Abstract: The flow behavior of viscoelastic and power-law oil-displacement agent in individual pore throat model and 2D stochastic channel bundle model was studied using numerical method.The individual pore throat of reservoir was modeled as a constricted channel and expanded one,which makes up the unit of the 2D stochastic channel bundle as porous media model.The channel bundles whose size conforms to same or different probability distribution were used to model homogeneous and heterogeneous porous media.On the basis of the flow in pore throat model,the relative expressions between pressure drop and flow rate of viscoelastic fluid and power-law fluid in 2D stochastic channel bundle were presented.The percolation models of the two kinds of fluid were developed on the basis of Darcy equation.Equivalent permeability was put forward to measure the seepage ability of non-Newtonian oil-displacement agent.The results show that for the viscoelastic oil-displacement agent,the seepage ability decreases with the increase of viscoelasticity,diurnal injection,and heterogeneity and mean pore size of porous media.For the power-law fluid,percolation is the function of power-law exponent and pore structure regardless of diurnal injection.The seepage ability increases with the decrease of power-law exponent,mean pore size and heterogeneity.

Key words: chemical flooding, viscoelastic fluid, power-law fluid, percolation capacity, equivalent permeability, oil-displacement agent, porous media

摘要： 以扩张-收缩和收缩-扩张流道模拟油藏中的孔喉,以流道尺寸服从同一和不同分布的二维随机变截面微管束模拟油藏中均质和非均质孔隙介质,采用数值方法对比考察了粘弹型和幂律型驱油剂在单个孔喉和二维随机变截面微管束模型中的流动特性.建立了驱油剂在变截面微管束中流量与压降的关系式,结合达西定律,得到了等效渗透率的表达式,并以该参数作为评价驱油剂在地层孔隙介质中渗流能力的重要指标.结果表明,粘弹型驱油剂在孔隙介质中的渗流能力随着粘弹性、平均孔隙尺寸、孔隙介质非均质性程度及日注入量的增加而降低.幂律型驱油剂的渗流能力与日注入量无关,而只是幂指数与孔隙结构的函数.其渗流能力随着幂指数的减小而增大,平均孔隙尺寸和孔隙介质的非均质性程度越小,其渗流能力越高.

关键词: 化学驱, 粘弹性流体, 幂律流体, 渗流能力, 等效渗透率, 驱油剂, 多孔介质