3D HYBRID ONE STEP WAVE EQUATION FORWARD MODELING
Xiong Gaojun 1, He Zhenhua 2, Zhang Yixiang 1, Jiang Shaoren 1, Yan Pin 1, Li Xiangui 3, Zhang Lin 4 (1.South China Sea Institute of Oceanology; 2.Chengdu University of Technology; 3.Southwest Petroleum Geology Bureau, China; 4.Sichuan Petro
The authors present the 3D phase shift plus finite difference hybrid extrapolating method in this paper. Based on this, the forward modeling of a complex structure with velocity varying arbitrarily can be done accurately and efficiently. In 2D media, the phase shift is a fast ,stable and accurate method in computation for dealing with steep dips, but it is difficult to process lateral velocity variation. In contrast, the finite difference formula is a very good way in the proceeding of arbitrary velocity variation , and in X domain, it is simple and stable in computation, but there are still many problems in dealing with steep dip events. If a fast 45° finite difference wave equation is used as a complement to phase shift extrapolation, a way suited to the variation of velocity in all directions will be got. In this way, a steep dip geological structure can be processed accurately. Now, the idea in 3D media’s data proceeding is used and expanded into 3D phase shift plus finite difference hybrid formula. Based on this, the so called 3D hybrid one step wave equation forward modeling formula is deduced.