DefinePK

Abstract

The main goal of the Russian O&G sector is to raise the oil recovery factor (ORF) through developing new and improving existing technologies of enhanced oil recovery. Among the latter, most efficient are physicochemical methods for the formation stimulation based on the use of different types of surfactants. Surfactants incorporated in chemical formulations bring about efficient residual oil displacement after flooding due to the ultra low oil/water interfacial tension and a change in the capillary number. According to a few studies the best effect in residual oil recovery was achieved with the formulations comprised of different types of surfactants. When mixed, such surfactants exert synergistic effects on the reagent’s surface activity, its rheology and behavior in the variable formation conditions. This paper discusses lab test results related to the impact of the size of compound micelles comprised of a mixture of anionic surfactants sourced from low quality hydrocarbon and nonionic surfactants on efficiency of residual oil displacement in high water cut wells. It has been proven that varying of the anionic/nonionic surfactant proportion in the mixture influences dramatically the size of the formed micelles, their interfacial activity, and efficiency of high viscosity oil displacement.