Kirchhoff 叠前偏移在天然气水合物准三维地震资料处理中的应用

在针对天然气水合物的准三维地震资料处理中，由于受观测系统不规则、横向覆盖次数变化剧烈以及空间假频的影响，叠后偏移难以取得良好的效果。本研究从目前天然气水合物准三维地震资料偏移成像研究现状入手，总结了叠后偏移成像存在的问题，对比分析了Kirchhoff叠前偏移和波动方程叠前偏移的原理和特点，认为Kirchhoff积分法受观测系统不规则和横向覆盖次数变化剧烈的影响较小，适合于天然气水合物准三维地震资料叠前偏移处理。并将Kirchhoff积分法叠前偏移应用到南海北部神狐海域天然气水合物准三维地震资料处理中，同叠后偏移处理相比，Kirchhoff叠前偏移处理获得了更好的效果。

Application of Kirchhoff Prestack Migration Technology on Interpretation of Quasi Three Dimensional Seismic Data of Gas Hydrate

In the course of processing quasi three dimensional seismic data of gas hydrate,the effect of poststack migration is unsatisfactory resulting from the influences of the irregularity of geometry,intense changes of folds and spatial aliasing.This paper studied the present development status of migration imaging on interpretation of quasi three dimensional seismic data of gas hydrate,and concluded the problems of poststack migration and analyzed the characteristics of main prestack migration algorithms.It is believed that Kirchhoff integral method is little effected by the irregularity of geometry and intense changes of velocity and is favorable to prestack migration processing of quasi three dimensional seismic data of gas hydrate.Kirchhoff integral method prestack migration was applied to process the quasi three dimensional seismic data collected in Shenhu area in northern South China Sea and obtained better effect than poststack migration.