摘要
为考察不同流变性质的驱油剂在油藏中的渗流规律,基于孔喉作为实际油藏多孔介质最基本的流通单元和孔隙尺度随机分布的特点,提出了多孔介质的微观简化模型——二维随机变截面微管束。采用数值方法研究了粘弹型驱油剂和幂律型驱油剂在单个孔喉和多孔介质微观简化模型中的流动特性。结果表明,对于粘弹型驱油剂,只有当注入强度达到一定值时,粘弹效应才能明显地体现出来,渗流阻力随粘弹性的增强而增加,随孔隙尺度和非均匀程度的减小而增加。对于幂律型驱油剂,其渗流阻力随流体非牛顿性的增强而降低,随孔隙尺度和非均匀程度的变化规律与粘弹型驱油剂大体一致,但是在数值上远小于后者。对比分析驱油剂在岩心中的渗流规律发现,二维随机变截面微管束可作为多孔介质的简化模型,以此作为研究驱油剂渗流机理的基础模型可以避免岩心试验中多因素的综合作用,体现单一因素如流变性、孔隙介质结构和非均质性对驱油剂渗流特性的影响。
According to pore throat as the basic flow cell of real porous media in reservoir and pore size stochastic distribution, the microscale model of porous media was simplified as 2D stochastic channel bundle with cross section variation. The flow behaviors of viscoelastic and power law oil displacement agents in pore throat model and microscale model of porous media were studied by numerical method. The results show that for viscoelastic oil displacement agent, the viscoelastic effect is obvious and seepage resistance increases markedly with viscoelastic property increasing when flow rate reaches a critical value. The seepage resistance increases with the decrease of heterogeneity and mean pore size of porous media. For power law one, the effects of flow rate, heterogeneity and mean pore size of porous media on the seepage resistance are similar to that on viscoelastic oil displacement agent. However, the seepage resistance of power law oil displacement agent is far less than that of viscoelastic one and decreases with the non-Newtonian property increasing. By comparison of three kinds of oil displacement agents flowing through cores and through 2D stochastic channel bundle, it is found that 2D stochastic channel bundle can be used as simple model of porous media, which overcomes muhi-factor synthetic effects and can illustrate the effect of one factor such as theological property, pore size and heterogeneity on the percolation behavior of oil displacement agent.
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第2期76-81,共6页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家重点基础研究发展计划('973'计划)(2005CB221300)
国家自然科学基金项目(50574060)
关键词
渗流阻力
驱油剂
微管束
粘弹性流体
幂律流体
聚合物驱
seepage resistance
oil displacement agent
micro-channel bundle
viscoelastic fluid
power law fluid
polymer flooding
