Vapor-dominated reservoir exceeding 600 degrees F at The Geysers, Sonoma County, California

Journal Article · Mon Jun 01 04:00:00 EDT 1987 · Geotherm. Hot Line; (United States)

OSTI ID:6812864

Walters, M A; Sternfeld, J N; Haizlip, J R; Drenick, A F; Combs, J

A high-temperature, vapor-dominated reservoir underlies a portion of the northwest Geysers area, Sonoma County, California. The high-temperature reservoir (HTR) is defined by flowing fluid temperatures exceeding 500/sup 0/F, rock temperatures apparently exceeding 600/sup 0/F, and steam enthalpies of about 1320 Btu/lb. The HTR in the northwest Geysers is probably a deep, evolving system in contrast to the shallower, leaky, and mature steam reservoir(s) in the central and southeastern portions of the field. Before natural venting and nearby production caused pressures to decline, the HTR was a liquid-dominated system with some connate water - the connate water being the source of the high gas contents, chloride, and unique isotopic composition relative to steam from a typical Geysers reservoir. Therefore, the present boundary between the typical reservoir and HTR is a transient, thermodynamic condition due to the recent evolution of a vapor-dominated zone from a liquid-dominated zone that has yet to cool down. It also demarks a previous liquid-to-vapor interface. Pressure in the two reservoirs is essentially the same because they are in communication with each other. In other words, the temperature change in the HTR is lagging (behind) the pressure change.

• OSTI ID: 6812864
• Journal Information: Geotherm. Hot Line; (United States), Journal Name: Geotherm. Hot Line; (United States) Vol. 18:1; ISSN GHLID
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150201* -- Geology & Hydrology of Geothermal Systems-- USA-- (-1989)
CALIFORNIA
ENTHALPY
FEDERAL REGION IX
FLUIDS
GASES
GEOTHERMAL FIELDS
GEOTHERMAL RESOURCES
GEYSERS GEOTHERMAL FIELD
HIGH TEMPERATURE
NORTH AMERICA
PHYSICAL PROPERTIES
RESERVOIR PRESSURE
RESERVOIR TEMPERATURE
RESOURCES
STEAM
TEMPERATURE GRADIENTS
THERMODYNAMIC PROPERTIES
USA
VAPORS