3D full-waveform inversion at Mariner — a shallow North Sea reservoir

We applied isotropic acoustic 3D full-waveform inversion (FWI) to OBC data from the Mariner field, a shallow heavy-oil field in the North Sea. This resulted in a multiphase workflow that can be adapted to imaging challenges in similar geological settings. FWI improves the resolution of the velocity field compared to the benchmark velocity field from reflection tomography. The background trend of and details introduced in the velocity model correlate well with the geology from seismic data and with well logs down to reservoir level. Resulting depth images show significantly better well tie in the overburden and improved definition of sand bodies at reservoir level.