Page 195 - Formulas and Calculations for Petroleum Engineering

188 Formulas and calculations for petroleum engineering

3.28 Dimensionless shut-in time for MDH method

Input(s)
k: Permeability (mD)
Dt: Total Shut-in Time (day)
ø: Porosity (fraction)
m: Viscosity (cP)
c t : Total Compressibility (1/psi)
2
A: Drainage Area (ft )

Output(s)
Dt DA : Dimensionless Shut-in Time (dimensionless)

Formula(s)

0:0002637 k Dt
Dt DA ¼
ø m c A
t
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1,
Page: 59.

3.29 Dimensionless storage constant for gases

Input(s)
0 2 2
C : Wellbore Storage (tons/(kg/cm ) )
Z: Real Gas Law Deviation Factor (ratio)
T: Absolute Formation Temperature (°K)
M: Molecular Weight (g/g mol)
∅: Porosity (Per cent)
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 Gases (dimensionless)

Formula(s)

0
27C ZT
C ¼
D 2
M∅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).

3.30 Dimensionless storage constant for liquids
Input(s)

C: Storage
B: Formation Volume Factor (Reservoir Volume/Standard Volume)