Approaches to predict viscosities of crude oil blends

Based on the viscosity of individual crude and its fraction in blends, the viscosity of crude blend was calculated with a mathematic model. Ten previous published empirical models including Arrhenius-type model, Bingham model, Cragoe model and so on, were reviewed and discussed. The study used 654 sets of viscosity data of 70 crude blends to verify these ten published models, with 14 crude oil samples from Xinjiang were involved. Among the ten models, the modified Cragoe model agreed best with the experimental data, which needs the input of the viscosity of every binary blend at a mixing ratio of 1:1. Its absolute average relative deviation is 7.7%. Furthermore, based on these data and the reported models, three new empirical models were developed. The new ones are available without the viscosity of every binary blend at a mixing ratio of 1:1. Their predicting data agree well with the experimental data when the absolute average relative deviations from 12% to 17%.