Reservoir monitoring by a 4-D electrical technique

Abstract

An advanced geoelectrical technique for imaging potential fractures has been developed by Engineering Geophysics Laboratory of Kyushu University. The method, fluid-flow tomography (FFT), has been applied to monitor fluid-flow behaviors during massive water/steam injection operations through a borehole. Fluid-flow behaviors in potential fractures could be continuously traced and visualized as a function of time by the FFT system. Potential fractures can be evaluated by 3-D inversion of self-potential (SP) anomalies based on a potential theory similar to the hypocenter of the earthquakes. The FFT method has been applied to determine the location of fractures in a geothermal area in Japan.