Gaussian Beam Pre-stack Depth Migration With Dip-angle Constraint and Its Practical Application

Abstract

In order to obtain higher S/N imags, a Gaussian beam Pre-stack Depth Migration (PSDM) method with dip-angle constraint is proposed in this paper. We extract common image gathers in dip-angle domain (DDCIGs), rather than in traditional angle/offset domain. These DDCIGs contain structure dip angle information, which can help us to analyze and select valuable imaging energy along the dimension of the dip angle. Thus we can stack CIGs in certain dip-angle ranges to suppress migration artifacts caused by low S/N data, the inability to completely collapse seismic events, the inability of multi-arrivals Gaussian beam migration (GBM) to process all arrivals, and the insufficiency of Green’s function by a Gaussian-beam summation. By using the Marmousi synthetic dataset and the low S/N field data, we demonstrate that our method can greatly eliminate those artifacts emerging in the conventional GBM profiles.