抄録
It is important to understand the geothermal reservoir behavior in order to produce geothermal fluid for a long time. Micro-gravity measurement is one of the suitable methods for geothermal reservoir monitoring. In the Takigami geothermal field, we have conducted repeat micro-gravity measurements using Scintrex CG-3 and CG-3M relative gravimeters since before 1996, when the Takigami geothermal power plant started power generation. We estimated the gravity change caused by shallow part fluid flow by using a computer code which calculates gravity change caused by precipitation. We divided the Takigami geothermal area into 3 areas and 5 stages from the pattern of the gravity change during 1996 and 2008. Based on these stages, we made a conceptual reservoir model of the Takigami geothermal field.
