吴建鲁^1,2,,
吴国忱^1,2
1. 中国石油大学(华东), 青岛 266580
2. 海洋国家实验室海洋矿产资源评价与探测技术功能实验室, 青岛 266071

基金项目: 国家重大专项（2016ZX05024-001-008）资助


详细信息

作者简介: 吴建鲁, 男, 1989年生, 在读博士, 主要从事地震全波形反演方面的研究.E-mail:wujianlu2008@163.com

中图分类号: P631

收稿日期:2017-09-23
修回日期:2018-03-22
上线日期:2018-06-05

Finite difference method for acoustic-elastic coupled equations of seismic waves in the frequency domain

WU JianLu^1,2,,
WU GuoChen^1,2
1. China University of Petroleum, Qingdao 266580, China
2. Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China


MSC: P631

--> Received Date: 23 September 2017
Revised Date: 22 March 2018
Available Online: 05 June 2018


摘要
摘要:本文针对声-弹耦合介质，为尽可能的减少频率域正演模拟的计算内存，提高计算效率，在一阶非均质位移-应力波动方程的基础上，借助等效交错网格思想并充分考虑密度参数空间变化对地震波传播的影响，推导了声-弹耦合地震波波动方程.在流相介质和固相介质中分别采用非均质情况频率域二阶声压标量波、二阶纯位移控制方程，为保证流、固相介质间地震波能量的稳定传输和有效交换，提出了声-弹耦合界面转换过渡层方法，并详细阐述了过渡层与上下介质空间差分具体耦合方法.在与非均质纯位移波动方程正演结果对比分析的基础上，首先采用各向同性单层流相介质模型进行正演模拟验证了声-弹耦合方程数值模拟中过渡层策略的有效性和准确性，随后又数值模拟了地震波在声-弹耦合介质简单模型和复杂Marmousi2模型中的传播，验证了本文方法稳定性和准确性，同时该方法可以简单的推广到三维情况.
关键词: 数值模拟/
声-弹耦合/
频率域/
有限差分

Abstract:In order to reduce the memory and enhance the computational efficiency of seismic forward modeling for fluid-solid media, the acoustic-elastic coupled equations of seismic wave are derived based on first-order heterogeneous displacement-stress equations utilizing the effective staggered grid method, in which the variation of density in space is considered. The heterogeneous second-order pressure equations and displacement equations are applied to fluid and solid phases, respectively, adding a transition layer on the fluid and solid boundary, which can make sure the correct exchange of energy of seismic waves between fluid phase and solid phase by mean of coupling two kinds of equations aforementioned. Compared with the results of seismic forward modeling of heterogeneous second-order displacement equations, the accuracy of the transition layer for acoustic-elastic coupled equations has been verified in a pure fluid model. The stability and validity of the method we propose are also proved by modeling tests on the sample fluid-solid model and Marmousi2 model. In addition, the method we describe can also been extended to the three-dimensional case.
Key words:Numerical modeling/
Acoustic-elastic coupling/
Frequency domain/
Finite-difference



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