黄骅坳陷齐家务地区的油源对比

Oil-Source Correlation of the Qijiawu Area in the Huanghua Depression

黄骅坳陷齐家务地区储油层主要为下第三系沙河街组沙一下段白云质灰岩。该区原油具有高密度、高粘度、高含硫量、中低凝固点、高初馏点和高胶质和沥青质含量等物理性质。在地球化学特征上,高碳数正构烷烃具有明显的奇偶优势,类异戊二稀烷烃具有植烷优势,甾烷组成具有明显的C27ααα甾烷优势,沙一段泥页岩的三环萜烷不发育、伽马蜡烷比较发育。这些地球化学特征表明该区原油为未熟—低熟油。分析原油和沙一段泥页岩的伽马蜡烷/C30藿烷与C29降藿烷/C30藿烷的关系以及伽马蜡烷/C30藿烷与Pr/Ph之间的关系,并结合地球化学特征,认为齐家务地区的烃源岩主要是沙一下段的泥页岩。

Oil reservoir in the Qijiawu area of the Huanghua Depression is dolomitic limestone in the lower Shayi Member of Shahejie Formation of Eogene. The crude oil of the Qijiawu area is characterized by high density, high paraffin, high content of sulfide and high content in asphalt. The crude oil shows distinct geochemical characteristics that are high normal paraffin hydrocarbons with distinct parity preponderance, isoprenoid alkanes with phytane preponderance and gonane components with evident C27ααα sterane preponderance. The mud shale in Shayi Member has developed more gammacerane-alkane and undeveloped tricyclic terpane. These characteristics indicate the crude oil of the Qijiawu area belongs to immaturity or lower maturity crude oil. According to the results of crossing the parameters （gammacerane-alkane/C30 hopane and C29 nor-hopane/C30 hopane, garnmacerane-alkane/C30 hopane and Pr/Ph） of the crude oil with the parameters of mud shale in lower Shayi Member, we draw a conclusion that the mud shale of lower Shayi Member of Shahejie Formation is the oil source rock in the project area.