地震散射偏移方法  

Seismic scatterring data migration based on scattering wave equation

作　　者：胡自多[1] 雍学善[1] 刘威[1] 陈生昌[2] 王艳香[1] HU Ziduo;YONG Xueshan;LIU Wei;CHEN Shengchang;WANG Yanxiang(Northwest Branch,Research Institute of Petroleum Exploration&Development,PetroChina,Lanzhou,Gansu 730020,China;School of Earth Sciences,Zhejiang University,Hangzhou,Zhejiang 310027,China)

机构地区：[1]中国石油勘探开发研究院西北分院,甘肃兰州730020 [2]浙江大学地球科学学院,浙江杭州310027

出　　处：《石油地球物理勘探》2020年第3期584-590,470-471,共9页Oil Geophysical Prospecting

基　　金：国家自然科学基金项目“地震数据的波形偏移方法理论研究”(41874133);“基于压缩感知的地球物理数据高效采集方法理论研究”(41374001);“基于反演理论的保幅偏移成像方法研究”(41074133);国家重点研发计划项目“面向E级计算的能源勘探高性能应用软件系统与示范”(2017YFB0202905)联合资助

摘　　要：现有的地震数据逆时偏移方法不区分散射数据与反射数据,成像公式是基于反射波传播概念建立的。从波动方程的扰动形式出发,根据地下非均匀体大小与波长之间的关系定义产生散射波的散射体和产生反射波的反射体,建立一次散射波数据的线性正演方程;然后利用线性反演理论推导出对散射体空间位置进行成像的地震散射数据偏移计算公式;应用Sigbee2A模型数据验证文中所提出的散射数据偏移方法。由理论和数值试验可知,对于散射数据的偏移成像,相较于基于反射概念建立的常规逆时偏移,所提出的散射数据偏移方法可以得到相位正确和分辨率更高的偏移结果。Present reverse time migration methods don’t distinguish scattering data from reflection data,and the imaging formula is established with the concept of reflected wave propagation.In this study,starting from the perturbation form of wave equation,we defined the scatterer generating scattering wave and the reflector generating reflected wave according to the relationship between the size of a underground heterogeneous body and the wavelength of seismic wave,and formulated a linear forward equation of primary scattering data,then derived the formula of calculating seismic reverse time migration on the spatial scattering location by the linear inverse theory,and finally tested the method on Sigbee2 A model data.Theory and numerical test have demonstrated that the scattering data migration method can provide migration results with more correct phase and higher resolution than those from the conventional reverse time migration method based on the concept of reflection.

关 键 词：散射体 地震散射数据 正演方程 线性反演 偏移 

分 类 号：P631.4[天文地球—地质矿产勘探]