Enhanced oil recovery performance of gemini surfactant-stabilized nanoemulsions functionalized with partially hydrolyzed polymer/silica nanoparticles

Nanoemulsion flooding is a novel route to enhanced recovery of petroleum resources over conventional water-flood by effective detachment and mobilization of residual oil trapped within rock-pores. In this article, we conducted experimental investigations to test the functionality of robust nanoemulsions comprising of gemini surfactant/polymer/silica nanoparticle assemblies; and explained mechanistic behavior of nanoemulsion-assisted oil displacement on a molecular scale. The presence of nano-sized oil droplets was confirmed by light scattering and CryoTEM imaging. Pseudoplastic behavior of nanoemulsions was identified, and viscous activation energies were determined using Arrhenius modeling. Viscoelasticity studies confirmed that elastic modulus dominated over viscous modulus, indicating that deforming forces do not exceed inter-droplet repulsions and interfacial stresses. Hence, nanoemulsion (oil) droplets retain their structural integrity under varying shear conditions. Core-flooding experiments showed that enhanced oil recoveries (EOR) of nanoemulsions improved over conventional aqueous fluids to 21-27% range of original oil in place (OOIP). (C) 2020 Elsevier Ltd. All rights reserved.