Advanced polymer-based surfactant for improved heat and salinity stability in enhanced oil recovery processes

Enhancing oil recovery through surfactants has proven to be a successful strategy in recent times. However, traditional surfactants have their limitations, particularly in terms of stability under high temperatures and salinity levels. This study delved into a groundbreaking macromolecular polymeric surfactant, S-AV, which holds the unique ability to transform rock surface characteristics, effectively stripping away residual oil while maintaining resilience against elevated temperatures and salinity. S-AV was synthesized through a free-radical copolymerization process, incorporating benzyl, perfluoroalkyl, alkyl-, benzyl-, ethylene glycol, and amide-alkyl-sulfonate groups, ultimately yielding a comb-like molecular structure. S-AV demonstrated exceptional prowess, swiftly reducing the underwater oil contact angle to 53.4 degrees in just 48 h. This synthesized surfactant also retained its phase stability up to salinity levels of 36,000 ppm, with temperature having no disruptive impact on its phase stability performance. Furthermore, S-AV showcased remarkable viscosity reduction in conditions of high temperature and salinity. The core flooding experiments underscored the potential of S-AV, as its injection led to a significant oil recovery rate of up to 83%. These findings position S-AV as a promising candidate for practical enhanced oil recovery applications.