Interferometric imaging by cross correlation in surface seismic profile with double green's function

Interferometric imaging aims to revise Green's function for the consequences of acquisition geometry far from the geologic target bodies. That comprises the influences of an irregular acquisition geometry and of complex geological bodies in the overburden such as salt body with very high velocity. The sources can be relocate to positions where receivers are by seismic interferometric technique and vice versa. It is often used in transform data between vertical seismic profile (VSP) and single well profile (SWP), surface seismic profile (SSP) and single well profile. In most cases, no receivers are available at the underground medium, however the propagation of seismic waves in vertical seismic profile can be simulated by finite-difference. By correlating the simulated VSP Green's function with surface seismic data, one can take the acquisition geometry from the surface closer to subsurface datum. The traditional interferometric imaging in surface seismic profile use one kind of VSP Green's function so it only can handle simple model. To overcome this problem, double VSP Green's function interferometric imaging (DGFII) is presented, which can handle complex model. Our numerical examples demonstrate that DGFII works perfectly not only in a homogeneous overburden, but also in a hetergeneous overburden.