A new correlation for the viscosity of waxy oils

Abstract

A number of laboratory and field experiments on the flow behavior of heavy and waxy oils were reported in the literature. These crudes are attractive, from the environmental viewpoint, because of their low sulphur contents. However, handling waxy oils is difficult. The flow of heavy and waxy crudes in pipelines and in reservoir formations is not as easy as light and medium oils. A mathematical correlation has been developed to describe the viscosity of waxy base oil as a function of shear rate, temperature, and wax concentration: μ=A exp (B/T+CW) γ ̇ D where μ is viscosity, T is temperature, W is % wax by weight, and γ is the shear rate. The experimental tests were performed by measuring the rheological properties of the waxy oils using rotational viscometer at different temperatures (9, 12, 15, 18, 21, 24°C) and wax concentrations (2%, 4%, 6% and 8% by weight). The proposed correlation was found to fit the experimental data well as demonstrated by high coefficient of correlation—95.71%. A computer program based on the least-square regression on orthogonal functions was used to determine the parameters A, B, C and D.