Page 200 - Formulas and Calculations for Petroleum Engineering

Well test analysis formulas and calculations Chapter 3 193

Output(s)

q o : Oil Flow Rate (STB/day)

Formula(s)

n
!
P wf
2
q ¼ q omax 1
o
P
Reference: Joshi, S. D. 1991, Horizontal Well Technology. Tulsa, Oklahoma: PennWell Publishing Company. Chapter: 7,
Page: 240.

3.40 Inflow performance relationship (IPR) for horizontal wells in solution gas-drive
reservoirs (Vogel)

Input(s)
q omax : Maximum Flow Rate for 100% Drawdown (STB/day)
P wf : Flowing Bottomhole Pressure (psi)
P: Shut in Pressure or Average Reservoir Pressure (psi)

Output(s)

q o : Oil Flow Rate (STB/day)

Formula(s)

P wf P wf
2 !
q ¼ q 1 0:2 0:8
o omax
P P
Reference: Joshi, S. D. 1991, Horizontal Well Technology. Tulsa, Oklahoma: PennWell Publishing Company. Chapter: 7,
Page: 240.

3.41 Interporosity flow coefficient in pressure build-up test

Input(s)
o: Storativity of the Fractures (dimensionless)
ø m : Matrix Porosity (fraction)
h m : Matrix Thickness (ft)
c m : Matrix Compressibility (1/psi)
m: Viscosity (cP)
r w : Wellbore Radius (ft)
k f : Fracture Permeability (mD)
t p : Production Time (day)
Dt: Shut-in Time (h)

Output(s)

l: Interporosity Flow Coefficient (dimensionless)