Page 45 - Formulas and Calculations for Petroleum Engineering

38 Formulas and calculations for petroleum engineering

Formula(s)
2
1688 Ø m c r
t
ln 2 s
k t
P ¼ P +70:6 q B m
wf
i
k h
Reference: Pressure Transient Testing, Lee, Rollins & Spivey, Page: 11.
1.86 Low-pressure region gas flow rate for non-circular drainage area

Input(s)
k: Permeability (mD)
h: Thickness (ft)
P r : Average Reservoir Pressure (psi)
P wr : Well Flowing Pressure (psi)
m gavg : Average Gas Viscosity (cP)
2
Z avg : Average Gas Compressibility Factor (Dimensionless) A: Drainage Area (ft )
C A : Shape Factor (dimensionless)
r w : Wellbore Radius (ft)
S: Skin (dimensionless)
T: Temperature (R)

Output(s)
Q g : Gas Flow Rate (MSCF/day)

Formula(s)

2
2
k h P P
r wf
Q ¼ ! !
g
4 A
T Z 0:5 ln + S
1422 m gavg avg 2
1:781 C r
A w
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3,
Page: 189.
1.87 Material balance for cumulative water influx—Havlena and Odeh
Input(s)

G: Gas in Place (SCF)
E G : Gas Expansion Term (bbl/SCF)
W e : Cumulative Water Influx (bbl)

Output(s)

F: Fluid Withdrawal (bbl)

Formula(s)
F ¼ G E +W e
G

Reference: Ahmed, T., McKinney P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3,
Page: 209.