| Title | Geophysical Monitoring with Reservoir Simulation in a Geothermal Field, Japan |
|---|---|
| Authors | Toshiyuki Tosha, Tsuneo Ishido, Mituhiko Sugihara |
| Year | 2008 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | geophysics, geothermal field, monitoring, computer simulation, self-potential survey, postprocessor |
| Abstract | Repeat and/or continuous geophysical measurements can be used to detect subsurface changes. However, the separation of signal from noise is often a difficult task. In geothermal reservoirs, it is very useful to predict changes in geophysical observables from changing reservoir conditions, computed by reservoir simulation. We calculated changes in selfpotential based upon a three-dimensional reservoir model of the Ogiri field, which was constructed based upon various data and calibrated against the long-term gravity monitoring data. The calculated SP variation is qualitatively consistent both with a relatively long-term change obtained by repeated surveys and a short-term change detected by continuous measurements, which was associated with a field-wide shut-in of production and reinjection wells for a maintenance of the power station in spring 2003. |