Improving the interfacial performance and the adsorption inhibition of an extended-surfactant mixture for enhanced oil recovery using different hydrophobicity nanoparticles

Chemical surfactant injection is one of the Enhanced Oil Recovery (EOR) technologies, revealing a large potential to recover the undisplaced oil into the porous media. Many techniques to improve this methodology have been proposed recently, such as the use of nanoparticles. However, very few studies have focused on the effect of the surface hydrophobicity of nanoparticles on the surfactant efficiency improvement. Furthermore, most studies focus on the use of formulations composed by a single molecule, but in common field applications, the use of surfactant mixtures is recommended since lower Interfacial Tensions (IFT) can be reached. This research work aims to study the use of two different hydrophobicity nanoparticles (Aerosil 308 and Aerosil R812S), to improve the efficiency of an anionic surfactant mix formulation (typically used for EOR processes) from oil/water interfacial reduction and adsorption inhibition. The main purpose is to analyze the resulting interactions between the nanoparticle and the surfactant molecules through IFT measurements and surfactant adsorption inhibition on a solid surface. All systems stability were determined using a Turbiscan, interfacial tensions were measured by a spinning drop tensiometer and, static and dynamic adsorption were calculated to determine the behavior of the main formulations. Results showed the surface nature of nanoparticles has an important effect on the oil-water interfacial tension evolution and on the surfactant adsorption inhibition. Both nanoparticles' types showed a good performance under specific conditions. However, hydrophilic nanoparticles exhibited a better performance than hydrophobics. The Interfacial performance displayed nonmonotonic trends, especially in adsorption assessments wherein static and dynamic experiments exhibited different behaviors for the same type and concentration of nanoparticle, displaying a different pattern from the literature.

Automated summary

Chemical surfactant injection is an effective method for Enhanced Oil Recovery (EOR) and the use of nanoparticles can further improve its efficiency. This study investigates the effect of nanoparticle surface hydrophobicity on surfactant efficiency. It is found that the nature of nanoparticles has a significant impact on oil-water interfacial tension and surfactant adsorption inhibition. Hydrophilic nanoparticles show better performance than hydrophobic ones. The results also demonstrate nonmonotonic trends in adsorption assessments, deviating from previous studies.