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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] Fluid-Temperature Logs for Selected Wells in Eastern Washington

  	This Open-File Report consists of fluid temperature logs compiled during studies of the geohydrology and low temperature geothermal resources of eastern Washington. The fluid temperature logs are divided ...
  	Citation × Citation Citation Abstract Copy Title: Fluid-Temperature Logs for Selected Wells in Eastern Washington Author: Stoffel, K. L. Year: 1983 This Open-File Report consists of fluid temperature logs compiled during studies of the geohydrology and low temperature geothermal resources of eastern Washington. The fluid temperature logs are divided into two groups. Part A consists of wells which are concentrated in the Moses Lake-Ritzville-Connell area. Full geophysical log suites for many of these wells are presented in Stoffel and Widness (1983) and discussed in Widness (1983, 1984). Part B consists of wells outside of the Moses Lake-Ritzville-Connell study area Title: Fluid-Temperature Logs for Selected Wells in Eastern Washington Author: Stoffel, K. L. Year: 1983 This Open-File Report consists of fluid temperature logs compiled during studies of the geohydrology and low temperature geothermal resources of eastern Washington. The fluid temperature logs are divided into two groups. Part A consists of wells which are concentrated in the Moses Lake-Ritzville-Connell area. Full geophysical log suites for many of these wells are presented in Stoffel and Widness (1983) and discussed in Widness (1983, 1984). Part B consists of wells outside of the Moses Lake-Ritzville-Connell study area Close

• 4. [Image] C. D. Hopkins, et al. , No. 2. Geothermal Well-Of-Opportunity, Wayne County, Georgia. Operational Report

  	An oil and gas exploration well, located near Jesup in Wayne County, Georgia (lat. 31/sup 0/32' N, long. 81/sup 0/43' W), was deepened and used for geothermal temperature-gradient measurements. The well ...
  	Citation × Citation Citation Abstract Copy Title: C. D. Hopkins, et al. , No. 2. Geothermal Well-Of-Opportunity, Wayne County, Georgia. Operational Report Author: Lohse, A. Year: 1978 An oil and gas exploration well, located near Jesup in Wayne County, Georgia (lat. 31/sup 0/32' N, long. 81/sup 0/43' W), was deepened and used for geothermal temperature-gradient measurements. The well was drilled from 4,009 to 4,341 feet, then diamond cored to 4,371 feet, 28 feet of core being obtained for analysis. After logging by the U.S.G.S. District Groundwater Office in Atlanta, the well was terminated with 3/sup 1///sub 2/'' tubing to 4,386 feet. The bottom-hole temperature was determined to be 60/sup 0/C (140/sup 0/F) at 1,331 meters (4,365 feet). Over the interval 47 to 1,331 meters (154 to 4,365 feet) the least-squares temperature gradient was 29.3 +- 0.14 /sup 0/C/km (1.61 +- 0.25 /sup 0/F/100 ft) Title: C. D. Hopkins, et al. , No. 2. Geothermal Well-Of-Opportunity, Wayne County, Georgia. Operational Report Author: Lohse, A. Year: 1978 An oil and gas exploration well, located near Jesup in Wayne County, Georgia (lat. 31/sup 0/32' N, long. 81/sup 0/43' W), was deepened and used for geothermal temperature-gradient measurements. The well was drilled from 4,009 to 4,341 feet, then diamond cored to 4,371 feet, 28 feet of core being obtained for analysis. After logging by the U.S.G.S. District Groundwater Office in Atlanta, the well was terminated with 3/sup 1///sub 2/'' tubing to 4,386 feet. The bottom-hole temperature was determined to be 60/sup 0/C (140/sup 0/F) at 1,331 meters (4,365 feet). Over the interval 47 to 1,331 meters (154 to 4,365 feet) the least-squares temperature gradient was 29.3 +- 0.14 /sup 0/C/km (1.61 +- 0.25 /sup 0/F/100 ft) Close

• 5. [Image] Neutron Formation Temperature Gauge and Neutron Activation Analysis Brine Flow Meter. Final Report, October 1, 1976--March 31, 1978

  	Feasibility studies of nuclear techniques applicable to the determination of geothermal formation temperature and two-phase brine flow downhole have been performed. The formation temperature gauging technique ...
  	Citation × Citation Citation Abstract Copy Title: Neutron Formation Temperature Gauge and Neutron Activation Analysis Brine Flow Meter. Final Report, October 1, 1976--March 31, 1978 Author: Vagelatos, N. Year: 1978 Feasibility studies of nuclear techniques applicable to the determination of geothermal formation temperature and two-phase brine flow downhole have been performed. The formation temperature gauging technique involves injection of fast neutrons into the formation and analysis of the moderated slow neutron energy distribution by appropriately filtered neutron detectors. The scientific feasibility of the method has been demonstrated by analytical computational and experimental evaluation of the system response. A data analysis method has been developed to determine unambiguously the temperature, neutron absorption cross section and neutron moderating power of an arbitrary medium. The initial phase of a program to demonstrate the engineering feasibility of the technique has been performed. A sonde mockup was fabricated and measurements have been performed in a test stand designed to simulate a geothermal well. The results indicate that the formation temperature determined by this method is independent of differences between the temperature in the borehole fluid and the formation, borehole fluid density, and borehole fluid salinity. Estimates of performance specifications for a formation temperature sonde have been made on the basis of information obtained in this study and a conceptual design of a logging system has been developed. The technique for the determination of fluid flow in a well is based on neutron activation analysis of elements present in the brine. An analytical evaluation of the method has been performed. The results warrant further, experimental evaluation Title: Neutron Formation Temperature Gauge and Neutron Activation Analysis Brine Flow Meter. Final Report, October 1, 1976--March 31, 1978 Author: Vagelatos, N. Year: 1978 Feasibility studies of nuclear techniques applicable to the determination of geothermal formation temperature and two-phase brine flow downhole have been performed. The formation temperature gauging technique involves injection of fast neutrons into the formation and analysis of the moderated slow neutron energy distribution by appropriately filtered neutron detectors. The scientific feasibility of the method has been demonstrated by analytical computational and experimental evaluation of the system response. A data analysis method has been developed to determine unambiguously the temperature, neutron absorption cross section and neutron moderating power of an arbitrary medium. The initial phase of a program to demonstrate the engineering feasibility of the technique has been performed. A sonde mockup was fabricated and measurements have been performed in a test stand designed to simulate a geothermal well. The results indicate that the formation temperature determined by this method is independent of differences between the temperature in the borehole fluid and the formation, borehole fluid density, and borehole fluid salinity. Estimates of performance specifications for a formation temperature sonde have been made on the basis of information obtained in this study and a conceptual design of a logging system has been developed. The technique for the determination of fluid flow in a well is based on neutron activation analysis of elements present in the brine. An analytical evaluation of the method has been performed. The results warrant further, experimental evaluation Close

• 6. [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

• 7. [Image] Formation Temperature Gauge Feasibility Study. Volume II, Interim Report

  	The present status of the formation temperature gauge feasibility study is reported. It also demonstrates the feasibility of the technique in the simplified situations examined to date both analytically ...
  	Citation × Citation Citation Abstract Copy Title: Formation Temperature Gauge Feasibility Study. Volume II, Interim Report Author: IRT Corporation Year: 1977 The present status of the formation temperature gauge feasibility study is reported. It also demonstrates the feasibility of the technique in the simplified situations examined to date both analytically and experimentally. The first section deals with the theory underlying the technique. The next three sections describe the temperature gauge, the simplified model calculations of the gauge response, and the preliminary experimental measurements performed to verify the results of the computational study. The final section describes the formation temperature test stand designed to demonstrate the feasibility of the technique in the geothermal well geometry. This test stand has been assembled and measurements of the gauge response will begin shortly. These are outlined at the end of this report Title: Formation Temperature Gauge Feasibility Study. Volume II, Interim Report Author: IRT Corporation Year: 1977 The present status of the formation temperature gauge feasibility study is reported. It also demonstrates the feasibility of the technique in the simplified situations examined to date both analytically and experimentally. The first section deals with the theory underlying the technique. The next three sections describe the temperature gauge, the simplified model calculations of the gauge response, and the preliminary experimental measurements performed to verify the results of the computational study. The final section describes the formation temperature test stand designed to demonstrate the feasibility of the technique in the geothermal well geometry. This test stand has been assembled and measurements of the gauge response will begin shortly. These are outlined at the end of this report Close

• 8. [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

• 9. [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

• 10. [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