125 Matching Results

Search Results

Advanced search parameters have been applied.

Decline curve analysis of production data from The Geysers geothermal field

Description: Production data for over two hundred wells at The Geysers geothermal field were compiled and analyzed. Decline curves for groups of wells with 5, 10, and 40 acre spacing are presented and compared to curves published previously by Budd (1972) and Dykstra (1981). Decline curves for several individual wells and leases are discussed to illustrate the effects of well spacing and location, as well as the heterogeneous nature of the reservoir.
Date: January 1, 1987
Creator: Ripperda, M. & Bodvarsson, G.S.
Partner: UNT Libraries Government Documents Department

Flow in geothermal wells. Part II. Working equations for one-dimensional flow through a circular vertical channel

Description: Field equations for two-phase flow based on irreversible thermodynamics are specialized to the point where the equations can be applied to the calculation of well flows in the form of an engineering approximation in that all fields are simplified to become functions of a single variable Z - the distance along the well axis. (MHR)
Date: December 1, 1980
Creator: Bilicki, Z. & Kestin, J.
Partner: UNT Libraries Government Documents Department

Flow in geothermal wells. Part I. Fundamentals of two-phase flow by the method of irreversible thermodynamics

Description: A derivation of the field equations for two-phase flow is presented, based on the classical methods of thermodynamics of irreversible processes and resulting in a homogeneous diffusion model. The equations are local and instantaneous and ignore turbulent fluctuations as well as the observable fluctuations of the phase boundaries. (MHR)
Date: December 1, 1980
Creator: Bilicki, Z. & Kestin, J.
Partner: UNT Libraries Government Documents Department

Two-phase flow in geothermal energy sources. Final technical report

Description: A geothermal well consisting of single and two-phase flow sections was modeled in order to explore the variables important to the process. For this purpose a computer program was developed in a versatile form in order to be able to incorporate a variety of two phase flow void fraction and friction correlations. A parametric study indicated that the most significant variables controlling the production rate are: hydrostatic pressure drop or void fraction in the two-phase mixture; and, heat transfer from the wellbore to the surrounding earth. Downhole instrumentation was developed and applied in two flowing wells to provide experimental data for the computer program. The wells (East Mesa 8-1, and a private well) behaved differently. Well 8-1 did not flash and numerous shakedown problems in the probe were encountered. The private well did flash and the instrumentation detected the onset of flashing. A Users Manual was developed and presented in a workshop held in conjunction with the Geothermal Resources Council.
Date: July 1, 1981
Partner: UNT Libraries Government Documents Department

Hydrocarbons associated with brines from geopressured wells

Description: The purpose of this research is to determine the concentration of the cryocondensates in fluids of the various USDOE Geopressured wells as a function of production volume, to correlate the production of these compounds with reservoir and well production characteristics, to precisely measure solubilities of cryocondensates components in water and sodium chloride solutions (brines) as a function of ionic strength and temperature and the component's distribution coefficients between these solutions and oil, to develop models of the reservoir which are consistent with the data obtained, to monitor the wells for the production of aliphatic oils and relate any such production with the data obtained, and to develop a harsh environment pH probe for use in well brines. Results are summarized.
Date: January 15, 1991
Partner: UNT Libraries Government Documents Department

Testing of the Pleasant Bayou Well through October 1990

Description: Pleasant Bayou location was inactive from 1983 until the cleanout of the production and disposal wells in 1986. The surface facilities were rehabilitated and after shakedown of the system, additional repair of wellhead valves, and injection of an inhibitor pill, continuous long-term production was started in 1988. Over two years of production subsequent to that are reviewed here, including: production data, brine sampling and analysis, hydrocarbon sampling and analysis, solids sampling and analysis, scale control and corrosion monitoring and control.
Date: August 1, 1992
Creator: Randolph, P.L.; Hayden, C.G.; Mosca, V.L. & Anhaiser, J.L.
Partner: UNT Libraries Government Documents Department

Mathematical model of damage collars in water reinjection wells

Description: A recent study of the Imperial Magma-San Diego Gas and Electric Geothermal Experimental Site near Niland, California suggests that damage collar formation caused by deep invasion of water-borne particulates into the reinjection reservoir may be an important mechanism in water reinjection well performance. A model of damage collar effects has been developed and appears to provide insight which is consistent with information provided by other sources. For effective reinjection system analysis where damage collars are thought to exist, a more explicit understanding of the movement of water-borne particulates through porous media needs to be developed.
Date: May 1, 1978
Creator: Jorda, R.M.
Partner: UNT Libraries Government Documents Department

Geothermal two-phase flow: a selective, annotated guide to the literature. Report No. GEOFLO/7

Description: This bibliography includes only those references considered useful for the solution of problems facing a geothermal plant designer. Historical developments and flow models are discussed. (MHR)
Date: June 1, 1980
Creator: Bilicki, Z.; DiPippo, R.; Michaelides, E.E.; Kestin, J. & Maeder, P.F.
Partner: UNT Libraries Government Documents Department

Analysis of well tests with variable discharge

Description: The development of a general technique of analyzing well tests with variable flow rates is reported. The variable flow is approximated by a series of sequential straight line segments of arbitrary length and slope. (MHR)
Date: December 1, 1976
Creator: Tsang, C.F.; McEdwards, D.G.; Narasimhan, T.N. & Witherspoon, P.A.
Partner: UNT Libraries Government Documents Department

Testing geopressured geothermal reservoirs in existing wells. Final report P. R. Girouard Well No. 1, Lafayette Parish, Louisiana. Volume II. Well test data

Description: The following data from the reopening of an abandoned well are presented: reservoir pressure drawdown and buildup data, Institute of Gas Technology test data, Insitute of Gas Technology sample log, reservoir fluid analysis, produced gas/water ratio, chemical analysis procedures, surface flow data, third party sampling and reports, sand detectors charts, and Horner-type buildup data. (MHR)
Date: January 1, 1981
Partner: UNT Libraries Government Documents Department

Geothermal field case studies that document the usefulness of models in predicting reservoir and well behavior

Description: The geothermal industry has shown significant interest in case histories that document field production histories and demonstrate the techniques which work best in the characterization and evaluation of geothermal systems. In response to this interest, LBL has devoted a significant art of its geothermal program to the compilation and analysis of data from US and foreign fields (e.g., East Mesa, The Geysers, Susanville, and Long Valley in California; Klamath Falls in Oregon; Valles Caldera, New Mexico; Cerro Prieto and Los Azufres in Mexico; Krafla and Nesjavellir in Iceland; Larderello in Italy; Olkaria in Kenya). In each of these case studies we have been able to test and validate in the field, or against field data, the methodology and instrumentation developed under the Reservoir Technology Task of the DOE Geothermal Program, and to add to the understanding of the characteristics and processes occurring in geothermal reservoirs. Case study results of the producing Cerro Prieto and Olkaria geothermal fields are discussed in this paper. These examples were chosen because they illustrate the value of conceptual and numerical models to predict changes in reservoir conditions, reservoir processes, and well performance that accompany field exploitation, as well as to reduce the costs associated with the development and exploitation of geothermal resources. 14 refs., 6 figs.
Date: March 1, 1989
Creator: Lippmann, M.J.
Partner: UNT Libraries Government Documents Department

Analysis of nonisothermal injection and falloff tests in layered reservoirs

Description: The effects of reservoir layering and gravity segregation on nonisothermal injection and falloff tests are investigated. Results show that layering does not affect injection or falloff data if all the layers are permeable and accept fluids from the wellbore. In such cases, the average permeability, skin factor, and distance to the thermal front can be calculated using the techniques developed for homogeneous reservoirs. Special considerations have to be taken for cases where several layers are impermeable or are permeable but do not accept fluids of the well face. In the first case (impermeable layers), knowledge of the total thickness of the permeable layers is required for the existing techniques to be applied successfully. In the second case, the existing techniques cannot be applied, but characteristic responses from injection and falloff test are seen; therefore, this case can be identified easily. 13 refs., 8 figs.
Date: March 1, 1985
Creator: Halfman, S.E. & Benson, S.M.
Partner: UNT Libraries Government Documents Department

Evaluation of potential geothermal well-head flow sampling and calorimeter methods

Description: The results of the evaluation of potential geothermal well-head calorimeter systems and flow sampling techniques are presented. The candidate calorimeter systems and flow sampling configurations are presented and discussed. The systems and configurations are compared and ranked relative to their potential usefulness for obtaining enthalpy measurements and representative sample flows at geothermal well heads. A preliminary test plan is presented to briefly indicate the type of field tests that are recommended for further development of selected candidate calorimeter methods and sample flow withdrawal apparatus.
Date: June 1, 1979
Creator: Cliff, W.C.; Apley, W.J. & Creer, J.M.
Partner: UNT Libraries Government Documents Department

Pumping tests of well Campbell et al. No. 2, Gila Hot Springs, Grant County, New Mexico

Description: Well Campbell et al. No. 2 near Gila Hot Springs in southwestern New Mexico (Section 5, Township 13 South, Range 13 West) was pumped for a five-step test and a 48-hour constant-rate test during October 1981. Measurements included depth to water in the pumping well and two observation wells, and discharge rates at the pumping well and two springs. The water level in the pumping well responded during both tests. However, water-level changes in the observation wells were too small for analytical use and discharge rates from the springs showed no change. Chemical analyses of water samples collected from two springs and the pumping well show very similar water chemistries. Estimates of hydraulic properties show transmissivity from 12,000 to 14,000 gpd/ft and a storativity of 0.05. Combining these parameters with well data gives the first-year optimum discharge rate as 50 gpm with 20 feet of drawdown. Pumping this well at 50 gpm for forty years should produce only small water-level changes in wells a few hundred feet away. It would diminish the flow of the springs, and for planning purposes the combined discharge of the springs and well should be considered constant.
Date: March 1, 1982
Creator: Schwab, G.E.; Summers, W.K.; Colpitts, R.M. Jr.; Teuten, C.E. & Young, W.K.
Partner: UNT Libraries Government Documents Department

Preliminary report on reservoir tests at East Mesa Geothermal Site, California

Description: Reservoir tests on the geothermal well field at East Mesa, California were conducted in two phases. The first phase was aimed at conducting a production test on well 31-1. This production test was to consist of placing the pressure gage (HP gage) at a depth of 5700 feet within 31-1, produce 31-1 at the rate of approximately 50 gpm for about 48 hours, and observe the consequent pressure changes. This production test could not be carried out successfully because the HP gage failed to function satisfactorily at a temperature of 318/sup 0/F (159/sup 0/C) prevalent at 5700 feet. During the second phase of the testing operations, an interference test was conducted with the help of two HP gages. The interference test consisted in producing 6-2 and observing the pressure changes in wells 6-1 and 8-1. The details of this test are reported. (JGB)
Date: March 4, 1976
Creator: Narasimhan, T.N. & Witherspoon, P.A.
Partner: UNT Libraries Government Documents Department

Status of geothermal reservoir engineering research projects supported by USDOE/Division of Geothermal Energy

Description: In the fall of 1977, the US Department of Energy (DOE), Division of Geothermal Energy (DGE) proposed that Lawrence Berkeley Laboratory (LBL) assume lead responsibility, on DGE's behalf, for geothermal reservoir engineering. This summary discusses briefly the DOE/DGE-sponsored geothermal reservoir engineering research program which includes LBL in-house research and research done by others through LBL. LBL in-house research has emphasized improvement of well test analysis methods and the development of geothermal reservoir performance simulators. Work by others has included 18 separate contracts on a variety of technical and scientific projects. Altogether, 29 distinguishable research topics have been addressed. Fourteen institutions, including eight private companies, have interacted with the program. Table 1, along with figures 2 and 3 summarized the status of the work.
Date: July 1, 1979
Creator: Howard, J.H. & Schwarz, W.J.
Partner: UNT Libraries Government Documents Department

Study of thermal effects in well test analysis

Description: Data analysis of well tests performed in non-isothermal (e.g., geothermal) reservoirs should take into account pressure changes resulting from fluid (and rock) temperature-dependent properties. For example the presence of zones of different temperatures may resemble permeability boundaries and will require careful interpretation of well test data. The present investigation employed a numerical model which incorporates temperature effects on fluid viscosity, density, and heat capacity. This study not only examines the influence of the viscosity variation but also the effects of the transition zone between hot and cold waters. A series of studies were performed to simulate the results from testing a well in a hot zone which is surrounded by a concentric cooler region. Observations were made at both the well itself and at observation wells. The cases include: (1) production tests to analyze long-term transient effects; (2) build-up tests to examine pressure variations after short periods of production; (3) injection tests of colder water into the hot zone to evaluate viscosity effects; and (4) partial penetration of the aquifer to study thermal effects on tests carried out using a partially penetrating production well.
Date: September 1, 1979
Creator: Mangold, D.C.; Tsang, C.F.; Lippmann, M.J. & Witherspoon, P.A.
Partner: UNT Libraries Government Documents Department

Well-test data from geothermal reservoirs

Description: Extensive well testing in geothermal resources has been carried out throughout the western United States and in northern Mexico since 1975. Each resource tested and each well test conducted by LBL during the eight-year period are covered in brief. The information, collected from published reports and memoranda, includes test particulars, special instrumentation, data interpretation when available, and plots of actual data. Brief geologic and hydrologic descriptions of the geothermal resources are also presented. The format is such that well test descriptions are grouped, in the order performed, into major sections according to resource, each section containing a short resource description followed by individual test details. Additional information regarding instrumentation is provided. Source documentation is provided throughout to facilitate access to further information and raw data.
Date: September 1, 1982
Creator: Bodvarsson, M.G. & Benson, S.M.
Partner: UNT Libraries Government Documents Department

Wellbore and soil thermal simulation for geothermal wells: comparison of geotemp predictions to field data and evaluation of flow variables. Part II report

Description: A better understanding of temperatures in a well is needed to improve casing selection, cement design, drilling fluid formulation, packer selection, and many other aspects of well design. Two applications of GEOTEMP are presented which provide the calculations needed. First, the results of testing GEOTEMP predictions with analytical solutions and with field temperature data are presented. And second, sensitivity studies establish the importance of certain well variables on downhole temperatures. (MHR)
Date: January 1, 1980
Creator: Wooley, G.R.
Partner: UNT Libraries Government Documents Department

Wellbore thermal simulation for geothermal wells. Survey of existing capability and industry needs and interest

Description: Four operating companies and five service companies in the petroleum and geothermal industry were contacted (1) to determine needs for wellbore temperature predictions during operations and (2) to evaluate interest in use of a wellbore thermal simulator (computer program) if developed by ERDA. As a basis for contacting industry, a literature survey was undertaken to assess the state-of-the-art and availability of wellbore thermal simulation capability. The literature review is summarized in the four tables of Appendix 1. Written abstracts of the individual articles is given in Appendix 2. The feedback from industry is presented in Appendix 3 in the form of completed questionaires.
Date: June 1, 1977
Creator: Goodman, M.A.
Partner: UNT Libraries Government Documents Department

Flow in geothermal wells. Part IV. Transition criteria for two-phase flow patterns

Description: Detailed considerations justifying the criteria for transitions between flow patterns are presented. The following are covered: transition from bubble to plug (or slug) flow, transition from plug flow to froth flow, transition from froth to annular mist flow, and model comparisons. (MHR)
Date: December 1, 1980
Creator: Bilicki, Z. & Kestin, J.
Partner: UNT Libraries Government Documents Department

Geothermal-well design handbook

Description: A simplified process is presented for estimating the performance of geothermal wells which are produced by natural, flashing flows. The well diameter and depth, and reservoir conditions must be known; then it is possible to determine the total pressure drop in a flowing well, and therefore to find the fluid pressure, temperature, and steam quality at the wellhead. By applying the handbook process to several input data sets, the user can compile sufficient information to determine the interdependence of input and output parameters. (MHR)
Date: February 1, 1982
Partner: UNT Libraries Government Documents Department