渤海湾盆地南堡凹陷北边界断层演化及其石油地质意义 New Understanding of Boundary Fault Evolution and Its Petroleum Geological Significance in Nanpu Sag, Bohai Bay Basin

本文在对三维联片地震资料构造解析及边界断层“跃迁”构造模式的基础上，提出了南堡凹陷北边界断裂形成演化的新认识，并阐述其石油地质意义。结果表明，① 南堡凹陷在断陷阶段，北边界断层存在显著的分段性，而且随着应力场的演化，位置、性质和作用是不断变迁的；② E2s3期边界断层(古西南庄断层)控制了南堡凹陷主力烃源岩的分布，并进一步控制北部周边凸起的油气成藏；③ 提出了裂陷边界断层物源口分布的预测模式，并预测了南堡凹陷北部边界的物源口分布；④ 边界断层主控性质的“跃迁”，导致南堡凹陷拾场次凹流体势场的变化。 On the basis of structural analysis of 3D seismic data and tectonic model of boundary faults migration in Nanpu sag, new understanding of boundary fault evolution is proposed, and its petroleum geological significance is analyzed. The results show that, (1) with evolution of tectonic stress field, the boundary faults of Nanpu sag are distinctly segmented, and their position, properties, roles and activation change significantly in different rifting stage. (2) The northern boundary fault in E2s3 (Paleo-Xinanzhuang Fault) controls main hydrocarbon source rock deposition, and further control oil and gas accumulation in the northern uplift. (3) Prediction model of sediment source port is proposed, and the distribution sediment source port along northern boundary fault is predicted in Nanpu sag. (4) The migration of boundary fault activation leads to change of fluid potential field in Shichang Sub-sag, Nanpu sag.