A general model for the viscosity of waxy oils

Abstract

A generalized viscosity model suitable for describing the non-Newtonian behaviour of waxy crudes has been developed. The model, which has the following expression predicts the viscosity as a function of shear rate, temperature, and wax concentration: μ = B1/γ [(γ + A1/A1)n - 1 ](1/n)e(C/T + D × W) where μ is the viscosity, γ is the shear rate, T is the temperature, W is the percentage of wax. The viscosity measurements were performed by measuring the rheological properties of the waxy oil at four different concentrations and five different temperatures. A reduced form of the model may be used to predict the viscosity of Newtonian and non-Newtonian fluids with or without yield stress. The proposed model was found to fit the experimental data well as demonstrated by a high coefficient of correlation (97.5%). The nonlinear regression analysis was used to determine the model parameters A, B, C, and n.