济阳坳陷渤南洼陷沙河街组二段多源供烃成藏模式

济阳坳陷渤南洼陷沙河街组二段具有顶底多源供烃的成藏特征。针对多源供烃油气成藏模式认识不清以及沙二段整体研究程度较低等问题，依据钻井、测井、地震和分析化验等资料对其开展了研究。结果表明，渤南洼陷沙二段油气成藏由沙四上亚段、沙三段和沙一段3套烃源岩提供油源，沙二段底部扇体及碳酸盐岩沉积与顶部泥岩构成了有利的储盖组合，断层和不整合面组成了立体输导体系；断裂体系和不整合对油气运移和聚集具有重要影响，储集层物性控制油气富集程度；据成藏期和油源不同，渤南洼陷沙二段油气成藏可分为"中期成藏、双源供烃"和"晚期成藏、三源供烃"2种模式；2种成藏模式下多形成由单源油和混源油组成的岩性圈闭、构造圈闭以及构造岩性复合圈闭油藏；自下而上、自洼陷中心向边缘，油气藏的形成时间由早到晚差异聚集。 

Reservoir-forming pattern with multiple sources in second member of Shahejie Formation,Bonan Sag,Jiyang Depression,Bohai Bay Basin

The second member of Shahejie Formation (Es₂) in the Bonan Sag of Jiyang Depression has multiple hydrocarbon sources, both from top and bottom. Drilling, logging, seismic and testing data were applied in the analyses of Es₂ in view of the unclear understanding of multi-source hydrocarbon accumulation models and the low overall study level of Es₂. It was concluded that the hydrocarbon in the Es₂ was sourced from three sets of source rocks in the upper section of the fourth member (Es₄), the third member (Es₃) and the first member (Es₁) of Shahejie Formation. The fans and carbonate rocks at the bottom and the mudstones on the top of Es₂ served as favorable reservoirs and cap rocks, respectively. Faults and unconformities formed a 3D transport system, which had a significant influence on hydrocarbon migration and accumulation. The physical properties of reservoirs restricted hydrocarbon enrichment. Two reservoir-forming patterns, ‘accumulation during the middle stage with two sources’ and ‘accumulation during the late stage with three sources’, were established according to the difference of accumulation stage and source. Lithologic, structural and structural-lithologic traps were formed with single or multiple sources under these two patterns. The major accumulation stages have a trend of being late gradually from bottom to up and from the sag center to the edge.