VINYL SULFONATE/VINYL AMIDE COPOLYMERS AND DIFFERENT SURFACTANTS AS SUITABLE SYSTEMS IN EOR AT HIGHER TEMPERATURES AND SALINITIES.

The aim of the present article is to demonstrate the influence of alkylphenol ethoxylates and their corresponding ether sulfonates on VS/VA/AM copolymer solutions. Aqueous solutions of such copolymers were added to varying quantities of nonionic and anionic surfactants at different temperatures using salinity scans. This article discusses the results of experiments with solutions of copolymers and surfactants in terms of compatibility, viscosity yield, flow properties, shear stability, injectability, thermostability, and oil recovery. Solutions of alkylphenol ethoxylates and/or ether sulfonates show nearly the same compatibility within a broad range of temperature and salinity, both with and without polymers. Relatively small amounts of surfactants are able to influence the EOR (Enhanced Oil Recovery) properties of the polymer solutions, giving several interesting aspects for improved oil recovery.