任意广角声波方程逆时偏移的吸收边界条件.PDFVIP

35 1 Vol. 35 No. 1 2010 1 JOURNAL OF CH INA COAL SOCIETY Jan. 2010 : 0253- 9993( 2010) 01- 010 - 04 1 1 2 何兵寿 , 张会星 , 张建军 ( 1, 2 100; 2 , 841000) : 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 值 的计算采用内层网格的波 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 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M armousi模型的偏移处理取得了满意效果 : 任意广角声波方程; 纵波; 逆时偏移; 边界条件 : P 315 : A Absorb ing boundary condition s of arb itrarily w ide-angle acoustic equation s reverse-tim e m igration 1 1 2 HE Bing-shou , ZHANG Hui-xing , ZHANG Jian-jun ( 1K ey La boratory of Submarine Geoscien ces and P rosp ecting T echniques,M in istry of Educa tion, O cean Un i ersity of Ch ina, Q ingdao 2 100, Ch ina; 2T ar- mi B ranch, BGP IN C. , Ch inaN a tiona lP e troleum Corp ora tion, K orla 841000, China) Abs tract: Stud ied the absorb ing boundary conditions (ABCs) for the prestack reverse-tmi e depth m igration based on the 2D arbitrarily w ide-angle one-way acousticw ave equation. The w avefield computation at the bottom boundary w as realized by the w avefield continuation algorithm of inner grids, w hile the boundary reflection at the top boundary w as elmi inated by comb ination of pseudo-grids and rigid boundary cond ition. As to the right and left boundaries, illustrated corresponding w avefield computation algorithm, and derived the fin ite-difference scheme for the reverse-tmi e continua- tion at these wt o boundaries. Num erical example of mi pu lse response in ho