面向盐下构造的染色逆时偏移成像  

Staining algorithm-based reverse time migration imaging for pre-salt structures

作　　者：赵国勇 张剑 刘畅[2,3] 任一 邢伯申 李自正 曲英铭 ZHAO Guo-Yong;ZHANG Jian;LIU Chang;REN Yi;XING Bo-Shen;LI Zi-Zheng;QU Ying-Ming(R&D Center of Science and Technology,Sinopec Geophysical Corporation,Nanjing 210005,China;Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;School of Geosciences,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中石化石油工程地球物理有限公司科技研发中心,江苏南京210005 [2]中国石油大学(华东)深层油气全国重点实验室,山东青岛266580 [3]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《物探与化探》2024年第4期1086-1093,共8页Geophysical and Geochemical Exploration

基　　金：国家自然科学基金项目(42174138,42074133);中国石化科技项目(P23176,P22165)。

摘　　要：逆时偏移技术能够精准模拟地震波在地下介质中的传播过程并对地下构造成像,但在弱照明区域,地震波会发生反射、折射、散射等现象,导致逆时偏移成像结果中部分区域信噪比降低。染色算法通过将波动方程推广到复数域,实现针对已知地质体的追踪和成像。在染色算法中,需要输入常规的实部速度场和一个虚部速度场。常规染色算法需要已知真实的地下结构,这不符合实际情况,本文提出区域染色,促进染色算法的实用化发展。本文聚焦盐下成像,提出面向盐下构造的基于染色算法的逆时偏移成像方法。通过盐丘模型证明该方法可以显著提高自选目标区域的成像信噪比与分辨率。The reverse time migration(RTM)technique can accurately simulate the propagation of seismic waves in subsurface media and image subsurface structures.However,seismic waves can be reflected,refracted,or scattered in weakly illuminated areas,leading to locally reduced signal-to-noise ratios(SNRs)in RTM imaging results.The staining algorithm can achieve the tracking and imaging of known geobodies by generalizing the wave equation to the complex domain.It requires a conventional real velocity and an imaginary velocity field as inputs.A conventional staining algorithm requires known real subsurface structures,which is impractical in this study.Hence,this study put forward regional staining to promote the practical development of the staining algorithm.Focusing on subsalt imaging,this study proposed a staining algorithm-based RTM imaging method for subsalt structures.The salt dome model demonstrated that the method proposed in this study can significantly improve the imaging SNRs and resolution of self-selected target regions.

关 键 词：提高照明度 染色算法 逆时偏移 盐下成像 

分 类 号：P631.4[天文地球—地质矿产勘探]