塔里木盆地走滑断裂分段性及控藏作用——以F_(Ⅰ)17断裂带为例

Segmentation of Strike-Slip Faults and Its Controls on Hydrocarbon Accumulation in Tarim Basin:A Case Study of F_(Ⅰ)17 Strike-Slip Fault Zone

塔里木盆地奥陶系碳酸盐岩发育走滑断裂断控特大型油气田,但沿走滑断裂带碳酸盐岩储集层与油气分布异常复杂,制约了井位部署与油气高效开发。以富油气F_(Ⅰ)17走滑断裂带为例,利用高精度地震资料,对F_(Ⅰ)17走滑断裂带开展精细构造解析,结合岩心、测井及生产资料分析,对其储集层分布及控藏特征进行研究。结果表明:F_(Ⅰ)17走滑断裂带从南至北依次可划分为平行雁列段、线性段、叠覆段、斜列叠覆段和马尾段5个区段;走滑断裂的分布、规模与类型控制了储集层分布与发育程度,从平行雁列段至斜列叠覆段断裂发育强度增大,储集层规模增大且连通性变好,北部马尾段储集层沿分支断裂分布,连通性差;F_(Ⅰ)17走滑断裂带断控油气藏可划分为线性定容型、连接叠覆型、叠覆断垒型和尾段分散型4类;走滑断裂的类型与规模控制了油气藏类型与油气富集程度,针对不同类型的断控油气藏,需要采取不同的钻探措施。

In the Ordovician carbonate rocks in the Tarim basin,there are extra-large oil and gas oilfields controlled by strike-slip faults.However,the distributions of carbonate reservoirs and hydrocarbons along the fault zones is extraordinarily complex,posing challenges for well deployment and efficient petroleum development.Taking the F_(Ⅰ)17 hydrocarbon-rich strike-slip fault zone as an example,a fine structural analysis was conducted by using high-resolution seismic data.Coupling with core,logging and production data,the reservoir distribution and its controls on hydrocarbon accumulation were investigated.The results show that the F_(Ⅰ)17 strike-slip fault zone can be divided into five segments from south to north:parallel en echelon segment,linear segment,superimposed segment,oblique superimposed segment,and horse-tail segment.The distribution,scale,and type of strike-slip faults govern the reservoir distribution and development.From the parallel en echelon segment to the oblique superimposed segment,the fault development intensifies,resulting in larger and more interconnected reservoirs.Conversely,the horse-tail segment in the north features reservoirs distributed along branch faults with poor connectivity.The fault-controlled hydrocarbon reservoirs in the F_(Ⅰ)17 strike-slip fault zone can be classified into four types:linear fixed-volume,connected superimposed,superimposed fault-block,and tail-end dispersed.The type and scale of strike-slip faults control the reservoir types and hydrocarbon enrichment levels,necessitating targeted drilling strategies for different fault-controlled reservoir types.