东海西湖凹陷早第三纪烃源岩生烃组分剖析

THE STUDY ON HYDROCARBON-GENERATING MACERALS OF LOWER TERTIARY SOURCE ROCKS IN XIHU SAG, EAST CHINA SEA BASIN

摘要: 采用有机岩石学分析方法,结合有机地球化学资料,剖析了东海盆地西湖凹陷早第三纪烃源岩。该烃源岩富镜质组,贫惰性组,含一定数量的壳质组和腐泥组(10%~30%)。壳质组+腐泥组含量与氯仿沥青、总烃和有效碳等参数密切正相关;树脂体和孢子体+藻类体分别是早期生烃和晚期生烃的重要组分。在此基础上提出了西湖凹陷烃源岩的生烃模式。

Abstract: Combined with data of organic geochemistry. this paper is carried out a detailed study on hydrocarbon sourse rocks (coal and mudstone) samples from Xihu sag, East China Sea Basin, mainly through the analystical method of organic petrology. The results demonstrate that source rocks of Xihu sag contain rich vitrinite (> 60%), poor inertinite (<10%) and a certain quantity of exinite plus sapropelinite (10%~30%). Exinite plus sapropelinite content has a close correlation to the yield of choloroform bitumen, total hydrocarbon content and pyrolytic effective carbon amount. Resinite and sporinite plus alginite are the important hydrogen-rich maceral for early and late oil generation, espectively. Based on these, a kind of hydrocarbon generation model is preliminary proposed.