冀中坳陷未熟油研究及勘探前景

冀中坳陷的晋县凹陷中，北部 E_s4-E_k1段盐湖相未成熟阶段含膏烃源岩中的可溶有机质所形成的原油属未熟油，如赵兰庄、赵县油田等。这种未熟油具有高密度（０.９８～１.０８ｇ/ｃｍ3)），高粘度、高胶质＋沥青质和高含硫量（６.５%～１５%）等特征；正构烷烃常常呈明显的偶数碳优势，环烷烃和异构烷烃含量很高，有的甚至掩盖正构烷烃的分布，表现出未熟油和非生物降解的特征。其盐湖相和强还原或硫酸盐环境沉积的含膏泥岩在未成熟阶段具有丰富的可溶有机质含量（“Ａ”大于０.２%）。并非干酪根热降解成烃，而是浮游水生生物的残留烃类，它具有较高的转化率，“Ａ”/ＴＯＣ平均达５５%和有利的排烃条件，具备了形成未熟油藏的条件而且具有良好的勘探前景。

Research on Immature Olls in the Jizhong Depression and Its Exploration Prospect

Immature oils in the Zhaolanzhuang and Zhaoxian oil-fields are generated from E_s4-E_k1source rocks(Ro around 0.4%)with gypsum collected form the north-middle Jingxian sag of the Jizhong depression.Characteristics of the immature oil are of high viscosity(0. 98-1.08 g/cm3)and H₂S( 6.5%-15%)amount of soluble organic matter is more than 0.2%,the ratio of soluble organic matter total organiccarldn is 55% It has abundant asphaltense, cyclohydrocarbons and isohydrocarbons. n-Alkanes are dom-inated by even carbon. The area has a favorable expulsion condition and bright exploration prospect.