渤海海域断裂相互作用及其油气地质意义

Fault interactions and their significances for hydrocarbon accumulation in offshore Bohai Bay Basin,eastern China

渤海海域发育大量不同方位与规模的伸展断裂和走滑断裂,并在平面和剖面上发生了复杂的相互作用,对油气聚集成藏也产生了重要影响。文章主要通过地震资料解释和构造编图,从区域和局部两个层次综合分析了渤海地区伸展断裂和走滑断裂在平面和剖面上的相互作用方式,并简要探讨了断裂相互作用对油气成藏的影响。区域范围内的断裂平面相互作用方式包括共轭型、直交型和斜交型,局部地区的相互作用方式包括帚状传递型、分支传递型、雁列断层传递型和变换构造传递型等,其中变换构造传递型进一步可分为斜坡型、地垒型和断块型。剖面上的断裂相互作用方式则主要包括X型、混合型和叠加型。渤海地区的断裂相互作用不仅对盆地结构有一定影响,对圈闭、储层和油气运移等也产生了重要影响。深入分析渤海地区的断裂相互作用特征,对油气勘探具有重要指导意义。

A great number of extensional and strike-slip faults of various orientations and scales occur in the offshore Bohai Bay Basin,eastern China. Complex areal and vertical combinations exist between these faults and they play a key role in hydrocarbon accumulation in this area. Based on seismic interpretation and structural mapping,this paper mainly focuses on the regional and local interaction patterns of the extensional faults and strike-slip faults and their significances for hydrocarbon accumulation in the study area. On map view,the regional patterns of fault interaction involve conjugate type,orthogonal crossing type and oblique crossing type,while the local patterns of fault interaction can be divided into broom-shaped transfer type,branch transfer type,en-echelon fault transfer type and transition structure transfer type,of which the last type can be subdivided into three sub-types including ramp,horst type and faulted-block. On sectional view,the fault interaction patterns mainly include X-shaped type,hybrid type and superposition type. The fault interaction not only influences basin architecture,but also impactes trap,reservoir and hydrocarbon migration. This study is of great significance for oil and gas exploration in the offshore Bohai Bay Basin.