地震勘探技术在南川地区页岩气勘探开发中的应用

Application of seismic exploration technology in shale gas exploration and development in Nanchuan area

针对南川探区地表地下“双复杂”的地质特点,通过地震资料采集、处理及解释技术攻关,探索形成了一套较为完整的页岩气地球物理勘探思路及技术流程,在南川地区页岩气勘探开发中取得了成功的应用效果。采集方面,通过实时优化激发点位,提高灰岩出露区、溶洞及采空区的地震资料品质;处理方面,采用复杂山地高精度静校正技术、溶洞及采空区针对性处理技术及各向异性叠前偏移成像技术,提高成像效果;解释方面,在精细构造解释基础上,从页岩气的富集性、储层的可改造性以及储层的驱动性三个维度开展页岩储层“甜点”预测,并在页岩气开发过程中,通过动态靶点埋深预测技术和水平井地层倾角预测技术,指导水平井钻探。

Considering of the“Multi-Complex”geological characteristics of the surface and underground in the Nanchuan District,a set of relatively complete ideas and technical processes for shale gas geophysics exploration have been explored through technical research on seismic data acquisition,processing and interpretation.And it has been successfully applied in shale gas exploration and development in Nanchuan District,including three aspects:(1)In terms of acquisition,the quality of seismic data in limestone outcrops,karst caves and mined-out areas can be improved through real-time optimization of excitation points;(2)In terms of processing,in order to improve the imaging effect,high-precision static correction technique in complex mountainous areas,the targeted processing technique in karst cave and goaf,and the Anisotropic Pre-Stack Migration Imaging technique are adopted;(3)In terms of interpretation,on the basis of fine structure interpretation,the“sweet spot”prediction of shale reservoir is carried out from three dimensions:the enrichment of shale gas,the remodelling of reservoir and the driving of reservoir.,and in the process of developing shale gas,horizontal well drilling is guided by prediction technology of dynamic target buried depth and formation dip prediction technique for horizontal wells.