库车坳陷依南2 “连续型” 致密砂岩气藏成藏临界物性条件

Critical Phyisical Conditions for Accumulation of Yinan 2 “Continuous” Tight Sandstone Gas Reservoir,Kuqa Depression

"连续型"致密砂岩气藏是一种重要的非常规油气资源.恢复储层临界物性条件的演化对于揭示致密砂岩气成藏机理及成藏过程具有重要的理论意义.以库车坳陷依南2"连续型"致密砂岩气藏为例,利用数值模拟方法结合盆地模拟技术,恢复了储层临界物性的演化过程,并根据临界物性条件和储层演化的耦合关系,确定了该地区"连续型"致密砂岩气藏可以成藏的最早时间.研究表明,"连续型"致密砂岩气成藏临界物性并不是固定不变的,它随着地质条件的变化而不断发生改变.依南2"连续型"致密砂岩气藏最早的形成时间为距今9Ma,对应的临界孔隙度为6.95%;现今储层临界孔隙度为7.26%.结合实际地质情况进一步证实了依南2气藏为"连续型"致密砂岩气藏.

It is necessary to reconstruct its evolution of critical physical conditions while researching the formation mechanism and accumulation process of＂Continuous＂tight sandstone gas reservoir since it is one of significant unconventional hydrocarbon resources.Taking Yinan 2 ＂continuous＂ tight sandstone gas reservoir as the study area,the evolution of critical physical conditions is reconstructed with numerical modeling as well as basin model technology.The earliest formation time of＂Continuous＂tight sandstone gas reservoir is determined based on the temporal coupling between critical physical conditions and reservoir evolution.The results show that critical physical conditions of＂Continuous＂tight sandstone gas reservoir are dynamic,changing with the geological settings.As for Yinan 2 ＂continuous＂ tight sandstone gas reservoir,the earliest formation time is about 9 Ma,and the corresponding porosity is about 6.95%.The present critical porosity is about 7.26%.Combined with the geological conditions,it is further confirmed that Yinan 2 gas reservoir is a＂Continuous＂tight sandstone gas reservoir.