A plausible two-dimensional vertical model of the East Mesa Geothermal Field, California

Journal Article · Tue Nov 10 04:00:00 EST 1981 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/JB086iB11p10719· OSTI ID:1064032

Goyal, K. P. ^[1]; Kassoy, D. R. ^[2]

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1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division
2. Univ. of Colorado, Boulder, CO (United States). Mechanical Engineering Dept.

For this study, a two-dimensional conceptual model of the East Mesa Geothermal system is developed on the basis of existing geological, geophysical, geochemical, heat flux, and borehole logging data. Hot water rising in a set of faults is assumed to charge the reservoir, which is overlaid by a clay-rich cap. The temperature-depth distribution observed at the site implies that the liquid is converting at a high Rayleigh number. In this approximation, liquid rises up the fault and spreads isothermally into the nearby sections of the reservoir. The cooling effect of the surface on the flow in the reservoir is confined to a thin layer adjacent to the cap-reservoir interface near the fault. This layer grows with the distance from the fault. Eventually, the entire depth of the reservoir is cooled by the surface. The mathematical model is based on the flow of liquid water in a saturated porous medium. Results are obtained for the velocities, pressures, and temperatures in the entire system consisting of fault zone, aquifer, and clay cap. Finally we compare the predicted surface heat flux to that measured at the site in shallow wells. We conclude that the model represents a plausible description of fault zone controlled systems like that at East Mesa.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-05CH11231; W-7405-ENG-48
• OSTI ID: 1064032
• Report Number(s): LBL--10617
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: B11 Vol. 86; ISSN 0148-0227
• Publisher: American Geophysical Union
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
58 GEOSCIENCES