赤峰盆地元宝山凹陷稠油地球化学特征及成因

Geochemical characteristics and genesis of viscous crude oil from Yuanbaoshan Depression,Chifeng Basin

根据分子有机地球化学理论,借助色谱和色质等先进测试手段,对赤峰盆地元宝山凹陷6个油样进行了分析研究。结果表明,元宝山凹陷的原油属重质稠油成熟度低生源物质以菌类和藻类微生物为主,后者大于前者;其生源物质形成于半咸水咸水湖相还原环境。利用有机显微组分荧光光谱研究了本区烃源岩的成烃机制,认为原油是生物类脂物早期生烃的产物。还对原油的稠化机理进行了分析认为可能是由其生源物质决定的,而后期又受轻微生物降解的影响,这与前人的研究成果迥然不同。同时,将本区原油与其他熟知的典型稠油进行对比,突出了本区原油的特殊性。

Six oil samples(2oil and 4oil sand samples)from Yuanbaoshan Depression,Chife ng Basin are analyzed based on the theory of molec ular organic geochemistry and by gas chromatography and gas chromatography-mass spectrometry(GC and GC-MS ).The results show that the oil is heavy-viscous crude oil with low maturity.Their organic precurs ors derived mainly from bacteria and alga of low microorganism,and forme d in brackish-saline lake reduction environment.The hydrocarbon-generating mechanism of the source rocks in t he study area is studied by maceral fluoresce ne spectrum,and it can be concluded t hat the oil is an early hydrocarbon-generating product of organism lipidal matter.Viscosify of the oil is controlled by organic pr ecursors and the viscous oil is probably of primary origin(only possibly affected slightly by b iodegradation),which differ greatly from the conclusion drawn pr eviously.The oil in the study area has its own characteristics compared with the typical known heavy-viscous crude o ils.