Page 196 - Formulas and Calculations for Petroleum Engineering

Well test analysis formulas and calculations Chapter 3 189

V sc : Specific Volume at Standard Conditions (cc/g)
∅: Porosity (fraction)
h: Net Formation Thickness (m)
2 1
c t : Total System Effective Isothermal Compressibility (kg/cm )
r w : Well Radius (m)

Output(s)

C D : Dimensionless Storage Constant for Liquids (dimensionless)

Formula(s)

CBV sc
C ¼
D 2
2p∅hc r
t w
Reference: Ramey Jr., H. J. (1981). Reservoir Engineering Assessment of Geothermal Systems. Department of Petroleum
Engineering, Stanford University, Page: (5.18).

3.31 Dimensionless time (linear flow/constant rate production/general case)

Input(s)
t: Production Time (h)
k: Permeability (mD)
ø: Porosity (fraction)
c t : Total Compressibility (1/psi)
m: Oil Viscosity (cP)
A: Cross Sectional Area (ft)

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

Formula(s)

0:0002637 k t
t AD ¼
ø m c A
t

Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 9.

3.32 Dimensionless time (linear flow/constant rate production/hydraulically
fractured wells)
Input(s)

t: Production Time (h)
k: Permeability (mD)
ø: Porosity (fraction)
c t : Total Compressibility (1/psi)
m: Oil Viscosity (cP)
L f : Half Length of Fracture (ft)