应用非线性KNN数据搜索的三维叠前自由表面多次波预测  

Three dimension pre⁃stack surface⁃related multiple prediction based on nonlinear KNN algorithm for data search

作　　者：谢飞 朱成宏[1,2,3] 高鸿 徐蔚亚[1,2,3] XIE Fei;ZHU Chenghong;GAO Hong;XU Weiya(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 102206,China;SINOPEC Key Laboratory of Seismic Elastic Wave Technology,Beijing 102206,China;SINOPEC Petroleum Exploration and Production Research Institute,Beijing 102206,China)

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室,北京102206 [2]中国石化弹性波理论与探测技术重点实验室,北京102206 [3]中国石化石油勘探开发研究院,北京102206

出　　处：《石油地球物理勘探》2024年第3期424-432,共9页Oil Geophysical Prospecting

基　　金：国家重点研发计划项目“高分辨率地震实时成像理论与技术”之课题“高分辨率地震成像软件系统开发及应用”(2018YFA0702505);中国石油化工股份公司科技攻关项目“π平台层间多次波压制与成像技术研发集成”(P24124)联合资助。

摘　　要：自由表面多次波预测(SRMP)是自由表面多次波消除(SRME)以及成像的重要环节。SRME技术尽管有效,但理论上需要规则而密集的地震数据采集方式。然而实际炮点、检波点空间分布稀疏,地震数据不能满足SRME理论要求,常规的做法是在SRME之前将地震数据规则化。为了避免数据规则化环节,首先建立索引数据树管理三维叠前地震数据,并采用基于树形数据结构的非线性K近邻算法(KNN)从地震数据中实时搜索两道近似地震数据;然后利用动校—反动校消除实时搜索得到的近似地震道与实际地震道之间的旅行时误差;由以上两步获得单道孔径内任意向下反射点(DRP)所需要的两道地震数据用于SRMP。单道孔径内任意DRP均可由SRMP预测对应的多次波模型道,叠加所有DRP对应的预测结果可获得该道稳定的多次波模型数据。将该方法用于扩展的三维Pluto模型数据,结果表明该方法能有效预测三维自由表面多次波,从而保证高质量的自由表面多次波衰减结果。实际地震数据的应用证明了方法的实用性。Surface-related multiple prediction(SRMP)is an important part of surface-related multiple elimina-tion(SRME)and imaging.Although SRME technology is effective,it requires a regular and dense seismic data acquisition in theory.However,the spatial distribution of actual shot points and receiver points is sparse,and the seismic data fails to meet the requirements of SRME.The conventional method is to regularize seismic data before SRME.To avoiding the pre-SRME data interpolation,3D pre-stack data has been organized by a K-dimensional index data tree,then a nonlinear K-nearest neighbor(KNN)algorithm comprehensively utilizes spa-tial location coordinates of sources and receivers,offset,azimuth to search from field data an approximate trace in real time,which is closest to an ideal trace.After that,a partial normal move-out correction is used to correct travel time difference because of the offset difference between the approximate trace and the ideal trace.Through the above two steps,the two seismic traces related with any downward reflection point(DRP)in the aperture of a single trace can be obtained and be used in SRMP.By convolution the two traces and stacking the results of all DRPs in the aperture of a single trace,a stable multiple model for that trace can be obtained.The method has been proven effective by testing on synthetic data of a modified 3D Pluto model and field seismic data in Northwest China.

关 键 词：自由表面多次波 预测 消除 索引数据树 非线性K近邻(KNN)算法 

分 类 号：P631[天文地球—地质矿产勘探]