With the development of the post-stack seismic inversion into the pre-stack seismic inversion, the prestack seismic inversion of the elastic impedance requires a large range of incident angle, i.e. a large offset range, which means a very smooth CRP gather from the pre-migration and a small NMO stretch. So after PSTM, a detailed processing on pre-stack gathers will be carried out to reduce the impact of the residual moveout. The most effective way to reduce the residual moveout and the NMO stretch is the anisotropic NMO, which requires exact anisotropic parameters VNMO and η. In this paper, an anisotropic NMO application process is introduced, which uses the high-density dual-spectral scanning method to obtain τ0 and dtn then converts τ0 and dtn to the anisotropic parameters VNMO and η, which are required for the anisotropic NMO using the shifted hyperbola approach, with the horizontal and vertical interpolation and smoothing. These two parameters will be used in the anisotropic NMO to avoid the bad effects of anisotropy. This method is applied to the synthetic data and field data and good results are obtained, which means that this method can obtain the quite accurate anisotropic parameter, reduce bad influences of residual moveout and NMO stretch on the CRP gather and increase the range of effective offset.
ZHANG Zheng;DI Bangrang;HU Ying;YAO Fengchang
. Application of Pre-stack Detailed Process Technique on CRP Traces Gather[J]. Science & Technology Review, 2012
, 30(27)
: 35
-40
.
DOI: 10.3981/j.issn.1000-7857.2012.27.004