摘要
在存在强衰减介质的区域进行逆时偏移成像,需要既能补偿地震波传播过程中的振幅衰减,又能保持其相位不变的高效算法.为此,本文提出了一种利用有限差分模拟进行声波衰减补偿的方法来实现考虑衰减的逆时偏移.这种方法以线性黏弹性体模型为基础,保持其复模量的实部不变,并采用多项式多级优化方法修正复模量的虚部,从而实现在保持相位不变的同时补偿振幅,进而有效提高偏移成像的清晰程度,尤其是对于介质对地震波衰减极为强烈的情形.这一方法在声波方程中只增加了整数阶微分算子进行修正,能够保证利用有限差分法进行数值求解,有利于进行高效的大规模细粒度并行计算和GPU加速计算.数值实验结果验证了这一方法的可行性和有效性,能够很好地提高强衰减介质区域的偏移成像质量.
In a region with high-attenuation media,high efficiently compensation of the attenuation in reverse time migration by simultaneously boosting the amplitude and keeping the phase of the wave is necessary for improving the imaging quality.We derive a newQ-compensation method for wave propagation in visco-acoustic media and propose a newQ-RTM scheme.This new method is based on the Generalized Standard Linear Solid model and uses polynomial multi-stage optimization technique to fit the imaginary part of complex moduli for GSLS while keeping the real part of the complex moduli unchanged.It successfully compensates the amplitude while keeping the phase velocity exactly unchanged,which can potentially correct all attenuation effects and fairly improve the imaging quality in and below the high attenuation regions.Because the polynomial multi-stage optimization technique only adds integer order differential operators to the wave equation,it can be implemented by a finite-difference method.As a result,the new method is flexible for domain decomposition and very suitable for high efficiency fine-grained parallelcomputation as well as GPU acceleration.Numerical tests show that it is a robust Q-RTM method.
作者
周彤
胡文毅
宁杰远
ZHOU Tong;HU WenYi;NING JieYuan(ITAG Institute of Theoretical and Applied Geophysics, School of Earth and Space Sciences Peking University, Beijing 100871, China;Advanced Geophysical Technology Inc. , Houston 77478, U. S. A)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第6期2433-2445,共13页
Chinese Journal of Geophysics
基金
中国地震科学台阵探测--华北地区中部项目(DQJB16A0307)
地震行业专项(201408013)资助
关键词
有限差分
衰减
补偿
逆时偏移
Finite difference
Attenuation
Q-compensation
Q-RTM
