摘要
二阶声波方程逆时偏移中,常规分裂完全匹配层(SPML)吸收边界条件是目前比较常用的吸收边界条件,但是常规SPML吸收边界条件存在变量个数多、计算存储量大、计算效率低下等缺点,影响了三维逆时偏移的实际应用。为此引进一种新的卷积完全匹配层(NCPML)吸收边界条件,将其拓展应用于三维声波方程正演模拟,然后应用于三维逆时偏移。该方法基于SPML吸收边界条件,忽略复数频率域中衰减因子的空变特性,反变换至时间域即得到二阶系统下声波方程的NCPML吸收边界条件。均匀介质模型实验表明,NCPML吸收边界条件在数值模拟中计算效率和内存占用上较常规SPML吸收边界条件更优。SEG/EAGE推覆体模型和实际资料的三维逆时偏移实验结果表明,NCPML吸收边界条件具有更好的稳定性。
In reserve time migration(RTM)based on a second-order system,a split perfectly matched layer(SPML)absorbing boundary condition is currently widely used.However,SPML is not applicable to three-dimensional RTM because of the large number of variables,large memory requirement,and low efficiency.A convolutional perfectly matched layer(NCPML)absorbing boundary condition was therefore applied to the three-dimensional forward modeling and RTM of the acoustic equation.In the proposed method,the SPML was first applied,ignoring the spatial variation of the damping coefficient in the complex-frequency domain.Then,the inverse Fourier transform was performed to revert to the time domain and obtain the NCPML absorbing boundary condition for the second-order acoustic wave equation.Numerical tests demonstrated the superiority of the NCPML over the SPML in terms of memory economy,efficiency,and robustness.
作者
李青阳
吴国忱
杨凌云
王玉梅
LI Qingyang;WU Guochen;YANG Lingyun;WANG Yumei(School of Geosciences,China University of Petroleum (East China),Qingdao 266580,China;Laboratory for Marine Mineral Resources,Qingdao National Laboratory for Marine Science and Technology,Qingdao 266071,China;Geophysical Resarch Institute of Shengli Oilfield,Sinopec,Dongying 257022,China)
出处
《石油物探》
EI
CSCD
北大核心
2020年第6期901-911,935,共12页
Geophysical Prospecting For Petroleum
基金
国家科技重大专项(2016ZX05024-001-008)资助。
关键词
卷积完全匹配层
二阶系统
声波方程
逆时偏移
内存优化
计算效率
鲁棒性
convolutional perfectly matched layer
second-order system
acoustic wave equation
reserve time migration
memory optimization
computational efficiency
robustness
