TTI介质中的纯qP波衰减补偿最小二乘逆时偏移成像方法  

Pure qP-wave attenuation-compensated LSRTM in TTI media

作　　者：李振春[1,2] 张闪闪 秦宁[3] 谷丙洛 丁奕文[1,2] LI Zhenchun;ZHANG Shanshan;QIN Ning;GU Bingluo;DING Yiwen(School of Geosciences in China University of Petroleum(East China),Qingdao 266580,China;State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;Shengli Oilfield Company Geophysical Research Institute of SINOPEC,Dongying 257100,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [2]深层油气全国重点实验室(中国石油大学(华东)),山东青岛266580 [3]中国石化胜利油田分公司物探研究院,山东东营257100

出　　处：《中国石油大学学报（自然科学版）》2024年第5期24-35,共12页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(42004093);中石油重大科技合作项目(ZD2019-183-003);山东省自然科学基金项目(ZR2020QD050);胜利油田博士后课题(YKB2420);泰山产业领军人才工程项目。

摘　　要：为有效提高衰减各向异性介质中地震波成像剖面的质量,实现稳定的TTI介质中的衰减补偿成像,提出一种基于黏声TTI纯qP波方程的最小二乘逆时偏移方法。在最小二乘偏移框架的基础上,推导相应的Born正演方程、伴随算子和梯度敏感核。由于伴随算子是衰减的,可以避免衰减补偿引起的数值不稳定性。通过同时考虑各向异性和吸收衰减的影响,衰减补偿最小二乘逆时偏移可以提供高分辨率、更少假象和振幅均衡的偏移结果。最后,通过模型试验和实际数据的测试及分析,验证了新方法的可行性和适用性。结果表明,黏声TTI最小二乘逆时偏移成像在衰减区域可进行高质量成像,丰富成像剖面中的波数成分,拓宽成像剖面中的频带宽度,提高地下介质成像剖面的分辨率及成像精度。To improve the quality of seismic wave imaging in attenuated anisotropic media and achieve stable attenuation-compensated imaging in TTI media,we propose a least-squares reverse time migration method(Q-TTI-LSRTM)based on a viscoacoustic TTI pure qP-wave equation.Within the least-squares migration framework,the corresponding Born modeling equation,the adjoint equation,and the gradient sensitivity-kernel for the Q-TTI-LSRTM are derived.The Q-TTI-LSRTM method naturally eliminates the numerical instability caused by attenuation compensation,as the amplitude attenuation is incorporated into the adjoint equation.Additionally,the method avoids qSV-wave inferference due to the use of the viscoacoustic TTI pure qP-wave equation.It produces migration images with high resolution,fewer artifacts,and balanced amplitude by accounting for anisotropy and absorption attenuation.Finally,model tests and field data analysis confirm the feasibility and applicability of the method.The imaging results demonstrate that the Q-TTI-LSRTM can privide high-quality imaging in attenuated regions,enhance wavenumber components,broaden frequency bandwidth,and improve the resolution and accuracy of subsurface media imaging.

关 键 词：衰减补偿 最小二乘逆时偏移 TTI介质 纯qP波 近似常Q模型 

分 类 号：P631.4[天文地球—地质矿产勘探]