Flow of polymer solutions in porous media: inadequacy of the capillary model

Experimental measurements show that conventional capillary models are inadequate for the description of the flow of nonlinear purely viscous solutions in porous media. A theoretical analysis indicates that any model for the flow of purely viscous polymer solutions in porous media must meet 2 criteria. First, the model must include expansion and contraction regions where excess pressure drops occur. Secondly, the rheologic model for the fluid must include the characteristic transition from Newtonian behavior at low shear rates to shear-thinning behavior at high shear rates. 17 references.