Page 12 - Formulas and Calculations for Petroleum Engineering

Reservoir engineering formulas and calculations Chapter 1 5

Output(s)

k avg : Average Permeability in Radial Systems Series (mD)

Formula(s)

r e
k k ln
a e r
k avg ¼ w
r
r
k ln e + k ln a
a e
r a r w
Reference: Applied Reservoir Engineering Vol. 1, Smith, Tracy & Farrar, Equation 7–7.
1.6 Average temperature of a gas column

Input(s)
T t : Tubing Head Temperature (°R)
T b : Wellbore Temperature (°R)

Output(s)

T: Arithmetic Average Temperature (°R)

Formula(s)
T + T b
t
T ¼
2

Reference: Ahmed, T., McKinney, P.D.2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3,
Page: 199.

1.7 Calculation of fractional flow curve
Input(s)

m w : Water Viscosity (cP)
k rw : Relative Permeability to Water (dimensionless)
k ro : Relative Permeability to Oil (dimensionless)
m o : Oil Viscosity (cP)

Output(s)

f w : Fraction of Total Flowing Stream Composed of Water (dimensionless)

Formula(s)
1
f ¼ m k
w
1+ w ro
rw
k m o
Reference: Craig Jr. F. F., 2004, the Reservoir Engineering Aspects of Waterflooding, Vol. 3. Richardson, Texas:
Monograph Series, SPE, Page: 112.