气液固三相相平衡热力学模型与计算方法

A Thermodynamic Model of Vapor/ Liquid/ Solid Three Phase Equilibrium and its Modeling Technique

李　闽¹,郭　平¹,张茂林¹,刘　武¹,李士伦¹,董莉瑛²

Li Min , Guo Ping, Zhang Maolin, et al

1. 西南石油学院,2. 中国石油西南分公司

Dept of Petroleum Eng. , Southwest Petro leum Institate Sichuan. 637001 P. R. China

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。在对高分子有机烃类沥青沉降机理有了一定的认识的基础上,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,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。

There exist many organic solid materials with high molecular weight in crude oil. Therefore , to describe phase equilibrium appearing in oil/ gas systemaccurately , it is essential to study vapor/ liquid/ solid three phase equilibrium. On the basis of the certain 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 put technique can model asphaltene precipitation quantitatively. Moreover , the paper , through the example described in the paper ,presents the calculation technique of reference fugacity , and the matching method to saturation pressure and amount of precipitated asphaltene.