Page 185 - Formulas and Calculations for Petroleum Engineering

178 Formulas and calculations for petroleum engineering

3.6 Average fracture permeability (pseudo-steady state case for pressure build-up test)

Input(s)
q: Flow Rate (bbl/d)
m: Viscosity (cP)
B: Formation Volume Factor (BBL/STB)
m: Slope of Horner Plot (psi/cycles)
h: Formation Thickness (ft)

Output(s)

k f : Average Fracture Permeability (mD)

Formula(s)

m
k ¼ 162:6 q B
f
m h
Notes: Horner Plot Analysis (Semi-Log Plot).

Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 107.

3.7 Bottomhole flowing pressure during infinite-acting pseudoradial flow

Input(s)
p i : Initial Reservoir Pressure (psi)
Q o : Well Flow Rate (STB/day)
B o : Oil Formation Volume Factor (bbl/STB)
m o : Oil Viscosity (cP)
k: Permeability (mD)
h: Thickness (ft)
t: Flowing Time (h)
ø: Porosity (fraction)
c t : Total Compressibility (1/psi)
r w : Wellbore Radius (ft)
S: Skin (dimensionless)

Output(s)
P wf : Wellbore Flowing Pressure (psi)

Formula(s)

162:6 Q m B o k
o
o
P ¼ p log tðÞ + log 3:23 + 0:87 S
wf i 2
k h ø m c r
o t w
p p ¼ Dp ¼ a + mlog tðÞ
i wf
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 1,
Page: 98.