Relative Microearthquake Locations at the Geysers

Abstract

Passive seismology has become widely used in geothermal, oil and shale gas areas to enhance the good management of resources by determination of the physical parameters of the reservoir, fluid flow paths, and the effects of reservoir engineering. In the case of well-designed networks, the dominant source of location error in geothermal areas is usually imperfectly known crustal structure. If induced seismicity is monitored, it can reveal details of the structure and physical parameters of the medium and changes in these parameters caused by production. In our study, we relocated seismic events associated with fluid injections in the NW Geysers geothermal area, over 270 days. We used relative location software, along with different velocity models. Our results show good agreement with injection operations.