稠油黏度与化学组成的关系

CORRELATION FOR THE VISCOSITY OF HEAVY OIL AND ITS CHEMICAL COMPOSITION

测定了辽河油田、胜利油田、大港油田、大庆油田、渤海油田、中原油田和吐哈油田的25个不同黏度的稠油和油砂抽提物的黏度,并采用柱色谱法定量分析了它们的化学族组成,研究稠油黏度和其各化学组分之间的关系,提出了稠油黏度指标(Iv)概念。结果表明,稠油的黏度随非烃组分含量的增加而呈指数函数升高,即非烃组分对稠油黏度作正贡献,在相同含量下,贡献大小顺序依次是酸性非烃、沥青质、高极性非烃、中性非烃。稠油的黏度随饱和烃和芳烃组分含量的增加而呈指数函数降低,即饱和烃和芳烃组分对黏度作负贡献。稠油的黏度是其各化学组分共同贡献并相互作用的结果,黏度指标(Iv)与稠油黏度之间具有良好的数学相关关系。

Results of an experimental study on the correlation of viscosity of heavy oil and its chemical composition were presented.A concept of viscosity index（Iv） was proposed on the basis of determining viscosities and analyzing chemical compositions of 25 heavy oils and tar sand extracts with a wide range of viscosity from 7 Oilfields of China,i.e.,Liaohe Oilfield,Shengli Oilfield,Dagang Oilfield,Daqing Oilfield,Bohai Oilfield,Zhongyuan Oilfield and Tuha Oilfield.The results showed that the viscosity of heavy oil increased with the mass fractions of its non-hydrocarbon fractions（containing N,S,O elements） in an exponential function manner.At the same mass fraction,the contribution of these non-hydrocarbon fractions to the viscosity of heavy oil was in the order of acidic fraction,asphaltene,high polar heterofraction,neutral heterofraction from great to small,while the contribution of hydrocarbon fractions to the viscosity of heavy oil was in the order of aliphatic hydrocarbons,aromatic hydrocarbons.The results furthermore revealed that the viscosity of heavy oil was a character related to its chemical composition,which was affected not only by any single component,but also by the interactions of all components as a whole.There was a perfect exponential function correlation of the viscosity index（Iv） to the viscosity for the 25 analyzed heavy oils and tar sand extracts.