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• 1. [Image] Steady-State and Transient Wellbore Temperatures during Drilling

  	An extensive literature search was made to locate technical publications and computer programs relating to wellbore temperatures during drilling operations. The search confirmed the need for knowledge ...
  	Citation × Citation Citation Abstract Copy Title: Steady-State and Transient Wellbore Temperatures during Drilling Author: McDonald, W.J. Year: 1976 An extensive literature search was made to locate technical publications and computer programs relating to wellbore temperatures during drilling operations. The search confirmed the need for knowledge of transient and steady state circulating temperatures in the design of geothermal bits. Two approaches were used in calculating borehole temperatures. The steady state solution of Holmes and Swift was programmed and 2100 cases calculated for various borehole configurations. For transient temperature studies, calculations were made for ten borehole configurations. These calculations help emphasize the need for better high temperature bit performance and improved engineering procedures in drilling. The conclusions and recommendations are based on latest available technology for calculating wellbore temperatures Title: Steady-State and Transient Wellbore Temperatures during Drilling Author: McDonald, W.J. Year: 1976 An extensive literature search was made to locate technical publications and computer programs relating to wellbore temperatures during drilling operations. The search confirmed the need for knowledge of transient and steady state circulating temperatures in the design of geothermal bits. Two approaches were used in calculating borehole temperatures. The steady state solution of Holmes and Swift was programmed and 2100 cases calculated for various borehole configurations. For transient temperature studies, calculations were made for ten borehole configurations. These calculations help emphasize the need for better high temperature bit performance and improved engineering procedures in drilling. The conclusions and recommendations are based on latest available technology for calculating wellbore temperatures Close

• 2. [Image] Potential Uses for a High-Temperature Borehole Gravimeter

  	It is possible to design a canister to cool a borehole gravimeter for use in geothermal and high-temperature (up to 350/sup 0/C) gas wells. Repeat surveys with such a gravimeter could (1) help estimate ...
  	Citation × Citation Citation Abstract Copy Title: Potential Uses for a High-Temperature Borehole Gravimeter Author: Hearst, J.R. Year: 1978 It is possible to design a canister to cool a borehole gravimeter for use in geothermal and high-temperature (up to 350/sup 0/C) gas wells. Repeat surveys with such a gravimeter could (1) help estimate the extent of reservoir plugging in geothermal injection well after one year of operation and (2) detect compaction of a geothermal aquifer if the change in thickness of the aquifer exceeds 1 m. The instrument could be used together with conventional logging tools to evaluate radial dependence of density around a well, or to estimate gas-filled porosity around wells drilled with mud. A high-temperature borehole gravimeter could also be used to evaluate structure and stratigraphy around geothermal and high-temperature gas wells Title: Potential Uses for a High-Temperature Borehole Gravimeter Author: Hearst, J.R. Year: 1978 It is possible to design a canister to cool a borehole gravimeter for use in geothermal and high-temperature (up to 350/sup 0/C) gas wells. Repeat surveys with such a gravimeter could (1) help estimate the extent of reservoir plugging in geothermal injection well after one year of operation and (2) detect compaction of a geothermal aquifer if the change in thickness of the aquifer exceeds 1 m. The instrument could be used together with conventional logging tools to evaluate radial dependence of density around a well, or to estimate gas-filled porosity around wells drilled with mud. A high-temperature borehole gravimeter could also be used to evaluate structure and stratigraphy around geothermal and high-temperature gas wells Close

• 3. [Image] Static Downhole Characteristics of Well CGEH-1 at Coso Hot Springs, China Lake, California

  	A series of measurements was made in the exploratory well CGEH-1 at Coso Hot Springs. The temperature measurements provide estimates for the thermal equilibration of the well and indicate that the fractures ...
  	Citation × Citation Citation Abstract Copy Title: Static Downhole Characteristics of Well CGEH-1 at Coso Hot Springs, China Lake, California Author: Goranson, C. Year: 1978 A series of measurements was made in the exploratory well CGEH-1 at Coso Hot Springs. The temperature measurements provide estimates for the thermal equilibration of the well and indicate that the fractures intersecting the well have different temperatures. The hottest fractures are in the upper-cased portion of the well. Downhole chemical sampling suggests that the borehole still contains remnants of drilling materials. The well has never been extensively flowed at this time Title: Static Downhole Characteristics of Well CGEH-1 at Coso Hot Springs, China Lake, California Author: Goranson, C. Year: 1978 A series of measurements was made in the exploratory well CGEH-1 at Coso Hot Springs. The temperature measurements provide estimates for the thermal equilibration of the well and indicate that the fractures intersecting the well have different temperatures. The hottest fractures are in the upper-cased portion of the well. Downhole chemical sampling suggests that the borehole still contains remnants of drilling materials. The well has never been extensively flowed at this time Close

• 4. [Image] Drilling fluid/formation interaction at simulated in situ geothermal conditions. Final report

  	Interaction of drilling fluids with a geothermal reservoir formation can result in significant permeability impairment and therefore reduced well productivity. This interaction is studied under simulated ...
  	Citation × Citation Citation Abstract Copy Title: Drilling fluid/formation interaction at simulated in situ geothermal conditions. Final report Author: Enniss, D.O Year: 1980 Interaction of drilling fluids with a geothermal reservoir formation can result in significant permeability impairment and therefore reduced well productivity. This interaction is studied under simulated in situ geothermal conditions of overburden stress, pore fluid pressure, temperature, and pore fluid chemistry. Permeability impairment of an East Mesa KGRA reservoir material is evaluated as a function of stagnation time, drilling fluid, and temperature. Results indicate that all of these parameters contribute significantly to the magnitude and the reversibility of the impairment. Title: Drilling fluid/formation interaction at simulated in situ geothermal conditions. Final report Author: Enniss, D.O Year: 1980 Interaction of drilling fluids with a geothermal reservoir formation can result in significant permeability impairment and therefore reduced well productivity. This interaction is studied under simulated in situ geothermal conditions of overburden stress, pore fluid pressure, temperature, and pore fluid chemistry. Permeability impairment of an East Mesa KGRA reservoir material is evaluated as a function of stagnation time, drilling fluid, and temperature. Results indicate that all of these parameters contribute significantly to the magnitude and the reversibility of the impairment. Close

• 5. [Image] Annual Report on the Project to Design and Experimentally Test an Improved Geothermal Drill Bit

  	Progress is reported in a research and development program to design, build, and test an improved geothermal drill bit. The major tasks of the Phase I effort are entitled: failure mechanisms of existing ...
  	Citation × Citation Citation Abstract Copy Title: Annual Report on the Project to Design and Experimentally Test an Improved Geothermal Drill Bit Author: Barker, L.M. Year: 1976 Progress is reported in a research and development program to design, build, and test an improved geothermal drill bit. The major tasks of the Phase I effort are entitled: failure mechanisms of existing bits; new steels and new bearing design; and new seals and lubricants. It appears that a significant gain in drill-bit life can be attained by the use of higher-temperature steels which retain more hardness at temperatures above 260/sup 0/C (500/sup 0/F). Such steels are available, and two research bits of high-temperature steels were made and will shortly be tested in a laboratory-simulated full-scale geothermal drilling environment. Two control bits of the same design, but made with conventional drill bit steels, were also obtained for identical laboratory test runs, so that the performance of the research bits can be meaningfully assessed. Base-line properties of the steels, such as hardness and fracture toughness as functions of temperature, are being measured to further assess the value of the high-temperature steels selected for the research bits. A geothermal test vessel was designed and fabricated in which the full-scale drill bits will be tested. The vessel is capable of temperature to 427/sup 0/C (800/sup 0/F) and pressures to 35 MPa (5,000 psi). Seal and lubrication designs were studied, and the state of the art in high-temperature seals and lubricants was assessed. Some candidate seals and lubricants have been obtained for testing, and others are being procured. In addition, a seal test vessel has been designed and will soon be completed which can simulate the geothermal drilling environment in full-scale testing of seal and lubricant designs and materials. (JGB) Title: Annual Report on the Project to Design and Experimentally Test an Improved Geothermal Drill Bit Author: Barker, L.M. Year: 1976 Progress is reported in a research and development program to design, build, and test an improved geothermal drill bit. The major tasks of the Phase I effort are entitled: failure mechanisms of existing bits; new steels and new bearing design; and new seals and lubricants. It appears that a significant gain in drill-bit life can be attained by the use of higher-temperature steels which retain more hardness at temperatures above 260/sup 0/C (500/sup 0/F). Such steels are available, and two research bits of high-temperature steels were made and will shortly be tested in a laboratory-simulated full-scale geothermal drilling environment. Two control bits of the same design, but made with conventional drill bit steels, were also obtained for identical laboratory test runs, so that the performance of the research bits can be meaningfully assessed. Base-line properties of the steels, such as hardness and fracture toughness as functions of temperature, are being measured to further assess the value of the high-temperature steels selected for the research bits. A geothermal test vessel was designed and fabricated in which the full-scale drill bits will be tested. The vessel is capable of temperature to 427/sup 0/C (800/sup 0/F) and pressures to 35 MPa (5,000 psi). Seal and lubrication designs were studied, and the state of the art in high-temperature seals and lubricants was assessed. Some candidate seals and lubricants have been obtained for testing, and others are being procured. In addition, a seal test vessel has been designed and will soon be completed which can simulate the geothermal drilling environment in full-scale testing of seal and lubricant designs and materials. (JGB) Close

• 6. [Image] Seal/lubricant systems for geothermal drilling equipment

  	The development and testing of seals and lubricants for journal-type roller-cone rock bits for drilling into geothermal reservoirs at temperatures over 260/sup 0/C (500/sup 0/F) are described. The conditions ...
  	Citation × Citation Citation Abstract Copy Title: Seal/lubricant systems for geothermal drilling equipment Author: Hendrickson, R.R. Year: 1980 The development and testing of seals and lubricants for journal-type roller-cone rock bits for drilling into geothermal reservoirs at temperatures over 260/sup 0/C (500/sup 0/F) are described. The conditions experienced by seals and lubricants subjected to geothermal drilling are reviewed along with the basic design requirements for roller-cone bit seals and journal bearing lubricants. Two unique test facilities are described: a seal test machine which simulates pressures, temperatures, and mechanical eccentricities, and a lubricant tester capable of evaluating load-bearing ability at temperature and pressure. Three candidate elastomeric compounds demonstrated 288/sup 0/C (550/sup 0/F) capability and several others demonstrated 260/sup 0/C (500/sup 0/F) or greater capability. Successful elastomeric seal candidates were proprietary compounds based on EPDM, Kalrez, and/or Viton polymers. Three mechanical seals for reservoir temperatures over 288/sup 0/C (550/sup 0/F) are presented. Lubricant screening tests on more than 50 products are summarized, and several newly developed lubricants which meet both the compatibility and lubrication requirements are described. Several seal/lubricant systems are recommended for laboratory or field geothermal drilling tests in roller-cone drill bits. The future availability of drill bits for geothermal use is discussed, as well as the potential spinoffs of the program findings for nongeothermal roller-cone bits; SAND-80-7101 Title: Seal/lubricant systems for geothermal drilling equipment Author: Hendrickson, R.R. Year: 1980 The development and testing of seals and lubricants for journal-type roller-cone rock bits for drilling into geothermal reservoirs at temperatures over 260/sup 0/C (500/sup 0/F) are described. The conditions experienced by seals and lubricants subjected to geothermal drilling are reviewed along with the basic design requirements for roller-cone bit seals and journal bearing lubricants. Two unique test facilities are described: a seal test machine which simulates pressures, temperatures, and mechanical eccentricities, and a lubricant tester capable of evaluating load-bearing ability at temperature and pressure. Three candidate elastomeric compounds demonstrated 288/sup 0/C (550/sup 0/F) capability and several others demonstrated 260/sup 0/C (500/sup 0/F) or greater capability. Successful elastomeric seal candidates were proprietary compounds based on EPDM, Kalrez, and/or Viton polymers. Three mechanical seals for reservoir temperatures over 288/sup 0/C (550/sup 0/F) are presented. Lubricant screening tests on more than 50 products are summarized, and several newly developed lubricants which meet both the compatibility and lubrication requirements are described. Several seal/lubricant systems are recommended for laboratory or field geothermal drilling tests in roller-cone drill bits. The future availability of drill bits for geothermal use is discussed, as well as the potential spinoffs of the program findings for nongeothermal roller-cone bits; SAND-80-7101 Close

• 7. [Image] Development of the high-temperature redox electrode. Interim report ending March 1980

  	The oxidation-reduction (known as redox) electrode was studied in a pH range corresponding to that found in a CO/sub 2/-silicate buffered system at temperatures ranging from 100 to 250/sup 0/C. Oxidizing ...
  	Citation × Citation Citation Abstract Copy Title: Development of the high-temperature redox electrode. Interim report ending March 1980 Author: Danielson, M.J. Year: 1980 The oxidation-reduction (known as redox) electrode was studied in a pH range corresponding to that found in a CO/sub 2/-silicate buffered system at temperatures ranging from 100 to 250/sup 0/C. Oxidizing conditions were created by injecting oxygen; the greatest reducing conditions, by using hydrogen. The sulfur system (H/sub 2/S, HS/sup -/, S/sup 2/) was not examined at this time, but future work will include this system since it is an important component of the geothermal brine. Both a platinized platinum (Pt-Pt) and a bare platinum (Pt-foil) electrode respond to the redox environment. The response does not appear to indicate thermodynamic equilibrium with the chemical environment; instead a mixed potential response is indicated. The difference in potential between a strong oxidizing environment (0.4-ppM O/sub 2/) and a strong reducing environment (0.5-atm H/sub 2/) is typically > 1 volt at all temperatures. The magnitude of this response makes the platinum electrode a suitable sensor for continuous monitoring of the geothermal environment for oxygen intrusions. The platinized platinum redox electrode is superior to the bare platinum electrode; PNL-3377 Title: Development of the high-temperature redox electrode. Interim report ending March 1980 Author: Danielson, M.J. Year: 1980 The oxidation-reduction (known as redox) electrode was studied in a pH range corresponding to that found in a CO/sub 2/-silicate buffered system at temperatures ranging from 100 to 250/sup 0/C. Oxidizing conditions were created by injecting oxygen; the greatest reducing conditions, by using hydrogen. The sulfur system (H/sub 2/S, HS/sup -/, S/sup 2/) was not examined at this time, but future work will include this system since it is an important component of the geothermal brine. Both a platinized platinum (Pt-Pt) and a bare platinum (Pt-foil) electrode respond to the redox environment. The response does not appear to indicate thermodynamic equilibrium with the chemical environment; instead a mixed potential response is indicated. The difference in potential between a strong oxidizing environment (0.4-ppM O/sub 2/) and a strong reducing environment (0.5-atm H/sub 2/) is typically > 1 volt at all temperatures. The magnitude of this response makes the platinum electrode a suitable sensor for continuous monitoring of the geothermal environment for oxygen intrusions. The platinized platinum redox electrode is superior to the bare platinum electrode; PNL-3377 Close

• 8. [Image] Report of the Geophysical Measurements in Geothermal Wells Workshop, Airport Marina Hotel, Albuquerque, New Mexico, September 17--19, 1975

  	This report presents results of a Workshop on Geophysical Measurements in Geothermal Wells, hosted in Albuquerque, September 17-19, by Sandia Laboratories and jointly sponsored by the United States Geological ...
  	Citation × Citation Citation Abstract Copy Title: Report of the Geophysical Measurements in Geothermal Wells Workshop, Airport Marina Hotel, Albuquerque, New Mexico, September 17--19, 1975 Author: Baker, L.E. Year: 1975 This report presents results of a Workshop on Geophysical Measurements in Geothermal Wells, hosted in Albuquerque, September 17-19, by Sandia Laboratories and jointly sponsored by the United States Geological Survey and the Energy Research and Development Administration. During the workshop, tutorial papers dealing with the geothermal resource, geothermal logging, and high temperature technology were followed by working panel sessions. Three panels deliberated, respectively, well and reservoir parameters, log interpretation, and high temperature technology. In a final session, the reports of the panels were heard and discussed by the full workshop. A summary of the workshop conclusions and recommendations, as well as the complete panel statements, are presented. (auth) Title: Report of the Geophysical Measurements in Geothermal Wells Workshop, Airport Marina Hotel, Albuquerque, New Mexico, September 17--19, 1975 Author: Baker, L.E. Year: 1975 This report presents results of a Workshop on Geophysical Measurements in Geothermal Wells, hosted in Albuquerque, September 17-19, by Sandia Laboratories and jointly sponsored by the United States Geological Survey and the Energy Research and Development Administration. During the workshop, tutorial papers dealing with the geothermal resource, geothermal logging, and high temperature technology were followed by working panel sessions. Three panels deliberated, respectively, well and reservoir parameters, log interpretation, and high temperature technology. In a final session, the reports of the panels were heard and discussed by the full workshop. A summary of the workshop conclusions and recommendations, as well as the complete panel statements, are presented. (auth) Close

• 9. [Image] Field Electrochemical Measurements of Corrosion Characteristics of Materials in Hypersaline Geothermal Brine

  	A flow cell (with appropriate accessories) was developed for use in short-term testing of the corrosion behavior of materials in approximately 100{sup 0}C, hypersaline geothermal brine. The apparatus was ...
  	Citation × Citation Citation Abstract Copy Title: Field Electrochemical Measurements of Corrosion Characteristics of Materials in Hypersaline Geothermal Brine Author: Harrar, J.E. Year: 1977 A flow cell (with appropriate accessories) was developed for use in short-term testing of the corrosion behavior of materials in approximately 100{sup 0}C, hypersaline geothermal brine. The apparatus was designed to accommodate commercial (Petrolite) corrosion measurement equipment and conducted experiments on-line at the Lawrence Livermore Laboratory Test Station in the Salton Sea Geothermal Field. The apparatus also permitted direct readings of corrosion potentials, solution redox potential (E{sub h}), brine flow rate, pH, and temperature. Estimates of general corrosion rates were obtained by the linear polarization resistance technique and from measurements of complete potentiodynamic polarization curves. The latter also afforded predictions of pitting susceptibilities of active-passive type materials. Twenty-two alloys (with various heat treatments) were tested and readily grouped according to general corrosion resistances in acidified hypersaline (approximately 4 M chloride) brine. Especially promising in regard to corrosion resistance-vs-cost is the series of low Cr--Mo steels. Prescaling of materials in unacidified (pH approximately 5.7) brine prior to exposure to acidified (pH 2 to 4.5) brine was found to be beneficial in reducing corrosion rates at 100{sup 0}C Title: Field Electrochemical Measurements of Corrosion Characteristics of Materials in Hypersaline Geothermal Brine Author: Harrar, J.E. Year: 1977 A flow cell (with appropriate accessories) was developed for use in short-term testing of the corrosion behavior of materials in approximately 100{sup 0}C, hypersaline geothermal brine. The apparatus was designed to accommodate commercial (Petrolite) corrosion measurement equipment and conducted experiments on-line at the Lawrence Livermore Laboratory Test Station in the Salton Sea Geothermal Field. The apparatus also permitted direct readings of corrosion potentials, solution redox potential (E{sub h}), brine flow rate, pH, and temperature. Estimates of general corrosion rates were obtained by the linear polarization resistance technique and from measurements of complete potentiodynamic polarization curves. The latter also afforded predictions of pitting susceptibilities of active-passive type materials. Twenty-two alloys (with various heat treatments) were tested and readily grouped according to general corrosion resistances in acidified hypersaline (approximately 4 M chloride) brine. Especially promising in regard to corrosion resistance-vs-cost is the series of low Cr--Mo steels. Prescaling of materials in unacidified (pH approximately 5.7) brine prior to exposure to acidified (pH 2 to 4.5) brine was found to be beneficial in reducing corrosion rates at 100{sup 0}C Close

• 10. [Image] Proceedings of the Geothermal Power Development Conference, University of California, Berkeley, June 18, 1974

  	The Atomic Energy Commission (AEC) is interested in receiving comments, recommendations and suggestions concerning arrangements appropriate to conduct during FY 1975 and into the early 1980's of research ...
  	Citation × Citation Citation Abstract Copy Title: Proceedings of the Geothermal Power Development Conference, University of California, Berkeley, June 18, 1974 Author: Lawrence Berkeley Laboratory Year: 1974 The Atomic Energy Commission (AEC) is interested in receiving comments, recommendations and suggestions concerning arrangements appropriate to conduct during FY 1975 and into the early 1980's of research and development work and pilot projects aimed at establishing the technical, economic and practical feasibility of electric and non-electric power production from geothermal resources, including possible cooperative programs between the AEC and other organizations. Responses received will be utilized in the further development of AEC's long-range geothermal program plan. The geothermal program objective is to stimulate and facilitate early and significant commercial utilization of these resources. This program is a part of the national geothermal energy research and development effort and is designed to contribute toward meeting overall national energy needs Title: Proceedings of the Geothermal Power Development Conference, University of California, Berkeley, June 18, 1974 Author: Lawrence Berkeley Laboratory Year: 1974 The Atomic Energy Commission (AEC) is interested in receiving comments, recommendations and suggestions concerning arrangements appropriate to conduct during FY 1975 and into the early 1980's of research and development work and pilot projects aimed at establishing the technical, economic and practical feasibility of electric and non-electric power production from geothermal resources, including possible cooperative programs between the AEC and other organizations. Responses received will be utilized in the further development of AEC's long-range geothermal program plan. The geothermal program objective is to stimulate and facilitate early and significant commercial utilization of these resources. This program is a part of the national geothermal energy research and development effort and is designed to contribute toward meeting overall national energy needs Close