A simple correlation to estimate natural gas viscosity

• Generalized natural gas viscosity correlation.
• Validity in temperature range from 241 to 473 K and pressures range between 0.1 and 137.8 MPa.
• AARE% of 5.05% in the comparison with experimental data.

A general investigation of the viscosity of natural gas as a function of temperature, pressure and composition was carried out to develop a generalized correlation. The model obtained was based on 3231 data points of 29 multicomponent mixtures in wide ranges of pressures (0.1–137.8 MPa), temperatures (241–473 K) and specific gravities (0.573–1.337). Correction terms for non-hydrocarbons of hydrogen sulfide, carbon dioxide and nitrogen were up to 70, 54.4 and 15.8 of mole percent, respectively. The arithmetic average of the model's absolute error was found to be 5.05%, which is acceptable in engineering calculations and has superiority over other methods in its class.