Formulation and characterisation of polymer and nanoparticle-stabilized anionic surfactant foam for application in enhanced oil recovery

This study investigates the synergistic effect of an anionic surfactant, nanoparticles, and polymer on enhancing foam properties for enhanced oil recovery (EOR). We screened various nanoparticles and found that silica, CaCO3, and boron nitride exhibit synergistic interactions with the surfactant alpha-olefin sulfonate (AOS). Among them, CaCO3 showed the highest foam stabilization at an optimal concentration of 500 ppm. The addition of nanoparticles increased electrostatic repulsion and altered ionic strength, reducing surface tension and leading to smaller, more stable foam bubbles. The nanoparticles formed networks within the foam lamellae, slowing liquid drainage and preventing bubble coalescence, particularly in the presence of oil. Incorporating the polymer polyacrylamide (PHPA) further enhanced foam stability and apparent viscosity, resulting in the most stable and oil-tolerant foam. The combined AOS, PHPA, and nanoparticle formulation achieved up to 27 % incremental oil recovery over secondary methods, highlighting significant synergistic effects. This formulation effectively addresses the limitations of traditional surfactant-stabilized foams, offering a promising solution for EOR applications by improving foam stability and oil recovery efficiency. [Display omitted]