杨尚倍^1,,
白超英^1,2,,,
周兵³
1. 长安大学地质工程与测绘学院地球物理系, 西安 710054
2. 长安大学计算地球物理研究所, 西安 710054
3. 阿联酋哈利法科技大学石油学院, 阿布扎比 2533


详细信息

作者简介: 杨尚倍, 1991年生, 长安大学在读博士研究生, 主要从事地震波场数值模拟技术的研究.E-mail:yangshangbei@126.com

通讯作者: 白超英, 长安大学地测学院教授, 主要从事地震学相关领域的教学及科研.E-mail:baicy@chd.edu.cn

中图分类号: P631

收稿日期:2017-10-12
修回日期:2018-05-03
上线日期:2018-08-05

Wavefield modeling in two-phase media including undulated topography based on reformulated BISQ model by Curvilinear Grid FD method

YANG ShangBei^1,,
BAI ChaoYing^1,2,,,
ZHOU Bing³
1. Dept. of Geophysics, School of Geology Engineering and Geomatics, Chang'an University, Xi'an 710054, China
2. Institute of Computational Geophysics, Chang'an University, Xi'an 710054, China
3. The Petroleum Institute, Khalifa University of Science and Technology, Po BOX 2533, Abu Dhabi, UAE


More Information

Corresponding author: BAI ChaoYing,E-mail:baicy@chd.edu.cn

MSC: P631

--> Received Date: 12 October 2017
Revised Date: 03 May 2018
Available Online: 05 August 2018


摘要
摘要:本文以基于改进BISQ模型的二维双相各向同性介质一阶速度-应力方程为基础，推导出了曲线坐标系下对应的方程，然后采用低频散、低耗散的同位网格MacCormack有限差分法来离散方程，并采用紧致的单边MacCormack差分格式结合牵引力镜像法来施加自由地表边界条件，实现了地震波场数值模拟.曲线网格有限差分法采用贴体网格来描述自由表面，地表的网格线紧贴地形，避免了台阶近似造成的数值散射.数值模拟结果表明，在双相介质起伏自由地表和分界面处，各类波型复杂的反射透射规律可以清晰展现，曲线网格有限差分法可以精确地解决地震波在含起伏地表的双相各向同性介质中的传播问题.
关键词: 起伏地表/
改进BISQ模型/
各向同性双相介质/
曲线网格/
有限差分法

Abstract:In this article, the corresponding equations in curvilinear coordinate system based on the first-order velocity stress equation of two-phase isotropic media based on the improved BISQ model are derived, then the equations are numerically solved by an optimized high-order non-staggered finite difference scheme, that is, DRP/opt MacCormack scheme. To implement the undulating free-surface topography, we derive the analytical relationship between derivatives of velocity components and use the compact finite-difference scheme and traction-image method. The curvilinear grid finite difference method uses body-conforming grid to describe the free surface, thus avoids the numerical approximation caused by scattering. In the undulating free surface and the undulating interface of two-phase medium, the complex reflection wave and transmission wave can be clearly demonstrated by the numerical simulation results. The simulation results show that the curvilinear grid finite-difference method can accurately solve the propagation problem of seismic waves in a two-phase isotropic medium with undulating surface.
Key words:Undulating surface/
Reformulated BISQ mechanism/
Porous isotropic media/
Curvilinear grid/
Finite difference method



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