Getting the Oil/Gas Mixture Out from the Ground
First we make a few mass balances:
Total Hydrocarbon Balance:
![](TotMB.gif)
Species Hydrocarbon Balance:
![](SpecMB.gif)
Water Balance:
![](WaterB.gif)
Then we handle the restrictions on system:
Saturations add up to 1
Saturation is the fraction of the V/L space that is a particular phase
Using:
Sl+Sw+Sv=1
And:
L=Total moles of liquid/pore volume
V=Total moles of vapor/pore volume
V=Sv*rhov
L=Sw*rhow
The restriction is:
![](rest1.gif)
Use the perfect gas law and the compressiblity factor.
In equilibrium, each phase has the same temperature and pressure
![](compress.gif)
|