Microseismic monitoring of the hydraulic-fracture growth and geometry in the Upper Bahariya member, Khalda concession, Western Desert, Egypt

Abstract

Three-component, downhole geophones are installed in production wells at the Khalda and Kahraman sites to monitor hydraulic fracturing treatment in a nearby well. Locatable microseismic events were distributed in space around the treatment well using the hypocenter-velocity inversion method. The E?W oriented microseismic pattern aligns with the proposed specifications of fracture model design at both the Khalda and Kahraman sites. Due to the small magnitude and long separation distance between the treatment well and the recording string, microseismicity was dominantly observed during the main fracturing operation at both the Khalda and Kahraman sites, with calculated magnitudes less than??0.3?Mw. In addition, the calculated confidence for locatable events was generally average or low. The seismic zone through the mainfrac treatment was estimated to spread over 58?m height and 320?m length at the Khalda site, while the zone of the Kahraman site was enclosed within 25?m height and 250?m length. The stimulated reservoir volume (SRV) at the Khalda site was estimated to be 433?200?m3, with asymmetrical wings around the stimulation well, but at the Kahraman site the stimulation imaging was marginally successful and the stimulated SRV was only 247?000?m3. In general, the two microseismic experiments at Khalda and Kahraman were relatively successful in locating the microseismic events and calculating the SRV within the producing horizon, elucidating the importance of the microseismic technique in monitoring reservoir stimulation.