摘要
It is of great significance to separate seismic diffractions from seismic data and apply the imaged results of these separated diffractions to the research of some complicated reservoirs,the karst reservoir for example.On the planar decomposition section,the dip difference between specular reflection events and diffraction events is remarkable in the case that the dips of reflection interfaces are small.Based on the above facts,we propose a hybrid method for diffraction separation:(1) We divide each planar decomposition section into two portions by local dip filtering: the portion d1 mainly containing diffraction information with high dip and the portion 1 containing the specular reflection r and residual diffraction information with low-dip(d2);(2) The separation of specular reflection r and residual diffraction information d2 from 1 obtained in step(1) is conducted by prediction inversion in F-X domain;(3) d2 added to d1 makes the estimation of diffractions.This separation method can get relatively complete diffraction information,which effectively avoids the problem appearing in the general filter methods based only on dip attribute that low dip portion of diffraction is lost and thus narrowing the spatial bandwidth of the diffraction which will damage the lateral resolution.The feasibility of the proposed method is proven by both theoretical and real data tests.