FWI with OBC Data From the Mariner Field, UK - The Impact on Mapping Sands at Reservoir Level

We applied isotropic acoustic 3D full-waveform inversion to OBC data over Mariner, a shallow heavy-oil field which is under development in the North Sea, to estimate P-wave velocities for improved reservoir imaging and characterization. With velocities obtained from FWI, shallow velocity anomalies are resolved and the resulting depth images show significantly better well tie in the overburden. At the reservoir level, the FWI velocity model results in some places in improved imaging and definition of the Heimdal sands, which makes the sands easier to map and can reduce the uncertainty in well planning. The FWI velocity model gives in addition rise to a different interpretation of the Top Maureen sandstone. The new interpretation fits better with available well picks than the interpretation obtained from the benchmark image, but prestack data alone are not sufficient to conclude about the quality elsewhere.