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• 131. [Image] National Hydrothermal Direct Applications Program Plan

  	The program will simultaneously address the range of problems facing the developer, from initial resource assessment to ultimate construction and end use. Initial emphasis will be on projects that have ...
  	Citation × Citation Citation Abstract Copy Title: National Hydrothermal Direct Applications Program Plan Author: Division of Geothermal Resource Management Year: 1980 The program will simultaneously address the range of problems facing the developer, from initial resource assessment to ultimate construction and end use. Initial emphasis will be on projects that have a known user and a known resource, next moving to known resources where users must be brought to the energy source, and finally moving to identification of previously unidentified resources Title: National Hydrothermal Direct Applications Program Plan Author: Division of Geothermal Resource Management Year: 1980 The program will simultaneously address the range of problems facing the developer, from initial resource assessment to ultimate construction and end use. Initial emphasis will be on projects that have a known user and a known resource, next moving to known resources where users must be brought to the energy source, and finally moving to identification of previously unidentified resources Close

• 132. [Image] Coso Geothermal Corrosion Studies

  	This report documents the results of geothermal corrosion studies conducted at the Coso Thermal Area, Naval Weapons Center, China Lake, California. Nine different common construction grade piping materials ...
  	Citation × Citation Citation Abstract Copy Title: Coso Geothermal Corrosion Studies Author: Finnegan, S.A. Year: 1977 This report documents the results of geothermal corrosion studies conducted at the Coso Thermal Area, Naval Weapons Center, China Lake, California. Nine different common construction grade piping materials were tested for periods up to about one year in three distinctive low-pressure, medium temperature environments (acid-sulfate steam, groundwater-diluted steam, and hot mineralized alkaline water) under anaerobic and aerobic conditions. Exposed specimens were analyzed principally by optical microscopy and X-ray diffraction techniques, and selectively by scanning electron microscopy, X-ray fluorescence, and atomic absorption spectroscopy. Corrosion/erosion modes, rates, and principal insoluble corrosion products were established and mechanisms based on established theory proposed to account for the modes of deterioration. Corrosion results were compared for the three fluid systems, and specific materials were then recommended for use in each of the fluid types found at the Coso Thermal Area Title: Coso Geothermal Corrosion Studies Author: Finnegan, S.A. Year: 1977 This report documents the results of geothermal corrosion studies conducted at the Coso Thermal Area, Naval Weapons Center, China Lake, California. Nine different common construction grade piping materials were tested for periods up to about one year in three distinctive low-pressure, medium temperature environments (acid-sulfate steam, groundwater-diluted steam, and hot mineralized alkaline water) under anaerobic and aerobic conditions. Exposed specimens were analyzed principally by optical microscopy and X-ray diffraction techniques, and selectively by scanning electron microscopy, X-ray fluorescence, and atomic absorption spectroscopy. Corrosion/erosion modes, rates, and principal insoluble corrosion products were established and mechanisms based on established theory proposed to account for the modes of deterioration. Corrosion results were compared for the three fluid systems, and specific materials were then recommended for use in each of the fluid types found at the Coso Thermal Area Close

• 133. [Image] Geothermal Resources of the Eastern United States

  	Known and potential geothermal resources of the eastern United States are reported. The resources considered are exclusively hydrothermal, and the study was confined to the 35 states east of the Rocky ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal Resources of the Eastern United States Author: Renner, J.L. Year: 1979 Known and potential geothermal resources of the eastern United States are reported. The resources considered are exclusively hydrothermal, and the study was confined to the 35 states east of the Rocky Mountains, excluding the Dakotas. Resource definition in these areas is based entirely on data found in the literature and in the files of a number of state geological offices. The general geology of the eastern United States is outlined. Six relatively homogeneous eastern geologic regions are discussed (MHR) Title: Geothermal Resources of the Eastern United States Author: Renner, J.L. Year: 1979 Known and potential geothermal resources of the eastern United States are reported. The resources considered are exclusively hydrothermal, and the study was confined to the 35 states east of the Rocky Mountains, excluding the Dakotas. Resource definition in these areas is based entirely on data found in the literature and in the files of a number of state geological offices. The general geology of the eastern United States is outlined. Six relatively homogeneous eastern geologic regions are discussed (MHR) Close

• 134. [Image] Near-Normal Geothermal Gradient Workshop, March 10-11, 1975

  	On March 10-11, 1975, the Energy Research and Development Administration and the Los Alamos Scientific Laboratory of the University of California, in cooperation with the U. S. Geological Survey, held ...
  	Citation × Citation Citation Abstract Copy Title: Near-Normal Geothermal Gradient Workshop, March 10-11, 1975 Author: Los Alamos Scientific Laboratory Year: 1975 On March 10-11, 1975, the Energy Research and Development Administration and the Los Alamos Scientific Laboratory of the University of California, in cooperation with the U. S. Geological Survey, held a workshop on Near-Normal Gradient. The purpose of the workshop was to review what was known of the geologic environments which might be suitable for developing geothermal energy from "dry" hot rocks, with particular emphasis on the Eastern United States. Individuals, expert in various aspects of this topic, were invited to present informal discussions. There was, in addition, attendance of other interested individuals as observers. In total 86 people attended the two day workshop Title: Near-Normal Geothermal Gradient Workshop, March 10-11, 1975 Author: Los Alamos Scientific Laboratory Year: 1975 On March 10-11, 1975, the Energy Research and Development Administration and the Los Alamos Scientific Laboratory of the University of California, in cooperation with the U. S. Geological Survey, held a workshop on Near-Normal Gradient. The purpose of the workshop was to review what was known of the geologic environments which might be suitable for developing geothermal energy from "dry" hot rocks, with particular emphasis on the Eastern United States. Individuals, expert in various aspects of this topic, were invited to present informal discussions. There was, in addition, attendance of other interested individuals as observers. In total 86 people attended the two day workshop Close

• 135. [Image] Brine and Gas Recovery from Geopressured Systems: I. Parametric Calculations

  	A series of parametric calculations was run with the S-CUBED geopressured-geothermal simulator MUSHRM to assess the effects of important formation, fluid and well parameters on brine and gas recovery ...
  	Citation × Citation Citation Abstract Copy Title: Brine and Gas Recovery from Geopressured Systems: I. Parametric Calculations Author: Garg, S. K. Year: 1984 A series of parametric calculations was run with the S-CUBED geopressured-geothermal simulator MUSHRM to assess the effects of important formation, fluid and well parameters on brine and gas recovery from geopressured reservoir systems. The specific parameters considered are formation permeability, pore-fluid salinity, temperature and gas content, well radius and location with respect to reservoir boundaries, desired flow rate, and possible shale recharge. It was found that the total brine and gas recovered (as a fraction of the resource in situ) were most sensitive to formation permeability, pore-fluid gas content, and shale recharge Title: Brine and Gas Recovery from Geopressured Systems: I. Parametric Calculations Author: Garg, S. K. Year: 1984 A series of parametric calculations was run with the S-CUBED geopressured-geothermal simulator MUSHRM to assess the effects of important formation, fluid and well parameters on brine and gas recovery from geopressured reservoir systems. The specific parameters considered are formation permeability, pore-fluid salinity, temperature and gas content, well radius and location with respect to reservoir boundaries, desired flow rate, and possible shale recharge. It was found that the total brine and gas recovered (as a fraction of the resource in situ) were most sensitive to formation permeability, pore-fluid gas content, and shale recharge Close

• 136. [Image] Chemical Analyses for Thermal and Mineral Springs Examined in 1982-1983

  	During late 1982 and early 1983., six water samples from three different spring systems were collected and analyzed for major element concentrations. This report presents the results of those analyses ...
  	Citation × Citation Citation Abstract Copy Title: Chemical Analyses for Thermal and Mineral Springs Examined in 1982-1983 Author: Korosec, M. A. Year: 1984 During late 1982 and early 1983., six water samples from three different spring systems were collected and analyzed for major element concentrations. This report presents the results of those analyses along with predicted reservoir temperatures using various geothermometers. In addition, a table of chemical analyses from the U.S. Geological Survey for Washington springs not previously reported in state geothermal reports is included. The tables in this report, together with the tables in Chapter 3 of Open File Report 83-7 (Korosec and others, 1983), present all available major element geochemistry for Washington's thermal and mineral springs determined by the Division and the U.S. Geological Survey Title: Chemical Analyses for Thermal and Mineral Springs Examined in 1982-1983 Author: Korosec, M. A. Year: 1984 During late 1982 and early 1983., six water samples from three different spring systems were collected and analyzed for major element concentrations. This report presents the results of those analyses along with predicted reservoir temperatures using various geothermometers. In addition, a table of chemical analyses from the U.S. Geological Survey for Washington springs not previously reported in state geothermal reports is included. The tables in this report, together with the tables in Chapter 3 of Open File Report 83-7 (Korosec and others, 1983), present all available major element geochemistry for Washington's thermal and mineral springs determined by the Division and the U.S. Geological Survey Close

• 137. [Image] Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States. Progress Report, May 1, 1976--October 31, 1976

  	Progress is reported in the development of procedures for the evaluation of low-temperature radiogenically-derived geothermal resources in the eastern United States utilizing geological geochemical, and ...
  	Citation × Citation Citation Abstract Copy Title: Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States. Progress Report, May 1, 1976--October 31, 1976 Author: Costain, J.K. Year: 1976 Progress is reported in the development of procedures for the evaluation of low-temperature radiogenically-derived geothermal resources in the eastern United States utilizing geological geochemical, and geophysical data. An optimum site for geothermal development in the tectonically stable eastern United States will probably be associated with crustal igneous rocks containing relatively high concentrations of radiogenic heat-producing elements buried beneath an insulating blanket of sediments of low thermal conductivity. Evaluation of plutonic rocks exposed in the Piedmont will aid in the interpretation of gravity and magnetic data for the Atlantic Coastal Plain. Initial results of determination of heat generation from surface samples in South Caroline are encouraging, especially if granitic igneous rocks of similar heat generation can be found beneath sedimentary insulation. Continues logging of existing wells in Coastal Plain sediments supports earlier conclusion that these sediments do behave as efficient sedimentary insulators. Higher temperatures appear to be reached at shallower depths for wells drilled in Coastal Plain sediments in the vicinity of the Georgetown, South Carolina gravity law. Detailed structural mapping in the vicinity of the warm springs in northwestern Virginia has confirmed structural control of the warm springs, and has revealed the existence of kink bands. The kink bands could be related to the development of zones of vertical permeability which serve as conduits in sedimentary rocks for ascending hot water. Title: Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States. Progress Report, May 1, 1976--October 31, 1976 Author: Costain, J.K. Year: 1976 Progress is reported in the development of procedures for the evaluation of low-temperature radiogenically-derived geothermal resources in the eastern United States utilizing geological geochemical, and geophysical data. An optimum site for geothermal development in the tectonically stable eastern United States will probably be associated with crustal igneous rocks containing relatively high concentrations of radiogenic heat-producing elements buried beneath an insulating blanket of sediments of low thermal conductivity. Evaluation of plutonic rocks exposed in the Piedmont will aid in the interpretation of gravity and magnetic data for the Atlantic Coastal Plain. Initial results of determination of heat generation from surface samples in South Caroline are encouraging, especially if granitic igneous rocks of similar heat generation can be found beneath sedimentary insulation. Continues logging of existing wells in Coastal Plain sediments supports earlier conclusion that these sediments do behave as efficient sedimentary insulators. Higher temperatures appear to be reached at shallower depths for wells drilled in Coastal Plain sediments in the vicinity of the Georgetown, South Carolina gravity law. Detailed structural mapping in the vicinity of the warm springs in northwestern Virginia has confirmed structural control of the warm springs, and has revealed the existence of kink bands. The kink bands could be related to the development of zones of vertical permeability which serve as conduits in sedimentary rocks for ascending hot water. Close

• 138. [Image] Subsurface investigations at the Roosevelt KGRA, Utah. Final report

  	An investigation of the geothermal reservoir in the Roosevelt Hot Springs Known Geothermal Resource Area in Utah was carried out. The objective of this effort was to develop predictions for well production ...
  	Citation × Citation Citation Abstract Copy Title: Subsurface investigations at the Roosevelt KGRA, Utah. Final report Author: Butz, J. Year: 1979 An investigation of the geothermal reservoir in the Roosevelt Hot Springs Known Geothermal Resource Area in Utah was carried out. The objective of this effort was to develop predictions for well production capacities, based on data taken during field tests and through use of a computer model. In turn, the production information could then be used in design optimization and economic analyses for development of the resource under study. Flow tests of a geothermal well, Utah State 14-2, were conducted. Data consisting of pressure and temperature logs as a function of depth were obtained. Maximum recorded temperature was 503/sup 0/F (262/sup 0/C) and maximum pressure, 954 psia (6.58MPa) as measured under flow conditions. Tests were run at rates up to 580,000 lb/hr (73.3 kg/sec) total flow. The information gathered during the testing was reduced and compared to results of a predictive computer model. Reservoir conditions in the Roosevelt Hot Springs KGRA are such that two-phase flow exists in the wellbore and, in some cases, also in the reservoir itself. The computer model employed in the analysis reflects current efforts to improve the state-of-the-art in the prediction of two-phase pressure drops in vertical systems. Predictions at flowrates of up to 300,000 lb/hr (38 kg/sec) matched quite well with test data, while modeling at higher flowrates (to maximum tested) showed progressively greater deviation from test data. Cause of the observed degradation is postulated to be the movement of the flash horizon into the reservoir, due to drawdown at high flowrates; DOE/ET/28389-1 Title: Subsurface investigations at the Roosevelt KGRA, Utah. Final report Author: Butz, J. Year: 1979 An investigation of the geothermal reservoir in the Roosevelt Hot Springs Known Geothermal Resource Area in Utah was carried out. The objective of this effort was to develop predictions for well production capacities, based on data taken during field tests and through use of a computer model. In turn, the production information could then be used in design optimization and economic analyses for development of the resource under study. Flow tests of a geothermal well, Utah State 14-2, were conducted. Data consisting of pressure and temperature logs as a function of depth were obtained. Maximum recorded temperature was 503/sup 0/F (262/sup 0/C) and maximum pressure, 954 psia (6.58MPa) as measured under flow conditions. Tests were run at rates up to 580,000 lb/hr (73.3 kg/sec) total flow. The information gathered during the testing was reduced and compared to results of a predictive computer model. Reservoir conditions in the Roosevelt Hot Springs KGRA are such that two-phase flow exists in the wellbore and, in some cases, also in the reservoir itself. The computer model employed in the analysis reflects current efforts to improve the state-of-the-art in the prediction of two-phase pressure drops in vertical systems. Predictions at flowrates of up to 300,000 lb/hr (38 kg/sec) matched quite well with test data, while modeling at higher flowrates (to maximum tested) showed progressively greater deviation from test data. Cause of the observed degradation is postulated to be the movement of the flash horizon into the reservoir, due to drawdown at high flowrates; DOE/ET/28389-1 Close

• 139. [Image] Downhole Electrical Detection of Hydraulic Fractures in GT-2 and EE-1

  	Electrical geophysical methods including mise a la masse and self-potential (SP) for determination of hydraulic fracture characteristics were used at the hot dry rock geothermal project. Electrical and ...
  	Citation × Citation Citation Abstract Copy Title: Downhole Electrical Detection of Hydraulic Fractures in GT-2 and EE-1 Author: Kintzinger, P.R. Year: 1977 Electrical geophysical methods including mise a la masse and self-potential (SP) for determination of hydraulic fracture characteristics were used at the hot dry rock geothermal project. Electrical and induction logs indicated that the resistivity contrast between the granite and 200/sup 0/C water at the 2926-m (9600-ft) depth is a factor of 1000 or more. Thus the water in a hydraulic fracture, formed to connect two adjacent deep holes, is a good conductor compared to the confining granite. Mise a la masse-type measurements were made to help determine the characteristics for hydraulic fractures formed in each of the two geothermal holes GT-2 and EE-1. Once a hydraulic fracture has been formed, mise a la masse effects are obtained both with the fracture pressurized above hydrostatic and when depressurized to hydrostatic. This indicates that once the fracture has been created, enough natural propping exists that a conductive zone persists even when the fracture is deflated. A fracture was formed in a 18-m (60-ft) zone immediately below 1957 m (6420 ft) in EE-1. Later a set of SP logs was run in this zone with no pressure, with pressure building, with pressure decreasing, and again with the fracture depressurized. Results show that during times of change of parameters in hydraulically fractured regions in the hole, natural SP logging helps to determine the position of the fracture. However, after a fracture has come to equilibrium with fluid parameters such as temperature, pressure, salinity, and pH, an effect of the fracture may not be evident. Self-potential logs provide an excellent method for locating the bottom of steel casing that has been set in the hole Title: Downhole Electrical Detection of Hydraulic Fractures in GT-2 and EE-1 Author: Kintzinger, P.R. Year: 1977 Electrical geophysical methods including mise a la masse and self-potential (SP) for determination of hydraulic fracture characteristics were used at the hot dry rock geothermal project. Electrical and induction logs indicated that the resistivity contrast between the granite and 200/sup 0/C water at the 2926-m (9600-ft) depth is a factor of 1000 or more. Thus the water in a hydraulic fracture, formed to connect two adjacent deep holes, is a good conductor compared to the confining granite. Mise a la masse-type measurements were made to help determine the characteristics for hydraulic fractures formed in each of the two geothermal holes GT-2 and EE-1. Once a hydraulic fracture has been formed, mise a la masse effects are obtained both with the fracture pressurized above hydrostatic and when depressurized to hydrostatic. This indicates that once the fracture has been created, enough natural propping exists that a conductive zone persists even when the fracture is deflated. A fracture was formed in a 18-m (60-ft) zone immediately below 1957 m (6420 ft) in EE-1. Later a set of SP logs was run in this zone with no pressure, with pressure building, with pressure decreasing, and again with the fracture depressurized. Results show that during times of change of parameters in hydraulically fractured regions in the hole, natural SP logging helps to determine the position of the fracture. However, after a fracture has come to equilibrium with fluid parameters such as temperature, pressure, salinity, and pH, an effect of the fracture may not be evident. Self-potential logs provide an excellent method for locating the bottom of steel casing that has been set in the hole Close

• 140. [Image] Hot Dry Rock Geothermal Energy Development Program. Annual Report, Fiscal Year 1983

  	Emphasis was on hydraulic-fracturing experiments at depths around 3.5 km (11,473 ft) in the two inclined wells of the Phase II system at Fenton Hill, New Mexico; on improved facilities and techniques for ...
  	Citation × Citation Citation Abstract Copy Title: Hot Dry Rock Geothermal Energy Development Program. Annual Report, Fiscal Year 1983 Author: Smith, M.C. (comp.) Year: 1985 Emphasis was on hydraulic-fracturing experiments at depths around 3.5 km (11,473 ft) in the two inclined wells of the Phase II system at Fenton Hill, New Mexico; on improved facilities and techniques for mapping the source locations of acoustic signals generated by the fracturing events; on mathematical modeling of the fracture systems produced in these and earlier experiments; and on development of a family of slimline high-temperature downhole instruments that can be used within or through relatively small-diameter pressure tubing. Hydraulic fracturing at a vertical depth of approximately 3500 m (11,500 ft) in well EE-2, the deeper well, produced fractures that, in acoustic maps, appear to occupy a large, roughly ellipsoidal volume whose major axis is directed to the north of the other well, EE-3. Hydraulic fracturing from EE-3 at a similar depth produced another set of fractures that appear to be approximately parallel to and centered about 180 m (600 ft) east of the earlier set. Subsequent fluid injections reduced the distance between the two sets, but no hydraulic connection between them was established. Modeling the silica concentrations of fluid circulated through the earlier Phase I system indicates that this type of permeation also contributes significantly to heat extraction during system operation. The precision and accuracy of locating the sources of acoustic signals detected during hydraulic-fracturing operations have been increased by improvements in equipment, drilling of another deep hole for geophone emplacement, and additional station calibrations. Analysis of the signals has also been improved and broadened. Development of slimline downhole instruments has included a detonator tool, a geophone package, and final design of a high-temperature borehole acoustic televiewer. A crosswell acoustic transceiver has also been developed for investigating rock type and structure between wellbores. 32 refs., 35 figs. Title: Hot Dry Rock Geothermal Energy Development Program. Annual Report, Fiscal Year 1983 Author: Smith, M.C. (comp.) Year: 1985 Emphasis was on hydraulic-fracturing experiments at depths around 3.5 km (11,473 ft) in the two inclined wells of the Phase II system at Fenton Hill, New Mexico; on improved facilities and techniques for mapping the source locations of acoustic signals generated by the fracturing events; on mathematical modeling of the fracture systems produced in these and earlier experiments; and on development of a family of slimline high-temperature downhole instruments that can be used within or through relatively small-diameter pressure tubing. Hydraulic fracturing at a vertical depth of approximately 3500 m (11,500 ft) in well EE-2, the deeper well, produced fractures that, in acoustic maps, appear to occupy a large, roughly ellipsoidal volume whose major axis is directed to the north of the other well, EE-3. Hydraulic fracturing from EE-3 at a similar depth produced another set of fractures that appear to be approximately parallel to and centered about 180 m (600 ft) east of the earlier set. Subsequent fluid injections reduced the distance between the two sets, but no hydraulic connection between them was established. Modeling the silica concentrations of fluid circulated through the earlier Phase I system indicates that this type of permeation also contributes significantly to heat extraction during system operation. The precision and accuracy of locating the sources of acoustic signals detected during hydraulic-fracturing operations have been increased by improvements in equipment, drilling of another deep hole for geophone emplacement, and additional station calibrations. Analysis of the signals has also been improved and broadened. Development of slimline downhole instruments has included a detonator tool, a geophone package, and final design of a high-temperature borehole acoustic televiewer. A crosswell acoustic transceiver has also been developed for investigating rock type and structure between wellbores. 32 refs., 35 figs. Close