| Title | 4-D Gravity at The Geysers |
|---|---|
| Authors | Gettings, P.; Chapman, D. S.; Allis, R. G. |
| Year | 2011 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | The Geysers; gravity monitoring; groundwater; geothermal systems |
| Abstract | Five high-precision gravity and GPS campaigns have been completed on The Geysers geothermal field between 2000 and 2011. Gravity changes for 4 campaigns between 2000 and 2006 are very consistent with aggregate production and injection mass totals, after correction for GPS-derived elevation changes and near-surface groundwater changes. Average change across the field varies from -86 ?Gal for April 2001-September 2000 to -6 ?Gal for September 2001-April 2001. Gravity change from 2006 to 2011 is 97 ?Gal higher than expected from reported production and injection totals to December 2010 and known groundwater changes in wells in the valleys around the production field. Detailed production and injection data are expected to become available for the monitoring period, which will be used to update and validate a reservoir model based on well temperature and pressure constraints. |