变换构造与油气藏关系——以彰武断陷为例

Relationship of transition structures with hydrocarbon reservoirs:a case study in Zhangwu fault depression

彰武断陷位于松辽盆地南部,为伸展背景下白垩系断陷盆地。在构造演化过程中,受基底的升降、断裂活动的不均衡性影响,彰武断陷发育伸展断裂系统下的变换构造。通过对断裂系统及其活动性以及断裂系统内部断层间位移传递方式的研究,认为变换带的传递方式为接力式,变换构造的类型为走向斜坡。同时变换构造对盆地的古地形、沉积体系、烃源岩、油藏均具有一定的影响,彰武油田的勘探实践证明,变换构造易发育岩性油藏。

Zhangwu fault depression located in the south of Songliao Basin,is an Early Cretaceous fault basin in the extensional setting. During the evolution of Zhangwu fault depression,various types of transfer structural accommodation systems have been formed in different parts of the extensional structure. According to the transfer structure theory of extensional fault system,the authors think that the Zhangwu fault depression developed in transfer structures. Through the research of the fault systems,the fault evolutions and the transition ways of displacement and their corresponding transfer structures among faults within each fault system and among the fault systems,the transfer way as determined as relaying,the way of the transformation resulted in wedge-shaped fault steps. At the same time,the transfer structure effected in a certain degree on topography,sedimentary system,hydrocarbon source rocks and reservoir of the basin. The exploration practice of Zhangwu Oil field shows that the transfer structures tend to develop lithological reservoir.