Progressive inversion for hypocenters and P wave and S wave velocity structure: Application to The Geysers, California, geothermal field

Journal Article · Wed Apr 10 04:00:00 EDT 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/91JB00154· OSTI ID:5494111

O'Connell, D R.H.; Johnson, L R ^[1]

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1. Univ. of California, Berkeley (USA)

Seismicity at The Geysers is induced by some aspect of steam production. Accurate earthquake locations, particularly hypocentral depth, are needed to determine the relationship between geothermal energy production and seismicity. Progressive P and S wave velocity-hypocenter inversions were done using data from 39 microearthquakes at The Geysers to estimate microearthquake locations and determine if the geothermal field has a distinctive seismic signature. Comparable final V{sub p}/V{sub s}, and V{sub p}/V{sub s} increases below the primary production zone, suggesting that reservoir rock becomes more fluid saturated with increasing depth. A V/{sub p}/V{sub s} peak at the condensation zone-production zone elevation delineates the top of the stream reservoir. Earthquake locations are confined to two depth intervals. A zone of shallow seismicity occurs immediately below the condensation zone and above maximum depths of steam production. A more arealy restricted zone of seismicity is located below maximum production depths and is abruptly terminated at an elevation of {minus}3.7 km.

• OSTI ID: 5494111
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:B4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150200* -- Geology & Hydrology of Geothermal Systems
DATA PROCESSING
DEPTH
DIMENSIONS
EARTHQUAKES
FLUIDS
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOTHERMAL FIELDS
GEOTHERMAL FLUIDS
GEYSERS GEOTHERMAL FIELD
HYPOCENTERS
MICROEARTHQUAKES
PROCESSING
PRODUCTION
RESERVOIR ROCK
SATURATION
SEISMIC EVENTS
SEISMIC P WAVES
SEISMIC S WAVES
SEISMIC WAVES
SEISMICITY
STEAM
VAPOR CONDENSATION
WAVE PROPAGATION