珠江口盆地白云凹陷北坡-番禺低隆起天然气成因类型及其烃源探讨  

Natural gas genetic types and source rocks in the northern slope of Baiyun Sag to Panyu Low Uplift in Pearl River Mouth Basin

作　　者：何家雄[1] 陈胜红 刘海龄[1] 刘士林[1] 

机构地区：[1]中国科学院边缘海地质重点实验室,广东广州510640 [2]中海石油(中国)有限公司深圳分公司,广东广州510240

出　　处：《石油学报》2009年第1期16-21,共6页Acta Petrolei Sinica

基　　金：国家重点基础研究发展规划(973)项目(2007CB411705);中国科学院知识创新工程项目(KZCX2-YW-203-2)联合资助

摘　　要：珠江口盆地白云凹陷北坡—番禺低隆起天然气的成因及其烃源问题,近年来引起了石油地质专家们的广泛关注。在前人工作基础上,根据天然气的组成、碳同位素及其甾萜类生物标志化合物特征,重点对天然气的成因类型及其烃源构成进行了深入分析。依据天然气甲烷碳同位素和乙烷碳同位素分布特征,将天然气成因类型划分为生物气、亚生物气、成熟偏煤型混合气、成熟—高熟偏油型混合气及成熟—高熟煤型气5类。天然气伴生凝析油的甾萜类生物标志物具有富集型煤系有机质和分散型Ⅲ型有机质两种明显不同的特征,由此认为油气主要来自成熟—高熟的渐新统恩平组煤系烃源岩、滨浅湖相烃源岩及始新统文昌组滨浅湖相烃源岩。通过油气地质及油气地球化学综合剖析,指出该区不仅具有巨大的天然气勘探潜力,而且具有石油资源勘探前景。The genetic types of natural gas and their source rock compositions were discussed in the northern slope of Baiyun Sag to Panyu Low Uplift in Pearl River Mouth Basin on the basis of former studies. According to the stable carbon isotope of methane and ethane, natural gas in the studied area can be classified into 5 main genetic types, including biogas, biothermal-catalytic gas, matured mixture coaliferous gas, matured to high matured mixture petroliferous gas and matured to high matured coaliferous gas. Sterane and terpane biomarkers of associated condensate oil in natural gas have two types of obviously different source compositions, which came from organic matter both enrichment-type coal and type-Ill dispersed kerogen. So, hydrocarbon in the studied area was mainly gener- ated from the matured to high matured source rocks located in coal beds of Oligocene Enping Formation, shore-shallow lacustrine source rocks of Oligocene Enping Formation and Eocene Wenchang Formation. The further analyses of petroleum geological and geochemical characteristics show that this area has a great exploration prospect of natural gas and good potential of petroleum resource.

关 键 词：珠江口盆地 白云凹陷北坡-番禺低隆起 天然气成因类型 古近系 煤系烃源岩 油气勘探前景 

分 类 号：TE112.111[石油与天然气工程—油气勘探]