Feasibility investigation and design study of optical well logging methods for high temperature geothermal wells. Semiannual technical progress report, 30 September 1976-31 March 1977
Measurement of the absorption-edge in the compound semiconductor GaAs shows that changes in temperature over a range from 200 to 500/sup 0/C produce a cut-off transmission wavelength approximately coincident with the optimum spectral transmission region of quartz optical fibers. Thin GaAs elements are thus shown to be suitable for use as passive optical temperature transducers in the logging of high temperature geothermal wells in conjunction with fiber-optic cables. Stress effects on the optical transmission properties of quartz fibers indicate increased attenuation amounting to approximately 5%, due to tensile stress of 90 ksi, or an elongation of 1%. Temperature effects on optical transmission were found to be negligible at 500/sup 0/C. Preliminary results of this study indicate that construction of a borehole geophysical cable based on single-fiber quartz waveguides is entirely feasible. Present upper temperature limits in successfully measuring certain geophysical parameters in boreholes can be extended appreciably by the use of such a cable in conjunction with passive optical transducers which require little or no down-hole electronics.
- Research Organization:
- Southwest Research Institute, San Antonio, TX (United States)
- DOE Contract Number:
- EY-76-C-05-5268
- OSTI ID:
- 5745981
- Report Number(s):
- ORO-5268-T1
- Country of Publication:
- United States
- Language:
- English
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Feasibility investigation and design study of optical well logging methods for high temperature geothermal wells
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Related Subjects
47 OTHER INSTRUMENTATION
GEOTHERMAL WELLS
WELL LOGGING EQUIPMENT
FIBER OPTICS
BOREHOLES
CONNECTORS
ELECTRIC CABLES
GALLIUM ARSENIDES
HIGH TEMPERATURE
QUARTZ
SEMICONDUCTOR MATERIALS
TEMPERATURE LOGGING
TENSILE PROPERTIES
TESTING
TRANSDUCERS
ARSENIC COMPOUNDS
ARSENIDES
CABLES
CAVITIES
CHALCOGENIDES
CONDUCTOR DEVICES
ELECTRICAL EQUIPMENT
EQUIPMENT
GALLIUM COMPOUNDS
MATERIALS
MECHANICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
SILICON OXIDES
WELL LOGGING
WELLS
Geothermal Legacy
150303* - Geothermal Exploration & Exploration Technology- Exploratory Drilling & Well Logging
440400 - Well Logging Instrumentation