叠前时间偏移技术在四川綦江页岩气地震勘探中的应用

Application of the pre-stack time migration in the shale gas seismic exploration in Qijiang area in Sichuan Basin

四川盆地綦江地区页岩油气资源丰富,但构造非常复杂。本文详细分析了Kirchhoff积分法叠前时间偏移处理中关键技术参数(偏移孔径、偏移倾角、偏移距分组等)对复杂构造成像的影响;进行叠前时间偏移和叠后时间偏移的对比。分析表明,叠前时间偏移处理结果包含了更加丰富的地震信息,深层复杂构造成像、断层及断点空间位置更加合理,能够较好地落实构造,反映其不整合及各种不同沉积结构的地质现象。

It is rich in the shale oil and gas in the Qijiang area of Sichuan basin, but the structures are very complicated。The affect of the key technical parameters（migration aperture, migration angle, offset grouping, etc）in the pre- stack time migration processing of the Kirchhoff integral method on the imaging of the complex structure are analyzed, and the pre-stack time migration and post-stack time migration are compared. It shows that results of the pre- stack time migration include richer seismic information, the imaging of the deep complex structure and spatial locations of fault and breakpoint are more rational, the structures are confirmed better, the geological phenomenas（such as the unconformity, kinds of deposition texture） are could be reflected.