不同类型断陷湖盆岩性-地层油气藏油气富集规律——以冀中坳陷和二连盆地岩性-地层油气藏对比为例

渤海湾盆地冀中坳陷是潮湿气候条件下发育的大型断陷湖盆，二连盆地则是半干旱气候条件下发育的小型断陷湖盆群。二者尽管构造演化特点相似，但湖盆规模、沉积环境和沉积特征差异很大，导致成藏条件和油气分布、富集规律不同。对比冀中坳陷和二连盆地近几年发现的岩性-地层油气藏，总结归纳出5方面油气藏分布与富集特征：①断陷湖盆大小决定凹陷油气资源及岩性-地层油气藏的规模。②成熟烃源岩厚度控制岩性-地层油气藏纵向分布范围。③主洼槽（生油中心）控制岩性-地层油气藏平面分布形态，例如，冀中坳陷岩性油气藏沿主洼槽带周缘呈“槽缘多环型”分布形态，二连盆地岩性油气藏在主洼槽内呈“槽内半环型”分布形态。④断陷湖盆地质结构决定油气运移主方向及岩性-地层油气藏分布格局。⑤断陷湖盆成藏组合控制岩性-地层油气藏的富集程度。图5参11

Petroleum enrichment rules in lithologic and stratigraphic pools in different faulted basins: An example from the correlation of lithologic and stratigraphic pools in Jizhong Depression and in Erlian Basin

Jizhong Depression in Bohai Bay Basin is a large-scale faulted basin developed in humid climate,while Erlian Basin is a small faulted basin group developed in semiarid climate.The pool-forming conditions and the rules of petroleum distribution and enrichment are different in them.Based on the correlation between the lithologic and stratigraphic pools found in Jizhong Depression and those in Erlian Basin,five rules of distribution and enrichment are summarized: the scale of basins decides the size of petroleum resources and pools;thickness of matured source rocks controls the pools longitudinal domains;the main oil-forming centers control the shapes of the pools planar distribution,e.g.lithologic pools along the main depressions in the Jizhong Depression are polycyclic-shaped along the depressions,while in Erlian Basin,the pools are hemicyclic-shaped inside the depressions;the geologic fabric builds the main direction of fluid potential and the pools distribution;plays in faulted basins control the pools enrichment.