New permeability model for gel coated porous media with radial flow

Abstract

Gel polymer has been widely used to reduce water production in mature oil reservoirs. One of the challenges in this area is evaluation of permeability of media after the gel treatment. Darcy's law has been used for this purpose while this equation has been developed for rigid porous media. In this study, a new mathematic model was introduced to calculate the permeability of gel coated porous media. For this purpose, a modified version of Brinkman equation was used. This model showed that permeability of gel impregnated porous media is a function of pressure drop, fluid viscosity, and gel viscoelastic properties. In order to obtain performance of new permeability model, several experiments were carried out in a porous media with radial flow. A copolymer of 2-acrylamido-2-methyl-propanesulfonic-acid sodium salt (AMPS) and acrylamide (AcA) gelant was used to form the gel in situ. Finally, to investigate the applicability of polymer gel treatment to water shut-off in porous media (sandpack), residual resistant factors (RRF) were calculated based on new permeability model.