Research Status and Prospect of Rheology of Waxy Crude Oil

In this paper, the rheological properties and viscosity reduction mechanism of waxy crude oil were reviewed. Firstly, the rheological behavior of waxy crude oil was introduced from the aspects of microscopic properties, viscosity, yield properties, thixotropy and viscoelasticity. Secondly, the effects of dissolved gas, light crude oil or alcohol on the rheological properties of crude oil were described respectively. Finally, the shortcomings and limitations of existing studies were further prospected. The future research will focus on exploring the mechanism of the effect of shear history on the microstructure of wax crystals, and establishing the constitutive model of crude oil considering the yield strain and yield stress based on the morphological and structural changes of wax crystals. Furthermore, to explore the mechanism and influence law of light component dissolution on crude oil rheology, and establish a reliable viscoelastic-thixotropic model of crude oil under the conditions of unsteady shear, wide range shear rate and ultra-low shear rate, will be the prerequisite and basis for the numerical calculation in restarting of gelled crude oil containing light component at low temperature.