# Homework Help: Calculate reservoir pore volume in field units and initial gas in place?

1. Dec 7, 2011

### marcoskids

1. The problem statement, all variables and given/known data

Calculate reservoir pore volume in field units and initial gas in place for a formation with total bulk volume of 1E8 m^3. A sample of the reservoir gas mixture has
15 moles of CH4 (Tc = 191K),Pc = 46.1bar),
2 Moles C2H6 (Tc =306K, Pc = 48.8 bar)
3 Moles C3H8 (Tc = 370K, Pc - 42.5 bar)

Reservoir pressure at midpoint of production pay zone is 250 bar whilst that corresponding to half pore volume is 206 bars.

Porosity = 0.15. Connate water saturation = 0.25, Reservoir Temperature = 950C

1barrel = 160 litre, 1000 litre = 1m^3, 1ft = 0.3m, 1bar= 0.1 Mpa

R = 8.314 Kpa*m^3 / kgmole*k

K = degrees C + 273, βg = 3.74E-4Z(T/P), T in K and P in Mpa

2. Relevant equations

Real gas law = PV = ZnRT
RVpore = Vb*Rf
Gas in place = (Vb*Rf (1-sw)*$\phi$) / Bo

3. The attempt at a solution

I know that pore volume = Recovery factor * bulk volume. Bulk volume is given but Rf isn't

I have found z and think its important but I don't know where to use it

N yi mw mwyi pi pi yi ti ti yi

ch4 15 0.75 16 12 46.1 34.575 191 143.5
C2H6 2 0.1 30 3 48.8 4.88 306 30.6
C3H8 3 0.15 44 6.6 42.5 6.375 370 55.5
20 MWg 21.6 45.83 229.6
pres 206 Tr 1.6
z 0.82