Pore-scale mechanism for selective permeability reduction by polymer injection

In this paper we discuss a pore-scale picture of the mechanism underlying the selective permeability reduction caused by the adsorption of a polymer layer in a water wet porous medium. Our analysis is based on the use of physically representative model of the porous medium, which allows us to estimate directly the expected permeability reduction. Comparison of model predictions with coreflood experimental data has revealed that the selectivity in permeability reduction cannot be explained if the polymer layer is modeled as a rigid, impenetrable layer. This result is consistent with the suggestion that swelling-shrinking phenomena of the adsorbed polymer later is responsible for the selectivity in the permeability modification induced by these treatments.