渤海海域莱州湾凹陷的形成和演化

利用钻井和三维地震资料,对凹陷的形成演化进行了研究.莱州湾凹陷是在新生代裂谷基础上形成的凹陷,孔店组-沙三段沉积时期走滑断层对沉积作用影响较小,主要以伸展断陷作用为主,沉积中心位于北部边界铲式大断层下降盘;沙一段和东营组沉积时期凹陷沉积中心沿走滑断层向东北迁移;新近系馆陶组和明化镇组沉积时期,受走滑挤压作用的影响,该区表现为挤压反转,产生了盐拱和反转构造.走滑断层对沙河街组烃源岩的分布影响较小,但对东营组烃源岩分布和沉积体系展布有较大的影响,对晚期成藏也有较大的影响.

Formation and evolution of Laizhou Bay Sag in Bohai Bay

The drilling data and 3D seismic profiles were used to study the formation and evolution of Laizhou Bay Sag in the southern area of Bohai Bay. The results demonstrated that the Laizhou Bay Sag formed on the basis of the Cenozoic rift. During the deposition period from Kongdian Formation to the third segment of Shahejie Formation, the Tanlu strike-slip faults had a small influence on the sag, and the influence mainly came from the extended faults. The deposition center was located at the boundary downthrown side of shovel-type big fault. During the deposition period from the first segment of Shahejie Formation to Dongying Formation, the deposition center migrated to the east-north direction along the Tanlu fault. During the deposition period of the Guantao and Minghuazhen formations in the Neogene, this area under the action of strike-slip compression showed the extrusion reverse and produced the salt arch and the reverse structure. The strike-slip fault slightly influenced distribution of hydrocarbon source rock in Shahejie Formation, but it had the tremendous influence on the distribution and the deposition of source rocks in Dongying Formation and also had the tremendous influence on the latest oil-gas accumulation.