Forward modeling of ocean-bottom cable data and wave-mode separation in fluid–solid elastic media with irregular seabed

作     者：Qu Ying-Ming Sun Jun-Zhi Li Zhen-Chun Huang Jian-Ping Li Hai-Peng Sun Wen-Zhi 曲英铭;孙军治;李振春;黄建平;李海鹏;孙文之

作者机构：Department of GeophysicsSchool of GeosciencesChina University of PetroleumQingdao 266580China SINOPEC Key Laboratory of GeophysicsNanjing 211103China 

出 版 物：《Applied Geophysics》 (应用地球物理（英文版）)

年 卷 期：2018年第15卷第3期

页      面：432-447页

核心收录：

学科分类：081801[工学-矿产普查与勘探] 081802[工学-地球探测与信息技术] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：financially supported by the Natural Science Foundation of China(No.41774133) the Open Funds of SINOPEC Key Laboratory of Geophysics(No.wtyjy-wx2017-01-04) National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2016ZX05024-003-011) 

主　　题：Irregular seabed fluid-solid elastic media ocean bottom cable data P-and S-wave separation curvilinear coordinates 

摘      要：In marine seismic exploration, ocean-bottom cable techniques accurately record the multicomponent seismic wavefield; however, the seismic wave propagation in fluid–solid media cannot be simulated by a single wave equation. In addition, when the seabed interface is irregular, traditional finite-difference schemes cannot simulate the seismic wave propagation across the irregular seabed interface. Therefore, an acoustic–elastic forward modeling and vector-based P-and S-wave separation method is proposed. In this method, we divide the fluid–solid elastic media with irregular interface into orthogonal grids and map the irregular interface in the Cartesian coordinates system into a horizontal interface in the curvilinear coordinates system of the computational domain using coordinates transformation. The acoustic and elastic wave equations in the curvilinear coordinates system are applied to the fluid and solid medium, respectively. At the irregular interface, the two equations are combined into an acoustic–elastic equation in the curvilinear coordinates system. We next introduce a full staggered-grid scheme to improve the stability of the numerical simulation. Thus, separate P-and S-wave equations in the curvilinear coordinates system are derived to realize the P-and S-wave separation method.