Viscoelastic Effects in Polymer Flow Through Porous Media
Authors: Gogarty W.B. , Levy G.L. , Fox V.G. 
Published: December 2007

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Introduction
The oil industry has shown a great deal of interest in polymer solutions for use in recovery operations. A small amount of polymer in the injected water of flooding polymer in the injected water of flooding operations reduces the mobility of the driving phase. With the use of polymer solutions for phase. With the use of polymer solutions for recovery operations, the need has developed to understand and describe the mechanisms of non-Newtonian flow through porous media.
Many investigators have studied the flow of fluids through porous media. Early investigators, such as Darcy and Kozeny, formulated equations for predicting pressure drop versus flow rate relationships for Newtonian fluids. In recent years, investigators have modified Darcy's equation to account for flow of purely viscous, non-Newtonian fluids. Some purely viscous, non-Newtonian fluids. Some workers have mentioned the effects of elasticity on flow through porous media. One rheological model has been reported where an empirical term is used to describe the effect of elasticity during flow through porous media. porous media. The present investigation shows how viscoelastic fluids behave while flowing through unconsolidated porous media. Details are given on the performance of various polymer solutions in a capillary flow device. polymer solutions in a capillary flow device. This instrument was used to determine if selected polymer solutions exhibited elastic properties. Rheological results are presented properties. Rheological results are presented for different polymer solutions. Flow results in porous media are given for these same polymer solutions. Rheological and flow results polymer solutions. Rheological and flow results are compared as a means of considering the effect of viscoelasticity on polymer solution flow through porous media. A modified form of Darcy's law is presented for use with viscoelastic liquids.

SOLUTION CHARACTERIZATION
Polymer solutions for this investigation were prepared as specified in Table 1. All polymers were mixed in distilled water. polymers were mixed in distilled water. Polymer was added slowly and the solution stirred Polymer was added slowly and the solution stirred gently by hand to avoid shear degradation. For the more concentrated solutions, the polymer addition period took up to one day. After polymer addition period took up to one day. After standing for a few days, solutions were filtered through a cotton cloth to remove any gelled material.