渤海湾地区断层相关褶皱及其油气地质意义

利用最新的地震解释资料,对渤海湾地区伸展和走滑断层相关褶皱的分类、形态特征、成因机制、不同褶皱之间关系及其时空展布特征进行分析,并结合勘探实践,研究不同类型断层相关褶皱对油气成藏的控制作用。结果表明,伸展和走滑两种断层相关褶皱在形态特征、发育过程和成因机制上具有较大差异,但相互之间也有联系:同一断裂的不同演化阶段可形成不同形态的相关褶皱,不同类型的褶皱可以互相改造、叠置。断层相关褶皱的时空分布与断裂的演化阶段密切相关:在时间上古近纪主要发育伸展断层相关褶皱,新近纪主要发育走滑断层相关褶皱;在空间上伸展断层相关褶皱在盆地内广泛分布,走滑断层相关褶皱呈条带状分布;在层位上孔店组-东二段主要发育伸展断层相关褶皱,明化镇组-第四系主要发育走滑断层相关褶皱。伸展和走滑断层相关褶皱均可形成良好的圈闭条件,并促进油气运移,但走滑断层相关褶皱可能导致局部地区烃源岩生排烃时间滞后,促使浅层晚期快速成藏。

Fault-related folds in Bohai Bay and its significance of hydrocarbon accumulation

Using latest seismic interpretation data, we analyze fold classification, morphological characteristics, the relation among folds, and spatial-temporal characteristics of extensional, and discuss strike-slip fault related folds, and fault related folds of hydrocarbon accumulation combining recent exploration practices. The results show that extensional fault related folds are different from strike-slip fault related folds in morphological characteristics, development process, and genetic mechanism, while there are still some relations between each other. Different evolutionary phases of the same fault can form different related folds. Different types of folds can transform each other and stack. The spatial and temporal distribution characteristics of fault-related folds are closely related on the evolution phases of faults: In the time domain, Paleogene mainly develop extensional fault related folds, and Neogene mainly develop strike-slip fault related folds. And in the space extensional fault related folds are widely distributed in the whole basin, and strike-slip fault related folds are zonal distribution. On the horizon, Kongdian-Dongying formation mainly develops extensional fault related folds, Minghuazhen formation-Quaternary mainly develops strike-slip fault related folds. Extensional and strike-slip fault related folds can form excellent trap conditions, and promote oil and gas migration. But strike-slip fault related folds may lead to the delay of hydrocarbon generation and expulsion in local area, resulting in late hydrocarbon accumulation in shallow horizons.