Comparison of correlations based on API gravity for predicting viscosity of crude oils

• Comparison of available correlations for predicting viscosity of crude oils.
• New correlation for viscosity prediction is proposed.
• High accuracy of proposed correlation for heavy crude oil.
• Two-coefficient correlation as a function of API gravity and absolute temperature.

Correlations for the prediction of dynamic viscosity of crude oils as a function of the absolute temperature and API gravity are compared. Twelve crude oils with wide range of API gravity (12.4–43°API) are used for comparison of correlations. It was identified the need of an accurate correlation for calculating viscosity of heavy crude oils. Thus, a new correlation is proposed, which was validated using viscosity values different to those used to derive it. Comparison of results using literature information and own set of data indicated better predictability over other correlations previously reported. High accuracy was observed with the developed correlation for crude oils with low API gravity (⩽21.1°API), so that it resulted to be more accurate for calculating viscosity of heavy crude oils.

%AAD value as a function of API gravity crude oil used in the validation analysis [Beggs (▵▵), Glaso (□), Kartoatmodjo (○), Hossain (◊), Egbogah (▴▴), Elsharkawy (■), Naseri (●), Alomair (♦), and this work (+)].Figure optionsDownload as PowerPoint slide