Multi-Well Hydraulic Fracture Monitoring in the Sultanate of Oman Using Surface and Downhole Microseismic Arrays

Abstract

Microseismic mapping provides essential information for monitoring effective fluid flow and stimulated reservoir volume, as well as for decision making on fracture operations and well completions. This work presents the microseismic monitoring results of a multiwell completion of a field located in the Sultanate of Oman. Target depth is about 1300 m from ground level. The treatments of three wells were monitored by both a surface array and a downhole array. The surface monitoring array was built using a 50-m inline spacing and 100 m crossline spacing geometry and comprised 1000, 974, and 975 3C geophones when monitoring the TW1, TW2, and TW3 wells, respectively. The downhole monitoring was performed using a 12-level 3C-geophone accelerometer array using 30-m-long interconnects deployed in the nearby well, MW. Both surface and downhole seismic data cover the complete stimulation campaign of all three treatment wells. Surface- and downhole-acquired data benefit from a combined inversion. Surface-acquired horizontal locations reveal the same event geometry as downhole results but with a more focused linear cloud. Mapped events indicate a well-bound stimulation along the vertical dimension while exhibiting predominantly strike-slip mechanisms.