Page 20 - Formulas and Calculations for Petroleum Engineering

Reservoir engineering formulas and calculations Chapter 1 13

1.25 Dimensionless time for interference testing in homogeneous
reservoirs—Earlougher

Input(s)
k: Permeability (mD)
ø: Porosity (fraction)
t: Time (h)
k: Overall Production (mD)
m: Viscosity (cP)
c t : Total Compressibility (1/psi)
r w : Wellbore Radius (ft)

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

Formula(s)
0:0002637 k t
t ¼
D
2
ø c m r
t w
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1,
Page: 117.

1.26 Dimensionless vertical well critical rate correlations—Hoyland, Papatzacos,
and Skjaeveland

Input(s)
h: Oil Column Thickness (ft)
k h : Effective Oil Permeability (mD)
r w : Water Density (g/cc)
m o : Oil Viscosity (cP)
r o : Oil Density (g/cc)
B o : Oil Formation Volume Factor (RB/STB)
q o : Critical Oil Rate (STB/day)

Output(s)
Q oD : Dimensionless Critical Rate (dimensionless)

Formula(s)
q o
QoD ¼ 651:4 m B
o o 2
h r r Þ k
ð
w o h
Reference: Reservoir Engineering Handbook, Fourth Edition, Ahmed, Page: 607.

1.27 Dimensionless wellbore storage coefficient of radial flow—Constant-rate
production
Input(s)

h: Reservoir Thickness (ft)
C: Wellbore Storage Coefficient (STB/psi)