The viscosity of multicomponent natural gas-mixtures containing hydrocarbon
s (C1 through C7) is predicted by modifying a previously published dilute-g
as viscosity model and extending its applicability to a wide range of tempe
rature and pressure conditions including liquid and gas states. Nitrogen, o
xygen, carbon dioxide, and helium are also included among components of mix
tures for which published viscosity data are available. The approach takes
advantage of currently available formulations and models For the density an
d viscosity of pure fluid constituents of natural gases. The predicted visc
osity is compared with available data in bath pas and liquid regions. Compa
risons of calculated values to the available measurements of viscosity of n
atural gas mixtures and of binary, ternary, and quaternary mixtures of cons
tituent fluids are summarized to illustrate the accuracy of the predicted v
alues.