Vector prestack depth migration of multi-component wavefield
He Bing-shou and Zhang Hui-xing. He Bing-shou,Institute of Oceanic Geo-Science, China University of Ocean, No.5, Yushan Road, Qingdao City, Shandong Province, 266003, China
The paper studied a vector prestack depth migration method—prestack inverse-time depth migration for two components records in 2D isotropic medium. Firstly, staring from the elastic wave equation, high-order finite-difference format of elastic wave inverse-time continuation in isotropic medium was deduced in staggering grid space; then, proceeding from the eikonal equation, the seismic travel time at each underground point was computed by inverse-time finite-difference format. In order to ensure the causality of seismic propagation and adaptability to complicated model, expanding wave front method was used to track wave front and search global minimum, taking above mentioned computational results as imaging condition of elastic wave inverse-time migration. The prestack inverse-time depth migration of 2D multi-component data can be realised. The tests of model and real single-shot records showed the prestack inverse-time depth migration considered the vector feature of seismic wave, which is an effective vector wavefield processing technique.