Efficient Wavefield Separation for Large 3D VSPs in Saudi Arabia

For large 3D VSP surveys that use large 3-component downhole receiver arrays to record of all the different wavefield components, it is not easy to apply conventional wavefield separation methods such as parametric decomposition or model based rotation. These methods usually fail for very large offsets because they are strongly dependent on the velocity model. In this paper we present a simple but efficient workflow for wavefield separation of large 3D VSPs. The workflow combines a wave-by-wave wavefield separation method with a covariance matrix method. The effectiveness of this technique is confirmed by application to 3D VSP data from Saudi Arabia.