天环坳陷南段侏罗系和延长组原油芳烃中芴系列化合物的特征与意义

Characteristics and Significance of Fluorene Series Compounds in Aromatic Hydrocarbon of Crude from Jurassic and Yanchang Formation of Southern Section of Tianhuan Depression

原油芳烃组分中的三芴（硫芴、氧芴和芴）系列化合物被认为源于同一母质，它们的含量变化可以反映原始沉积环境。通过分析鄂尔多斯盆地侏罗系2个原油样品、延长组9个原油样品、2个泥岩样品芳烃化合物，结果表明来源高等植物的生物标志物丰度低，反映原油母质以腐泥性为主。芳烃各组分相对含量、三芴系列相对含量、硫芴／氧芴、二苯并噻吩／菲等参数反映了原油母质总体形成于弱氧化一弱还原的淡水一微咸水环境，但延长组长7原油的还原性和水体盐度稍高于侏罗系和延长组长3、长6和长8原油，长7泥岩的沉积环境与长7原油母质的沉积环境相似，可推测长7原油主要来源于自身烃源岩；利用甲基二苯并噻吩比值换算的镜质组反射率（R。）指示侏罗系和延长组长3、长6和长8原油处于低熟一成熟阶段。

A series of compounds of dibenzothiophene, dibenzofuran and fluorene（DBT-DF-F） in the aromatic hydrocarbon or arene components of crude oil is considered as being derived from the same parent material （kerogen）. The variation of their contents can reflect the original deposition environment. By analyzing two Jurassic crude samples, nine Yanchang Fin crude samples, and two mndstone samples containing aromatic compounds from the Ordos Basin, results show that the biomarkers fl＇om higher plants have low abundance. It reflects the kerogen is mainly sapropel-type. Parameters such as the relative contents of each aromatic component, relative contents of the DBT-DF-F series, dibenzothiophene / dibenzofurans, and dibenzothiophene / phenanthrene reflect that the kerogen overall formed in the weak oxidation - weak reduction environment with fresh water - brackish water. The reduction and water salinity of the Yanchang Fm Chang7 crude is slightly higher than those of the Jurassic, Yanchang Fm Chang3, Chang6 and Chang8 crude oil. The sedimentary environment of Chang7 mudstone is similar to that of the kerogen of Chang7 crude oil. It can be speculated or conjectured that the Chang7 crude oil comes mainly from their own source rock. The vitrinite reflectance （Ro） converted from the methyl dibenzothiophene ratio indicates that the Jurassic and Yanchang Fm Chang3, Changr, and Chang8 crude oil is at low mature - mature stages.