气液沥青三相相平衡热力学模型与计算方法

原油中含有大量的高分子有机固相物质，因此，要准确地描述油气体系相平衡，必须对气液固三相相平衡进行研究。目前，人们对高分子有机烃类沥青沉降机理有了一定的认识；在此基础上，文章提出了大的交互作用系数可以描述沥青与原油中轻烃不相容性的程度。根据对油气烃类混合物体系的一般性认识与提出的沥青组分特征化方法，导出了与之相应的有其自身特殊性的气—液—沥青三相相平衡物料平衡方程组。用考虑沥青沉降三相闪蒸数值算法，该方法能对沥青沉降进行有效的量化模拟计算。此外，结合实例分析，给出了沥青质参考逸度的计算、饱和压力和沉降量的拟合方法。

A Thermodynamic Model of Vapor/Liquid/Solid Three Phase Equilibrium and Its Moleling Technique

There exists many organic solid substance with high molecular weight in crude oil. Therefore, in order to describe phase equilibrium appearing in oil/gas system accurately, it is essential to study vapor/liquid/solid three phase equilibrium. On the basis of understanding to asphaltene precipitation mechanism, the paper comes up with the view that the incompatibility between asphaltene components and light hydrocarbons can be described with larger interaction coefficients. The present paper also puts forward vapor/liquid/solid material balance equations which has their own characterization in line with the generic opinion and the method for characterizing asphaltene components. With three phase algorithm which takes asphaltene precipitation into account, the technique can model asphaltene precipitation quantitatively. Moreover, by examples described in the paper, calculation method of reference fugacity and matching method of saturation pressure and amount of precipitated asphaltene have been presented.