Background velocity replacement and reconstruction of velocity field by wavefield continuation
Cui Xingfu1, Zhang Guanquan2
Computing Centre, Exploration &: Development Research Institute, Liaohe Oilfield Branch Cooperation, CNPC, Panjing City, Liaoning Province, 124010, China
Abstract:In common midpoint-half-offset domain,utilizing prestack double square-root operator ofwave equation to realize downward continuation for shot and receiver layer by layer,through using replacement velocity to replace overlaying strata velocity and eliminate the impact of background velocity on strata imaging,resulted in improving the processing quality of deep seismic data. Through downward continuation of wavefield at shot and receiver points by prestack double-square-root operator and stripping layer by layer,we can do precise velocity analysisto eliminatetheinfluenceofoverlying strata on velocity and to reconstruct velocity field,so that the precision of velocity analysis can be improved,that provides a reliable velocity analysis means for prestack migration imaging.