夏口断层封闭性及对油气成藏的控制作用模式

惠民凹陷西部的临南洼陷是该凹陷的主要生烃中心，其南侧的夏口断层的封闭性控制了临南地区的油气运移方向和油气藏分布。影响夏口断层封闭性的主要因素是其活动性、断面特征和断移地层的泥地比，通过夏口断层的断面形态成图和断层泥涂抹系数计算，定量评价其封闭能力，认为其东段、西段封闭性好于中段，东段封闭性又好于西段。据此认为，位于该断层西段的临南油田油气藏的形成有赖于断面阻隔了油气继续向临南斜坡运移，而位于该断层中段的曲堤油田的形成是因为断面不封闭，成为来自临南洼陷的油气运移至断层上盘断块圈闭成藏的输导通道。图4表3参9

The sealing of Xiakou fault and its model of controlling on the petroleum accumulation

Linnan Sub sag, located in the west of Huimin Sag, is the main hydrocarbon generation center of the sag. The sealing of Xiakou fault in the southern sag controlled the migration of hydrocarbon and the reservoirs distribution. The sealing of the Xiakou fault is related to its activity, status of fault surface and the shale gouge ratio. Based on the fault section figures and the calculation of shale smear factor of the Xiakou fault, its sealing was evaluated, which shows that the sealing condition of the fault is better in the east and the west then in the medium, and is better in the east than in the west of the fault. The formation of Linnan oilfield depends on that the fault obstructed the oil to migrate to Linnan slope. However, the Qudi oilfield formed because of the fault's unsealing, and the fault became migration pathway for oil from Linnan Sub sag to the upper side of the fault.