Effect of resins, waxes and asphaltenes on water-oil interfacial properties and emulsion stability

In this paper, the interfacial properties of simulating water with different components of crude oil, including resins, waxes and asphaltenes, are investigated by interfacial tensiometer, surface viscoelasticity and zeta potential instruments and the results are then correlated with emulsion stability. The results show that the interfacial tension of the O/W (oil-in-water) emulsion formed by resins is lower and the interfacial shearing viscosity is higher than that formed by waxes. Besides, the O/W emulsion with resins has the largest absolute value of zeta potential and accordingly it shows the highest stability. And the O/W emulsion with waxes presents the lowest stability which has the lowest interfacial shearing viscosity. Differently, the stability of the W/O (water-in-oil) emulsion with asphaltenes is strongest, followed by that with resins or waxes. This is mainly because the interfacial shear viscosity of asphaltenes and water is the largest, resulting in the strongest strength of interfacial film. This work provides more insights into the mechanism of emulsion stability caused by resins and asphaltenes which can be useful for the petroleum science and industry. (C) 2016 Elsevier B.V. All rights reserved.