Abstract: Through interpretation of 3D seismic data, the extensional-shear fault system in the Neogene in Yakela fault block has two main features of blocks distributed along east-west and zones distributed along north-south, which develops four fault structural styles, including stepladder fault structure, tilted fault block structure, graben-horst block structure and negative flower shaped structure. There are four trap structural styles associated with extensional-shear fault system, namely fault nose and faulted anticline, tilted fault block, reverse drag anticline and horst. The traps formed by the extensional-shear faults, whose main active period are Suwiyi-Jidike epoch of neogene, well match the periods of hydrocarbon formation reservoirs. The hydrocarbon vertical migration along the extensional-shear fault appears clearly in the process of hydrocarbon accumulation in Cretaceous and Tertiary, but lateral sealing of the extensional-shear fault is vital in the process of pools of petroleum accumulation.

Key words: Yakela fault block, Mesozoic-Cenozoic, extensional-shear fault system, trap structural styles, lateral sealing

摘要： 通过对三维地震资料的解释可知, 雅克拉断凸中的晚第三纪张扭性断裂系统具有东西分块、南北分带的基本特征, 主要发育4种断裂构造样式: 阶梯状断裂构造、掀斜断块构造、堑垒式构造和负花状构造。与张扭性断裂系统有关的圈闭构造样式主要有4种: 断鼻与断背斜、掀斜断块、逆牵引背斜和地垒。张扭断裂系统主要活动期为晚第三纪吉迪克期和康村期, 其形成的圈闭与生烃期有较好的匹配关系。雅克拉断凸张扭性断裂系统在白垩系和第三系油气聚集过程中, 断裂的垂向运移通道作用表现得极为明显, 但是断层的侧向封堵对油气的聚集成藏也起到了至关重要的作用。

关键词: 雅克拉断凸, 中新生界, 张扭断裂体系, 圈闭样式, 侧向封堵