The effect of resins concentration and polarity on the viscosity and impedance of electrically-treated waxy oils

Applying an electric field to waxy oil may significantly improve its cold flowability. Our previous study has demonstrated that the accumulation of asphaltenes and resins on the surface of wax particles, i.e., interfacial polarization of wax particles, is the essential mechanism of this electrorheological phenomenon. The influence of asphaltenes concentration on the performance of the electrical treatment has been studied. In this paper, the influence of the concentration of resins, the most abundant non-hydrocarbon component in crude oil, on electrically-treated waxy oil's viscosity and impedance was investigated for the first time by using model oils containing resins in the concentration range of 0.05 wt% - 5.00 wt%. It is found that the effect of resins concentration on viscosity and impedance is not monotonous, with both the viscosity reduction and impedance increment induced by the electric field decreased first and then increased with increasing resins concentration at a given amount of precipitated wax. Increasing the polarity of resins would alleviate the viscosity reduction and impedance increment. This work further demonstrates that resins accumulation on the wax particles surface does occur.