Migration scheme for imaging offset VSP data within local phase space  

局域化相空间中的VSP偏移成像方法(英文)

作　　者：周艳辉[1] 高静怀[1] 王保利[1] 何洋洋[1] 

机构地区：[1]西安交通大学电子与信息工程学院波动与信息研究所,陕西西安710049

出　　处：《Applied Geophysics》2010年第1期31-40,99,共11页应用地球物理（英文版）

基　　金：supported by the National Hi-Tech Research and Development Program of China (Grant No.2006AA09A102-11);the National Natural Science Fund of China (Grant No.40730424 and 40674064)

摘　　要：The imaging of offset VSP data in local phase space can improve the image of the subsurface structure near the well.In this paper,we present a migration scheme for imaging VSP data in a local phase space,which uses the Gabor-Daubechies tight framebased extrapolator（G-D extrapolator） and its high-frequency asymptotic expansion to extrapolate wavefields and also delineates an improved correlation imaging condition in the local angle domain.The results for migrating synthetic and real VSP data demonstrate that the application of the high-frequency G-D extrapolator asymptotic expansion can effectively decrease computational complexity.The local angle domain correlation imaging condition can be used to weaken migration artifacts without increasing computation.对VSP资料进行偏移成像可提高井附近地下结构的成像分辨率。本文给出了一种基于局域化相空间波场分解的VSP偏移成像方法。此方法采用了基于Gabor-Daubechies紧标架的延拓算子(G-D延拓算子)及其高频渐近形式对相空间波场进行延拓;基于局部平面假设,提出了一种局部角度域相关成像条件。合成和实际VSP资料的偏移成像结果表明,在满足渐近展开的条件下利用G-D延拓算子的高频近似式能够有效的减少计算时间;采用局部角度域相关成像条件能够在不增加计算量的同时,有效减弱VSP成像剖面上的偏移假象。

关 键 词：VSP data Gabor-Daubechies tight frame high-frequency asymptotic expansion imaging condition migration artifact 

分 类 号：P631.4[天文地球—地质矿产勘探]