New correlations to predict natural gas viscosity and compressibility factor

This study proposed two new accurate simple explicit numerical methods for calculating the z-Factor and viscosity of natural gases. Results of these correlations are compared versus experimental data. Proposed correlation for z-Factor has 0.402 and 1.366 of Absolute Average Percent Error (AAE%) respectively versus Standing and Katz chart and experimental data. The output of this correlation can be directly assumed or be used as an initial value of other implicit correlations. In addition, this correlation is valid for gas coefficient of isothermal compressibility (cg) calculations. The new method for viscosity accounts for the presence of heptane plus and non-hydrocarbon components. This model was derived from 1260 experimental measurement of gas viscosity of eleven different mixtures with AAE% of 2.083. This model is simpler and more efficient than published correlations, and the comparisons indicate superiority of the proposed model over other methods.