塔里木盆地寒武系—奥陶系层序格架中生储盖组合特征与勘探意义

Characteristics of the petroleum system in Cambrian and Ordovician sequence frameworks of the Tarim Basin and its exploration significance

塔里木盆地在早古生代属于不同类型克拉通盆地沉积,构造运动和海平面升降是控制寒武系—奥陶系层序地层发育的主要因素。综合露头、岩心、测井以及地震资料,并结合井—震标定结果,在塔里木盆地寒武系—奥陶系识别出15个层序界面,将寒武系划分为6个层序、奥陶系划分为8个层序。根据层序地层发育特征,并考虑断层和不整合面在油气运聚成藏中的重要作用,将塔里木盆地寒武系—奥陶系层序格架中生储盖组合划分为连续型、间断型和复合型3大类8小类。现实的生储盖组合包括侧变式连续型和间断型,潜在的生储盖组合包括上生中储上盖连续型和复合型,值得探索的生储盖组合包括下生中储上盖连续型和封闭式连续型。

In Early Paleozoic,the Tarim Basin was a craton basin with diverse deposits,where tectonic movements and eustatic sea-level changes dominated the development of Cambrian and Ordovician sequence formations.Integrated with outcrop,core,well logging and seismic data,we identified 15 sequence interfaces in the Cambrian and Ordovician of the Tarim Basin and divided the Cambrian into 6 sequence formations and the Ordovician into 8 sequence formations.Based on characteristics of these sequence formations and in view of the importance of faults and unconformity interfaces in hydrocarbon migration and accumulation,petroleum systems of Cambrian and Ordovician sequence frameworks in the Tarim Basin were divided into three different types,the continuous,discontinuous and complex.In practice,the exploration of petroleum systems includes continuous or discontinuous source-reservoir-cap rock combinations with lateral changes and the exploration of potential source-reservoir-cap rock combinations encompasses also continuous or complex source-reservoir-cap rock combinations characterized by an upper source-middle reservoir-upper seal play.It is worth exploring continuous or enclosed-continuous source-reservoir-cap rock combinations characterized by a lower source-middle reservoir-upper seal play.