Wang Shangxu

Application of amplitude ratio profiles extracted with prestack Kirchhoff integral migration

TheZ component andX component profiles of seismic waves extracted with the prestack Kirchhoff integral migration could approximate to the primary wave (P wave) and converted shear wave (PS wave) profiles under certain conditions. The relative change of their reflection amplitude reflects the formation stress anomaly and subsurface media anisotropy. The principle and method for extracting amplitude ratios were studied and the application of amplitude ratio profiles was also examined when processing and interpreting actual seismic data. The amplitude ratio profile is an effective supplementary means of identifying the stratigraphic boundary and lithology.

Optimized non-hyperbolic stack imaging based on interpretation model

In complex media, especially for seismic prospecting in deep layers in East China and in the mountainous area in West China, due to the complex geological condition, the common-mid-point (CMP) gather of deep reflection event is neither hyperbolic, nor any simple function. If traditional normal move-out (NMO) and stack imaging technology are still used, it is difficult to get a clear stack image. Based on previous techniques on non-hyperbolic stack, it is thought in this paper that no matter how complex the geological condition is, in order to get an optimized stack image, the stack should be non time move-out stack, and any stacking method limited to some kind of curve will be restricted to application conditions. In order to overcome the above-mentioned limit, a new method called optimized non-hyperbolic stack imaging based on interpretation model is presented in this paper. Based on CMP/CRP (Common-Reflection-Point) gather after NMO or pre-stack migration, this method uses the interpretation model of reflectors as constraint, and takes comparability as a distinguihing criterion, and finally forms a residual move-out correction for the gather of constrained model. Numerical simulation indicates that this method could overcome the non hyperbolic problem and get fine stack image.