Effects of Polymer Adsorption on the Oil Recovery during Polymer Flooding Processes

The influence of water-soluble polymer adsorption on the flow behavior and oil recovery was investigated. This article presents results from an extensive numerical simulation performed for a two-well model in a five-spot pattern operating under polymer flood followed by waterflood. For different systems of adsorption parameters, slug sizes, and reservoir properties performances were compared in terms of cumulative recovery and water-oil ratio (WOR) at the production well. Properties of polymers and reservoir rocks such as adsorption parameters and vertical permeability heterogeneity are shown to impact the predicted recovery. Improvement in oil recovery and reduction in WOR was obtained for smaller values of adsorption parameters. Polymer flood in reservoirs with a severe permeability contrast between horizontal strata leads to lower volumetric sweep efficiency and displacement efficiency. The size of the polymer bank also affects the predicted recovery.