Abstract:

Flow mechanisms of multi-phase multi-component of CO₂-crude oil system in porous media are very important for displacement process for CO₂ flooding,enhanced oil recovery and even geology sequestration of CO₂,etc.Phase behavior and percolation characteristics of multi-phase multi-component of CO₂-crude oil system in porous media were studied by slim tube test,multi-contact test and numerical model considering mass transport.The results showed that CO₂ flooding can vaporize not only the light hydrocarbons less than carbon 11,but even the heavy hydrocarbon components such as carbon 32.The displacement combined vaporizing and condensing process,and the miscible zone was just near the gas displacement front.Higher temperature and higher contents of N₂ and CH₄,larger the minimum miscibility pressure(MMP)was.

Key words: CO₂ flooding, reservoir oil, multi-phase multi-component, porous flow mechanisms, minimum miscibility pressure, simulation experimert

摘要：

二氧化碳与烃类体系的多相多组分渗流机理,对于深入理解实际油田注二氧化碳的驱替特征、提高采收率及地质埋存等都具有非常重要的意义。应用细管和多次接触实验以及包含相间传质的多相多组分CO₂驱油藏数值模拟模型,系统研究了CO₂—原油体系的相变规律以及多组分体系的变相态渗流特征。结果表明,CO₂能够大量蒸发C₁₁以下的烃组分,甚至能够蒸发C₃₂等重烃组分;CO₂气驱过程是一个蒸发与凝析的混合过程,混相带出现在气驱前缘附近;温度越高,CH₄和N₂含量越大,最小混相压力越大。

关键词: 二氧化碳驱油, 地层原油, 多相多组分, 渗流机理, 最小混相压力, 模拟实验