A Perspective Review on Nanoparticles as Mitigating Agents for Surfactant Retention in Enhanced Oil Recovery
Lucas Rego Barros Rebello, João Victor Nicolini, Helen Conceição Ferraz, Matthew T. Balhoff, Yingda Lu
Abstract
High Resolution Image Download MS PowerPoint Slide Surfactant loss due to retention in porous media can significantly impair the efficiency and cost-effectiveness of surfactant formulations for enhanced oil recovery (EOR). This retention arises from a combination of mechanisms, including precipitation, phase trapping, and adsorption, which collectively hinder surfactant performance. Given the central role of surfactant flooding in chemical EOR, minimizing surfactant retention remains a critical technical and economic challenge. To overcome these limitations, various strategies have been developed, such as employing surfactants with charges matching the rock surface and the use of alkalis, cosolvents, polymers, ionic liquids, chelating agents, negative salinity gradients, low-salinity water, and nanoparticles. In this context, this review specifically aims to provide a focused analysis of the role of nanoparticles in mitigating surfactant retention, filling a gap not fully addressed by previous reviews and highlighting their unique technical and economic advantages. We provide a comprehensive overview of the surfactant adsorption reduction capacities of different types of nanoparticles and compile the mechanisms by which they generate such an effect. Key findings show that nanoparticles can achieve significant adsorption reduction at very low concentrations (0.001–0.01 wt %), outperforming conventional inhibitors such as alkalis and polyelectrolytes while maintaining stability under high salinity and temperature reservoir conditions. We also highlight studies investigating the role of nanoparticles as surfactant nanocarriers, which facilitate enhanced reduction of the oil–water interfacial tension while simultaneously minimizing direct contact between surfactant molecules and the rock surface. Finally, we outline key challenges and propose future research directions aimed at optimizing the design and deployment of nanomaterials for improved surfactant flooding performance in EOR applications.