改进的CO_2-原油体系范德华型组分混合规则  

An improved vdW-type component mixing-rule applied in CO_2-crude system

作　　者：杨思玉[1,2,3] 廉黎明[1,2,3] 李实[1,2,3] 杨永智[1,2,3] 陈兴隆[1,2,3] 

机构地区：[1]提高石油采收率国家重点实验室 [2]国家能源二氧化碳驱油与埋存技术研发(实验)中心 [3]中国石油勘探开发研究院石油采收率研究所

出　　处：《石油勘探与开发》2016年第3期442-447,共6页Petroleum Exploration and Development

基　　金：国家油气重大专项"CO2驱油与埋存油藏工程技术及应用"(2016ZX05016-001);中国石油天然气股份有限公司专项"长庆油田低渗透油藏CO2驱油与埋存关键技术研究应用"(2014E3606)

摘　　要：基于混合物状态方程分析、分子间相互作用关系理论,考虑温度、压力和非烃类组分相互作用等影响因素,改进了广泛应用的范德华型方程的混合规则,并推导出了对比状态的计算公式,形成了适用于高温高压条件下CO_2-原油体系的新混合规则。通过还原为第二维里系数依赖关系的方法,证明了改进混合规则的理论严格性。以油田现场油样实测气相和液相组分数据为基础,在油藏温度和压力条件下,对混合规则改进前后计算油气组分等参数的精度进行对比。结果表明,新混合规则不仅计算简便,而且精度显著提高,组分计算加权平均误差由15%降至4%,密度计算加权平均误差由10%降至3%以下,满足工程应用要求。A new vdW-type mixing-rule has been proposed considering the interaction among the affecting factors of temperature, pressure and non-hydrocarbon components, through analysis of equation of state and theory of interaction among molecules. By the derivation of the formulation at reduced state, a new mixing-rule has been established for the conditions of high pressure and high temperature. The theoretical strictness of the rule has been demonstrated through reducing to the dependency relationship of second virial coefficients. With the in situ petroleum samples data of vapor and liquid phase components from actual measurement, comparison has been taken between the calculation precisions of components and densities parameters calculated by the new rule and the old one. The new mixing-rule has a better accuracy to meet the industrial requirement, and its calculation is also simplified. The weighted mean error of components calculation declines from 15% to 4% and that of density calculation from 10% to 3%.

关 键 词：CO2-原油体系 状态方程 组分混合规则 对比状态 闪蒸计算 逸度方程 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]