An Alternate Model to Correlate Natural Gas Viscosity Based on Corresponding States and Lennard-Jones Averaged Intermolecular Potential Field

The viscosity of natural gas has considerable theoretical and practical significance in the design and operation of gas transportation, production, and processing. In order to quickly and cheaply obtain the viscosity data of natural gas, an alternate predictive model was developed based on corresponding states and Lennard-Jones averaged intermolecular potential field. Then, the accuracy of the model was assessed with 2389 experimental data points from 15 natural gas specimens after 2000, which sat in temperature and pressure ranges: 241–454 K, 0.1–140 MPa. The result shows that the averaged absolute percent deviation was less than 2.1%, wherein for the 793 data points measured via the same device within 0.5% relative uncertainty, the averaged and maximum absolute percent deviation were ≤ 0.72% and 2.7%. While comparing against ten existing models, the new model had the advantages of simplicity, accuracy, convenience, and theoretical background. In the natural gas viscosity analysis, calculation, and design, the use of the new model is recommended.