Page 32 - Formulas and Calculations for Petroleum Engineering

Reservoir engineering formulas and calculations Chapter 1 25

Formula(s)

0:17525 r B
R ¼ V
s
Ø S
m om
Reference: Ahmed, T., McKinney, P.D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3,
Page: 222.

1.54 Geertsma’s model for porosity/transit-time relationship

Input(s)
K b : Bulk Modulus Constant for Formation (dimensionless)
3
s b : Bulk Density (kg/m )
m b : Poisson Ratio for Formation (dimensionless)
K ma : Bulk Modulus Constant for Matrix (dimensionless)
3
s ma : Matrix Density (kg/m )
m ma : Poisson (dimensionless)

Output(s)

V b : Acoustic Velocity in Bulk Formation (m/s)
V ma : Acoustic Velocity in Matrix (m/s)

Formula(s)

0:5
K b 1 m b
V ¼ 3 *
b
s b 1+ m b
0:5
K ma ma
V ¼ 3 * 1 m
ma
s ma 1+ m ma
Reference: Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4.
Chapter 3, Page: 55.

1.55 Geothermal gradient
Input(s)

T bh : Maximum Recorded Temperature (degree °F)
T s : Temperature Near Surface (degree °F)
D bh : Total Depth of Logged Borehole (ft)

Output(s)

g G : Geothermal Gradient (degree °F/100 ft)

Formula(s)

T T s

bh
g ¼ 100
G
D bh
Reference: Bassiouni, Z., 1994, Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4.
Chapter 4, Page: 75.