中国西北侏罗纪煤系显微组分热解油生物标志物特征及其意义  

Biomarker and its implication of pyrolysis oils of macerals from Jurassic coal measures,Northwest China

作　　者：陈建平[1] 邓春萍[1] 王汇彤[1] 韩德馨[2] 

机构地区：[1]中国石油勘探开发研究院 [2]中国矿业大学煤炭资源教育部重点实验室,北京100083

出　　处：《地球化学》2006年第2期141-150,共10页Geochimica

基　　金：国家自然科学基金(40373026)

摘　　要：从西北地区侏罗纪煤中分离出来的不同显微组分热解油生物标志物总体上比较相似,但在一些特殊生物标志物的分布上存在明显差异。藻类体、孢子体、角质体热解油Pr/Ph比值一般在1.5～2.0之间,镜质体和基质镜质体热解油Pr/Ph比值在3～4之间,但均只有相应原煤抽提物Pr/Ph比值的一半。在常规生物标志物甾烷和萜烷组成中,藻类体和孢子体含有相对丰富的C27甾烷,角质体其次,镜质体和基质镜质体C27甾烷含量很低或者基本不含C27甾烷;藻类体和角质体含有较高的伽马蜡烷,而与藻类体来自相同原煤的孢子体伽马蜡烷含量很低;镜质体和基质镜质体基本上不含伽马蜡烷;分离显微组分的原煤伽马蜡烷含量均很低。由此可见,伽马蜡烷的含量不仅与有机质沉积水体的盐度有关,与母源的成分也有关系。显微组分热解油与煤系原油生物标志物组成特征对比表明,煤系原油是藻类体、孢子体、角质体等富氢组分和相对贫氢的镜质组生成产物的混合物。不同油气藏中的原油,每一类显微组分的贡献可能不尽相同,有些原油可能主要来源于藻类体和孢子体等富氢显微组分,而有些原油除了富氢显微组分有贡献外,镜质组对其也有一定的贡献,但富氢显微组分应该是煤系含油气盆地中主要的生油显微组分。Biomarkers in the pyrolysis oils produced by various macerals from Jurassic coals, the Northwest China are generally similar, with distinct differences in some special compounds. The oils generated by alginite, sporinite and cutinite have a lower Pr/Ph ratio range from 1.5 to 2.0, and the oils produced by vitrinite and desmocollinite have a higher value from 3 to 4, but Pr/Ph ratios of all pyrolysis oils are just a half of that of the extracts from the relevant raw coals. In the distribution of steranes and terpanes, the pyrolysis oils generated by alginite and sporinite contain relatively abundant C27 steranes, and cutinite, a little less. The pyrolysis oils produced by vitrinite and desmocollinite have extremely low C27 steranes, and even have no C27 steranes. The pyrolysis oils from alginite and cutinite show distinctly more gammacerane, and the Gammacerane/C31 hopanes （22S ＋ 22R） ratio reaches 0.27, but the oil from sporinite isolated from the same coal with alginite contains little gammacerane. This indicates that the concentration of gammacerane is not only controlled by the salinity of depositional environment, but also concerned with the component of the contributing organic matter. The pyrolysis oils derived from vitrinite and desmocollinite demonstrate a very low concentration of gammacerane, with the Gammacerane/C31 hopanes （22S ＋ 22R） ratio less than 0. 06. Biomarker correlation between the pyrolysis oils from various macerals and the crude oils from coal measures basins indicates that the crude oils in the coal-bearing basins are a mixture of the oils produced by hydrogen-rich macerals such as alginite, sporinite, cutinite, and by hydrogen-poor macerals such as vitrinite and desmocollinite. The contribution of each maceral to different crude oils varies. Some oils are probably derived from those of hydrogen-rich macerals, and Other oils may be partly derived from those of hydrogen-poor macerals, beside the hydrogen-rich macerals. Generally, the hydrogen-rich macerals are main organic matt

关 键 词：侏罗纪 煤系 显微组分 热解油 原油 生物标志物 

分 类 号：P593[天文地球—地球化学]