Viscosity of natural-gas mixtures: Measurements and prediction

New measurements of the viscosity of a natural-gas mixture are reported. Th e measurements were performed in a vibrating-wire viscometer, in the temper ature range fi om 313 to 455 K at a pressure close to atmospheric and in th e temperature range from 240 to 353 K at pressures up to 15 MPa. The uncert ainty of the reported measurements is estimated to be +/-1%. The data were employed to validate further an existing method of predicting the viscosity of mixtures at high pressures.