Rheological properties and performance evaluation of synthesized anionic polymeric surfactant for its application in enhanced oil recovery

Polymeric surfactant is an attractive alternative to conventional surfactant-polymer system for application in enhanced oil recovery, as it plays dual role of reduction of interfacial tension (IFT) and improvement of mobility ratio. The present paper deals with the synthesis and rheological characterization of a novel polymeric surfactant derived from Jatropha oil. Molecular aggregation of polymer in aqueous solution has been confirmed by DLS studies, which increases with increase in concentration. The viscosity results indicate the good shear stability of system at higher shear rate as well as higher temperature for application in conventional oil reservoir. The polymeric solutions show peculiar behaviour with shear thinning nature at low shear rate and shear thickening nature at higher shear rate because of its unique molecular properties. The viscoelastic properties of the solutions were investigated and it has been found that storage modulus (G′) and loss modulus (G″) follow the Maxwellian fluid behavior. Specific frequency (SF) indicated by the crossing point between G′ and G″ on the viscoelastic curve represents the point of transition between elastic and viscous phases of the polymeric surfactant system. The effect of silica nanoparticle on polymer viscosity was also studied and it has been found that introduction of silica nanoparticle dramatically increases the polymer viscosity and stability of the solution with respect to temperature.