High angle prestack depth migration with absorption compensation  

补偿吸收衰减的高角度叠前深度偏移方法(英文)

作　　者：周辉[1,2,3] 林鹤 盛善波[1,2,3] 王颖 

机构地区：[1]油气资源与探测国家重点实验室 [2]CNPC物探重点实验室 [3]中国石油大学(北京),北京102249

出　　处：《Applied Geophysics》2012年第3期293-300,360,361,共10页应用地球物理（英文版）

基　　金：supported in part by the National Natural Science Foundation of China(No.40974069,41174119);the Research of Novel Method and Technology of Geophysical Prospecting,CNPC(No.2011A-3602);the National Major Science and Technology Program(No.2011ZX05010,2011ZX05024)

摘　　要：The absorption effect of actual subsurface media can weaken wavefield energy, decrease the dominating frequency, and further lead to reduced resolution. In migration, some actions can be taken to compensate for the absorption effect and enhance the resolution. In this paper, we derive a one-way wave equation with an attenuation term based on the time- space domain high angle one-way wave equation. A complicated geological model is then designed and synthetic shot gathers are simulated with acoustic wave equations without and with an absorbing term. The derived one-way wave equation is applied to the migration of the synthetic gathers without and with attenuation compensation for the simulated shot gathers. Three migration profiles are obtained. The first and second profiles are from the shot gathers without and with attenuation using the migration method without compensation, the third one is from the shot gathers with attenuation using the migration method with compensation. The first and third profiles are almost the same, and the second profile is different from the others below the absorptive layers. The amplitudes of the interfaces below the absorptive layers are weak because of their absorption. This method is also applied to field data. It is concluded from the migration examples that the migration method discussed in this paper is feasible.实际介质的吸收衰减使地震波能量减弱,主频降低,影响分辨率。在偏移过程中,可以实现吸收衰减的补偿,提高地震资料的分辨率。本文基于高角度时间-空间域单程波方程,推导出能补偿介质吸收衰减的叠前深度偏移波场外推公式。设计了一个复杂构造的地质模型,用声波方程模拟了无吸收衰减和有吸收衰减介质存在时的两种地震炮集记录。用没有补偿吸收衰减和本文讨论的补偿吸收衰减的偏移方法分别处理了两种地震资料,得到无吸收衰减、吸收衰减未得到补偿和得到补偿的三个偏移叠加剖面。补偿后的偏移剖面与没有吸收衰减的地震记录的偏移剖面几乎相同,而有吸收衰减的地震记录用无吸收衰减补偿的偏移方法处理,由于介质的吸收衰减,使吸收衰减层下方的反射信号衰减,主频降低,能量减弱。实际资料的处理结果表明,补偿吸收的偏移剖面的分辨率得到了明显改善。

关 键 词：one-way wave equation prestack depth migration absorption compensation time-space domain 

分 类 号：P631.4[天文地球—地质矿产勘探]