作　　者： ; ; ; ; ; ; ;

机构地区： 中国科学院广州地球化学研究所

出　　处： 《地球化学》 2003年第3期271-281,共11页

摘　　要： 达尔其油田原油的粘度差异很大,稀油、普通稠油和特稠油均有分布。大部分稠油和特稠油正构烷烃分布完整,未见生物降解等次生变化的迹象,具有原生稠油的特征。通过对几个代表性原油和烃源岩的族组成、饱和烃GC和GC/MS分析可知,Da2O1和Da14O2类型成熟稀油来源于埋藏较深、热演化程度较高的下白垩统腾格尔组和阿尔善组烃源岩,而Da12O1类型未熟、特稠油则来源于埋藏浅、热演化程度低的下白垩统都红木组一段烃源岩。由油样Da2O1和Da12O1混合(质量比68.7∶31.3)而成的油样Da2+12,其族组成、饱和烃色谱和甾、萜烷分布特征与Da14O1类原油接近。详细对比二者之间的差异,结果表明Da14O1类原油比混合油Da2+12含有更多的成熟稀油,稀油比例大于68.7%。Da14O1油层油砂样连续抽提实验结果表明,早期注入该油层的原油为Da2O1和Da14O2类成熟稀油。晚期注入的原油为Da12O1类未熟特稠油,这进一步证实了Da14O1类油为混源油。 Oils are greatly different in viscosity within the Daerqi oilfield.There are ordinary oil,viscous oil and extremely viscous oil.The presence of a full range of intact n-alkanes demonstrates that these viscous and extremely viscous oils are primary,and not bio degraded.Based on the results of gro ss composition,and GC and GC-MS analyses of saturated fraction,it i s concluded that the ordinary,matur e oil(e.g.Da2O1and Da14O2)is derived from the deeper buried,Lower Cretaceous Tengeer Formation and /or Aersh an Formation source rocks with high maturities,while the extremely vis cous and immature oil(e.g.Da12O1)is derived from Duhongmu Formation source rocks with very low maturity.The gross and molecular composition s of an artificial oil Da2+12,a mixtu re of oils Da2O1and Da12O1with mass ratio of 68.7∶31.3,are similar to those of oil Da14O1,which indicates that oil Da14O1,an ordinary one with low matu rity,is very likely a mixture of matu re oil and immature oil.The minor difference between them demonstrates that oil Da14O1apparently contains more mature oil than the artificia l oil Da2+12,i.e.more than 68.7%mature o il in mass.The result of sequential e xtraction on a side-cut oil sand sample,collected from the same oil l ayer in the same borehole of oil Da14O1,shows that this oil layer was charg ed,at first,with mature oil(like oils Da2O1and Da14O2),and then,with immature oil(like oil Da12O1).This result further supports the assumpt ion that oil Da14O1is a mixture of mature oil and immature oil.

关 键 词： 白音查干凹陷 达尔其油田 原油地球化学 粘度 烃源岩 饱和烃 热演化程度 阿尔善组 腾格尔组 萜烷

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