The lack of durability of foams, due to the inherent instability of its bubbles, is the main reason why the foam injection for gas mobility control is not a widespread method for enhanced oil recovery. As a solution to the problem of foam stability, nanoparticles have been used in synergy with surfactants to improve foam durability. Hence, it is relevant to evaluate the interaction between nanoparticles and surfactants. In a fluid, nanoparticles generally have a net surface charge and the same can be said of ionic surfactants, so in the dispersions of nanoparticles in surfactant solutions (nanofluids), the adsorption processes of surfactant on nanoparticles occur mainly by electrostatic interactions. Due to the adsorption of surfactants onto nanoparticles, their surface wettability can change, leading them to migrate from the bulk of the fluid to the interface of the bubbles formed by the foam. In this work, silica nanoparticles with different surface characteristics were used in conjunction with an alpha-olefin sulfonate surfactant to stabilize natural gas foams. The findings indicate that the addition of nanoparticles in natural gas foams improved the performance of the surfactant up to 70%. Besides, nanoparticle-surfactant interactions were analyzed through adsorption experiments to provide better insights into the effect of the nanomaterials in the stability behavior of natural gas foams. In this sense, the adsorption of the surfactant is higher in on silica nanoparticles that exhibit less acidic surface and a lower net surface charge. Thus, indicates that these parameters have a substantial effect in the adsorption of surfactants, which means that the electrostatic interactions are mainly responsible for the adsorption process. The foam stability tests indicate that there is an optimal surfactant/nanoparticle ratio that generates greater foam stability for each nanomaterial, where higher surfactant adsorption leads to lower nanoparticles amount to be used. |