Analysis and application of pseudo-offset method in the converted-wave prestack time migration  

作　　者：Zhang Liyan Liu Yang 

机构地区：[1]CNPC Key Lab of Geophysical Exploration, ina University of Petroleum, Beijing 102249.

出　　处：《Applied Geophysics》2006年第1期18-26,共9页应用地球物理（英文版）

基　　金：This work is sponsored by the Nation's Key Scientific & Technologic Projects (2003 BA613-09).

摘　　要：Pseudo-offset migration （POM） is a new method for prestack time migration of converted waves that improves on equivalent-offset migration （EOM）. The mapping of POM is different than EOM but the purpose of the two methods is to map the input samples to the common conversion scatter point （CCSP） gathers. This paper introduces the principles of the two migration methods and model parameter sensitivity tests for both POM and EOM. At large offset-to-depth ratios the hyperbolic approximation, the three-term approximation and the double square root （DSR） equation are used to NMO-correct the mapped POM gathers to obtain more accurate migration velocities. These equations were derived and calculated by small pseudo offset. POM is then used to image complex structure and prestack time migration.伪偏移量移植(POM ) 是为在相等偏移量的移植(EOM ) 上改善的变换波浪的 prestack 时间移植的一个新方法。印射 POM 比 EOM 不同，但是二个方法的目的是印射到普通变换的样品散布的输入点(CCSP ) 集合。这篇论文为 POM 和 EOM 介绍二个迁居方法和模型参数敏感测试的原则。逍遥法外 offset-to-depth 比率夸张近似，三术语的近似和双方形的根(数据设置就绪) 方程习惯于 NMO 正确获得更精确的迁居速度的印射的 POM 集合。这些方程被小假偏移量导出并且计算。POM 然后习惯于图象建筑群结构和 prestack 时间移植。

关 键 词：converted-wave Pseudo-offset migration equivalent-offset migration time migration NMO correction. 

分 类 号：P631.4[天文地球—地质矿产勘探]