API 43 Crude

[oilcivil]

Hey Gang,

Does anyone out there know (or know how to figure out) the molecular weight for API 43 Crude. I'm looking all over for it.

Thanks in advance.

 

[DrillerNic]

As crude oil is a mixture of all sorts of hydrocarbons, it doesn't have a single molecular weight. API gravity is just a measure of the of the relative density of the fluid.

°API = (141.5/ Fluid SG) - 131.5

So a API 43 crude will have an SG of 141.5/(43 + 131.5) = 0.81.

So it's a pretty light crude oil, so I'd guess quite a lot C4- C10, not much waxes.

 

[chemjock]

Fig 2B2.2 in the API data book correlates Mole wt vs API gravity. You need the Watson K factor though.

 

[KernOily]

You can estimate the Watson factor if you know something about the crude, i.e. is it paraffinic or asphaltic. There are some charts in the Campbell Vol. 1 book that tells how to do this.

 

[jmw]

ASTM D2502 lets you estimate the molecular weight from the viscosity.

JMW

http://www.ViscoAnalyser.com