Experimental Evaluation of Models for Calculating Shear Rates of Polymer Solution in Porous Media

Abstract

Abstract One of the difficulties of characterizing polymer flooding comes from the non-Newtonian and time-dependent properties of polymer solutions, and shear rates must be determined to calculate the viscosity of polymer solutions flowing in porous media. Although there have been many models to do so, it is still difficult to choose which shear rate model to conduct the calculations. In this study, several polymer flooding experiments were designed and conducted in rock samples with different permeabilities to evaluate the models for determining shear rates of polymer flooding in porous media. Experiments were also conducted in simple glass capillary tubes to reduce the effect of polymer adsorption on the evaluation. Four frequently-used shear rate models for porous media were chosen to be evaluated. Using the experimental data, the values of shear rate of the four models were computed respectively, as well as the pseudopermeability of the core samples under single-phase flow but different flow rates. The best shear rate model among the four frequently-used models was determined, and the rule of making the judgments was proposed and verified, that is, the pseudopermeability at the intrinsic shear rate should be equal or close to the absolute permeability of the sample in the cases of capillary tubes.