基于照明补偿的单程波最小二乘偏移  

One-way wave equation least-squares migration based on illumination compensation

作　　者：周华敏[1] 陈生昌[1] 任浩然[1] 王汉闯[1] 陈国新[1] 

机构地区：[1]浙江大学地球科学系,杭州310027

出　　处：《地球物理学报》2014年第8期2644-2655,共12页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41074133;41304089;41374001);中国石化地球物理重点实验室开放基金项目资助

摘　　要：最小二乘偏移是一种基于反射地震数据与地下反射率间线性关系而建立起来的地震数据线性反演方法,相比常规偏移成像具有更好的保幅性能.本文提出了一种基于照明补偿的单程波最小二乘偏移方法,首先利用单程波方程的稳定Born近似广义屏波场传播算子构建反射地震数据与地下反射率间的线性算子,然后再应用线性最优化方法求解最小二乘偏移所对应的线性反问题.在迭代求解最优化问题的过程中,以地震波场的地下照明强度作为迭代反演的预条件算子加快迭代的收敛速度.单程波传播过程中考虑了速度分界面产生的透射效应,并用单极震源代替常规偏移中的偶极震源.把本文提出的方法应用于层状理论模型和Marmosi模型地震数据的数值试验中均取得了理想的结果.Least-squares migration is a linear seismic inversion method which is established based on the linear relationship between seismic reflection data and underground reflection. Compared with conventional imaging technique, it has better performance in preserving amplitude. This paper presents a one-way wave equation least-squares migration based on illumination compensation. Firstly, we use the stable Born approximation generalized screen one-way wave field propagator to construct the linear operator between reflected seismic data and underground reflection. Then we use the linear optimization method to solve the linear inverse problem of the least-squares migration. In the process of solving the optimization problems iteratively, we use the seismic wave illumination as a preconditioned operator of the iterative inversion, so as to accelerate the convergence speed of iteration. During the one-way wave propagation, we consider the transmission effect arising from velocity interface, and substitute monopole source for dipole source in conventional migration. Applying the method proposed in this paper to the layered theoretical model and the Marmosi model has achieved ideal results.

关 键 词：单程波 最小二乘偏移 照明强度 广义屏 振幅均衡性 

分 类 号：P631[天文地球—地质矿产勘探]