Abstract: The porous medium was regarded as a converging-diverging pore model.On the assumption that the total pressure drop of polymer solution flowing through the converging-diverging pore model is equal to the pressure drop of shear flow adding the pressure drop of elongation flow,a formula of elastic viscosity was established by the use of the microelement analysis method.This model can describe the elongation flow degree of polymer solution through converging-diverging pore model.Based on the flow experiment data of three kinds of hydrolyzed polyacrylamide solutions with different relative molecularmasses flowing through artificial cores,the relative curves of elastic viscosity with Deborah number were plotted.The curves show that the elastic viscosity of polymer solution will increase obviously,as Deborah number is from 0.02 to 0.03,which indicates that the elastic viscosity formula can show the elongation flow degree of polymer solution through porous medium.

Key words: polymer solution, porous medium, converging-diverging pore model, elastic viscosity, shear flow, elongation flow

摘要： 将多孔介质视为缩扩孔隙模型,对聚合物溶液在这种模型中的流动总压降等于剪切压降和拉伸压降之和的假设下,用微元分析方法建立了表征聚合物溶液在缩扩孔隙模型中拉伸流动弹性粘度公式.用3种不同相对分子质量的聚丙烯酰胺(HPAM)溶液在人造岩心中的流动实验数据绘制了弹性粘度与Deborah数的关系图,关系曲线表明,当Deborah数大于0.02～0.03时,弹性粘度显著增大.由此推导的弹性粘度公式可用来表征聚合物溶液在多孔介质中拉伸流动发生的程度.

关键词: 聚合物溶液, 多孔介质, 缩扩孔隙模型, 弹性粘度, 剪切流动, 拉伸流动