聚合物溶液在孔隙介质中的渗流机理

以收缩流道作为孔喉模型,采用数值方法研究了粘弹性流体、幂律流体和牛顿流体在孔喉中的流动压力梯度随流变参数和喉道直径的变化,以此作为流体在多孔介质中渗流的理论基础,探讨了3种具有不同流变性质的流体在多孔介质中的流动阻力特性。结果表明,对于粘弹性流体,阻力系数随着松弛时间和流速的增加而增大,随充填颗粒尺寸的减小而增大;对于牛顿流体,阻力系数为常数;对于幂律流体,阻力系数为幂指数、稠度系数、孔隙度和渗透率的函数。

Percolation mechanism of polymer solution through porous media

The flow behavior of viscoelastic fluid, power law fluid and Newtonian fluid in pore throat was studied by numerical method. The individual pore throat was modeled by a constricted channel. The relationship between the pressure gradient and velocity relationship and the variation of pressure gradient with rheological parameter and throat diameter were presented, which provide a basis for theoretical simulation of micro-flow characteristics in random porous medium. The resistance equations for power law fluid and viscoelastic fluid through porous media were developed. The results show that the dimensionless loss coefficient increases with the increase of relaxation time and velocity as well as the decrease of grain size for viscoelastic fluid. The dimensionless loss coefficient is a constant for Newtonian fluid, and a function of power law exponent, consistency coefficient, porosity and permeability for power law fluid.