渤海湾盆地“埕北-垦东”构造转换带形成演化及成藏特征

Evolution and reservoir characteristics of the “Chengbei-Kendong” structural transfer zone in the Bohai Bay Basin

吴智平 张勐 张晓庆 王迪 程燕君

Zhiping Wu Meng Zhang Xiaoqing Zhang Di Wang Yanjun Cheng

以渤海湾盆地“埕北-垦东”构造转换带为研究对象，通过几何学特征的静态刻画和形成演化过程的动态分析，系统揭示了该转换带与两侧坳陷及其内部发育演化的时-空差异，明确了油气成藏特征。结果表明，“埕北-垦东”构造转换带呈NW向展布的凸凹格局，被NNE向和NEE向断裂切割改造，与由NEE向伸展断裂主控的济阳坳陷和NNE向伸展-走滑断裂主控的渤中坳陷既有联系又有差异；NW向的埕北-五号桩断裂是新生代盆地的先存基底断裂，对构造转换带的形成起到了决定性作用；在古近纪近SN向区域拉张的背景下，构造转换带受郯庐断裂走滑的影响程度不同，发生了差异演化并出现分区效应；该构造转换带是潜山油气藏发育的有利区带，古近纪的差异演化使得带内埕北、桩海-桩西、长堤-孤东-垦东等不同区段的油气成藏各具特点。对“埕北-垦东”构造转换带的研究有利于指导渤海湾盆地的构造解析及油气勘探实践。

The “Chengbei-Kendong” structural transfer zone in the Bohai Bay Basin has been geometrically characterized and dynamically analyzed to reveal the temporal and spatial differences between the zone and flanking depressions for clarifying the internal evolution and defining the characteristics of hydrocarbon accumulation. The results show that the “Chengbei-Kendong” structural transfer zone exhibits a NW-trending convex concave pattern， which is offset and transformed by NNE- and NEE-trending faults. It has both similarities and differences with the Jiyang Depression controlled by NEE-trending extensional faults and the Bozhong Depression controlled by NNE-trending extensional strike-slip faults. The NW-trending Chengbei-Wuhaozhuang fault is a pre-existing basement fault within the Cenozoic basin， which plays a decisive role in the formation of the zone. Under a tectonic setting of nearly SN regional extension during the Paleogene， the zone experienced differential evolution due to the different degrees of influence by the strike-slip movement of the Tan-Lu fault zone. The structural transfer zone is a favorable zone for the development of buried-hill oil/gas reservoirs. The differential evolution during the Paleogene controls the hydrocarbon accumulation of the Chengbei， Zhuanghai-Zhuangxi， Changdi-Gudong-Kendong areas within the zone. The results and understanding of this study have theoretical and practical significances for structural analysis and hydrocarbon exploration in the Bohai Bay Basin.

10.11743/ogg20220604