Field on Alaska`s North Slope. Oil is reservoired within two Early Cretaceous shallow marine sandstone formations, separated stratigraphically by an erosionally truncated marine silt/shale. Subjected to several phases of tectonism, this highly compartmentalized reservoir has been developed on regular 160 acre direct line drive patterns. An integrated team of geoscientists and engineers from BP Exploration (Alaska) Inc. and ARCO Alaska Inc. is presently quantifying the benefits of infill drilling at Kuparuk, and identifying the best locations for well placement. The two primary reservoir characteristics believed to impact the effectiveness of infill drilling are large-scale reservoir heterogeneity, and reservoir comparmentation due to faulting. Multiple thin pay zones within the two reservoir intervals are isolated laterally by faults with magnitudes greater than pay zone thickness. A process and tools designed to construct and maintain a structurally complex reservoir description, shared by the geoscientists and reservoir engineers, are described. Cross-discipline integration is aided by the use of Tech*Logic`s IREX 3-D reservoir modeling and visualization application. The unique architecture of the IREX model allows for representation of very complex structural geometries, and facilitates iteration between reservoir description and simulation, along the seismic to simulation continuum. Modifications to the reservoir description are guided by well-level history matching within the constraints of all available geoscience information. The techniques described will be of particular interest to those working on reservoir description and simulation of structurally complex fields.

Walsh, T.P. [Alaska Petrotechnical Services Inc., Anchorage, AK (United States); Leander, M.H.; Wilcox, T.C. [BP Exploration (Alaska) Inc., Anchorage, AK (United States)] [and others

1995-08-01T23:59:59.000Z

311

Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements  

SciTech Connect

In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

Locke, C.D.; Salamy, S.P.

1991-09-01T23:59:59.000Z

312

Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements. Final report  

SciTech Connect

In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

Locke, C.D.; Salamy, S.P.

1991-09-01T23:59:59.000Z

313

Effects of capillarity and vapor adsorption in the depletion of vapor-dominated geothermal reservoirs  

DOE Green Energy (OSTI)

Vapor-dominated geothermal reservoirs in natural (undisturbed) conditions contain water as both vapor and liquid phases. The most compelling evidence for the presence of distributed liquid water is the observation that vapor pressures in these systems are close to saturated vapor pressure for measured reservoir temperatures (White et al., 1971; Truesdell and White, 1973). Analysis of natural heat flow conditions provides additional, indirect evidence for the ubiquitous presence of liquid. From an analysis of the heat pipe process (vapor-liquid counterflow) Preuss (1985) inferred that effective vertical permeability to liquid phase in vapor-dominated reservoirs is approximately 10{sup 17} m{sup 2}, for a heat flux of 1 W/m{sup 2}. This value appears to be at the high end of matrix permeabilities of unfractured rocks at The Geysers, suggesting that at least the smaller fractures contribute to liquid permeability. For liquid to be mobile in fractures, the rock matrix must be essentially completely liquid-saturated, because otherwise liquid phase would be sucked from the fractures into the matrix by capillary force. Large water saturation in the matrix, well above the irreducible saturation of perhaps 30%, has been shown to be compatible with production of superheated steam (Pruess and Narasimhan, 1982). In response to fluid production the liquid phase will boil, with heat of vaporization supplied by the reservoir rocks. As reservoir temperatures decline reservoir pressures will decline also. For depletion of ''bulk'' liquid, the pressure would decline along the saturated vapor pressure curve, while for liquid held by capillary and adsorptive forces inside porous media, an additional decline will arise from ''vapor pressure lowering''. Capillary pressure and vapor adsorption effects, and associated vapor pressure lowering phenomena, have received considerable attention in the geothermal literature, and also in studies related to geologic disposal of heat generating nuclear wastes, and in the drying of porous materials. Geothermally oriented studies were presented by Chicoine et al. (1977), Hsieh and Ramey (1978, 1981), Herkelrath et al. (1983), and Nghiem and Ramey (1991). Nuclear waste-related work includes papers by Herkelrath and O'Neal (1985), Pollock (1986), Eaton and Bixler (1987), Pruess et al. (1990), Nitao (1990), and Doughty and E'ruess (1991). Applications to industrial drying of porous materials have been discussed by Hamiathy (1969) arid Whitaker (1977). This paper is primarily concerned with evaluating the impact of vapor pressure lowering (VPL) effects on the depletion behavior of vapor-dominated reservoirs. We have examined experimental data on vapor adsorption and capillary pressures in an effort to identify constitutive relationships that would be applicable to the tight matrix rocks of vapor-dominated systems. Numerical simulations have been performed to evaluate the impact of these effects on the depletion of vapor-dominated reservoirs.

Pruess, Karsten; O'Sullivan, Michael

1992-01-01T23:59:59.000Z

314

Low-to-moderate-temperature hydrothermal reservoir engineering handbook  

DOE Green Energy (OSTI)

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.

Not Available

1982-06-01T23:59:59.000Z

315

Improved energy recovery from geothermal reservoirs  

DOE Green Energy (OSTI)

Numerical simulation methods are used to study how the exploitation of different horizons affects the behavior of a liquid-dominated geothermal reservoir. The reservoir model is a schematic representation of the Olkaria field in Kenya. The model consists of a two-phase vapor-dominated zone overlying the main liquid dominated reservoir. Four different cases were studied, with fluid produced from: 1) the vapor zone only, 2) the liquid zone only, 3) both zones and 4) both zones, but assuming lower values for vertical permeability and porosity. The results indicate that production from the shallow two-phase zone, although resulting in higher enthalpy fluids, may not be advantageous in the long run. Shallow production gives rise to a rather localized depletion of the reservoir, whereas production from deeper horizons may yield a more uniform depletion proces, if vertical permeability is sufficiently large.

Boedvarsson, G.S.; Pruess, K.; Lippmann, M.; Bjoernsson, S.

1981-06-01T23:59:59.000Z

316

Definition: Hydrothermal Reservoir | Open Energy Information  

Open Energy Info (EERE)

Hydrothermal Reservoirs are underground zones of porous rock containing hot water and steam, and can be naturally occurring or human-made.1 References x Ret LikeLike...

317

Heat deliverability of homogeneous geothermal reservoirs  

DOE Green Energy (OSTI)

For the last two decades, the petroleum industry has been successfully using simple inflow performance relationships (IPR's) to predict oil deliverability. In contrast, the geothermal industry lacked a simple and reliable method to estimate geothermal wells' heat deliverability. To address this gap in the standard geothermal-reservoir-assessment arsenal, we developed generalized dimensionless geothermal inflow performance relationships (GIPR's). These ''reference curves'' may be regarded as an approximate general solution of the equations describing the practically important case of radial 2-phase inflow. Based on this approximate solution, we outline a straightforward approach to estimate the reservoir contribution to geothermal wells heat and mass deliverability for 2-phase reservoirs. This approach is far less costly and in most cases as reliable as numerically modeling the reservoir, which is the alternative for 2-phase inflow.

Iglesias, Eduardo R.; Moya, Sara L.

1991-01-01T23:59:59.000Z

318

Heat deliverability of homogeneous geothermal reservoirs  

SciTech Connect

For the last two decades, the petroleum industry has been successfully using simple inflow performance relationships (IPR's) to predict oil deliverability. In contrast, the geothermal industry lacked a simple and reliable method to estimate geothermal wells' heat deliverability. To address this gap in the standard geothermal-reservoir-assessment arsenal, we developed generalized dimensionless geothermal inflow performance relationships (GIPR's). These ''reference curves'' may be regarded as an approximate general solution of the equations describing the practically important case of radial 2-phase inflow. Based on this approximate solution, we outline a straightforward approach to estimate the reservoir contribution to geothermal wells heat and mass deliverability for 2-phase reservoirs. This approach is far less costly and in most cases as reliable as numerically modeling the reservoir, which is the alternative for 2-phase inflow.

Iglesias, Eduardo R.; Moya, Sara L.

1991-01-01T23:59:59.000Z

319

Reservoir performance characterized in mature steam pattern  

Science Conference Proceedings (OSTI)

A detailed reservoir description provided new insight in an investigation of a ten-year-old steam flood. Mobil Oil Corporation conducted this study of the Pleistocene upper Tulare sands in South Belridge field, located in the San Joaquin basin, Kern County, California. The study area is on the gently dipping (6/degrees/) southwestern flank of the South Belridge anticline. Wireline logs from 19 wells in a 10-ac (660 ft x 660 ft) pattern were correlated in detail. Seven post-steam conventional cores (1523 ft) aided (1) the evaluation of vertical and lateral steam-sweep efficiency, (2) evaluation of reservoir and fluid changes due to steam, (3) influence of lithofacies in reservoir quality, and (4) provided insight to the three-dimensional reservoir flow-unit geometries.

Miller, D.D.; McPherson, J.G.; Covington, T.E.

1989-04-01T23:59:59.000Z

320

PROCEEDINGS TWENTIETH WORKSHOP GEOTHERMAL RESERVOIR ENGINEERING  

NLE Websites -- All DOE Office Websites (Extended Search)

a global reservoir value of the amount of adsorbed liquid water per kg of rock (called ADS in the present paper). We simulated the natural state with different values of ADS,...

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321

Characterization of geothermal reservoir crack patterns using...  

Open Energy Info (EERE)

the time delays of the split waves they determined tomographically the 3-D fracture density distribution in the reservoir. Author(s): Lou, M.; Rial, J.A. Published: Geophysics,...

322

Reservoir screening criteria for underbalanced drilling  

Science Conference Proceedings (OSTI)

Properly designed and executed underbalanced drilling operations can eliminate or significantly reduce formation damage, mud or drill solids invasion, lost circulation, fluid entrainment and trapping effects, and potential adverse reactions of drilling fluids with the reservoir matrix or in-situ reservoir fluids. The key to selecting appropriate reservoir candidates is achieving a balance of technical, safety and economic factors. Not every reservoir is an ideal candidate for an underbalanced drilling operation and in some cases distinct disadvantages may exist in trying to execute an underbalanced drilling operation in comparison to a simpler more conventional overbalanced application. Extensive field experience has played an important role in determining the following key criteria and design considerations that should be examined when evaluating a well. Screening criteria are also provided to help operators ascertain if a given formation is, in fact, a viable underbalanced drilling candidate.

Bennion, D.B. [Hycal Energy Research Labs. Ltd., Calgary, Alberta (Canada)

1997-02-01T23:59:59.000Z

323

Fracture Modeling and Flow Behavior in Shale Gas Reservoirs Using Discrete Fracture Networks  

E-Print Network (OSTI)

Fluid flow process in fractured reservoirs is controlled primarily by the connectivity of fractures. The presence of fractures in these reservoirs significantly affects the mechanism of fluid flow. They have led to problems in the reservoir which results in early water breakthroughs, reduced tertiary recovery efficiency due to channeling of injected gas or fluids, dynamic calculations of recoverable hydrocarbons that are much less than static mass balance ones due to reservoir compartmentalization, and dramatic production changes due to changes in reservoir pressure as fractures close down as conduits. These often lead to reduced ultimate recoveries or higher production costs. Generally, modeling flow behavior and mass transport in fractured porous media is done using the dual-continuum concept in which fracture and matrix are modeled as two separate kinds of continua occupying the same control volume (element) in space. This type of numerical model cannot reproduce many commonly observed types of fractured reservoir behavior since they do not explicitly model the geometry of discrete fractures, solution features, and bedding that control flow pathway geometry. This inaccurate model of discrete feature connectivity results in inaccurate flow predictions in areas of the reservoir where there is not good well control. Discrete Fracture Networks (DFN) model has been developed to aid is solving some of these problems experienced by using the dual continuum models. The Discrete Fracture Networks (DFN) approach involves analysis and modeling which explicitly incorporates the geometry and properties of discrete features as a central component controlling flow and transport. DFN are stochastic models of fracture architecture that incorporate statistical scaling rules derived from analysis of fracture length, height, spacing, orientation, and aperture. This study is focused on developing a methodology for application of DFN to a shale gas reservoir and the practical application of DFN simulator (FracGen and NFflow) for fracture modeling of a shale gas reservoir and also studies the interaction of the different fracture properties on reservoir response. The most important results of the study are that a uniform fracture network distribution and fracture aperture produces the highest cumulative gas production for the different fracture networks and fracture/well properties considered.

Ogbechie, Joachim Nwabunwanne

2011-12-01T23:59:59.000Z

324

Optimizing injected solvent fraction in stratified reservoirs  

E-Print Network (OSTI)

Waterflooding has become standard practice for extending the productive life of many solution gas drive reservoirs, but has the disadvantage of leaving a substantial residual oil volume in the reservoir. Solvent flooding has been offered as a method whereby oil may be completely displaced from the reservoir, leaving no residual volume. Field results have demonstrated that solvent floods suffer from early solvent breakthrough and considerable oil by-passing owing to high solvent mobility. The injection of both water and solvent has been demonstrated to offer advantages. Water partially mitigates both the adverse mobility and high cost of solvent floods, while solvent mobilizes oil which would be left in the reservoir by water alone. The process is equally applicable to reservoirs currently at residual oil saturation (tertiary floods) and to reservoirs at maximum oil saturation (secondary floods). In stratified reservoirs high permeability layers may be preferentially swept by solvent floods, while low permeability layers may be scarcely swept at all. Presence or absence of transverse communication between layers can modify overall sweep efficiency. This work is a study of water-solvent injection in stratified reservoirs based on computer simulation results. Fractional oil recovery as a function of injected solvent fraction, permeability contrast between layers, initial oil saturation, and presence or absence of transverse communication between strata has been determined. Results are presented as a series of optimization curves. Permeability contrast between layers is shown to be the dominant control on fractional oil recovery. Transverse communicating reservoirs are shown to require a higher solvent-water ratio in order to attain recoveries comparable to transverse noncommunicating reservoirs. In actual field projects, water and solvent are injected alternately as discrete slugs. This process is known as "WAG" for "water-alternating-gas". In the simulations used in this study, continuous water-solvent injection at a fixed fraction rather than true WAG was employed. It is demonstrated that the two methods give equivalent results. In summary, this work is the first comprehensive study of the behavior of stratified reservoirs undergoing water-solvent injection.

Moon, Gary Michael

1993-01-01T23:59:59.000Z

325

The LBL geothermal reservoir technology program  

DOE Green Energy (OSTI)

The main objective of the DOE/GD-funded Geothermal Reservoir Technology Program at Lawrence Berkeley Laboratory is the development and testing of new and improved methods and tools needed by industry in its effort to delineate, characterize, evaluate, and exploit hydrothermal systems for geothermal energy. This paper summarizes the recent and ongoing field, laboratory, and theoretical research activities being conducted as part of the Geothermal Reservoir Technology Program. 28 refs., 4 figs.

Lippmann, M.J.

1991-03-01T23:59:59.000Z

326

Reservoir assessment of The Geysers Geothermal field  

DOE Green Energy (OSTI)

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.

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

1981-01-01T23:59:59.000Z

327

Improved efficiency of miscible CO{sub 2} floods and enhanced prospects for CO{sub 2} flooding heterogeneous reservoirs. Quarterly technical progress report, January 1, 1995--March 31, 1995  

SciTech Connect

The objective of this research is to improve the effectiveness of CO{sub 2} flooding in heterogeneous reservoirs. Activities include: exploration of the applicability of selective mobility reduction utilizing foams; possible higher economic viability of floods at slightly reduced CO{sub 2} injection pressures; and taking advantage of gravitational forces during flooding in fractured reservoirs.

Grigg, R.B.; Heller, J.P.; Schechter, D.S.

1995-06-01T23:59:59.000Z

328

Pressure Tubes  

Science Conference Proceedings (OSTI)

Table 8   Specifications for carbon and alloy steel pressure tubes (ASTM)...medium-strength carbon-molybdenum alloy

329

Dynamic Pressure  

Science Conference Proceedings (OSTI)

... The higher pressure range will cover the important application of gas turbine engine testing. Gas turbines are used for propulsion on aircraft and ...

2013-07-15T23:59:59.000Z

330

Thermo-Poroelastic Modeling of Reservoir Stimulation and Microseismicity Using Finite Element Method with Damage Mechanics  

E-Print Network (OSTI)

Stress and permeability variations around a wellbore and in the reservoir are of much interest in petroleum and geothermal reservoir development. Water injection causes significant changes in pore pressure, temperature, and stress in hot reservoirs, changing rock permeability. In this work, two- and three-dimensional finite element methods were developed to simulate coupled reservoirs with damage mechanics and stress-dependent permeability. The model considers the influence of fluid flow, temperature, and solute transport in rock deformation and models nonlinear behavior with continuum damage mechanics and stress-dependent permeability. Numerical modeling was applied to analyze wellbore stability in swelling shale with two- and three-dimensional damage/fracture propagation around a wellbore and injection-induced microseismic events. The finite element method (FEM) was used to solve the displacement, pore pressure, temperature, and solute concentration problems. Solute mass transport between drilling fluid and shale formation was considered to study salinity effects. Results show that shear and tensile failure can occur around a wellbore in certain drilling conditions where the mud pressure lies between the reservoir pore pressure and fracture gradient. The fully coupled thermo-poro-mechanical FEM simulation was used to model damage/fracture propagation and microseismic events caused by fluid injection. These studies considered wellbore geometry in small-scale modeling and point-source injection, assuming singularity fluid flux for large-scale simulation. Damage mechanics was applied to capture the effects of crack initiation, microvoid growth, and fracture propagation. The induced microseismic events were modeled in heterogeneous geological media, assuming the Weibull distribution functions for modulus and permeability. The results of this study indicate that fluid injection causes the effective stress to relax in the damage phase and to concentrate at the interface between the damage phase and the intact rock. Furthermore, induced-stress and far-field stress influence damage propagation. Cold water injection causes the tensile stress and affects the initial fracture and fracture propagation, but fracture initiation pressure and far-field stress are critical to create a damage/fracture plane, which is normal to the minimum far-field stress direction following well stimulation. Microseismic events propagate at both well scale and reservoir-scale simulation; the cloud shape of a microseismic event is affected by permeability anisotropy and far-field stress, and deviatoric horizontal far-field stress especially contributes to the localization of the microseismic cloud.

Lee, Sang Hoon

2011-12-01T23:59:59.000Z

331

Third workshop on geothermal reservoir engineering: Proceedings  

DOE Green Energy (OSTI)

The Third Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 14, 1977, with 104 attendees from six nations. In keeping with the recommendations expressed by the participants at the Second Workshop, the format of the Workshop was retained, with three days of technical sessions devoted to reservoir physics, well and reservoir testing, field development, and mathematical modeling of geothermal reservoirs. The program presented 33 technical papers, summaries of which are included in these Proceedings. Although the format of the Workshop has remained constant, it is clear from a perusal of the Table of Contents that considerable advances have occurred in all phases of geothermal reservoir engineering over the past three years. Greater understanding of reservoir physics and mathematical representations of vapor-dominated and liquid-dominated reservoirs are evident; new techniques for their analysis are being developed, and significant field data from a number of newer reservoirs are analyzed. The objectives of these workshops have been to bring together researchers active in the various physical and mathematical disciplines comprising the field of geothermal reservoir engineering, to give the participants a forum for review of progress and exchange of new ideas in this rapidly developing field, and to summarize the effective state of the art of geothermal reservoir engineering in a form readily useful to the many government and private agencies involved in the development of geothermal energy. To these objectives, the Third Workshop and these Proceedings have been successfully directed. Several important events in this field have occurred since the Second Workshop in December 1976. The first among these was the incorporation of the Energy Research and Development Administration (ERDA) into the newly formed Department of Energy (DOE) which continues as the leading Federal agency in geothermal reservoir engineering research. The Third Workshop under the Stanford Geothermal Program was supported by a grant from DOE through a subcontract with the Lawrence Berkeley Laboratory of the University of California. A second significant event was the first conference under the ERDA (DOE)-ENEL cooperative program where many of the results of well testing in both nations were discussed. The Proceedings of that conference should be an important contribution to the literature. These Proceedings of the Third Workshop should also make an important contribution to the literature on geothermal reservoir engineering. Much of the data presented at the Workshop were given for the first time, and full technical papers on these subjects will appear in the professional journals. The results of these studies will assist markedly in developing the research programs to be supported by the Federal agencies, and in reducing the costs of research for individual developers and utilities. It is expected that future workshops of the Stanford Geothermal Program will be as successful as this third one. Planning and execution of the Workshop... [see file; ljd, 10/3/2005] The Program Committee recommended two novel sessions for the Third Workshop, both of which were included in the program. The first was the three overviews given at the Workshop by George Pinder (Princeton) on the Academic aspect, James Bresee (DOE-DGE) on the Government aspect, and Charles Morris (Phillips Petroleum) on the Industry aspect. These constituted the invited slate of presentations from the several sectors of the geothermal community. The Program Committee acknowledges their contributions with gratitude. Recognition of the importance of reservoir assurance in opting for geothermal resources as an alternate energy source for electric energy generation resulted in a Panel Session on Various Definitions of Geothermal Reservoirs. Special acknowledgments are offered to Jack Howard and Werner Schwarz (LBL) and to Jack Howard as moderator; to the panelists: James Leigh (Lloyd's Bank of California), Stephen Lipman (Union Oil), Mark Mathisen (PG&E), Patrick M

Ramey, H.J. Jr.; Kruger, P. (eds.)

1977-12-15T23:59:59.000Z

332

RESEARCH OIL RECOVERY MECHANISMS IN HEAVY OIL RESERVOIRS  

SciTech Connect

The United States continues to rely heavily on petroleum fossil fuels as a primary energy source, while domestic reserves dwindle. However, so-called heavy oil (10 to 20{sup o}API) remains an underutilized resource of tremendous potential. Heavy oils are much more viscous than conventional oils. As a result, they are difficult to produce with conventional recovery methods such as pressure depletion and water injection. Thermal recovery is especially important for this class of reservoirs because adding heat, usually via steam injection, generally reduces oil viscosity dramatically. This improves displacement efficiency. The research described here was directed toward improved understanding of thermal and heavy-oil production mechanisms and is categorized into: (1) flow and rock properties; (2) in-situ combustion; (3) additives to improve mobility control; (4) reservoir definition; and (5) support services. The scope of activities extended over a three-year period. Significant work was accomplished in the area of flow properties of steam, water, and oil in consolidated and unconsolidated porous media, transport in fractured porous media, foam generation and flow in homogeneous and heterogeneous porous media, the effects of displacement pattern geometry and mobility ratio on oil recovery, and analytical representation of water influx. Significant results are described.

Anthony R. Kovscek; William E. Brigham

1999-06-01T23:59:59.000Z

333

The Ahuachapan geothermal field, El Salvador: Reservoir analysis  

DOE Green Energy (OSTI)

The Earth Sciences Division of Lawrence Berkeley Laboratory (LBL) is conducting a reservoir evaluation study of the Ahuachapan geothermal field in El Salvador. This work is being performed in cooperation with the Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) and the Los Alamos National Laboratory (LANL). This report describes the work done during the first year of the study (FY 1988--89), and includes the (1) development of geological and conceptual models of the field, (2) evaluation of the initial thermodynamic and chemical conditions and their changes during exploitation, (3) evaluation of interference test data and the observed reservoir pressure decline, and (4) the development of a natural state model for the field. The geological model of the field indicates that there are seven (7) major and five (5) minor faults that control the fluid movement in the Ahuachapan area. Some of the faults act as a barrier to flow as indicated by large temperature declines towards the north and west. Other faults act as preferential pathways to flow. The Ahuachapan Andesites provide good horizontal permeability to flow and provide most of the fluids to the wells. The underlying Older Agglomerates also contribute to well production, but considerably less than the Andesites. 84 refs.

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

1989-08-01T23:59:59.000Z

334

Application of integrated reservoir management and reservoir characterization to optimize infill drilling, Class II  

SciTech Connect

The major purpose of this project was to demonstrate the use of cost effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability carbonate reservoirs such as the North Robertson (Clearfork) Unit.

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

2000-03-16T23:59:59.000Z

335

Simulation study to investigate development options for a super-heavy oil reservoir  

E-Print Network (OSTI)

A reservoir simulation study was performed on a heavy oil reservoir with the main objective of evaluating possible development options beyond the existing cold production method. The 206-acre area simulated - part of a significantly larger oil accumulation - lies about 3000 ft. ss. and has a gross thickness of 560 ft. The simulated area contains 120 MMSTB oil of 9° API gravity with in situ viscosity of 6,000 cp. Production began in 1992 with the reservoir being drained by one vertical well, one slanted well and one horizontal well. The simulation study was conducted in a systematic manner using two types of commercial reservoir simulators to minimize computational time. For history matching the cold production period and forecasting of cold production cases, a black oil simulator was used (ECLIPSE 100). A fairly satisfactory match of the production and pressure data was obtained which required an analytical aquifer to be attached to the northern part of the reservoir. For thermal EOR cases, the oil was simulated as a hydrocarbon consisting of three pseudo components. These cases were run using a thermal compositional simulator (ECLIPSE 300). Simulation results indicate oil recovery, for the area developed by the existing horizontal well and two new horizontal wells, to be as follows. For cold production, the oil recovery amounts to 13% of original-oil-in-place (OOIP). With cyclic steam injection, the recovery factor is slightly increased to 15% OOIP. However, with steam flooding -utilizing the new horizontal wells as injectors - the recovery factor is significantly increased to 22% OOIP. Steam flooding is evidently superior to cyclic steam injection primarily due to the fact that the reservoir is pressurized in the former EOR method and not in the latter, and to the fact that cyclic steam injection is more a near-wellbore thermal stimulation process as opposed to a more reservoir-wide heating process under steam flooding. Finally, with steam-propane injection (at a constant steam:propane mass ratio of 100:5), the oil recovery factor is further increased to 26% OOIP. Simulation results indicate this EOR method creates a more favorable distribution of heat in the reservoir, thus better sweep efficiency and reduction in produced water cut. Selection of development options to be implemented would depend on the economics of each case. Economic evaluation of the various cases has not been covered in the thesis and is best done by the operator of the field.

Diaz Franco, Jose Manuel

2001-01-01T23:59:59.000Z

336

Fracture Surface Area Effects on Fluid Extraction and the Electrical Resistivity of Geothermal Reservoir Rocks  

DOE Green Energy (OSTI)

Laboratory measurements of the electrical resistivity of fractured analogue geothermal reservoir rocks were performed to investigate the resistivity contrast caused by active boiling and to determine the effects of variable fracture dimensions and surface area on water extraction. Experiments were performed at confining pressures up to 10 h4Pa (100 bars) and temperatures to 170 C. Fractured samples show a larger resistivity change at the onset of boiling than intact samples. Monitoring the resistivity of fractured samples as they equilibrate to imposed pressure and temperature conditions provides an estimate of fluid migration into and out of the matrix. Measurements presented are an important step toward using field electrical methods to quantitatively search for fractures, infer saturation, and track fluid migration in geothermal reservoirs.

Roberts, J J; Detwiler, R L; Ralph, W; Bonner, B

2002-05-09T23:59:59.000Z

337

Reservoir Characterization, Production Characteristics, and Research Needs for Fluvial/Alluvial Reservoirs in the United States  

Science Conference Proceedings (OSTI)

The Department of Energy's (DOE's) Oil Recovery Field Demonstration Program was initiated in 1992 to maximize the economically and environmentally sound recovery of oil from known domestic reservoirs and to preserve access to this resource. Cost-shared field demonstration projects are being initiated in geology defined reservoir classes which have been prioritized by their potential for incremental recovery and their risk of abandonment. This document defines the characteristics of the fifth geological reservoir class in the series, fluvial/alluvial reservoirs. The reservoirs of Class 5 include deposits of alluvial fans, braided streams, and meandering streams. Deposit morphologies vary as a complex function of climate and tectonics and are characterized by a high degree of heterogeneity to fluid flow as a result of extreme variations in water energy as the deposits formed.

Cole, E.L.; Fowler, M.L.; Jackson, S.R.; Madden, M.P.; Raw-Schatzinger, V.; Salamy, S.P.; Sarathi, P.; Young, M.A.

1999-04-28T23:59:59.000Z

338

Seismic imaging of reservoir flow properties: Resolving waterinflux and reservoir permeability  

SciTech Connect

Methods for geophysical model assessment, in particuale thecomputation of model parameter resolution, indicate the value and thelimitations of time-lapse data in estimating reservoir flow properties. Atrajectory-based method for computing sensitivities provides an effectivemeans to compute model parameter resolutions. We examine the commonsituation in which water encroaches into a resrvoir from below, as due tothe upward movement of an oil-water contact. Using straight-forwardtechniques we find that, by inclusing reflections off the top and bottomof a reservoir tens of meters thick, we can infer reservoir permeabilitybased upon time-lapse data. We find that, for the caseof water influxfrom below, using multiple time-lapse 'snapshots' does not necessarilyimprove the resolution of reservoir permeability. An application totime-lapse data from the Norne field illustrates that we can resolve thepermeability near a producing well using reflections from threeinterfaces associated with the reservoir.

Vasco, D.W.; Keers, Henk

2006-11-27T23:59:59.000Z

339

Improved recovery from Gulf of Mexico reservoirs. Volume III (of 4): Characterization and simulation of representative resources. Final report, February 14, 1995--October 13, 1996  

Science Conference Proceedings (OSTI)

Significant innovations have been made in seismic processing and reservoir simulation. In addition, significant advances have been made in deviated and horizontal drilling technologies. Effective application of these technologies along with improved integrated resource management methods offer opportunities to significantly increase Gulf of Mexico production, delay platform abandonments, and preserve access to a substantial remaining oil target for both exploratory drilling and advanced recovery processes. In an effort to illustrate the impact that these new technologies and sources of information can have upon the estimates of recoverable oil in the Gulf of Mexico, additional and detailed data was collected for two previously studied reservoirs: a South March Island reservoir operated by Taylor Energy and Gulf of Mexico reservoir operated by Mobil, whose exact location has been blind-coded at their request, and an additional third representative reservoir in the Gulf of Mexico, the KEKF-1 reservoir in West Delta Block 84 Field. The new data includes reprocessed 2-D seismic data, newly acquired 3-D data, fluid data, fluid samples, pressure data, well test data, well logs, and core data/samples. The new data was used to refine reservoir and geologic characterization of these reservoirs. Further laboratory investigation also provided additional simulation input data in the form of PVT properties, relative permeabilities, capillary pressures, and water compatibility. Geologic investigations were also conducted to refine the models of mud-rich submarine fan architectures used by seismic analysts and reservoir engineers. These results were also used, in part, to assist in the recharacterization of these reservoirs.

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

1997-01-13T23:59:59.000Z

340

PROCEEDINGS, Thirty-Fourth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, February 9-11, 2009  

E-Print Network (OSTI)

models. Hence relatively much shorter run-times are associated. These models provide a good alternative that is cooling the reservoir. Since the system is closed as shown in Figure 7, the fluid volume is decreased because of the cooling which causes a decrease in the pressure as well. The cooling effect of the injected

Stanford University

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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341

PROCEEDINGS, Thirty-Fifth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, February 1-3, 2010  

E-Print Network (OSTI)

given by l v q q . 1 1 1 - + = . (5) Using numerical formulae for (1b) and for specific volumes was 23.4 m/s which occurred at 1.0=p MPa and 000626.0=q , i.e. at atmospheric pressure, when the vapour1 PROCEEDINGS, Thirty-Fifth Workshop on Geothermal Reservoir Engineering Stanford University

Stanford University

342

PROCEEDINGS, Thirty-Sixth Workshop on Geothermal Reservoir Engineering Stanford University, Stanford, California, January 31 -February 2, 2011  

E-Print Network (OSTI)

FOR MONITORING THERMAL DRAWDOWN IN GEOTHERMAL RESERVOIRS Mitchell A. Plummer, Carl D. Palmer, Earl D. Mattson. Second, by identifying fracture geometries that are consistent with operating conditions (well pressures of the Laplace transformed equation of Gringarten et al. (1975) (Figure 3). Transport of a reactive tracer slug

Stanford University

343

Base Technologies and Tools for Supercritical Reservoirs Geothermal Lab  

Open Energy Info (EERE)

Technologies and Tools for Supercritical Reservoirs Geothermal Lab Technologies and Tools for Supercritical Reservoirs Geothermal Lab Call Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Base Technologies and Tools for Supercritical Reservoirs Project Type / Topic 1 Laboratory Call for Submission of Applications for Research, Development and Analysis of Geothermal Technologies Project Type / Topic 2 High-Temperature Downhole Tools Project Description Development of downhole tools capable of reliable operation in supercritical environments is a significant challenge with a number of technical and operational hurdles related to both the hardware and electronics design. Hardware designs require the elimination of all elastomer seals and the use of advanced materials. Electronics must be hardened to the extent practicable since no electronics system can survive supercritical temperatures. To develop systems capable of logging in these environments will require a number of developments. More robust packaging of electronics is needed. Sandia will design and develop innovated, highly integrated, high-temperature (HT) data loggers. These data loggers will be designed and developed using silicon-on-insulator/silicon carbide (SOI/SiC) technologies integrated into a MultiChip Module (MCM); greatly increasing the reliability of the overall system (eliminating hundreds of board-level innerconnects) and decreasing the size of the electronics package. Tools employing these electronics will be capable of operating continuously at temperatures up to 240 °C and by using advanced Dewar flasks, will operate in a supercritical reservoir with temperatures over 450 °C and pressures above 70 MPa. Dewar flasks are needed to protect the electronic components, but those currently available are only reliable in temperature regimes in the range of 350 °C; promising advances in materials will be investigated to improve Dewar technologies. HT wireline currently used for logging operations is compromised at temperatures above 300 °C; along with exploring the development of a HT wireline for logging purposes, alternative approaches that employ HT batteries (e.g., those awarded a recent R&D 100) will also be investigated, and if available will enable deployment using slickline, which is not subject to the same temperature limitations as wireline. To demonstrate the capability provided by these improvements, tools will be developed and fielded. The developed base technologies and working tool designs will be available to industry throughout the project period. The developed techniques and subsystems will help to further the advancement of HT tools needed in the geothermal industry.

344

Optimal Reservoir Management and Well Placement Under Geologic Uncertainty  

E-Print Network (OSTI)

Reservoir management, sometimes referred to as asset management in the context of petroleum reservoirs, has become recognized as an important facet of petroleum reservoir development and production operations. In the first stage of planning field development, the simulation model is calibrated to dynamic data (history matching). One of the aims of the research is to extend the streamline based generalized travel time inversion method for full field models with multimillion cells through the use of grid coarsening. This makes the streamline based inversion suitable for high resolution simulation models with decades long production history and numerous wells by significantly reducing the computational effort. In addition, a novel workflow is proposed to integrate well bottom-hole pressure data during model calibration and the approach is illustrated via application to the CO2 sequestration. In the second stage, field development strategies are optimized. The strategies are primarily focused on rate optimization followed by infill well drilling. A method is proposed to modify the streamline-based rate optimization approach which previously focused on maximizing sweep efficiency by equalizing arrival time of the waterfront to producers, to account for accelerated production for improving the net present value (NPV). Optimum compromise between maximizing sweep efficiency and maximizing NPV can be selected based on a 'trade-off curve.' The proposed method is demonstrated on field scale application considering geological uncertainty. Finally, a novel method for well placement optimization is proposed that relies on streamlines and time of flight to first locate the potential regions of poorly swept and drained oil. Specifically, the proposed approach utilizes a dynamic measure based on the total streamline time of flight combined with static and dynamic parameters to identify "Sweet-Spots" for infill drilling. The "Sweet-Spots" can be either used directly as potential well-placement locations or as starting points during application of a formal optimization technique. The main advantage of the proposed method is its computational efficiency in calculating dynamic measure map. The complete workflow was also demonstrated on a multimillion cell reservoir model of a mature carbonate field with notable success. The infill locations based on dynamic measure map have been verified by subsequent drilling.

Taware, Satyajit Vijay

2012-08-01T23:59:59.000Z

345

A reservoir management study of a mature oil field  

E-Print Network (OSTI)

An integrated geological, petrophysical and reservoir engineering review was performed for a mature, producing oil field. Like many older fields, important data are missing or were not collected. The techniques used in this thesis may be applied to other mature oil fields to make sound engineering and business decisions. I interpreted the geological structure and stratigaphy of the salt dome oil field. Structure, isopach and cross-sectional maps were constructed. Depositional environments of the producing horizons were identified. Potential for additional reserves was assessed. Well logs, core data, water resistivity and produced fluids data were analyzed. Average values of porosity, permeability, and oil saturation were determined for the field. Potential reserves behind casing were identified. Based on the revised geological and petrophysical data, the original oil in place was estimated from volumetrics to be 42.3 MMSTB. Cumulative oil production was determined for the first time since 1963. The field, individual reservoir, and individual well production performances were reviewed. Initial production histories of more than 220 wells were documented. I collected wellhead fluid samples and analyzed oil gravity and viscosity. Other fluid properties were estimated from correlations. Pressure data from the field was collated and analyzed. Primary production mechanisms and aquifer influx were estimated by reviewing early producing history and performing material balance calculations. Water influx was calculated. The performances of analogous salt dome reservoirs were compared to that of the field. All past well stimulations were reviewed and suggestions made for better implementation. Water injection in the field was reviewed. Problems of implementation and reservoir response were identified. The best areas in the field for waterflooding were identified and analyzed with an analytical model. Based on existing development, the oil ultimate recovery is estimated to be 14.4 MMSTB or 34.0 % of original oil in place. To determine whether oil recovery can be improved, incremental, after tax economic analysis was applied to several schemes. Infill drilling, hydraulic fracturing and waterflooding were analyzed. A course of action to maximize economic return is outlined for the field. Hydraulic fracturing appears to be the most viable technique to improve oil production from the field.

Peruzzi, Tave

1995-01-01T23:59:59.000Z

346

Reservoir Simulation Used to Plan Diatomite Developement in Mountainous Region  

E-Print Network (OSTI)

In Santa Barbara County, Santa Maria Pacific (an exploration and production company) is expanding their cyclic steam project in a diatomite reservoir. The hilly or mountainous topography and cut and fill restrictions have interfered with the company's ideal development plan. The steep hillsides prevent well pad development for about 22 vertical well locations in the 110 well expansion plan. Conventional production performs poorly in the area because the combination of relatively low permeability (1-10 md) and high viscosity (~220 cp) at the reservoir temperature. Cyclic steam injection has been widely used in diatomite reservoirs to take advantage of the diatomite rocks unique properties and lower the viscosity of the oil. Some companies used deviated wells for cyclic steam injection, but Santa Maria Pacific prefers the use only vertical wells for the expansion. Currently, the inability to create well pads above 22 vertical well target locations will result in an estimated $60,000,000 of lost revenue over a five year period. The target locations could be developed with unstimulated deviated or horizontal wells, but expected well rates and expenses have not been estimated. In this work, I use a thermal reservoir simulator to estimate production based on five potential development cases. The first case represents no development other than the cyclic wells. This case is used to calibrate the model based on the pilot program performance and serves as a reference point for the other cases. Two of the cases simulate a deviated well with and without artificial lift next to a cyclic well, and the final two cases simulate a horizontal well segment with and without artificial lift next to a cyclic well. The deviated well with artificial lift results in the highest NPV and profit after five years. The well experienced pressure support from the neighboring cyclic well and performed better with the cyclic well than without it. Adding 22 deviated wells with artificial lift will increase the project's net profit by an estimated $7,326,000 and NPV by $2,838,000 after five years.

Powell, Richard

2012-08-01T23:59:59.000Z

347

Application of inverse modeling to geothermal reservoir simulation  

DOE Green Energy (OSTI)

The authors have developed inverse modeling capabilities for the non-isothermal, multiphase, multicomponent numerical simulator TOUGH2 to facilitate automatic history matching and parameter estimation based on data obtained during testing and exploitation of geothermal fields.The ITOUGH2 code allows one to estimate TOUGH2 input parameters based on any type of observation for which a corresponding simulation output can be calculated. Furthermore, a detailed residual and error analysis is performed, and the uncertainty of model predictions can be evaluated. Automatic history matching using ITOUGH2 is robust and efficient so that model parameters affecting geothermal field performance can reliably be estimated based on a variety of field measurements such as pressures, temperatures, flow rates, and enthalpies. The paper describes the methodology of inverse modeling and provides a detailed discussion of sample problems to demonstrate the application of the method to data from geothermal reservoirs.

Finsterle, S.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.; Bullivant, D.P.; O`Sullivan, M.J. [Univ. of Auckland (New Zealand). Dept. of Engineering Science

1997-01-01T23:59:59.000Z

348

Fractured shale reservoirs: Towards a realistic model  

Science Conference Proceedings (OSTI)

Fractured shale reservoirs are fundamentally unconventional, which is to say that their behavior is qualitatively different from reservoirs characterized by intergranular pore space. Attempts to analyze fractured shale reservoirs are essentially misleading. Reliance on such models can have only negative results for fractured shale oil and gas exploration and development. A realistic model of fractured shale reservoirs begins with the history of the shale as a hydrocarbon source rock. Minimum levels of both kerogen concentration and thermal maturity are required for effective hydrocarbon generation. Hydrocarbon generation results in overpressuring of the shale. At some critical level of repressuring, the shale fractures in the ambient stress field. This primary natural fracture system is fundamental to the future behavior of the fractured shale gas reservoir. The fractures facilitate primary migration of oil and gas out of the shale and into the basin. In this process, all connate water is expelled, leaving the fractured shale oil-wet and saturated with oil and gas. What fluids are eventually produced from the fractured shale depends on the consequent structural and geochemical history. As long as the shale remains hot, oil production may be obtained. (e.g. Bakken Shale, Green River Shale). If the shale is significantly cooled, mainly gas will be produced (e.g. Antrim Shale, Ohio Shale, New Albany Shale). Where secondary natural fracture systems are developed and connect the shale to aquifers or to surface recharge, the fractured shale will also produce water (e.g. Antrim Shale, Indiana New Albany Shale).

Hamilton-Smith, T. [Applied Earth Science, Lexington, KY (United States)

1996-09-01T23:59:59.000Z

349

Summary of reservoir engineering data: Wairakei geothermal field, New Zealand  

DOE Green Energy (OSTI)

This is an abbreviated summary of the final project report on an extensive collection of fundamental field information concerning the history of the Wairakei geothermal field in New Zealand. The purpose of the effort was to accumulate any and all pertinent data so that various theoretical reservoir simulation studies may be carried out in the future in a meaningful way. Categories of data considered include electrical resistivity measurements, magnetic force surveys, surface heat flow data and a catalog of surface manifestations of geothermal activity, geological and stratigraphic information, residual gravity anomaly surveys, laboratory measurements of formation properties, seismic velocity data, measurements of fluid chemical composition, monthly well-by-well mass and heat production histories for 1953 through 1976, reservoir pressure and temperature data, and measurements of subsidence and horizontal ground deformation. The information is presented in three forms. A review of all the data is contained in the final project report. The present report summarizes that information. In addition, a magnetic tape suitable for use on a computer has been prepared. The magnetic tape contains a bank of information for each well in the field, on a well-by-well basis. For each well, the tape contains the completion date, the surface altitude, the bottomhole depth, the geographic location, the slotted and perforated interval locations, the bottomhole diameter, locations of known casing breaks, the geologic drilling log, fault intersections, shut-in pressure measurements, and month-by-month production totals of both mass and heat for each month from January 1953 through December 1976.

Pritchett, J.W.; Rice, L.F.; Garg, S.K.

1979-01-01T23:59:59.000Z

350

Producing Gas-Oil Ratio Performance of Conventional and Unconventional Reservoirs.  

E-Print Network (OSTI)

?? This study presents a detailed analysis of producing gas-oil ratio performance characteristics from conventional reservoir to unconventional reservoir. Numerical simulations of various reservoir fluid… (more)

Lei, Guowen

2012-01-01T23:59:59.000Z

351

Advanced Oil Recovery Technologies for Improved Recovery From Slope Basin Clastic reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico  

Science Conference Proceedings (OSTI)

The overall goal of this project is to demonstrate that an advanced development drilling and pressure maintenance program based on advanced reservoir management methods can significantly improve oil recovery. The plan included developing a control area using standard reservoir management techniques and comparing its performance to an area developed using advanced methods. A key goal is to transfer advanced methodologies to oil and gas producers in the Permian Basin and elsewhere, and throughout the US oil and gas industry.

Mark B. Murphy

1998-04-30T23:59:59.000Z

352

Gulf Coast geopressured-geothermal reservoir simulation: final task report (year 4). Final report, 1 August 1979-31 July 1980  

DOE Green Energy (OSTI)

The results of the short-term production tests run on the Pleasant Bayou No. 2 well are summarized. These tests were analyzed using conventional pressure test analysis methods. The effects of reservoir heterogeneties onm production behavior and, in particular, permeability distribution and faulting of reservoir sand were studied to determine the sensitivity of recovery to these parameters. A study on the effect of gas buildup around a producing well is reported. (MHR)

MacDonald, R.C.; Sepehrnoori, K.; Ohkuma, H.

1982-10-01T23:59:59.000Z

353

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

SciTech Connect

The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California, through the testing and application of advanced reservoir characterization and thermal production technologies. The hope is that successful application of these technologies will result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block II-A (Tar II-A) has been relatively inefficient because of several producibility problems which are common in SBC reservoirs: inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery and reduce operating costs, including: (1) Development of three-dimensional (3-D) deterministic and stochastic reservoir simulation models--thermal or otherwise--to aid in reservoir management of the steamflood and post-steamflood phases and subsequent development work. (2) Development of computerized 3-D visualizations of the geologic and reservoir simulation models to aid reservoir surveillance and operations. (3) Perform detailed studies of the geochemical interactions between the steam and the formation rock and fluids. (4) Testing and proposed application of a novel alkaline-steam well completion technique for the containment of the unconsolidated formation sands and control of fluid entry and injection profiles. (5) Installation of a 2100 ft, 14 inch insulated, steam line beneath a harbor channel to supply steam to an island location. (6) Testing and proposed application of thermal recovery technologies to increase oil production and reserves: (a) Performing pilot tests of cyclic steam injection and production on new horizontal wells. (b) Performing pilot tests of hot water-alternating-steam (WAS) drive in the existing steam drive area to improve thermal efficiency. (7) Perform a pilot steamflood with the four horizontal injectors and producers using a pseudo steam-assisted gravity-drainage (SAGD) process. (8) Advanced reservoir management, through computer-aided access to production and geologic data to integrate reservoir characterization, engineering, monitoring and evaluation.

Unknown

2001-08-08T23:59:59.000Z

354

Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico, Class III  

SciTech Connect

The overall objective of this project was to demonstrate that a development program-based on advanced reservoir management methods-can significantly improve oil recovery at the Nash Draw Pool (NDP). The plan included developing a control area using standard reservoir management techniques and comparing its performance to an area developed using advanced reservoir management methods. Specific goals were (1) to demonstrate that an advanced development drilling and pressure maintenance program can significantly improve oil recovery compared to existing technology applications and (2) to transfer these advanced methodologies to oil and gas producers in the Permian Basin and elsewhere throughout the U.S. oil and gas industry.

Murphy, Mark B.

2002-01-16T23:59:59.000Z

355

Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, New Mexico, Class III  

SciTech Connect

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

Murphy, Michael B.

2002-02-21T23:59:59.000Z

356

Numerical investigations into the formation of a high temperature reservoir''  

DOE Green Energy (OSTI)

This paper summarizes an ongoing numerical modeling effort aimed at describing some of the thermodynamic conditions observed in vapor- dominated reservoirs, including the formation of a high temperature reservoir (HTR) beneath the typical'' reservoir. The modeled system begins as a hot water geothermal reservoir, and evolves through time into a vapor-dominated reservoir with a HTR at depth. This approach taken here to develop a vapor-dominated system is similar to that of Pruess (1985), and involves induced boiling through venting. The reservoir description is intentionally generic, but serves to describe a means of evolution of conditions observed (in particular) The Geysers.

Shook, M.

1993-01-01T23:59:59.000Z

357

Numerical investigations into the formation of a ``high temperature reservoir``  

DOE Green Energy (OSTI)

This paper summarizes an ongoing numerical modeling effort aimed at describing some of the thermodynamic conditions observed in vapor- dominated reservoirs, including the formation of a high temperature reservoir (HTR) beneath the ``typical`` reservoir. The modeled system begins as a hot water geothermal reservoir, and evolves through time into a vapor-dominated reservoir with a HTR at depth. This approach taken here to develop a vapor-dominated system is similar to that of Pruess (1985), and involves induced boiling through venting. The reservoir description is intentionally generic, but serves to describe a means of evolution of conditions observed (in particular) The Geysers.

Shook, M.

1993-04-01T23:59:59.000Z

358

Recent developments in pressure coring  

SciTech Connect

The current rapid growth in the number of enhanced oil and gas recovery projects has created a strong demand for reservoir data such as true residual oil saturations. The companies providing pressure coring services have moved to fill this need. Two recent developments have emerged with the potential of significantly improving the present performance of pressure coring. Coring bits utilizing synthetic diamond cutters have demonstrated coring rates of one-foot per minute while improving core recovery. It is also apparent that cores of a near-unconsolidated nature are more easily recovered. In addition, a special low invasion fluid that is placed in the core retriever has demonstrated reduced core washing by the drilling mud and a decrease in the complexity of preparing cores for analysis. This paper describes the design, laboratory, and field testing efforts that led to these coring improvements. Also, experience in utilizing these developments while recovering over 100 cores is discussed.

McFall, A. L.

1980-01-01T23:59:59.000Z

359

Continuous reservoir simulation incorporating uncertainty quantification and real-time data  

E-Print Network (OSTI)

A significant body of work has demonstrated both the promise and difficulty of quantifying uncertainty in reservoir simulation forecasts. It is generally accepted that accurate and complete quantification of uncertainty should lead to better decision making and greater profitability. Many of the techniques presented in past work attempt to quantify uncertainty without sampling the full parameter space, saving on the number of simulation runs, but inherently limiting and biasing the uncertainty quantification in the resulting forecasts. In addition, past work generally has looked at uncertainty in synthetic models and does not address the practical issues of quantifying uncertainty in an actual field. Both of these issues must be addressed in order to rigorously quantify uncertainty in practice. In this study a new approach to reservoir simulation is taken whereby the traditional one-time simulation study is replaced with a new continuous process potentially spanning the life of the reservoir. In this process, reservoir models are generated and run 24 hours a day, seven days a week, allowing many more runs than previously possible and yielding a more thorough exploration of possible reservoir descriptions. In turn, more runs enabled better estimates of uncertainty in resulting forecasts. A new technology to allow this process to run continuously with little human interaction is real-time production and pressure data, which can be automatically integrated into runs. Two tests of this continuous simulation process were conducted. The first test was conducted on the Production with Uncertainty Quantification (PUNQ) synthetic reservoir. Comparison of our results with previous studies shows that the continuous approach gives consistent and reasonable estimates of uncertainty. The second study was conducted in real time on a live field. This study demonstrates the continuous simulation process and shows that it is feasible and practical for real world applications.

Holmes, Jay Cuthbert

2006-12-01T23:59:59.000Z

360

Ecology of large piscivorous fishes in Guri Reservoir, Venezuela, with notes on fish community structure  

E-Print Network (OSTI)

Venezuela's growing human population is accompanied by a growing need for electricity which has largely been met with hydroelectric power, and yet the full effects of river impoundment on river ecosystems are not known. Venezuela currently has the second largest hydroelectric facility in the world, the Raul Leoni Dam (Guri Reservoir). Formed by the blackwater Caroni River, Guri is characterized by low pH, low nutrients, and high dissolved organic matter. Water level fluctuations associated with hydroelectric facility operations may have large effects on tropical fish spawning, feeding, and survival. The primary sportfishes in the reservoir are the peacock basses (Cichla spp.), that exhibited heightened fish production immediately after inundation. However, during the 1990's, sportfishermen at Guri began complaining about decreased catches. To investigate claims of declining Cichla populations and to compare current fish community structure with a previous survey, the four large piscivorous fishes of Guri Reservoir were sampled. Samples from the northern area of the reservoir had 50 species representing 18 different families. The dominant species in seine samples was the characid Hemigrammus micropterus. In these samples, Cichla temensis, Cichla cf orinocensis, Plagioscion squamosissimus and Hydrolycus scomberoides had greater body condition compared with values for conspecifics from a previous study. Conversely, catch per unit effort for Cichla in gillnets decreased in the current study. Prochilodus rubrotaeniatus, a detritivorous characiform, was the dominant species captured in gillnets. Cichla spp. appear to breed throughout the year with a peak before the rainy season. Hydrolycus scomberoides and Plagioscion squamosissimus partitioned resources, with the former consuming the largest prey and the smallest prey consumed by the latter. Cichla temensis and Plagioscion squamosissimus had high diet overlap among prey types but consumed prey of different sizes. Niche breadths for all species were low. Claims of declining Cichla populations in Guri appear to have some foundation. Blackwater physicochemistry, the reservoir "boombust" cycle, and fishing pressure all influence fish ecology in Guri Reservoir.

Williams, John David

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "adequate reservoir pressures" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Magic Reservoir Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

Magic Reservoir Geothermal Area Magic Reservoir Geothermal Area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermal Resource Area: Magic Reservoir Geothermal Area Contents 1 Area Overview 2 History and Infrastructure 3 Regulatory and Environmental Issues 4 Exploration History 5 Well Field Description 6 Geology of the Area 7 Geofluid Geochemistry 8 NEPA-Related Analyses (0) 9 Exploration Activities (0) 10 References Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"TERRAIN","zoom":6,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"300px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.32833333,"lon":-114.3983333,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

362

Second workshop geothermal reservoir engineering: Proceedings  

DOE Green Energy (OSTI)

The Arab oil embargo of 1973 focused national attention on energy problems. A national focus on development of energy sources alternative to consumption of hydrocarbons led to the initiation of research studies of reservoir engineering of geothermal systems, funded by the National Science Foundation. At that time it appeared that only two significant reservoir engineering studies of geothermal reservoirs had been completed. Many meetings concerning development of geothermal resources were held from 1973 through the date of the first Stanford Geothermal Reservoir Engineering workshop December 15-17, 1975. These meetings were similar in that many reports dealt with the objectives of planned research projects rather than with results. The first reservoir engineering workshop held under the Stanford Geothermal Program was singular in that for the first time most participants were reporting on progress inactive research programs rather than on work planned. This was true for both laboratory experimental studies and for field experiments in producing geothermal systems. The Proceedings of the December 1975 workshop (SGP-TR-12) is a remarkable document in that results of both field operations and laboratory studies were freely presented and exchanged by all participants. With this in mind the second reservoir engineering workshop was planned for December 1976. The objectives were again two-fold. First, the workshop was designed as a forum to bring together researchers active in various physical and mathematical branches of the developing field of geothermal reservoir engineering, to give participants a current and updated view of progress being made in the field. The second purpose was to prepare this Proceedings of Summaries documenting the state of the art as of December 1976. The proceedings will be distributed to all interested members of the geothermal community involved in the development and utilization of the geothermal resources in the world. Many notable occurrences took place between the first workshop in December 1975 and this present workshop in December 1976. For one thing, the newly formed Energy Research and Development Administration (ERDA) has assumed the lead role in geothermal reservoir engineering research. The second workshop under the Stanford Geothermal Program was supported by a grant from ERDA. In addition, two significant meetings on geothermal energy were held in Rotarua, New Zealand and Taupo, New Zealand. These meetings concerned geothermal reservoir engineering, and the reinjection of cooled geothermal fluids back into a geothermal system. It was clear to attendees of both the New Zealand and the December workshop meetings that a great deal of new information had been developed between August and December 1976. Another exciting report made at the meeting was a successful completion of a new geothermal well on the big island of Hawaii which produces a geothermal fluid that is mainly steam at a temperature in excess of 600 degrees F. Although the total developed electrical power generating capacity due to all geothermal field developments in 1976 is on the order of 1200 megawatts, it was reported that rapid development in geothermal field expansion is taking place in many parts of the world. Approximately 400 megawatts of geothermal power were being developed in the Philippine Islands, and planning for expansion in production in Cerro Prieto, Mexico was also announced. The Geysers in the United States continued the planned expansion toward the level of more than 1000 megawatts. The Second Workshop on Geothermal Reservoir Engineering convened at Stanford December 1976 with 93 attendees from 4 nations, and resulted in the presentation of 44 technical papers, summaries of which are included in these Proceedings. The major areas included in the program consisted of reservoir physics, well testing, field development, well stimulation, and mathematical modeling of geothermal reservoirs. The planning forth is year's workshop and the preparation of the proceedings was carried out mainly by my associate Paul

Kruger, P.; Ramey, H.J. Jr. (eds.)

1976-12-03T23:59:59.000Z

363

A Review of the Geothermal Reservoir Well Stimulation Program  

DOE Green Energy (OSTI)

Republic Geothermal, Inc., and its subcontractors have planned and executed four experimental fracture stimulation treatments under the Department of Energy-funded Geothermal Reservoir Well Stimulation Program (GRWSP). The 2-year program, begun in February 1979, is Ultimately to include six full-scale field hydraulic and chemical stimulation experiments in geothermal wells. This paper describes the overall program and the four treatments completed to date. The GRWSP is organized into two phases. Phase I consists of literature and theoretical studies, laboratory investigations, and numerical work. The main purpose of this work is to establish the technological bases for geothermal well stimulation design. Phase I1 will include the planning, execution, and evaluation of six well stimulation treatments which utilize the technology developed in Phase I. Two stimulation experiments were performed at the Raft River, Idaho, known geothermal resource area (KGRA) in late 1979. This is a naturally fractured, hard rock reservoir with a relatively low geothermal resource temperature 149 C {+-} (300 F{+-}). A conventional planar hydraulic fracture job was performed in Well RRGP-5 and a ''Kiel'' dendritic, or reverse flow, technique was utilized in Well RRGP-4. In mid-1980, two stimulation experiments were performed at the East Mesa, California, KGRA. The stimulation of Well 58-30 provided the first geothermal well fracturing experience in a moderate temperature, 177 C {+-} (350 F{+-}), reservoir with matrix-type rock properties. The two treatments consisted of a conventional hydraulic fracture of a deep, low-permeability zone and a mini-frac ''Kiel'' treatment of a shallow, high-permeability zone in the same well. The stimulation experiment results to date were evaluated using short-term production tests, conventional pressure transient analysis, interference pressure data, chemical and radioactive tracers, borehole acoustic televiewer surveys and numerical models. This combination of evaluation techniques yielded an interpretation of fracture geometry and productivity enhancement. However, the evaluation of artificially induced fractures in naturally fractured formations was found to lead to possibly non-unique solutions. In all the field experiments, artificial fractures were created and well productivity was increased. A discussion of the prestimulation and poststimulation data and their evaluation are provided for each experiment in this report.

Campbell, D. A.; Hanold, R. J.; Sinclair, A. R.; Vetter, O. J.

1981-01-01T23:59:59.000Z

364

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

SciTech Connect

The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California through the testing and application of advanced reservoir characterization and thermal production technologies. The successful application of these technologies will result in expanding their implementation throughout the Wilmington Field and, through technology transfer, to other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block II-A (Tar II-A) has been relatively inefficient because of several producibility problems which are common in SBC reservoirs: inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery and reduce operating costs.

Scott Hara

2001-06-27T23:59:59.000Z

365

Analytical Estimation of CO2 Storage Capacity in Depleted Oil and Gas Reservoirs Based on Thermodynamic State Functions  

E-Print Network (OSTI)

Numerical simulation has been used, as common practice, to estimate the CO2 storage capacity of depleted reservoirs. However, this method is time consuming, expensive and requires detailed input data. This investigation proposes an analytical method to estimate the ultimate CO2 storage in depleted oil and gas reservoirs by implementing a volume constrained thermodynamic equation of state (EOS) using the reservoir?s average pressure and fluid composition. This method was implemented in an algorithm which allows fast and accurate estimations of final storage, which can be used to select target storage reservoirs, and design the injection scheme and surface facilities. Impurities such as nitrogen and carbon monoxide, usually contained in power plant flue gases, are considered in the injection stream and can be handled correctly in the proposed algorithm by using their thermodynamic properties into the EOS. Results from analytical method presented excellent agreement with those from reservoir simulation. Ultimate CO2 storage capacity was predicted with an average difference of 1.3%, molar basis, between analytical and numerical methods; average oil, gas, and water saturations were also matched. Additionally, the analytical algorithm performed several orders of magnitude faster than numerical simulation, with an average of 5 seconds per run.

Valbuena Olivares, Ernesto

2011-12-01T23:59:59.000Z

366

Real-time and post-frac' 3-D analysis of hydraulic fracture treatments in geothermal reservoirs  

SciTech Connect

Economic power production from Hot Dry Rock (HDR) requires the establishment of an efficient circulation system between wellbores in reservoir rock with extremely low matrix permeability. Hydraulic fracturing is employed to establish the necessary circulation system. Hydraulic fracturing has also been performed to increase production from hydrothermal reservoirs by enhancing the communication with the reservoir's natural fracture system. Optimal implementation of these hydraulic fracturing applications, as with any engineering application, requires the use of credible physical models and the reconciliation of the physical models with treatment data gathered in the field. Analysis of the collected data has shown that 2-D models and 'conventional' 3-D models of the hydraulic fracturing process apply very poorly to hydraulic fracturing in geothermal reservoirs. Engineering decisions based on these more 'conventional' fracture modeling techniques lead to serious errors in predicting the performance of hydraulic fracture treatments. These errors can lead to inappropriate fracture treatment design as well as grave errors in well placement for hydrothermal reservoirs or HDR reservoirs. This paper outlines the reasons why conventional modeling approaches fall short, and what types of physical models are needed to credibly estimate created hydraulic fracture geometry. The methodology of analyzing actual measured fracture treatment data and matching the observed net fracturing pressure (in realtime as well as after the treatment) is demonstrated at two separate field sites. Results from an extensive Acoustic Emission (AE) fracture diagnostic survey are also presented for the first case study aS an independent measure of the actual created hydraulic fracture geometry.

Wright, C.A.; Tanigawa, J.J.; Hyodo, Masami; Takasugi, Shinji

1994-01-20T23:59:59.000Z

367

Three-dimensional geomechanical simulation of reservoir compaction and implications for well failures in the Belridge diatomite  

SciTech Connect

This paper describes an integrated geomechanics analysis of well casing damage induced by compaction of the diatomite reservoir at the Belridge Field, California. Historical data from the five field operators were compiled and analyzed to determine correlations between production, injection, subsidence, and well failures. The results of this analysis were used to develop a three-dimensional geomechanical model of South Belridge, Section 33 to examine the diatomite reservoir and overburden response to production and injection at the interwell scale and to evaluate potential well failure mechanisms. The time-dependent reservoir pressure field was derived from a three-dimensional finite difference reservoir simulation and used as input to three-dimensional non-linear finite element geomechanical simulations. The reservoir simulation included -200 wells and covered 18 years of production and injection. The geomechanical simulation contained 437,100 nodes and 374,130 elements with the overburden and reservoir discretized into 13 layers with independent material properties. The results reveal the evolution of the subsurface stress and displacement fields with production and injection and suggest strategies for reducing the occurrence of well casing damage.

Fredrich, J.T. [SPE, Richardson, TX (United States); Argueello, J.G.; Thorne, B.J.; Wawersik, W.R. [SPE, Richardson, TX (United States)]|[Sandia National Lab., Albuquerque, NM (United States)] [and others

1996-11-01T23:59:59.000Z

368

Characterization of oil and gas reservoir heterogeneity  

SciTech Connect

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

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

1992-10-01T23:59:59.000Z

369

Quantification of Libby Reservoir Water Levels Needed to Maintain or Enhance Reservoir Fisheries, 1983 Final Report.  

DOE Green Energy (OSTI)

The first six months of the fishery investigations in Libby Reservoir were aimed at developing suitable methodology for sampling physical-chemical limnology, fish food availability, fish food habits, and seasonal distribution and abundance of fish populations. Appropriate methods have been developed for all aspects with minor modification of original proposed methodologies. Purse seining has yet to be tested. Physical-chemical limnologic sampling could be reduced or subcontracted with the U.S. Geologic Survey to allow for more intensive sampling of fish food or fish distribution portions of the investigation. Final sample design will be determined during 1983-84. Future directions of the study revolve around two central issues, the potential for flexibility in reservoir operation and determination of how reservoir operation affects fish populations. Simulated maximum drawdown levels during a 40-year period were controlled by power in seven out of eight years. Drawdowns were generally within 10 feet of the flood control rule curve, however. There may be more flexibility with regards to timing of refill and evacuation. This aspect needs to be evaluated further. Production and availability of fish food, suitability of reservoir habitat, and accessibility of off-reservoir spawning and rearing habitat were identified as components of fish ecology which reservoir operation could potentially impact. Two models based on trophic dynamics and habitat suitabilities were suggested as a framework for exploring the relationship of reservoir operation on the fish community.

Shepard, Bradley B.

1984-07-01T23:59:59.000Z

370

Characterization of oil and gas reservoir heterogeneity  

SciTech Connect

The objective of the cooperative research program is to characterize Alaskan reservoirs in terms of their reserves, physical and chemical properties, geologic configuration and structure, and the development potential. The tasks completed during this period include: (1) geologic reservoir description of Endicott Field; (2) petrographic characterization of core samples taken from selected stratigraphic horizons of the West Sak and Ugnu (Brookian) wells; (3) development of a polydispersed thermodynamic model for predicting asphaltene equilibria and asphaltene precipitation from crude oil-solvent mixtures, and (4) preliminary geologic description of the Milne Point Unit.

Not Available

1991-01-01T23:59:59.000Z

371

Geothermal reservoir engineering code: comparison and validation  

DOE Green Energy (OSTI)

INTERCOMP has simulated six geothermal reservoir problems. INTERCOMP's geothermal reservoir model was used for all problems. No modifications were made to this model except to provide tabular output of the simulation results in the units used in RFP No. DE-RP03-80SF-10844. No difficulty was encountered in performing the problems described herein, although setting up the boundary and grid conditions exactly as specified were sometimes awkward, and minor modifications to the grid system were necessitated. The results of each problem are presented in tabular and (for many) graphical form.

Not Available

1981-02-27T23:59:59.000Z

372

A model for determining when an analysis contains sufficient detail to provide adequate NEPA coverage for a proposed action  

SciTech Connect

Neither the National Environmental Policy Act (NEPA) nor its subsequent regulations provide substantive guidance for determining the Level of detail, discussion, and analysis that is sufficient to adequately cover a proposed action. Yet, decisionmakers are routinely confronted with the problem of making such determinations. Experience has shown that no two decisionmakers are Likely to completely agree on the amount of discussion that is sufficient to adequately cover a proposed action. one decisionmaker may determine that a certain Level of analysis is adequate, while another may conclude the exact opposite. Achieving a consensus within the agency and among the public can be problematic. Lacking definitive guidance, decisionmakers and critics alike may point to a universe of potential factors as the basis for defending their claim that an action is or is not adequately covered. Experience indicates that assertions are often based on ambiguous opinions that can be neither proved nor disproved. Lack of definitive guidance slows the decisionmaking process and can result in project delays. Furthermore, it can also Lead to inconsistencies in decisionmaking, inappropriate Levels of NEPA documentation, and increased risk of a project being challenged for inadequate coverage. A more systematic and less subjective approach for making such determinations is obviously needed. A paradigm for reducing the degree of subjectivity inherent in such decisions is presented in the following paper. The model is specifically designed to expedite the decisionmaking process by providing a systematic approach for making these determination. In many cases, agencies may find that using this model can reduce the analysis and size of NEPA documents.

Eccleston, C.H.

1994-11-01T23:59:59.000Z

373

INCREASING WATERFLOOD RESERVES IN THE WILMINGTON OIL FIELD THROUGH IMPROVED RESERVOIR CHARACTERIZATION AND RESERVOIR MANAGEMENT  

Science Conference Proceedings (OSTI)

This project increased recoverable waterflood reserves in slope and basin reservoirs through improved reservoir characterization and reservoir management. The particular application of this project is in portions of Fault Blocks IV and V of the Wilmington Oil Field, in Long Beach, California, but the approach is widely applicable in slope and basin reservoirs. Transferring technology so that it can be applied in other sections of the Wilmington Field and by operators in other slope and basin reservoirs is a primary component of the project. This project used advanced reservoir characterization tools, including the pulsed acoustic cased-hole logging tool, geologic three-dimensional (3-D) modeling software, and commercially available reservoir management software to identify sands with remaining high oil saturation following waterflood. Production from the identified high oil saturated sands was stimulated by recompleting existing production and injection wells in these sands using conventional means as well as a short radius redrill candidate. Although these reservoirs have been waterflooded over 40 years, researchers have found areas of remaining oil saturation. Areas such as the top sand in the Upper Terminal Zone Fault Block V, the western fault slivers of Upper Terminal Zone Fault Block V, the bottom sands of the Tar Zone Fault Block V, and the eastern edge of Fault Block IV in both the Upper Terminal and Lower Terminal Zones all show significant remaining oil saturation. Each area of interest was uncovered emphasizing a different type of reservoir characterization technique or practice. This was not the original strategy but was necessitated by the different levels of progress in each of the project activities.

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

2002-02-28T23:59:59.000Z

374

PRESSURE TRANSDUCER  

DOE Patents (OSTI)

A pressure or mechanical force transducer particularly adaptable to miniature telemetering systems is described. Basically the device consists of a transistor located within a magnetic field adapted to change in response to mechanical force. The conduction characteristics of the transistor in turn vary proportionally with changes in the magnetic flux across the transistor such that the output (either frequency of amplitude) of the transistor circuit is proportional to mechanical force or pressure.

Sander, H.H.

1959-10-01T23:59:59.000Z

375

Geothermal reservoir engineering computer code comparison and validation calculations using MUSHRM and CHARGR geothermal reservoir simulators  

DOE Green Energy (OSTI)

The essential features of the reservoir codes CHARGR and MUSHRM are described. Solutions obtained for the problem set posed by DOE are presented. CHARGR was used for all six problems; MUSHRM was used for one. These problems are: the 1-D Avdonin solution, the 1-D well test analysis, 2-D flow to a well in fracture/block media, expanding two-phase system with drainage, flow in a 2-D areal reservoir, and flow in a 3-D reservoir. Results for the last problem using both codes are compared. (MHR)

Pritchett, J.W.

1980-11-01T23:59:59.000Z

376

SEISMIC DETERMINATION OF RESERVOIR HETEROGENEITY; APPLICATION TO THE CHARACTERIZATION OF HEAVY OIL RESERVOIRS  

SciTech Connect

The objective of the project is to examine how seismic and geologic data can be used to improve characterization of small-scale heterogeneity and their parameterization in reservoir models. The study is performed at West Coalinga Field in California. We continued our investigation on the nature of seismic reactions from heterogeneous reservoirs. We began testing our algorithm to infer parameters of object-based reservoir models from seismic data. We began integration of seismic and geologic data to determine the deterministic limits of conventional seismic data interpretation. Lastly, we began integration of seismic and geologic heterogeneity using stochastic models conditioned both on wireline and seismic data.

Matthias G. Imhof; James W. Castle

2003-11-01T23:59:59.000Z

377

A petrophysics and reservoir performance-based reservoir characterization of Womack Hill (Upper Smackover) Field (Alabama)  

E-Print Network (OSTI)

Womack Hill is one of the 57 Smackover fields throughout the Gulf Coast region. Since its discovery in 1970, Womack Hill Field has produced 30 million STB from the Upper Smackover sequence of carbonate reservoirs. Since production reached its peak in 1977, oil and gas rates have declined substantially. During the last ten years, the production decline has accelerated despite an increase in the water injection rate. This production decline along with the increase in the operating costs has caused a considerable drop in profitability of the field. The field currently produces 640 STB/D of oil and 330 MSCF/D of gas, along with 6,700 STB/D of water, which implies a water cut of over 90 percent. In order to optimize the reservoir management strategies for Womack Hill Field, we need to develop an integrated reservoir study. This thesis addresses the creation of an integrated reservoir study and specifically provides a detailed reservoir description that represents the high level of heterogeneity that exists within this field. Such levels of heterogeneity are characteristic of carbonate reservoirs. This research should serve as a guide for future work in reservoir simulation and can be used to evaluate various scenarios for additional development as well as to optimize the operating practices in the field. We used a non-parametric regression algorithm (ACE) to develop correlations between the core and well log data. These correlations allow us to estimate reservoir permeability at the "flow unit" scale. We note that our efforts to reach an overall correlation were unsuccessful. We generated distributions of porosity and permeability throughout the reservoir area using statistically derived estimates of porosity and permeability. The resulting reservoir description indicates a clear contrast in reservoir permeability between the western and eastern areas - and in particular, significant variability in the reservoir. We do note that we observed an essentially homogenous porosity distribution. We provided analysis of the production and injection data using various techniques (history plots, EUR plots, and decline type curve analysis) and we note this effort yielded a remaining recoverable oil of 1.9 MMSTB (under the current operating conditions). This analysis suggests a moderate flow separation between the western and eastern areas and raised some questions regarding the suitability of the hydraulic "jet pumps" (the water rate increased coincidentally with the installation of the jet pumps).

Avila Urbaneja, Juan Carlos

2002-01-01T23:59:59.000Z

378

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

Science Conference Proceedings (OSTI)

The project involves using advanced reservoir characterization and thermal production technologies to improve thermal recovery techniques and lower operating and capital costs in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. Through December 2001, project work has been completed on the following activities: data preparation; basic reservoir engineering; developing a deterministic three dimensional (3-D) geologic model, a 3-D deterministic reservoir simulation model and a rock-log model; well drilling and completions; and surface facilities on the Fault Block II-A Tar Zone (Tar II-A). Work is continuing on research to understand the geochemistry and process regarding the sand consolidation well completion technique, final reservoir tracer work, operational work and research studies to prevent thermal-related formation compaction in the Tar II-A steamflood area, and operational work on the Tar V steamflood pilot and Tar II-A post-steamflood projects. During the First Quarter 2002, the project team developed an accelerated oil recovery and reservoir cooling plan for the Tar II-A post-steamflood project and began implementing the associated well work in March. The Tar V pilot steamflood project will be converted to post-steamflood cold water injection in April 2002. The Tar II-A post-steamflood operation started in February 1999 and steam chest fillup occurred in September-October 1999. The targeted reservoir pressures in the ''T'' and ''D'' sands are maintained at 90 {+-} 5% hydrostatic levels by controlling water injection and gross fluid production and through the bimonthly pressure monitoring program enacted at the start of the post-steamflood phase. Most of the 2001 well work resulted in maintaining oil and gross fluid production and water injection rates. Reservoir pressures in the ''T'' and ''D'' sands are at 88% and 91% hydrostatic levels, respectively. Well work during the first quarter and plans for 2002 are described in the Reservoir Management section. The steamflood operation in the Tar V pilot project is mature and profitable. Recent production performance has been below projections because of wellbore mechanical limitations that have been addressed during this quarter. As the fluid production temperatures were beginning to exceed 350 F, our self-imposed temperature limit, the pilot steamflood was converted to a hot waterflood project in June 2001 and will be converted to cold water injection next quarter.

Scott Hara

2002-04-30T23:59:59.000Z

379

Reservoir description of low resistivity sandstones in the Mugrosa Formation (Oligocene) of Gala-Llanito Fields, Colombia, South America  

E-Print Network (OSTI)

The Gala-Llanito oil fields are located in the Middle Magdalena Valley Basin in northern Colombia, South America. These fields are operated by Empresa Colombiana de Petroleos (ECOPETROL) which is the oil national company. They are in the primary production phase and ECOPETROL is planning to develop new blocks and implement some type of secondary or EOR process in the depleted blocks. The C and B zones of Mugrosa Formation are the productive horizons in these fields. Usually formations showing high resistivity log response produce oil. However, some of these reservoirs which present a low-resistivity response on well logs still produce water-free oil irrespective of the calculated water saturation value. Identification of the fluid saturations from well logs is very difficult A reservoir description study was performed on the Gala Block of these fields to solve the problem of low resistivity response in oil bearing sandstones of the C zone. Clay mineral and capillary pressure effects, and non-traditional concepts in the formation evaluation, such as depositional environment were of primary concern in this reservoir description study. The C zone reservoirs were characterized stratigraphically as layered reservoirs composed of both finning upward and coarsening upward sequences. In the upper C zone four subzones were identified and within these subzones seven flow units were defined. Multiple water/oil contacts (WOCS) controlled by the sealing character of the faults and by the existing blocks were identified for each flow unit. Within a specific block of the Gala Block, each flow unit exhibits an independent WOC which is caused by the variation in the reservoir quality and by capillary pressure effects. The solution of the problem of low-resistivity response was based on the integration of the geological and petrophysical reservoir characteristics. This integration showed that the resistivity response in these reservoirs is strongly controlled by the environment of deposition and the position of the reservoir with respect to the water/oil contact. Simandoux's equation combined with generated capillary pressure curves appears to be the best model to estimate water saturation in a prospective sandstone in C Zone of Mugrosa Formation in Gala Block.

Bernal Guerrero, Maria Cristina

1993-01-01T23:59:59.000Z

380

Utah Dry Natural Gas New Reservoir Discoveries in Old Fields...  

U.S. Energy Information Administration (EIA) Indexed Site

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Utah Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3...

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381

Evaluating human fecal contamination sources in Kranji Reservoir Catchment, Singapore  

E-Print Network (OSTI)

Singapore government through its Public Utilities Board is interested in opening Kranji Reservoir to recreational use. However, water courses within the Kranji Reservoir catchment contain human fecal indicator bacteria ...

Nshimyimana, Jean Pierre

2010-01-01T23:59:59.000Z

382

California Dry Natural Gas New Reservoir Discoveries in Old Fields...  

Annual Energy Outlook 2012 (EIA)

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) California Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1 Year-2...

383

Ohio Dry Natural Gas New Reservoir Discoveries in Old Fields...  

Annual Energy Outlook 2012 (EIA)

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Ohio Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3...

384

Utah Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Utah Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6...

385

New Mexico--East Crude Oil Reserves in Nonproducing Reservoirs...  

U.S. Energy Information Administration (EIA) Indexed Site

Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) New Mexico--East Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3...

386

Ohio Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Ohio Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6...

387

Kansas Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) Kansas Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6...

388

Michigan Dry Natural Gas New Reservoir Discoveries in Old Fields...  

U.S. Energy Information Administration (EIA) Indexed Site

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Michigan Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1 Year-2...

389

U.S. Coalbed Methane Proved Reserves New Reservoir Discoveries...  

Annual Energy Outlook 2012 (EIA)

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) U.S. Coalbed Methane Proved Reserves New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1...

390

Colorado Dry Natural Gas New Reservoir Discoveries in Old Fields...  

Gasoline and Diesel Fuel Update (EIA)

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Colorado Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1 Year-2...

391

New Mexico Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) New Mexico Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

392

West Virginia Crude Oil Reserves in Nonproducing Reservoirs ...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) West Virginia Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

393

North Dakota Crude Oil Reserves in Nonproducing Reservoirs (Million...  

U.S. Energy Information Administration (EIA) Indexed Site

Reserves in Nonproducing Reservoirs (Million Barrels) North Dakota Crude Oil Reserves in Nonproducing Reservoirs (Million Barrels) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5...

394

Texas Dry Natural Gas New Reservoir Discoveries in Old Fields...  

Gasoline and Diesel Fuel Update (EIA)

New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Texas Dry Natural Gas New Reservoir Discoveries in Old Fields (Billion Cubic Feet) Decade Year-0 Year-1 Year-2 Year-3...

395

Combustor oscillation pressure stabilizer  

DOE Patents (OSTI)

In accordance with the objective of the present invention, the active control of unsteady combustion induced oscillations in a combustion chamber fired by a suitable fuel and oxidizer mixture, such as a hydrocarbon fuel and air mixture, is provided by restructuring and moving the position of the main flame front and thereby increasing the transport time and displacing the pressure wave further away from the in-phase relationship with the periodic heat release. The restructuring and repositioning of the main flame are achieved by utilizing a pilot flame which is pulsed at a predetermined frequency corresponding to less than about one-half the frequency of the combustion oscillation frequency with the duration of each pulse being sufficient to produce adequate secondary thermal energy to restructure the main flame and thereby decouple the heat release from the acoustic coupling so as to lead to a reduction in the dynamic pressure amplitude. The pulsating pilot flame produces a relatively small and intermittently existing flame front in the combustion zone that is separate from the oscillating main flame front but which provides the thermal energy necessary to effectively reposition the location of the oscillating main flame front out of the region in the combustion zone where the acoustic coupling can occur with the main flame and thereby effectively altering the oscillation-causing phase relationship with the heat of combustion.

Gemmen, R.S.; Richards, G.A.; Yip, M.T.J.; Robey, E.; Cully, S.R.; Addis, R.E.

1996-12-31T23:59:59.000Z

396

Geolocation of man-made reservoirs across terrains of varying complexity using GIS  

Science Conference Proceedings (OSTI)

The Reservoir Sedimentation Survey Information System (RESIS) is one of the world's most comprehensive databases of reservoir sedimentation rates, comprising nearly 6000 surveys for 1819 reservoirs across the continental United States. Sediment surveys ... Keywords: DEM, GIS, Reservoir sedimentation, Terrain complexity

David M. Mixon; David A. Kinner; Robert F. Stallard; James P. M. Syvitski

2008-10-01T23:59:59.000Z

397

Water Sampling At Blackfoot Reservoir Area (Hutsinpiller & Parry...  

Open Energy Info (EERE)

Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Water Sampling At Blackfoot Reservoir Area (Hutsinpiller & Parry, 1985) Exploration Activity...

398

Underground natural gas storage reservoir management: Phase 2. Final report, June 1, 1995--March 30, 1996  

SciTech Connect

Gas storage operators are facing increased and more complex responsibilities for managing storage operations under Order 636 which requires unbundling of storage from other pipeline services. Low cost methods that improve the accuracy of inventory verification are needed to optimally manage this stored natural gas. Migration of injected gas out of the storage reservoir has not been well documented by industry. The first portion of this study addressed the scope of unaccounted for gas which may have been due to migration. The volume range was estimated from available databases and reported on an aggregate basis. Information on working gas, base gas, operating capacity, injection and withdrawal volumes, current and non-current revenues, gas losses, storage field demographics and reservoir types is contained among the FERC Form 2, EIA Form 191, AGA and FERC Jurisdictional databases. The key elements of this study show that gas migration can result if reservoir limits have not been properly identified, gas migration can occur in formation with extremely low permeability (0.001 md), horizontal wellbores can reduce gas migration losses and over-pressuring (unintentionally) storage reservoirs by reinjecting working gas over a shorter time period may increase gas migration effects.

Ortiz, I.; Anthony, R.V.

1996-12-31T23:59:59.000Z

399

Dispersion measurement as a method of quantifying geologic characterization and defining reservoir heterogeneity. Final report  

Science Conference Proceedings (OSTI)

The main objective of this research project is to investigate dispersion as a method of quantifying geological characterization and defining reservoir heterogeneity in order to enhance crude oil recovery. The dispersion of flow of a reservoir rock (dispersion coefficient and dispersivity) was identified as one of the physical properties of a reservoir rock by measuring the mixing of two miscible fluids, one displacing the other in a porous medium. A rock was 100% saturated with a resident fluid and displaced by a miscible fluid of equal viscosity and equal density. Some specific experiments were performed with unequal densities. Produced fluid was analyzed by refractometer, nuclear reaction, electrical conductivity and X-ray scan. Several physical and flow characteristics were measured on the sand rock sample in order to establish correlations with the measured dispersion property. Absolute permeability, effective porosity, relative permeability, capillary pressure, the heterogeneity factor and electrical conductivity were used to better understand the flow system. Linear, transverse, 2-D and 3-D dispersions were measured and used to characterize the rock heterogeneity of the flow system. A new system of measuring dispersion was developed using a gas displacing gas system in a porous medium. An attempt was also made to determine the dispersion property of an actual reservoir from present day well log data on a producing well. 275 refs., 102 figs., 17 tabs.

Menzie, D.E.

1995-05-01T23:59:59.000Z

400

Underground natural gas storage reservoir management  

SciTech Connect

The objective of this study is to research technologies and methodologies that will reduce the costs associated with the operation and maintenance of underground natural gas storage. This effort will include a survey of public information to determine the amount of natural gas lost from underground storage fields, determine the causes of this lost gas, and develop strategies and remedial designs to reduce or stop the gas loss from selected fields. Phase I includes a detailed survey of US natural gas storage reservoirs to determine the actual amount of natural gas annually lost from underground storage fields. These reservoirs will be ranked, the resultant will include the amount of gas and revenue annually lost. The results will be analyzed in conjunction with the type (geologic) of storage reservoirs to determine the significance and impact of the gas loss. A report of the work accomplished will be prepared. The report will include: (1) a summary list by geologic type of US gas storage reservoirs and their annual underground gas storage losses in ft{sup 3}; (2) a rank by geologic classifications as to the amount of gas lost and the resultant lost revenue; and (3) show the level of significance and impact of the losses by geologic type. Concurrently, the amount of storage activity has increased in conjunction with the net increase of natural gas imports as shown on Figure No. 3. Storage is playing an ever increasing importance in supplying the domestic energy requirements.

Ortiz, I.; Anthony, R.

1995-06-01T23:59:59.000Z

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401

Fourteenth workshop geothermal reservoir engineering: Proceedings  

DOE Green Energy (OSTI)

The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.; Cook, J.W.

1989-01-01T23:59:59.000Z