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=
B
1
γ
γ+A
1
A
1
n−1
(1/n)
e
(C/T+D×W)
where
μ is the viscosity,
γ is the shear rate,
T is the temperature, and
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.