On the viscosity of natural gas

This study reports new experimental viscosity measurements at high pressure and high temperature for a sour natural gas mixture. The measurements were conducted with a capillary tube viscometer at pressures ranging from 10.3 to 138 MPa and temperatures up to 444 K. The study develops a comprehensive model to predict natural gas viscosity in a wide range of pressures, temperatures and compositions. The arithmetic average of the model’s absolute error was found to be 2.4% compared with experimental data from the literature (containing the experimental data of the current study), which is acceptable for accurate engineering calculations; the absolute error demonstrates that this model is superior to other methods.