中国东部陆相盆地隐蔽油气藏成藏机理与模式

以渤海湾盆地、松辽盆地为研究对象,在对盆地构造演化和构造类型、沉积演化和沉积特征、储集性能与烃源岩生烃潜力等成藏地质要素进行分析的基础上,揭示了中国东部陆相盆地隐蔽油气藏的发育特征与勘探潜力.渤海湾断坳型盆地内隐蔽油气藏类型多,资源丰富;松辽盆地断陷结构发育早,坳陷结构发育明显,但该大型盆地内隐蔽油气藏勘探潜力大.在对隐蔽圈闭形成、油气运移及时空配套史等成藏作用分析的基础上,结合已发现油气藏的类型、空间分布特点,对中国东部陆相盆地隐蔽油气藏总结出5类基本成藏模式,包括潜山、地层超覆、地层不整合遮挡、岩性圈闭及火山岩等.图3表1参18

Formation mechanism and model of subtle traps in continental basins of east China

The distribution and exploration potential of subtle reservoirs were analyzed based on the integrated analysis of the basin structural evolution and styles, sedimentary evolution and characteristics, reservoirs and hydrocarbon source rocks of two typical rift basins of Bohai Bay Basin, Songliao Basin in east of China. The research shows that the Bohai Bay Basin has multiple types of subtle reservoir and abundant hydrocarbon resources. The Songliao Basin has also abundant hydrocarbon resources of subtle reservoir though only a relatively single type is distributed in this large-size basin with the post-rift subsidence structure developed but the synrifting structure undeveloped. By associated consideration of subtle trap formation mechanism, hydrocarbon migration, petroleum system events and founded subtle reservoir types as well as distribution rules, five accumulation models and ten sub-models of continental rift basins in east China are constituted, that is, remnant paleo-buried hill, faulty paleo-buried hill, stratigraphic overlap in slope zone, stratigraphic overlap in paleo- high, stratigraphic truncation, shallow lithology, pinchout in slope zone, sand lens, lava overlap and lava lithology.