活动断层地震勘探中的高精度偏移与反偏移技术  

High-accuracy migration and demigration techniques for active fault seismic exploration

作　　者：张扬 李稳[2,4] Zhang Yang;Li Wen(Institute of Geology,China Earthquake Administration,Beijing 100029,China;Geophysical Exploration Center,China Earthquake Administration,Zhengzhou 450002,China;Henan Earthquake Agency,Zhengzhou 450016,China;School of Earth Sciences and Engineering,Nanjing University,Nanjing 210008,China;State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China;Shanxi Taiyuan Continental Rift Dynamics National Observation and Research Station,Beijing 100029,China.)

机构地区：[1]中国地震局地质研究所,北京100029 [2]中国地震局地球物理勘探中心,郑州450002 [3]河南省地震局,郑州454016 [4]南京大学地球科学与工程学院,南京210023 [5]中国地震局地质研究所地震动力学国家重点实验室,北京100029 [6]山西太原大陆裂谷动力学国家野外科学观测研究站,太原030025

出　　处：《Applied Geophysics》2023年第2期198-208,241,242,共13页应用地球物理（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.62175100);Spark Program of Earthquake Sciences of CEA(No.XH22015A);Henan Province Seismic Structure Exploration project(YCZC-2020-950);Special Fund of Chinese Central Government for Basic Scientific Research Operations in Commonweal Research Institutes(No.IGCEA1902)。

摘　　要：为了进一步发展活动断层空间位置和精细结构探查技术,解决在活动断层探测地震数据处理过程中,缺少一种通过数学手段对地震成像结果进行可靠性评价的问题,开展了将‘反偏移’这一地震波偏移成像的逆运算引入活动断层探测地震数据处理的研究。分析了偏移与反偏移的关系,提出了以叠前深度域逆时偏移和波动方程反偏移为核心的主动源地震勘探数据高精度处理流程。选择了生长断层、花状构造等有代表性的复杂断裂构造实际探测数据进行处理。处理结果表明,利用本文提出的以波动方程逆时偏移和反偏移为核心的地震数据处理流程,能够有效提高活动断层地震成像剖面的可靠性和精确度。通过本次研究可以认为将偏移和反偏移这一对严格对应的地震数据处理算子引入活动断层探测领域,有助于推动活动断层探测精确度和分辨力的提升。尤其是在开展钻孔联合地质剖面探测或科学钻探研究时,应用本文方法进行地震勘探数据高精度成像处理,利用多种数学手段相互检验,能够有效确保断层上断点定位准确,节约钻探成本。Developing a mathematical method for evaluating the reliability of imaging results in seismic data processing is essential for further advancing methods for active fault exploration based on accurately locating the spatial position and fine structures of faults.This study introduces demigration—a technique that is the inverse of seismic wave migration—into seismic data processing for active fault exploration.By analyzing the relationship between migration and demigration,a high-precision flow for the processing of active source seismic exploration data is proposed.This flow involves prestack depth-domain reverse time migration and wave equation-based demigration.This study focuses on processing the exploration data of complex fault structures,such as growth faults and flower structures.Processing results demonstrate that the proposed processing flow for seismic data effectively enhances the accuracy and reliability of the seismic imaging profiles of active faults.The introduction of seismic data processing operators for migration and demigration(which are inverse operations)into the field of active fault seismic exploration is expected to improve the accuracy and resolution of results considerably.The proposed technique can be used for the high-precision imaging of seismic data before joint geological drilling or other scientific drilling research.By combining multiple mathematical means for cross-checking,it can effectively ensure the positioning accuracy of the uppermost point of a fault,thereby reducing corresponding drilling costs.

关 键 词：活动断层地震勘探 叠前深度偏移 反偏移 地震 波速度建模 主动源地震成像 

分 类 号：P631.4[天文地球—地质矿产勘探]