沙南凹陷新生代断裂发育特征及控藏作用

为明确沙南凹陷新生代断裂活动特征以及对油气富集的控制作用,利用高精度三维地震资料及钻井资料,对研究区主要断裂的几何学特征、运动学特征开展研究,并对断裂活动对烃源岩、储层、圈闭及油气运移的控制作用进行了探讨。结果认为：研究区断裂可划分为三级及上、下两套断裂系统,孔店组~沙三段沉积期、东营组沉积期是断裂活动高峰期;高活动速率主要同沉积断层下降盘为优质烃源岩发育区,凹陷北侧不同类型断层边界决定了多种类型砂体发育模式,断裂作用控制了构造及岩性圈闭的形成,断裂及断裂砂体耦合是研究区主要的油气运移通道;发育凹陷内部中央隆起区南北两侧“断控”双通道近源成藏、凹陷北侧陡坡带“断-砂耦合”阶梯状网毯输导远源成藏、凹陷斜坡下部“断控”前缘砂体源内成藏三种断裂控藏模式;凹陷北侧深层岩性圈闭、凹陷北侧陡坡带中浅部构造圈闭是后续有利勘探方向。

Fault development characteristics of Cenozoicand its controlling effect on hydrocarbon accumulations in Shanan sag

In order to clarify the features of Cenozoic fault activity and its control on hydrocarbon enrichment in Shanan Sag, the geometric and kinematic characteristics of the main faults in the study area were studied by using high-precision 3D seismic data and drilling data. In addition, discussions were also conducted on the control of fault development on source rocks, reservoirs, traps and hydrocarbon migration. The results show that the faults in the study area can be divided into three levels horizontally and two systems vertically, and the deposition period of Kongdian Formation to the third member of the Shahejie Formation and the deposition period of the Dongying Formation are the peak periods of fault activity. Excellent source rocks are often found in the footwall area of high activity rate synsedimentary faults, and various sand body development modes are controlled by different types of fault boundaries on the north side of the sag. The formation of structural and lithologic traps are controlled by faults, and both faults and sand bodies are the main hydrocarbon migration pathways in the study area. There are three types of fault-controlled accumulation modes: (1) near-source accumulation with "fault-controlled" double pathways on the north and south sides of the central uplift area in the sag, (2) remote-source accumulation with "fault-sand body coupling" ladder-shaped meshwork-carpet conduction in the steep slope on the north side of the sag, (3) interior-source accumulation with "fault controlled" front sand body in the lower part of the sag slope. Deep lithologic traps in the north of the sag and structural traps in the middle and shallow part of the steep slope zone in the north of the sag are favorable exploration targets in the future.