摘要
中国近海珠江口盆地、渤海湾盆地和印度尼西亚巽它盆地部分深湖相烃源岩及原油碳同位素组成异常重,一般干酪根碳同位素组成大于-24‰,原油碳同位素组成大于-25‰,与常规的地球化学理论相悖。在分析碳同位素组成、干酪根显微组分及生物标志物的基础上,对湖相烃源岩碳同位素组成异常的成因进行了探讨。认为热带、亚热带气候和藻类高生产率是形成深湖相泥(页)岩碳同位素组成异常重的主要原因。烃源岩及原油生物标志物组成以C30-4甲基甾烷丰富、伽马蜡烷含量低为特征。无定形体和藻质体是该类烃源岩有机质的重要来源,形成于缺氧的淡水—半咸水沉积环境。该类烃源岩具有高的有机质丰度、生烃潜力和氢指数,是优质的油源岩。
Kerogen carbon isotope and oil carbon isotope are heavier than --24‰ and --25‰, respectively, in some deep lacustrine source rocks and oils in the Pearl River Mouth Basin, Bohai Bay Basin of China and the Sunda Basin of Indonesia. This is different from the geochemistry regular pattern. The analysis of carbon isotope, kerogen maceral and biomarkers reveals that the heavy carbon isotope anomalies are mainly resulted from tropical and subtropical climates as well as high algae productivity. The biomarker components indicate that C30-4 methyl sterane is rich and gammacerane is poor. Organic materials in the source rocks come dominantly from amorphous and algal solids, and are formed in the anoxic fresh to brackish water environment. These source rocks are rich in organic matter and high in hydrogen index, and are excellent hydrocarbon source rock.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2009年第5期609-616,共8页
Petroleum Exploration and Development
关键词
湖相烃源岩
碳同位素组成
藻类生产率
古气候
生物标志物
lacustrine source rock
carbon isotopic composition
algae productivity
paleo-climate
biomarkers
