The Influence of the Microstructure of W/O Emulsion of Waxy Crude Oil on Its Rheology

Abstract

In this article, the viscosity-temperature characteristics of W/O waxy crude oil emulsion under different microstructures were studied, and the characteristics of the microstructure were described by the analysis of the dispersed phase parameters including the average particle size, the degree of dispersion, and the nonuniformity of average particle size. On this basis, we discuss the effects of temperature, shear rate and the microstructure on the apparent viscosity of Daqing crude oil emulsion. The results showed that with the increasing of stirring speed, the number of droplets and the degree of dispersion phase dispersion increased, average droplet size and nonuniformity of average particle size reduced; the average particle size of the dispersed phase decreased by 0.5 μm, and the abnormal point increased by about 1°C. For emulsions with the same microstructure, as the temperature or shear rate rising, the rate and percentage of the reduction in apparent viscosity decreased. At the same temperature or shear rate, the reduction rate in apparent viscosity increases with the average particle size of dispersed phase decreases, in contrast to the percentage of reduction in apparent viscosity, which revealed a definitive correlation between average particle size of dispersed phase and the apparent viscosity in the non-Newtonian fluid that from 34°;C to 48°;C; the absolute value of Pearson’s correlation coefficient was above 0.8, which was highly negatively correlated; as the temperature rose, the absolute value of Pearson’s correlation coefficient decreased from 0.839 to 0.216.