Page 29 - Formulas and Calculations for Petroleum Engineering

22 Formulas and calculations for petroleum engineering

1.47 Gas flow under laminar viscous conditions

Input(s)
k: Permeability (mD)
h: Thickness (ft)
’ r : Average Reservoir Real-Gas Pseudo-Pressure (psi)
’ wf : Real-Gas Pseudo-flowing Pressure (psi)
T: Temperature (R)
2
A: Drainage Area (ft )
C A : Shape Factor (dimensionless)
r w : Wellbore Radius (ft)
S: Skin (dimensionless)

Output(s)
Q g : Gas Flow Rate (MSCF/d)

Formula(s)

k h ’ ’
r wf
Q ¼
g 4 A
1422 T 0:5 ln + S
1:781 C r 2
A w
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3,
Page: 188.

1.48 Gas formation volume factor

Input(s)
z: Gas Deviation Factor (dimensionless)
T: Temperature (R)
P: Pressure (psi)

Output(s)
B g : Gas Formation Volume Factor (bbl/SCF)

Formula(s)
0:005035 z T
B ¼
g
P
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1,
Page: 15.

1.49 Gas hydrate dissociation pressure

Input(s)

g h : Specific Gravity of Hydrate-forming Components (dimensionless)
F m : Molar Ratio between the Non-hydrate-forming and Hydrate-forming Components (dimensionless)
T: Temperature (°R)