Reservoir Monitoring Using Induced Seismicity Magnitude – A Case Study from Oman

We present a case history of passive seismic monitoring with location and characterization of seismic events induced by oil and gas production and water injection at a petroleum field in Oman. Two different monitoring networks have recorded thousands of microseismic events in the field over the last 9 years. We used data from both networks to locate the events and to analyze the patterns and causes of induced seismicity in the field. Locations of these events correlate with preexisting fault maps derived from surface seismic, and delineate structures that were previously unmapped by the same. Spatial and temporal analyses of event locations indicate large scale fault reactivation in the field. Comparisons between induced seismicity and production/injection data in the field suggest gas production as the primary cause of inducing seismicity in the field. The use of passive seismic technology in this field has been very effective in the characterization and surveillance of the reservoir.