任意广角声波方程逆时偏移的吸收边界条件  

Absorbing boundary conditions of arbitrarily wide-angle acoustic equations reverse-time migration

作　　者：何兵寿[1] 张会星[1] 张建军[2] 

机构地区：[1]中国海洋大学海底科学与探测技术教育部重点实验室,山东青岛266100 [2]中国石油集团东方地球物理勘探有限责任公司塔里木经理部,新疆库尔勒841000

出　　处：《煤炭学报》2010年第1期106-109,共4页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(40804021);国家自然科学基金重点资助项目(40839901);国家重点基础研究发展计划(973)基金资助项目(2009CB219603)

摘　　要：研究了二维任意广角单程声波方程叠前逆时深度偏移的吸收边界条件。底边界处波场值的计算采用内层网格的波场延拓算法实现,顶边界处采用虚网格加刚性边界条件来消除边界反射,对于左右边界,文中给出了波场计算方法,并推导了该边界条件逆时延拓的有限差分格式。均匀介质中的脉冲响应试验表明,只需要边界处镶边3层即可有效吸收入射到截断边界的外行波,消除边界反射。Marmousi模型的偏移处理取得了满意效果。Studied the absorbing boundary conditions （ABCs） for the prestack reverse-time depth migration based on the 2D arbitrarily wide-angle one-way acoustic wave equation. The wavefield computation at the bottom boundary was realized by the wavefield continuation algorithm of inner grids, while the boundary reflection at the top boundary was eliminated by combination of pseudo-grids and rigid boundary condition. As to the right and left boundaries, illustrated corresponding wavefield computation algorithm, and derived the finite-difference scheme for the reverse-time continuation at these two boundaries. Numerical example of impulse response in homogeneous medium shows that the outgoing waves that fall on the truncation boundary can be effectively absorbed with as few as three absorbing layers added, leaving no boundary reflection. Also, migration for Marmousi model based on these ABCs is satisfactorily fine in its result.

关 键 词：任意广角声波方程 纵波 逆时偏移 边界条件 

分 类 号：P631.5[天文地球—地质矿产勘探]