Attenuation compensation in multicomponent Gaussian beam prestack depth migration  

基于吸收衰减补偿的多分量高斯束叠前深度偏移（英文）

作　　者：吴娟[1,2] 陈小宏[1,2] 白敏[1,2] 刘国昌[1,2] 

机构地区：[1]中国石油大学(北京)海洋石油勘探国家工程实验室,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249

出　　处：《Applied Geophysics》2015年第2期157-168,273,274,共14页应用地球物理（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.U1262207);the National Science and Technology Major Project of China(Nos.2011 ZX05023-005-005 and 2011 ZX05019-006);the PetroChina Innovation Foundation(No.2013D-5006-0303)

摘　　要：Gaussian beam prestack depth migration is an accurate imaging method of subsurface media. Prestack depth migration of multicomponent seismic data improves the accuracy of imaging subsurface complex geological structures. Viscoelastic prestack depth migration is of practical significance because it considers the viscosity of the subsurface media. We use Gaussian beam migration to compensate for the attenuation in multicomponent seismic data. First, we use the Gaussian beam method to simulate the wave propagation in a viscoelastic medium and introduce the complex velocity Q-related and exact viscoelastic Zoeppritz equation. Second, we discuss PP- and PS-wave Gaussian beam prestack depth migration algorithms for common-shot gathers to derive expressions for the attenuation and compensation. The algorithms correct the amplitude attenuation and phase distortion caused by Q, and realize multicomponent Gaussian beam prestack depth migration based on the attenuation compensation and account for the effect of inaccurate Q on migration. Numerical modeling suggests that the imaging resolution of viscoelastic Gaussian beam prestack depth migration is high when the viscosity of the subsurface is considered.高斯束叠前深度偏移是对地下介质进行精确成像的方法之一,多分量地震资料的叠前深度偏移技术可以对复杂构造进行更准确的成像。由于实际地下介质具有粘滞性,研究粘弹性叠前深度偏移具有一定的现实意义。本文采用高斯束偏移方法对多分量地震数据进行吸收衰减补偿,首先利用高斯束模拟粘弹性介质中传播的地震波,并在模拟中引入与品质因子Q有关的复速度和精确的粘弹性Zoeppritz方程,合成地震记录;然后给出纵波和转换波共炮域高斯束叠前深度偏移原理,在此基础上推导补偿吸收衰减的表达式,校正Q引起的振幅衰减和相位畸变,实现基于吸收衰减补偿的多分量高斯束叠前深度偏移,并分析Q误差对偏移结果的影响。数值实验表明,在考虑地下介质的粘滞性时,本文方法具有更高的成像分辨率。

关 键 词：Attenuation compensation MULTICOMPONENT Gaussian beam viscoelastic simulation prestack depth migration 

分 类 号：P631.44[天文地球—地质矿产勘探]