渗流过程中聚合物溶液的流变性

Rheological behavior of polymer solution in the course of seepage flow

通过实验研究了聚丙稀酰胺 (HPAM)溶液在渗流过程的流变行为及其流变参数沿渗流方向的变化 ,建立了描述HPAM溶液流变参数沿渗流方向的变化规律的基本模型 ;探讨了HPAM溶液在高速渗流条件下所表现的弹性效应 ,建立了临界弹性流速的计算式 .结果表明 :HPAM溶液在低渗透率岩心中的剪切降解大于高渗透岩心 ;注入速度越大 ,剪切降解也越严重 ;在渗流过程中 ,HPAM溶液的流变参数沿渗流方向是变化的 ,稠度系数沿程按e指数规律下降 ,幂律指数呈线性增加 ;HPAM溶液在高速渗流时表现出粘弹效应 ;根据弹性临界流速计算模型可预测实际油藏中弹性效应表现的明显区域 .在文中实验条件下 ,计算的临界弹性流速为 2 .32 8× 10 - 3cm/s,与实验结果基本一致 .

In this paper, the rheological behaviors of polymer solution (HPAM) in the course of seepage flow and the variation of rheological behavior along the seepage flow direction are studied through experiments. The basic models about the variation of rheological parameters along the seepage flow direction are developed. The viscous\|elastic effect exhibited by polymer solution in high seepage flow velocity is discussed. The equation of elastic critical flow velocity is given. Researches show that shear degradation of HPAM solution in low permeability rock is larger than high permeability rock, and injection rate is larger, and shear degradation is more serious. In the course of seepage flow, rheological behavior along the seepage flow direction is various, and consistency coefficient decreases in index rule along the flow direction and power\|law exponent increases in liner rule. The visco\|elastic effect is exhibited in high seepage rate. Based on the critical elastic flow rate, the dominant region of elastic effect can be calculated in real reservoir. In this paper, the critical elastic flow velocity is 2.328×10 -3 cm/s in the experiment conditions.