苏北盆地油气藏分布规律和主要控制因素

Petroleum Reservoirs Distribution and Controlling Factors in Subei Basin

对近300个油藏特征的分析,表明苏北盆地主要以构造油气藏为主,几乎所有的油气藏与断裂有关。油气藏纵向分布在E_1f_4、E_1f_2和K_2t_2三套主力烃源层的上下;平面上围绕箕状烃源灶呈扇形或环带分布。油气藏分布主要受凹陷沉降类型、生储盖组合、断层和构造高带控制。以高邮、溱潼和金湖凹陷为代表的沉降持续发育型和早期发育型凹陷中油气最为富集。生储盖组合控制着含油层位主要分布在E_2s、E_2d、E_1f_3、E_1f_2底-E_1f_1顶、K_2t_1构造控制油气富集带,断层的形成时间、形态、断距大小综合控制油气藏的形成、富集程度和油柱高度。这些认识能更有效地指导成熟探区的精细勘探。

The type of petroleum reservoirs is very rich in Subei Basin,east China. Geological parameters of about 300 petroleum reservoirs show that reservoirs are almost relevant to faults and fractures ,tectonic reservoirs are main and complex reservoirs are secondary. Distribution of petroleum reservoirs have a strong regularity,vertical distribution in upper and lower formations of E1f4, E1f2 and K2t2 hydrocarbon source,and horizon fan-shaped or ring distribution around the hydrocarbon source kitchens. Reservoir distribution is mainly affected by depression sedimentary type,source-reservoir-cap combination,faults and tectonic highbands. Most petroleum accumulates in the continued development depressions and the early development depressions,for example Gaoyou,Qintong and Jinhu sag. Oil-bearing strata mainly distributing in E2s,E2d,E1f3,E1f2 Iower-E1f1 upper and K2t1 are controlled by source-reservoir-seal combination. Petroleum-rich zones are controlled by tectonic.The formation, enrichment extent and height of oil column of reservoir is controlled respectively by formation time,shape and breaking size of fault. These understandings could guide fine exploration more effectively in mature exploration areas.