Geochemical data and conceptual model for the steamboat hills geothermal system, Washoe County, Nevada
- Geological Survey, Menlo Park, CA (United States)
Geothermal fluids from the Steamboat Hills are silica-rich, Na-Cl waters. Maximum temperatures in the geothermal system are at least 230{degrees} to 235{degrees}C based on sulfate-water isotope and enthalpy-chloride relations and possibly as high as 243{degrees}C based on Na-K and gas geothermometry. The hottest geothermal well in the system (23-5) may have excess enthalpy. Chloride concentrations in the deep thermal fluid are {>=}706 ppm. Geothermal fluids are currently produced from both a high-temperature and a moderate-temperature well field. The high-temperature fluids are related to one another and to the moderate-temperature fluids principally by boiling. As the high-temperature fluids boil and cool to moderate temperatures, silica precipitates from solution, calcium and magnesium concentrations increase, and K/Na values partially adjust to the lower temperatures. Full chemical equilibrium may occur only in the high-temperature waters. In the new part of the moderate-temperature field (wells PW2-1 to PW3-4), K/Na values were initially very similar, but utilization has caused some wells to change composition. However, the general trend over time is to lower silica and K/Na values in all moderate-temperature wells. This trend probably indicates that heat is being {open_quotes}mined{close_quotes} from the aquifer-rock. Mixing of cold, low-chloride ground water with thermal water is important only near the toe of the system in the sediments which fill the valley. Steam-heated ground waters occur in the sediments along the north side of the Steamboat Hills.
- DOE Contract Number:
- AI01-91CE31020
- OSTI ID:
- 175624
- Report Number(s):
- CONF-951037-; TRN: 95:008065-0035
- Resource Relation:
- Conference: Annual meeting of the Geothermal Resources Council, Reno, NV (United States), 8-11 Oct 1995; Other Information: PBD: 1995; Related Information: Is Part Of Accomplishments of the past and challenges of the future. Transactions, Volume 19; PB: 604 p.
- Country of Publication:
- United States
- Language:
- English
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