Multiwave velocity analysis based on Gaussian beam prestack depth migration  

多波高斯束叠前深度偏移速度分析(英文)

作　　者：韩建光 王赟[3,1] 韩宁[4] 邢占涛[1] 芦俊[5] 

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]中国科学院大学,北京100049 [3]中国科学院地球化学研究所,贵阳550002 [4]西南大学资源环境学院,重庆400716 [5]中国地质大学(北京),北京100083

出　　处：《Applied Geophysics》2014年第2期186-196,253,254,共13页应用地球物理（英文版）

基　　金：supported by the National Special Fund of China(No.2011ZX05035-001-006HZ,2011ZX05008-006-22,2011ZX05049-01-02,and 2011ZX05019-003);the National Natural Science Foundation of China(No.41104084);the PetroChina Innovation Foundation(No.2011D-5006-0303)

摘　　要：Prestack depth migration of multicomponent seismic data improves the imaging accuracy of subsurface complex geological structures. An accurate velocity field is critical to accurate imaging. Gaussian beam migration was used to perform multicomponent migration velocity analysis of PP- and PS-waves. First, PP- and PS-wave Gaussian beam prestack depth migration algorithms that operate on common-offset gathers are presented to extract offsetdomain common-image gathers of PP- and PS-waves. Second, based on the residual moveout equation, the migration velocity fields of P- and S-waves are updated. Depth matching is used to ensure that the depth of the target layers in the PP- and PS-wave migration profiles are consistent, and high-precision P- and S-wave velocities are obtained. Finally, synthetic and field seismic data suggest that the method can be used effectively in multiwave migration velocity analysis.多分量地震资料叠前深度偏移技术可以对地下复杂地质构造进行更准确的成像,精确成像的前提是获取准确的纵横波偏移速度。本文采用高斯束偏移方法对多波地震数据进行偏移速度分析,首先分别给出纵波和转换波共偏移距域高斯束叠前深度偏移方法原理,在此基础上抽取纵波和转换波偏移距域共成像点道集;然后根据共成像点道集拉平准则,分别对纵波和横波速度进行更新;当两种波成像深度不一致时,对纵波和转换波成像剖面进行深度匹配,完成高精度的纵横波偏移速度分析。模型数据和实际资料试算表明,该方法是一种有效的多波偏移速度分析方法。

关 键 词：Gaussian beam migration multiwave migration velocity analysis common-image gathers 

分 类 号：P631.4[天文地球—地质矿产勘探]