Physical processes of subsidence in geothermal reservoirs [electronic resource]
Geothermal Legacy.
Saved in:
| Online Access: |
Online Access |
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| Corporate Authors: | , |
| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Berkeley, Calif. : Oak Ridge, Tenn. :
Lawrence Berkeley National Laboratory ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy,
1982.
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| Subjects: |
| Summary: | Geothermal Legacy. |
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| Abstract: | The objectives of this project were to acquire core and fluid from producing geothermal reservoirs (East Mesa, United States, and Cerro Prieto, Mexico); to test specimens of this core for their short-term and long-term (creep) compaction response; and to develop a compaction constitutive model that would allow future analysis of reservoir compaction and a surface subsidence. A total of approximately two hundred feet of core was obtained from eleven wells in the two geothermal fields. Depths and porosities ranged from 3500 to 11,000 feet and 15 to 40 percent, respectively. Several samples of geothermal fluids were also obtained. After geologically and geochemically describing the materials obtained, selected specimens were tested for their response to the pressures and temperatures of the geothermal environment and to simulated changes in those conditions that would be caused by production. Short-term tests (for example, tests for compressibility extending over a time interval of an hour or less in the laboratory) indicated that these sedimentary materials behaved normally with respect to the expected behavior of reservoir sandstones of these depths and porosities. Compressibilities were of the order 1 x 10⁶ psi. Long-term tests, extending up to several weeks in duration, indicated that pore pressure reduction, simulating reservoir production, tended to cause creep compaction at an initial rate of about 1 x 10⁻⁷ percent porosity reduction per second. |
| Item Description: | Published through the Information Bridge: DOE Scientific and Technical Information. 06/01/1982. "lbl-14605" " gsrmp-12" "DE83011017" Schatz, J.F. |
| Physical Description: | Pages: 151 : digital, PDF file. |