Surfactants for enhanced oil recovery: A critical review of mechanisms, performance, reservoir compatibility, and field applications
Year: 2026
Type: article
Abstract: The use of surfactants in enhanced oil recovery (EOR) is a promising technique for mobilizing trapped oil after primary and secondary recovery. Analysis of the existing literature revealed that conventional surfactants can effectively alter interfacial tension (IFT), emulsification, wettability, and adsorption behaviour under ambient conditions. However, under harsh reservoir conditions, these surfactant properties are limited due to complex mechanisms. Therefore, understanding of these mechanisms is essential for developing surfactants that are compatible with reservoir fluids under demanding conditions, which is currently limited in the literature. This review provides a comprehensive evaluation of the mechanisms and performance of various surfactants that are currently used for EOR. Moreover, it describes in detail the significance of chemical stability, salt tolerance, and thermal resistance for reservoir compatibility through a comparative study of surfactant classes. Studies conclude that surfactants reduce IFT and mobilize oil. Furthermore, emulsification aids in displacing oil by forming a stable emulsion, while wettability changes rock surfaces towards aqueous-wet, which allows oil to be easily displaced. However, surfactant loss remains a major challenge due to adsorption. The maximization of surfactant performance requires an ultralow IFT (≤10 −3 mNm −1 ), controlled emulsification, efficient wettability alteration, and reduced adsorption. Finally, future directions are outlined, and guidelines for elucidating surfactant-reservoir interactions to enhance oil recovery under extreme conditions are recommended.
Institution: King Fahd University of Petroleum and Minerals
Language: English
Subfield: Ocean Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,190
OpenAlex ID: W7222998092