FLOW OF POLYMER SOLUTION THROUGH POROUS MEDIA.

Abstract

Addition of a small amount of soluble polymers in flood water is known to improve its sweep efficiency considerably because of decrease in the mobility of the driving fluid. The flow of a polymer solution in porous media, however, exhibits anomalous behavior and is not adequately understood, particularly in respect of polymer retention in porous media and its influence on flow behavior. Flow studies were conducted with two hydrolyzed polyacrylamides. It is concluded that (i) hydrolyzed polyacrylamide solutions exhibit pseudo-plastic behavior at low shear rates expected in porous media, (ii) the resistance factor increases with increase in the flow rate due to forcing of polymer molecules in smaller pores, (iii) mechanical entrapment is the dominant mechanism of polymer retention, and (iv) the optimum slug size in polymer flood is about one pore volume of the medium.