Page 262 - Petrophysics

FORMATION RESISTIVITY FACTOR 235

SANDSTONE
30 Low Elf~ctiv. Str.8
20 - High Effootivo Stros

-
- 10 -
a
K -
m -
-
0
E
*-
-
e
2 5-
- -
e
e
a
0
C
2-
11 I I I . , I .
0.2 0.3 0.4 0.5 0.8
Brine Saturation, S,
Figure 4.22. Effect of stress on resistivity index-drainage curves [15].

SATURATION EXPONENT Vb STRESS
Runs 11 & 13 -Water Wet Cores

-I+ + stress (dr.)
stress (dr.)
--;-,-
+ stress (imb.
I

0 1000 2000 3000 4000 5000
Stress (psi)
Pi@we 4.23. Influence of stress on tbe saturation exponent for water-wet cores during
drainage and imbibition saturation cycles [I GI.