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Effect of Temperature and Solution Composition on the Permeability of St. Peters Sandstone: Role of Iron (III)

Description: The purpose of this study was to systematically investigate effects of temperature and fluid composition on the permeability of quartz sandstones. We have concentrated our initial efforts on the time and flow dependence at 2 elevated temperatures (100°C, 200°C).
Date: December 16, 1980
Creator: Potter, J. M.; Nur, A. & Dibble Jr., W. E.
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Partner: UNT Libraries Government Documents Department
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Comparison of Two Hot Dry Rock Geothermal Reservoirs

Description: Two hot dry rock (HDR) geothermal energy reservoirs were created by hydraulic fracturing of granite at 2.7 t o 3.0 km (5000 to 10000 ft ) at the Fenton Hill site, near the Valles Caldera in northern New Mexico. Both reservoirs are research reservoirs, in the sense that both are fairly small, generally yielding 5 MWt or less, and are intended to serve as the basic building blocks of commercial-sized reservoirs, consisting of 10 t o 15 similar fractures that would yield approximately 35 MWt over … more
Date: December 16, 1980
Creator: Murphy, H. D.; Tester, J. W. & Potter, R. M.
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Partner: UNT Libraries Government Documents Department
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Geothermal Fields on the Volcanic Axis of Mexico

Description: At present in Mexico, geothermal energy is receiving a great impulse due to the excellent results obtained in the Cerro Prieto geothermal field, in which a geothermoelectric plant is operated. This plant has four units of 37.5 MW each, with a total capacity of 150 MW, and under program 470 MW more by 1984. The Government Institution, Comisi6n Federal de Electricidad, is in charge of the exploration and exploitation of geothermal fields as well as construction and operation of power plants in Me… more
Date: December 16, 1980
Creator: Mercado, S. & Gonzalez, A.
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Partner: UNT Libraries Government Documents Department
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Well Test Analysis Research

Description: Well test analysis offers a rapid way to perform an initial assessment of geothermal systems. Well testing includes both pressure drawdown and buildup testing, and interference testing. Development of new well test analyses receives major emphasis in the Stanford Geothermal Program. During the year, quite a few studies were completed, and reports and papers presented on a variety of well test analysis methods. The paper summarizes some of the more important results.
Date: December 16, 1980
Creator: Ramey, H.J. Jr.; Horne, R.N.; Miller, F.G. & Brigham, W.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Analysis of Preliminary Flow Data from Pleasant Bayou No. 2 Geopressured Well

Description: The main purpose of this study is to analyze pressure drawdown and buildup data to evaulate formation parameters. In this connection, we note that the, flow periods 1 and 2 were too short (13 minutes and 184 minutes respectively) to give meaningful data for analysis purposes. Also, flow data for part of flow period 3 and pressure buildup data for practically all of buildup period 4 are missing. The complete flow and pressure drawdown/buildup data are, however, available for flow/shutin period S… more
Date: December 16, 1980
Creator: Garg, S.K.
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Partner: UNT Libraries Government Documents Department
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Hydrology and Model of the Okoy Geothermal Field, Negros Oriental, Republic of the Philippines

Description: Ward (1980) described the exploration of the Okoy geothermal field. Resistivity surveying using Schlumberger traverses has covered an area of approximately 800 km2 in the southern part of the Island of Negros. Hot springs and other thermal manifestations occur in the Okoy valley, Valencia and at Tabac Magaso, Dauin. Initial shallow exploratory drilling indicated a possible sub-surface flow of hot water in the Okoy valley. Further deep exploratory drilling to the West has located two high temper… more
Date: December 16, 1980
Creator: Smith, E. W.
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Partner: UNT Libraries Government Documents Department
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Log Interpretation Techniques to Identify Production Zones in Geothermal Wells

Description: Identification of production zones in a fractured or faulted qeotherrnal well is quantitatively difficult. Temperature and spinner surveys along with flow tests are the techniques generally used to identify and describe these fractured zones during production testing. These techniques generally do not describe the production zones in any detail and they miss or bypass potential zones of production when fractures have been closed or plugged during the drilling process. These latter zones could p… more
Date: December 16, 1980
Creator: Mathews, Mark
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Preliminary Test Results of the First Geopressured-Geothermal Design Well, Brazoria County, Texas

Description: The Pleasant Bayou #2 Geopressured-Geothermal test well was completed in the summer of 1979. The C sand of the Frio formation was selected for completion on the basis of core analysis, well logs, and drill stem tests. The purpose of this paper is to summarize the results of the short term production tests run on the Pleasant Bayou #2 well during 1979 and the Fall of 1980. These tests were analyzed using conventional transient pressure test analysis methods. The most significant test run during … more
Date: December 16, 1980
Creator: MacDonald, R. C. & Dorfman, M. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Numerical Code Comparison Project - A Necessary Step Towards Confidence in Geothermal Reservoir Simulators

Description: A necessary first step in resolving differences and in evaluating the usefulness of numerical simulators for geothermal reservoir analysis is the comparison of simulator results for a set of well-specified problems involving processes applicable in reservoir analysis. Under the direction of DOE'S Geothermal Reservoir Engineering Management Program (GREMP), a set of six test problems has been developed in an attempt to meet this need. The problem set covers a range of reservoir situations includ… more
Date: December 16, 1980
Creator: Sorey, Michael L.
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Partner: UNT Libraries Government Documents Department
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Is Geothermal Simulation a "Catastrophe"?

Description: All numerical simulators of geothermal reservoirs depend upon an accurate representation of the thermodynamics of steam-water systems. These relationships are required to render tractable the system of balance equations derived from the physics of flow through porous media. While it is generally recognized that the steam-water system (i.e. two phase) is not in thermodynamic equilibrium, equihbrium thermodynamics are employed in its description. In this paper, we present an alternative view base… more
Date: December 16, 1980
Creator: Nguyen, V.V. & Pinder, George F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Three-Dimensional Geothermal Reservoir Simulation

Description: The authors present a three-dimensional model for reservoir simulation to show some behaviors of fluid flow in a geothermal reservoir, assuming water influx and heat conduction from heat sources under the reservoir.
Date: December 16, 1980
Creator: Hirakawa, Seiichi; Fujinaga, Yoshinobu & Miyoshi, Michinori
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Effect of Measured Wellhead Parameters and Well Scaling on the Computed Downhole Conditions in Cerro Prieto Wells

Description: This paper is devoted to the discussion of the wellbore model and its describing equations, comparison between the computed and measured pressures and the effect of measured wellhead parameters on the downhole pressures in the well. Finally a wellbore model with multiple inside diameters is discussed and the effect of well scaling on the bottom hole pressures is studied.
Date: December 16, 1980
Creator: Goyal, K. P.; Miller, C. W. & Lippmann, M. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Hydrothermal Alteration Minerals of the Geysers Steam Field, California and their Potential Use in Exploration

Description: Little information has been published on the hydrothermal alteration minerals occurring at depth in the Geysers steam field, California. Steiner (1958) reported the occurrence of wairakite from a well; McNitt (1964) identified pyrite, sericite, calcite, quartz, siderite, apatite and chlorite in cores of Franciscan graywacke and greenstone. Recently, Union Oil Geothermal Division furnished a set of well cores from the cap rock overlying the steam reservoir for geophysical studies (Lockner -e t -… more
Date: December 16, 1980
Creator: Moore, Diane
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Numerical Studies of the Energy Sweep in Five-Spot Geothermal Production/Injection Systems

Description: Most recent interest in the injection of cold water into a geothermal reservoir has been related to the disposal of geothermal brines. Injection also offers the potential benefit of prolonging the useful life of a vapor-dominated system by providing additional water to extract energy out of the rock matrix. In a liquid-dominated reservoir injection may help to maintain pressures near the production wells by pushing the hot water toward them and preventing too much local boiling. Pressure mainte… more
Date: December 16, 1980
Creator: O'Sullivan, M.J. & Pruess, K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Determination of TDS in Geothermal Systems by Well-Log Analysis

Description: An estimate of t h e chemistry of the fluid within a geothermal reservoir is required to establish the geological source and the possible environmental impact of the fluid as well as scaling and corrosion problems which might develop during production. While a detailed analysis of the chemical composition of a geothermal fluid can only be obtained from a water sample, an estimate of the total dissolved solids (TDS) in equivalent sodium chloride (NaCl) concentration can be obtained from well log… more
Date: December 16, 1980
Creator: Brown, Susan L.; Gobran, Brian D. & Sanyal, Subir K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The Effect of Temperature on the Absolute Permeability to Distilled Water of Unconsolidated Sand Cores

Description: The work presented herein is a study of the effect of temperature on the absolute permeability to distilled water of unconsolidated sandstones at one confining pressure. The absolute permeability to distilled water of Ottawa silica sand was not dependent on the temperature level.
Date: December 16, 1980
Creator: Sageev, A.; Gobran, B.D.; Brigham, W.E. & Ramey, H.J. Jr.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Eliminating the Wellbore Response in Transient Well Test Analysis

Description: The main purpose of this work is to show that it is possible to calculate the sandface flowrate given wellhead conditions and the downhole pressure transients. It is not necessary t o know anything about the reservoir itself. First, it is of interest to look at the nonuniform pressure changes in the well, and to illustrate nonisothermal effects on pressure transient data.
Date: December 16, 1980
Creator: Miller, Constance W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A Geologic, Hyrologic and Geochemical Model of the Serrazzano Zone of the Larderello Geothermal Field

Description: The large number of nonproductive wells lying along the northern and western margins of the Larderello field have indicated some boundaries of the productive area but have also prevented us, so far, from fully understanding the pheiomena controlling the behavior of the geothermal system in these areas. In 1980 ENEL re-opened some wells that had been shut-in immediately after drilling, thus offering us the possibility to complete the geochemical picture by means of numerous samplings of steam, g… more
Date: December 16, 1980
Creator: Calorie, C.; Celati, R.; D'Amore, F.; Squarci, P. & Truesdell, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Collection and Analysis of Reservoir Data from Testing and Operation of the Raft River 5 MW Power Plant

Description: The Raft River 5 MW power plant will be on-line some time this spring. During testing of the supply and injection system prior to plant start-up and during testing of the plant itself, data can be collected and used to calibrate computer models, refine predicted drawdowns and interference effects, monitor changing temperatures, and recalculate reservoir parameters. Analytic methods have been used during reservoir testing at Raft River to calculate reservoir coefficients. However, anisotropy of … more
Date: December 16, 1980
Creator: Petty, Susan
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A Numerical Simulation of the Natural Evolution of Vapor-Dominated Hydrothermal Systems

Description: We describe simulation of the transient evolution of a "cold" hydrothermal system into a steady-state partially vapor-dominated system. In our study we have neglected the effects of salts and gases and have assumed that rock properties are time independent and homogeneous within each part of the system. Despite these simplifications we believe that our model demonstrates the essential features of a natural hydrothermal convection system (NHCS).
Date: December 16, 1980
Creator: Pruess, K. & Truesdell, A.H.
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Partner: UNT Libraries Government Documents Department
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Identification of Geothermal Reserves and Estimation of their Value

Description: This paper discusses a procedure for estimating the value of a hot water geothermal property from a resource owner's point of view. Two methods make up the procedure: a "conservative" method of estimation and an "optimistic" one. Value of a property by both methods is estimated t o equal the present value of future income less the cost of resource extraction. The two methods share a common set of assumptions (e.g., that the price of hot water at the start of cash flow from a project will be the… more
Date: December 16, 1980
Creator: Howard, J. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Application of a Downhole Flowmeter to Detecting Casing Breaks in a Geothermal Well

Description: The downhole flowmeter logging system for high temperature geothermal wells developed at Wairakei, New Zealand, is proving to be an invaluable tool for use during workovers to repair or reinstate problem wells. This contribution describes a straightforward example of identifying breaks in plain casing near the top of a productive well.
Date: December 16, 1980
Creator: Syms, Margot C.; Syms, Peter H. & Bixley, Paul F.
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Partner: UNT Libraries Government Documents Department
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An Evaluation of Geopressured Brine Injectability

Description: We-have developed an apparatus with a capability for evaluating geopressured brine injectability at elevated pressures and temperatures. The apparatus utilizes membrane filters as injection zone reservoir analogs and permits injectability tests to be performed in accordance with Barkman and Davidson Methdology. A field evaluation of geopressured brine injectability was completed during September 22-25, 1980 at the DOE, Brazoria test site in Texas. Membrane filters, with pore sizes of 0.4-{micro… more
Date: December 16, 1980
Creator: Owen, L. B.; Blair, C. K.; Harrar, J. E. & Netherton, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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