歧口凹陷板桥斜坡区新生代断裂特征及油气地质意义

歧口凹陷发育多类型斜坡构造，为地层岩性油气藏主要富集区。板桥斜坡为歧口凹陷西缘受边界断裂控制的旋转掀斜型斜坡，斜坡内断裂特征复杂。在钻井及高分辨地震三维解释基础上，对板桥斜坡区内断裂特征进行分析，并探讨其油气地质意义。研究表明，板桥斜坡内部发育3组不同类型的断裂系，其组合类型、变形特征及成因机制具有显著差异。西侧的大张坨平行断裂系受控于差异伸展作用，缓岸带一侧发育一组平行排列的张性断裂，断裂走向与斜坡倾向垂直，形成断鼻背景上的单一斜坡构造；东侧的长芦羽状断裂系及高沙岭帚状断裂系形成受伸展走滑作用共同控制，断裂走向与地层倾向平行，形成顺向复杂断裂斜坡构造。斜坡区演化经历了初始裂陷期-旋转掀斜期-坳陷沉降期3个阶段，控制了斜坡区古地貌特征、沉积体系类型及砂体展布。断裂活动特征的差异则控制了油气运聚特征的不同，早衰型断裂易于油气短距离运移在中深部富集成藏，继承型断裂两侧具多目的层立体含油的特征。 

Cenozoic fault characteristics and petroleum geological significance in Banqiao slope area of Qikou Depression

Qikou Depression has developed many types of slope structures, which are the main enrichment areas of stratigraphic and lithologic reservoirs.Banqiao slope is a rotating tilting slope controlled by boundary faults in the western margin of Qikou Depression, and its fracture characteristics are complex.Based on the three-dimensional interpretation of drilling and high resolution seismic data, this paper analyses the fracture characteristics in Banqiao slope area and discusses the geological significance of its petroleum.The results show that there are three different types of fault systems in Banqiao slope, and their combination types, deformation characteristics and genetic mechanism are significantly different.The Dazhangtuo parallel fault system on the western side is controlled by differential extension.A group of parallel tensional faults are developed on one side of the gentle bank zone.The strike of the faults is perpendicular to the inclination of the slope, forming a single slope structure on the background of the fault nose.The Changlu pinnate fault system on the eastern side and the Kaolin broom fault system are superimposed by extensional strike-slip action.Controlled, the strike of faults is parallel to the stratum tendency, forming a complex faulted slope structure along the direction.The evolution of the slope area has gone through three stages: initial rifting stage, rotary tilting stage and depression subsidence stage, which control the palaeogeomorphological characteristics, sedimentary system types and sand body distribution in the slope area.The difference of fault activity characteristics controls the difference of oil and gas migration and accumulation characteristics.Early-aging faults are easy to accumulate oil and gas in the middle and deep depths, and the inherited faults have the characteristics of multi-objective layers and three-dimensional oil-bearing on both sides.