Which viscosity correlation for low presure system?

[cmlpetro]

I need to calculate natural gas viscosity for these ranges:

SG 0.5 to 0.65
Temperature 2 to 30 degrees celsius
Pressure 30 to 650 psia

I was planning on using the Lee correlation but it is only valid for pressures greater than 100psia.

Are there any non-graphical correlations that would work well?

Thanks

 

[dcasto]

the gpsa data book has a series of equation. the equation is a function of the criticle temperature, criticle pressure and mole wt of the mixture with and adjustment that takes into account another fomula that has the reduced temperature

section 20, equations 23-20 to 23-26.

 

[Malimedo]

I'd try Carr-Cobayashi-Burrows correlation