Influence of Polymer Gel Types on Relative Permeability Changes: A Review

Abstract Numerous studies have investigated the impact of gels on relative permeability changes. Most of them focus on the reduction of permeability in porous media, which is assessed by examining the increase in pressure required for fluid injection. In this context, F rrw and F rro are defined and analyzed for their variations. Besides, gels behave as porous media with respect to water, exhibiting significantly lower permeability compared to water itself. However, when subjected to oil, these gels function as impermeable materials due to the application of injection pressure. As the rate of water injection increases within the porous medium, the value of F rrw decreases. This decrease does not necessarily correlate with an increase in F rro ; if an increase does occur, it typically does not revert to the original F rro value observed before the increase. This phenomenon is attributed to irreversible alterations in the gel structure. Consequently, this review examines various types of gels.