Page 19 - Formulas and Calculations for Petroleum Engineering

12 Formulas and calculations for petroleum engineering

B: Formation Volume Factor (bbl/STB)
m: Viscosity (cP)
DP: Pressure Difference (psi)

Output(s)
DP d : Dimensionless Pressure (dimensionless)

Formula(s)
k h DP
DP ¼
d
141:2 Q m B
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1,
Page: 125.

1.23 Dimensionless radius of radial flow—Constant-rate production

Input(s)
r: Effective Radius/Reservoir Radius (ft)
r w : Wellbore Radius (ft)

Output(s)

r d : Dimensionless Radius (dimensionless)

Formula(s)
r
r ¼
d
r
w
Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 8.

1.24 Dimensionless time—Myhill and Stegemeier’s method

Input(s)
3
M s : Volumetric Heat Capacity of Steam (btu/ft K)
3
M R : Volumetric Heat Capacity of the Reservoir (btu/ft K)
2
a s : Overburden Heat Transfer Coefficient (ft /d)
h t : Thickness of Column (ft)
t: Time (day)

Output(s)
t D : Dimensionless Time (dimensionless)

Formula(s)
2
M s a s

t ¼ 4 t
D 2
M R h t
Reference: Prats, M. 1986. Thermal Recovery. Society of Petroleum Engineers, New York, Chapter: 5, Page: 44.