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° 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.