走滑断层作用对南堡凹陷油气成藏的控制

Control of strike-slip faulting on reservoir formation of oil and gas in Nanpu sag

综合利用地震、重力、钻井等资料,对南堡凹陷柏各庄断裂和西南庄断裂进行重新认识,分析构造变形对南堡凹陷油气成藏的控制作用。柏各庄断裂和西南庄断裂在深部合并成一条基底断裂(柏各庄—西南庄断裂),具走滑断裂性质,该基底断裂在燕山期发生明显的左行走滑并持续到古近纪沙河街组沉积期,对沙河街组沉积有明显的控制作用。南堡凹陷古近纪成盆演化主要受柏各庄—西南庄基底断裂左行走滑活动控制,属于走滑-伸展凹陷。新近纪以来的断层走滑活动,形成了北东向和北西向两组共轭剪切走滑断层带,控制了二级构造带的展布。南堡凹陷油气大量成藏期与新近纪以来的断层活动期相吻合,利于油气运移及圈闭的形成,油气沿断裂带纵向多层系分布。

According to the data of seism, gravity, drilling, etc, this paper reexamines the Baigezhuang fracture and the Xi＇nanzhuang fracture and analyzes the control of structural deformation on the hydrocarbon accumulation in the Nanpu sag. The Baigezhuang and Xi＇nanzhuang fractures merged into a base strike slip fracture which had distinct left strike-slip at the Yanshan stage lasting until the Es stage and controlled on the Es deposition. The Paleogene basin-forming in the Nanpu sag was controlled by the left strike-slip Baigezhuang Xi＇nanzhuang base fracture and the Nanpu sag was a strike-slip stretching sag. The NE and NW strike-slip fault belts with conjugate shearing were formed by the Neogene fault strike slipping and controlled the distribution of secondary structural belts. The substantial hydrocarbon accumulation in the Nanpu sag has matched in time with the Neogene fault movement, which is favorable to oil and gas migration and trap formation, so the oil and gas are distributed vertically along fault belts as muhiple layers.