Study of the effect of Fe2+ on rheological behavior of HPAM

In view of serious viscosity losses of the fluid solution into wells in the process of polymer flooding, the paper analyzed the reasons of the loss of polymer solution viscosity, mainly about the influence of Fe2+ concentration on polymer rheological properties. We respectively studied the influencing laws of different Fe2+ concentration in the solution to polymer intrinsic viscosity, viscoelasticity and tensile rheological property. The results showed that when Fe2+ concentration was under 0.5 mg/L, HPAM solution intrinsic viscosity, apparent viscosity and stretching rheological property were greatly reduced with the increase of Fe2+ concentration, while the influence trend slowed down gradually when Fe2+ concentration was over 0.5 mg/L. Thus, Fe2+ concentration of the injected water should be controlled under 0.5 mg/L, which can effectively eliminated the adverse impact of Fe2+ on the polymer solution viscosity.