Wide-azimuth PP/PS Depth Imaging at Ekofisk Using Full Waveform Inversion

A large part of the Ekofisk field is seismically obscured due to gas-charged overburden layers. This has always represented a significant challenge for seismic imaging and interpretation. With the newly installed Ekofisk permanent seabed seismic system, acquisition of wide-azimuth, long-offset multicomponent data has permitted the use of powerful imaging and processing techniques. We present a state of the art velocity model building workflow using FWI and joint PP-PS tomography. Applied in combination with wide-azimuth multicomponent processing, it has enabled to significantly reduce the extent of the Seismic Obscured Area for both PP and PS data, as well as noticeably improve data quality for interpretation of more subtle geological features.