Page 197 - Petrophysics 2E

170 PETROPHYSICS: RESERVOIR ROCK PROPERTIES

TABLE 3.7
PERMEABILITY DATA FOR WELL HBK5

Interval K, mD
1 120
2 213
3 180
4 200
5 212
6 165
7 145
8 198
9 210
10 143
11 79
12 118
13 212
14 117

The arithmetic, geometric and harmonic averages of the core-derived
permeability values are, respectively:

Cki 120+ 213 + * e . + 117 = 165 mD
-- -
n 14
14
fklk~k3.. . kn = 4120 * 213 * . . . * 117 = 158.7 mD
n
- 14 = 151.4mD
1 1 +- 1
(.2 kl;) - 120 + Ti5 +..- 117
I= I
The harmonic averaging technique yields, as expected, the lowest
value of average permeability. But the difference between the three
averages is not significant, implying that the formation is essentially
homogeneous.
(2) The effective permeability of this 14-meter thick formation is
estimated from Equation 3.124.
From Equation 3.125, we calculate the geometric mean of the natural
log of the corederived permeability values:

kG=$nklInk21nk3 ... lnkn=(7.173x lo’)& =5.05SmD