注CO_2气开发低渗油田影响因素数值模拟研究

Numerical Simulation on Influence Factors of Injecting CO_2 Gas to Develop Low Permeable Reservoir

本文针对低渗透储层,利用数值模拟方法,研究了渗透率、原油相对密度及非均质性等因素对CO2驱油效果的影响,并且在分析启动压力梯度对低渗透油藏CO2驱替效果的影响基础上,建立了考虑启动压力梯度的CO2驱非达西渗流规律数学模型。根据数值模拟结果,随着渗透率的增加,CO2驱采出程度增大;随着原油相对密度的增加,CO2驱采出程度降低;非均质性性越强,CO2驱采出程度越低;考虑考虑启动压力梯度的影响,建立数学模型,对于低渗透油田CO2驱油实践具有一定指导意义。

Based on low permeability reservoir, this paper uses numerical simulation method to study the effect of intiltration rates, relative density of crude oil, heterogeneity and other factors on oil displacement effect of CO2, established a mathematical model of CO2 driving non-Darcy percolation rules by considering threshold pressure gradient on the basis of analysing the effect of starting pressure gradient on low-permeability oil reservoirs CO2 displacement. According to the results of numerical simulation, as the increase of penetration rate, the CO2 flooding level increases; As the increase of relative density of crude oil, the CO2 flooding level reduces; the non-homogeneity is more greater, the CO2 flooding level is more lower; Thinking the effect of starting pressure gradient to build mathematical models has a certain significance for CO2 flooding in low permeability oilfield practice.