Page 31 - Formulas and Calculations for Petroleum Engineering

24 Formulas and calculations for petroleum engineering

Formula(s)

!
1 1
G ¼ 43560 A h Ø 1 S Þ
ð
p wi
B B
gi g
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3,
Page: 202.

1.52 Gas saturation—Water-drive gas reservoirs

Input(s)

G: Gas Initially in Place (SCF)
G p : Cumulative Gas Production (SCF)
B g : Volume Factor (bbl/SCF)
B gi : Initial Gas Formation Factor (bbl/SCF)
W e : Cumulative Water Influx (bbl)
W p : Cumulative Water Production (STB)
B w : Water Formation Volume Factor (rb/STB)
S wi : Initial Water Saturation (fraction)
S grw : Residual Gas Saturation to Water Displacement (fraction)

Output(s)

S g : Gas Saturation (fraction)

Formula(s)

W W B w

e
p
G G p B S grw
g
1 S S
wi grw
S ¼
g !
G B gi W W B w
e
p

1 S wi 1 S S grw
wi
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3,
Page: 208.
1.53 Gas solubility in coalbed methane reservoirs
Input(s)
r B : Bulk Coal Steam Density (g/cc)
Ø m : Actual Coalbed Cleat Porosity (fraction)
S om : Initial Oil Saturation (fraction)
V: Gas Content (SCF/STB)

Output(s)

R s : Equivalent Gas Solubility (dimensionless)