Characterization of SPN Pickering emulsions for application in enhanced oil recovery

Abstract

Abstract Emulsion, stabilized by solid particles that get adsorb on to the surface of the interface is known as Pickering emulsion, which has potential application in enhanced oil recovery (EOR). In present study, a stable oil-in-water surfactant–polymer–nanoparticle (SPN) Pickering emulsion has been formulated using light mineral oil, carboxy methyl cellulose (CMC) and silica nanoparticles (SiO 2 ) in presence of anionic surfactant, for use in EOR. The nanoparticles (NPs) show synergetic effect in presence of surfactant and polymer thus prevents the droplets from coalescence and lowers the interfacial tension (IFT) at the oil–water interface. The emulsion was characterized in terms of particle size, creaming behavior and zeta potential measurements. The viscosity remains stable in wide range temperature (30–100 °C) indicating thermal stability of the Pickering emulsion. The emulsion exhibits pseudo-plastic behavior in wide range of shear rate (1–1000 s −1 ). The investigation of viscoelastic properties (G′ and G″) of the Pickering emulsion as a function of pressure (0–5 MPa) and temperature (30–100 °C) shows a stable value of G″ indicating better flow ability of the emulsion. The emulsions show viscous behavior below the specific frequency (SF) indicated by the crossing point between G′ and G″ on the viscoelastic curve and elastic behavior above the SF. Flooding experiment was conducted on sand pack system to study the efficiency of Pickering emulsion in EOR and additional recovery of more than 24% was observed after conventional water flooding.