Surface tension, dynamic light scattering and rheological studies of a new polymeric surfactant for application in enhanced oil recovery

Abstract

The present paper deals with the synthesis of a new polymeric surfactant (PMES) and characterization of its aqueous solution for application in enhanced oil recovery. The synthesized polymeric surfactant possesses properties of both surfactant and polymer. Surface tension, particle size distribution and rheological properties of the polymeric surfactant have been studied and analyzed under the influence of various factors. IFT was found to decrease with concentration of PMES and salt addition. The reduction of surface tension at optimum salinity is comparable to any commercial surfactant. DLS measurement showed that hydrodynamic particle diameter generally increased with concentration of PMES due to aggregation of molecules and decreased with salt addition due to disaggregation of molecules. Viscosity was found to increase with increase with PMES concentration but decreased with temperature rise and salt addition. Analysis of rheological data showed that polymeric surfactant behaved ideally up to a critical shear rate of 50s−1 but exhibited shear-thinning or pseudoplastic behavior at higher shear rates. Its viscoelastic properties were studied and showed that storage modulus G′ and loss modulus G″ increased with increasing PMES concentration. 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.