声波方程数值模拟中的任意广角单程波吸收边界  

Arbitrarily wide-angle wave equation absorbing boundary condition in acoustic numerical simulation

作　　者：张红静[1,2] 周辉[1,2] 陈汉明[1,2] 林鹤[1,2] 王杰[1,2] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]中国石油大学CNPC物探重点实验室,北京102249

出　　处：《石油地球物理勘探》2013年第4期576-582,676+502,共7页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目(40974069;41174119);国家科技重大专项(2011ZX05010;2011ZX05024);中国石油天然气集团公司"十二五"物探新方法新技术研究项目(2011A-3602)联合资助

摘　　要：地震数值模拟需要使用稳定有效的吸收边界条件,以达到衰减人工截断边界反射的目的。本文将一种高精度单程波方程,即任意广角波动方程(AWWE)用作二阶声波方程的吸收边界条件,采用有限差分法给出边界的计算公式,并对角点进行了特殊处理。均匀模型与解析分析法结果的对比及Marmousi模型波场模拟证实:AWWE用作吸收边界能适用于较大入射角情况,其吸收效果明显优于传统的二阶傍轴近似吸收边界条件(CE2);AWWE吸收边界几乎不增加额外计算量,并且不影响内部区域数值计算的稳定性。To attenuate artificial edge reflections arising at truncation boundary,stable and effective absorbing boundary conditions(ABC) should be applied in seismic numerical simulation.In this paper,we use a high accurate one-way wave equation,named arbitrarily wide-angle wave equation(AWWE),as ABC in second-order acoustic wave equation simulation.We give out the corresponding discrete formulation of the boundary condition using the finite-difference method.Meanwhile,the corner regions are carefully treated.The numerical simulations of a homogeneous medium and 2D Marmousi model show that AWWE boundary condition can adapt to a wide range of incident angle and has a better absorption effect than second-order paraxial approximations(CE2 in short).The computation efficiency of the AWWE boundary condition is almostidentical to CE2.In addition,such an ABC has noinfluence to the interior stability.

关 键 词：地震波数值模拟 AWWE吸收边界条件 有限差分 声波方程 

分 类 号：P631[天文地球—地质矿产勘探]