Studying the Mechanistic Behavior of Heavy Oil Displacement Using a Group of Alkalis and Surfactant Mixtures

Abstract

In this study, a mixture-based sulfonate-based surfactant with a novel formula capable of functioning in real oil reservoir conditions was prepared and some microscopic parameters, like its compatibility state, emulsion behavior, interfacial tension, and temperature dependency in the presence of a heavy oil sample, and two of the most popular alkalis were analyzed; then the results were compared with those of a commercial sulfate-based surfactant. The designed surfactant provided an optimum three-phase region in relatively high salinity media; however, its optimum value decreased when adding any alkaline materials; this trend was reversed for the solutions made with the sulfate-based surfactant. Increasing the ions' concentration and the extra reaction by adding alkali to the solutions stabilized the generated emulsions in all the solutions but considerably changed the optimum salinity area. Increasing the temperature reduced the optimum salinity strength by weakening the effective electrostatic forces around the droplets. The novel surfactant provided solutions with quite low IFT values in high salinity media but did not have relative synergy with alkali addition. The overall mechanistic results and the proper compatibility of this novel surfactant make it a favorable chemical for fluid displacement and emulsion generation in porous media even in the absence of any extra alkalis.