(57a) Interfacially-Active Nanohybrids for Improved Oil Recovery

Development of enhanced oil recovery (EOR) techniques is an important challenge for engineers and researchers working in the oil industry.   In recent years, the use of nanoparticles for application of chemical EOR has attracted significant attention.  In this contribution, a novel technique for potential enhancement of oil. The technique consists in injecting amphiphilic nanoparticles into the water.  These hybrid nanoparticles can simultaneously act as emulsion stabilizers as well as carriers for catalytic species such as a metal that can be active for partial oxidation and hydrogenation reactions. Partial oxidation of organic compounds can lower the water – oil interfacial tension. Partial hydrogenation can enhance the viscosity of the oil phase in the emulsion, thus improving the mobility ratio. In addition, partial hydrogenation can be an effective pre – treatment of the oil to favor the subsequent partial oxidation.

We have investigated the application of nanohybrid particles that preferentially locate at the water/oil interface and catalyze oxidation and hydrogenation, and pondered how these reactions could impact EOR operations.   In a previous study, we demonstrated the stabilization of Pickering emulsions by nanohybrid particles composed of Single-Walled Nanotubes (SWNT) and silica.  We found that the volume fraction of emulsion and droplet size can be controlled by adjusting the water/oil (W/O) ratio and the amount of nanohybrids.  Here, we describe the applications of the concept by incorporating active species on the surface of nanohybrids, which catalyze reactions at the oil-water interface.  We found that the oxidation of aromatic compounds and hydrocarbons at the interface reduces the oil – water IFT since the species with higher dipole moment (oxygenates) dominate the interface. Also, the complete hydrogenation of the polyaromatic molecules increases the viscosity of the resulting products. The selective hydrogenation could be an appropriate strategy to increase the viscosity of the sweeping fluid (emulsion), improving the oil mobility.

In addition, we have conducted mobility studies on crushed Berea sand columns and demonstrated that the synthesized nanohybrids successfully flow through the porous media, particularly with the aid of small amounts of polymers.