频率域稳定化的黏声波逆时偏移方法及其应用  

Stabilized viscoacoustic reverse time migration in the frequency domain and its application

作　　者：马雄 申天赐 田永净 韩刚 桂志先[1,2] 彭晓波[1,2] MA Xiong;SHEN Tianci;TIAN Yongjing;HAN Gang;GUI Zhixian;PENG Xiaobo(College of Geophysics and Petroleum Resources,Yangtze University,Wuhan,Hubei 430100,China;Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education,Yangtze University,Wuhan,Hubei 430199,China;CNOOC Research Institute Co.,Ltd,Beijing 100028,China)

机构地区：[1]长江大学地球物理与石油资源学院,湖北武汉430100 [2]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100 [3]中海油研究总院有限责任公司,北京100028

出　　处：《石油地球物理勘探》2024年第6期1315-1329,共15页Oil Geophysical Prospecting

基　　金：中国博士后科学基金第73批面上项目“频率域Q补偿逆时偏移稳定化策略和优化算法研究”(2023M730364);油气资源与勘探技术教育部重点实验室(长江大学)开放基金资助项目(K2023-04);中海石油(中国)有限公司“十四五”重大科技项目“陆上非常规天然气勘探开发关键技术”(KJGG-2022-1001);中海石油(中国)有限公司“七年行动计划”课题“煤储层精细描述与产能主控因素研究(2021OTXNY09)”联合资助。

摘　　要：地震波的吸收衰减和频散均与频率有关,因此,在频率域研究黏声波逆时偏移具有完备的理论基础和明确的物理含义。与时间域黏声波逆时偏移一样,频率域方法在补偿地层吸收衰减时也将不可避免的引起高频噪声放大,造成吸收衰减补偿的不稳定问题,影响偏移算法的稳定性和成像精度。为此,利用Kolsky-Futterman模型在频率域建立黏声波波动方程,并据此实现了一种稳定化的黏声波逆时偏移方法。其实现过程如下:首先,利用Kolsky-Futterman模型推导出频率域的黏声波波动方程,在该方程中振幅衰减和相速度频散是解耦的;然后,基于该方程的解耦特性,利用黏声波波场和仅含频散波场的稳定化比值,构建一种稳定化的吸收衰减补偿算子;最后,利用稳定化的吸收衰减补偿算子对震源正传波场和检波点反传波场分别进行吸收补偿处理,并应用互相关成像条件对地下结构进行黏声波偏移成像。模型实验和实际资料应用表明:该方法在补偿地层吸收的同时,较好地抑制了高频噪声的放大,保证了偏移算法的稳定性和成像精度,改善了成像剖面的质量。The absorption attenuation and dispersion of seismic waves are both related to frequency.Therefore,it is theoretically and physically reasonable to study the viscoacoustic reverse time migration in the frequency domain.Similar to that in the time domain,the method in the frequency domain will inevitably cause the amplification of high-frequency noise while compensating for the absorption attenuation,thus lowering the stability and imaging accuracy of the migration algorithm due to the instable compensation.To solve this problem,we use the Kolsky-Futterman model to derive a viscoacoustic wave equation in the frequency domain,and then achieve a stabilized viscoacoustic reverse time migration.First,we derive the above equation,where the amplitude attenuation is decoupled with the phase velocity dispersion,based on the Kolsky-Futterman model.Then,based on the decoupling characteristics of the equation,we construct a stabilized absorption attenuation compensation operator by utilizing the ratio of the dispersion-only and viscoacoustic wavefields.Finally,we use the stabilized operator to perform absorption attenuation compensation on both source forward wavefields and receiver back-ward wavefields,and further apply the cross-correlation imaging condition to perform the viscoacoustic migration imaging on the underground structure.The experiments and data applications show that the proposed method can effectively suppress the amplification of high-frequency noise while compensating for the absorption,ensuring the stability,imaging accuracy,and quality of the migration algorithm.

关 键 词：地层吸收 Kolsky-Futterman模型 黏声波 黏声波逆时偏移 稳定化 

分 类 号：P631[天文地球—地质矿产勘探]