Analysis of induced seismicity for fault zone identification

Abstract The location of micro-seismic events induced by various fluid injections in two wells drilled in granite has helped identify two plannar structures at distances up to 100 m from the injection wells. While sonic and petrofabric logs confirm the results of the microseismicity analysis, electrical imaging logs have been found to be inapropriate for determining the dip and azimuth of such large structures. Further, in a hydraulically opened fracture system, the microseismicity is found to outline only zones with high interstitial pressure; it does not help identify the main flow zones away from the injection wells.