Angle-dependent Water Column Statics Correction through Sparse TauP Inversion

Water column statics caused by tidal variation and water velocity change during seismic surveys is one major source of noise in marine 4D projects. Correction of this statics effect is a key step in any marine 4D processing. Applying water column statics correction requires a good knowledge of the distance or surface take-off angle when waves travel through the water column, which conventional methods such as ray tracing are not able to obtain accurately when the subsurface velocity is complex.

We propose a new method to apply water column statics correction through progressive sparse TauP inversion. This method does not need prior inputs of subsurface velocity and reflector dips, as required for ray-tracing methods, and benefits from the progressive sparse TauP inversion engine that can properly handle spatially aliased marine seismic data and mitigate energy leakage in the TauP domain.

We demonstrate the effectiveness of this new method using synthetic ocean bottom seismometer (OBS) data derived from a SEAM velocity model and using real OBS data from 4D surveys over the Atlantis field in the Green Canyon area of the Gulf of Mexico (GOM).