东濮凹陷卫城-文明寨地区原油地球化学特征

对卫城-文明寨地区烃源岩样、原油样和油砂样进行了族组分、饱和烃色谱-质谱实验分析,实验结果表明,该区存在3类特征的原油:在沙一段及其下部沙二段、沙三段均分布有低熟油,甾烷系列中C27含量占优势,以水生生物输入为主,兼有陆源高等植物混合输入的特征,形成于沙三段-沙四段半咸水湖沉积环境;沙一段少数低熟油样品显示出其源岩母质为高等植物输入的特征,C29甾烷含量高,同时γ-蜡烷含量较低,其源岩母质形成于水体比较浅的淡水-微咸水的沉积环境;存在少量成熟度较高的原油,其γ-蜡烷含量高,甾烷C27占优势,其源岩母质来源于水生生物输入的盐湖沉积环境.

Investigation on the geochemistry characteristics of crude oil from Weicheng-Wenmingzhai area in Dongpu Depression

The group composition of oil,chromatogram and mass spectrum of aliphatic were analysed on the samples of source rocks and crude oil from Weicheng-Wenmingzhai area in the Dongpu Depression.The results demonstrated that there were three types of oil in the area.The immature oil,distributed in the Member 1,Member 2 and Member 3 of Shahejie Formation was characterized by high content of C27 steranes and gammancerane,and its hydrocarbon source matter was mainly from the import of hydrophilic biology and formed in the middle-salt water lake.The fewer sample of immature oil in the Member 1 of Shahejie Formation was characterized by high content of C29 steranes and low content of gammancerane,and its hydrocarbon source matter was mainly from the import of altitude plant and formed in the tiny salt water lake.The fewer sample of mature oil in the Member 3 and Member 4 of Shahejie Formation was characterized by high content of C27 steranes and gammancerane,and its hydrocarbon source matter was mainly from the import of hydrophilic biology and formed in the high-salt water lake.