春风油田稠油地球化学特征及油源分析

春风油田位于准噶尔盆地车排子地区，分布有轻质油和稠油两类原油，其中稠油分布比较广泛，石炭系、侏罗系、白垩系、古近系及新近系均有分布。根据稠油的地球化学特征，将春风油田的稠油划分为三大类，其中A类稠油遭受严重的生物降解，正构烷烃损失严重，原油的稳定碳同位素偏轻，一般都低于－30‰；B类稠油也遭受生物降解，存在低碳数的正构烷烃和25－降藿烷共存的现象，原油的稳定碳同位素一般都在－28‰～－30‰之间；C类稠油遭受中等生物降解，甾萜类化合物具有与轻质油相似的特征，原油中稳定碳同位素偏重。油源地球化学特征对比表明，研究区A类稠油主要来源于昌吉凹陷二叠系烃源岩，B类稠油为二叠系和侏罗系烃源岩的混源油，C类稠油主要来源于侏罗系烃源岩。

Oil source analysis and geochemical characteristics of heavy oil in Chunfeng Oilfield

There are light and heavy oils in Chunfeng Oilfield,which lied in the Chepaizi area of Junggar Basin.The heavy oils are widely distributed in the Carboniferous,Jurassic,Cretaceous and Tertiary.According to the geochemical char-acteristics of the heavy oils,they are divided into three types.The type A oil had serious biodegradation,heavily destroyed n-alkanes,and less than -30‰theδ13C in the oil.The type B oil also had serious biodegradation,existing lower carbon number n-alkanes and the 25-norhopanoids compounds at the same time,and the δ13C of the oil from -28‰ to -30‰.The type C oil had medium biodegradation,terpenoid compound similar to the light oil,and higher the δ13C of the oil.Compared with geochemical characteristics of source rocks,the results showed hat the type A oil was mainly from the source rock of Permian,the type B oil was from the source rock of Permian and Jurassic,and the type C oil was from the source rock of Jurassic.