沾化凹陷五号桩地区高蜡油地球化学特征

Geochemical characteristics of high-waxy oil in Wuhaozhuang Area of Zhanhua Sag

金洪蕊 陈致林 刘 旋 宋长玉 王 忠

胜利油田分公司地质科学研究院，山东 东营 257015

Geological Research Institute, Shengli Oilfield Company, SINOPEC, Dongying 257015, China

在沾化凹陷五号桩地区分布着大量的高蜡油，其蜡质量分数为20%～50％，最高达63.75％。通过对高蜡油样品进行地球化学分析，明确了高蜡油中饱和烃、芳烃生物标志物特征，认为该地区高蜡油母质为低等水生生物、藻类和陆源高等植物混源输入，其烃源岩的沉积环境为淡水—微咸水、弱氧化—弱还原的沉积环境。在有机质的演化过程中，有细菌的积极参与。甾烷异构化参数C2920S/（20S+20R）为0.39~0.47，表明高蜡油为成熟油，但其尚未进入高演化阶段。

A large amount of high-waxy oil was found in Wuhaozhuang Area of Zhanhua Sag, with the wax content being 20%-50％and the highest value up to 63.75%. Based on the geochemical analysis of high-waxy oil samples in the area, the characteristics of saturated hydrocarbon and aromatic hydrocarbon biomarkers are known. It is believed that the biological source of high-waxy oil was the mixed importation of low-grade aquatic life, alga and higher plants of land sources. The source rocks were deposited in the depositional environment of fresh water-brackish water and weak oxidation-weak reduction. The microbe had actively participated
in the evolutionary process of organic matter. The sterane isomerization parameter, C2920S/(20S+20R), is 0.39-0.47, showing that the high-waxy oil is mature, but it does not go into a high-grade evolutionary phase.