Geologically Guided Prestack Depth Imaging - a Case History From Greater Burgan, Kuwait

Prestack depth migration (PSDM) can provide superior seismic volumes even in areas of low relief structures. A pilot PSDM study over the Greater Burgan oilfield in Kuwait demonstrated not only the uplift versus prestack time migration (PSTM), but also pointed to areas of further improvement in the velocity model building workflow. A full field (FF) study was subsequently performed, and incorporated the lessons learned from the pilot. The main area for enhancement was the integration of geological information into the velocity model. This included near-surface velocity characterization and incorporation of existing 3D log-based velocity models into the initial PSDM model, plus implicit geological constraints during the model updating workflow. The results were a more geologically plausible velocity model with enhanced imaging versus both the legacy PSTM and pilot PSDM volumes, establishing the FF PSDM volume as the main seismic volume for interpretation, well planning and reservoir characterization for the Greater Burgan field.