Static adsorption and dynamic retention of an anti‐salinity polymer in low permeability sandstone core

Abstract

ABSTRACTThe technical viability of enhancing oil recovery (EOR) using polymer flooding has been verified. Through correcting the unfavorable mobility ratio, polymer flooding could significantly improve the macroscopic sweep efficiency of waterflooding, which makes it attractive in middle to high permeability reservoirs. However, as the depletion of these easy‐to‐produce resources, the interests of oil industry will be diverted to low permeability reservoirs and polymer flooding is believed to be one of the key methods for this type of reservoir. To meet this technological tendency, the current work investigated the applicability of an anti‐salinity polymer (KYPAM) in low permeability sandstone reservoirs. The interactions between polymer and sandstone surface including static adsorption and dynamic retention were addressed. Static adsorption data proved that the adsorptive behavior of this anti‐salinity polymer was closely related to molecular weight and concentration. The quantity of the detained KYPAM polymer in the sandstone core rapidly increased once the permeability dropped below 38 mD. High molecular weight KYPAM experienced noticeable retention compared with low molecular weight polymers resulting from the large hydrodynamic size. Due to polymer retention, the permeability of the sandstone core was significantly influenced particularly for the low permeability cores. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44487.