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位于准噶尔盆地腹部的石南油田，四面分别与玛湖凹陷、盆1井西凹陷和石南凹陷相邻，其石油地质储量超过1×108t。石南凹陷二叠系烃源岩有机质成熟度低、类型差、生烃量小；盆1井西凹陷二叠系烃源岩有机质从成熟—过成熟均有分布、有机质类型好、生烃量巨大，玛湖凹陷烃源岩与盆1井西凹陷烃源岩石油地质特征相似，但因其中生界构造特征而被排除。文章运用有机地球化学方法，分析并类比了烃源岩和原油中C₂₀、C₂₁、C₂₃三环二萜烷和甾烷等生物标志化合物特征，确定：①石南油田油气主要来源于盆1井西凹陷二叠系风城组和下乌尔禾组烃源岩；②油气运移的通道主要是断层和不整合面；③油气至少有两期成藏。

RESERVOIR GEOCHEMICAL CHARACTERISTICS OF SHINAN OIL FIELD IN ZHUNGE’ER BASIN

Shinan oil field being located in the center of Zhunge’er Basin is surrounded by Mahu Seg,West Well Pen 1 Seg and Shinan Seg,and its oil in place is above 1×10８ t.The Permian hydrocarbon source rocks in Shinan Seg are of these characteristics as low organic matter muturity,poor kerogen nature,and a small quantity of hydrocarbon generation;those in West Well Pen 1 Seg are characterized by multiple organic matter maturity (from mature to postmature phases),good kerogen nature and a large quanlity of hydrocarbon generation;and the petroleum geological characteristics of the hydrocarbon source rocks in Mahu Seg are similar to those in the West Well Pen 1 Seg,but the Mahu Seg was excluded from consideration because of its bad Mesozoic structural conditions.Through analyzing and contrasting the characteristics of the biomarkers,as C20,C21,C23,tricyclic diterpane and sterane,etc.,in both hydocarbon source rocks and crude oil by applying organic geochemical methods,it was determined that the oil and gas in Shinan oil field mainly came from the hydrocarbon source rocks of the Fengcheng Formation and Lower Wu’erhe Formation,Permian,in the West Well Pen 1 Seg;the oil and gas migration pathways were mainly the faults and unconformity surfaces;and there were two reservoiring stages at least there.