Improving seismic image in complex structures by new solving strategies in the CO-CRS and the CO-CDS methods

Conventional seismic imaging possesses problem in exposing structural detail in complex geological media. Nevertheless, some recently introduced methods reduce this ambiguity to some extent, by using data based imaging operator or emancipation from the macro-velocity model. The zero offset common reflection surface (ZO-CRS) stack method is a velocity independent imaging technique which is frequently used in seismic imaging. Various modifications of this method were introduced through its development. The ZO diffraction stacking operator, the common offset CRS (CO-CRS) and anisotropic CRS methods were introduced to enhance the final seismic image. As diffraction events are carriers of structural details information, we adhere to improve response diffraction to obtain more structural details in the final image. Thus we combined advantages of the CO-CRS method by the diffraction operator to make the CO-CDS stack operator. The parameters of the reflection operator were changed to fulfill conditions of a diffraction response in CO domain. Meanwhile, to resolve the problem of conflicting dips, the solving strategy was modified in order to consider all possible angles and make a contribution to them in their related operators. Thus it was expected that the CO-CDS stack reveals weak diffraction events in the stacked section, in favor of further depth migration. The introduced method was applied to a synthetic and land data. Utilizing the CO-CDS method on the synthetic data brings out as much as diffraction in the stacked result. For land data set, the CO-CDS operator boosted the share of diffraction in the stack section which was further underwent depth migration procedure by the robust Gaussian Beam algorithm with a smooth velocity model. Outstanding enhancement in the final result compared to the conventional and the CRS methods were depicted by depth imaging of the CO-CDS result, which was a consequence of improved diffraction based operator of the CRS method.