Page 197 - Formulas and Calculations for Petroleum Engineering

190 Formulas and calculations for petroleum engineering

Output(s)

: Dimensionless Time (dimensionless)
t L fD
Formula(s)

0:0002637 k t
t ¼
ø m c L
L fD 2
t f
Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 10./

3.33 Dimensionless time (radial flow/constant rate production)

Input(s)

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

Output(s)

t d : Dimensionless Time (dimensionless)

Formula(s)

0:0002637 k t
t ¼
d
ø m c r 2 w
t
Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 8.

3.34 Dimensionless time function (transient heat transfer to the formation)

Input(s)
2
a: Thermal Diffusivity of the Formation (ft /day)
r: Diffusion Depth (ft)
t: Production Time (day)

Output(s)
f(t): Dimensionless Time Function that Represents the Transient Heat Transfer to the formation (dimensionless)

Formula(s)

r
ftðÞ ¼ ln p 0:290
ffiffiffiffi
2 at
Reference: Ramey Jr, H. J. (1981). Reservoir Engineering Assessment of Geothermal Systems. Department of Petroleum
Engineering, Stanford University, Equation no (6.3).