Evaluation of Geothermal Reservoir Structures by a New Downhole Seismic Technique

Abstract

Downhole seismic measurement is one of the most promising techniques for evaluation of reservoir structures, especially for deep geothermal development. We have developed new multicomponent seismic techniques which can derive useful information from three-component seismic signals. A combined technique of three-component signal processing and frequency-time distribution analysis enables the precise detection of wave onset even for the signal which has very low signal to noise ratio. Another technique termed as "triaxial doublet analysis" reveals a geothermal reservoir structure in a "cloud" of mapped seismic sources. It is feasible to use these techniques in seismic measurements with a sparse downhole network for the deep geothermal development.