渤中凹陷西次洼断裂演化特征及控藏作用

渤中凹陷西次洼位于渤海西部海域,勘探程度相对较低,受区域应力影响,断裂特征复杂多样。为了搞清研究区断裂的发育规律及其控藏作用,利用新三维地震资料,并结合勘探实践,在不同时期形成断裂划分及特征分析的基础上,对断裂的成因演化及断裂对油气成藏的控制作用进行了探讨。研究结果表明:渤中凹陷西次洼的断裂演化阶段可以划分为早期基底断裂左旋走滑阶段、古近纪伸展作用阶段和新近纪—第四纪(新构造运动时期)双向走滑作用阶段。断裂的形成和演化控制了沉积体系的发育,形成了多种类型圈闭,为油气垂向运移提供了主要的运移通道。研究成果对该区目标优选及油气勘探评价具有指导意义。

EVOLUTION CHARACTERISTICS AND THEIR CONTROLLING ACTIONS ON THE HYDROCARBON ACCUMULATION FOR THE FAULTS IN WEST SUBSAG OF BOZHONG SAG

West Subsag in Bozhong Sag is located in West Bohai,which is characterized by relatively lower exploration degree.Influenced by the regional stress,the fault characteristics are complex and diversified.In order to make clear of the development laws and controlling actions of the faults on the hydrocarbon accumulation in the study area,with the help of the new 3D seismic data and combined with the exploration practice,on the basis of the developed fault classification and the characteristic analysis in different periods,the origin evolution of the faults and their controlling actions on the hydrocarbon accumulation were discussed.The study achievements show that the evolutionary stages of West Subsag in Bozhong Sag can be divided into the sinistral strike-slip period of the early basement,Paleogene extension period and Neogene-Quaternary (new structural movement period) bidirectional strike-slip period.The development and evolution of the faults control the development of the sedimentary system,and form various types of the trap,and moreover present the main channels of the vertical petroleum migration.The research achievements have the guiding significances for the target choice and the oil-gas exploration evaluation in the area.