焉耆盆地侏罗纪煤系源岩显微组分组合与生油潜力

焉耆盆地为我国西部含煤、含油气盆地, 侏罗系含煤地层是最重要的潜在源岩.对侏罗纪煤系中的暗色泥岩、碳质泥岩和煤层分别进行了有机岩石学、Rock-Eval热解分析和核磁共振分析.泥岩、碳质泥岩和煤层具有不同的有机岩石学和有机地球化学特征, 其中煤层具有3种有机显微组分组合类型, 不同显微组分组合类型的煤层具有不同的生油、生气潜力或倾油、倾气性.基质镜质体、角质体、孢子体等显微组分是煤中的主要生烃组分.侏罗系泥岩、碳质泥岩和煤层具有不同的生物标志物分布特征, 生物标志物组合分析表明焉耆盆地已发现原油是泥岩、碳质泥岩和煤层生成原油的混合产物.含煤地层的地球化学生烃潜力分析和已发现原油的油源对比均表明, 含煤地层不仅是重要的气源岩, 而且可成为有效的油源岩. 

Maceral Composition and Oil Potential of the Jurassic Coal-Bearing Series in the Yanqi Basin

The Yanqi basin is a coal-bearing petroleum basin in northwest China. The most important potential source rock interval in this basin is the Jurassic coal-bearing series. Organic petrological analysis, Eval-Rock pyrolysis and 13C NMR analysis have been carried out on shale, carbonaceous shale and coal samples. Shales, carbonaceous shales and coals from the Jurassic coal-bearing series have different organic petrological and organic geochemical characteristics. There are three coal types with different maceral associations, each type having different oil/gas potential. Desmocollinite, cutinite and sporinite are the major oil-generating macerals in the coals. The Jurassic shales, carbonaceous shales and coals have different biomarker compositions. Detailed analysis of biomarker association and oil-source rock correlation suggest that the oil found in this basin is a mixture of oil generated from Jurassic shales, carbonaceous shales and coals. This study confirms that coal-bearing series are not only important gas source rocks, but also can become effective oil source rocks.