Page 296 - Petrophysics 2E

LABDERIVED EVALUA’IION OF SHALY 267

- CORE 2797 G; Q, a 0.88 oquiv /litor
c
5 0.03 -
I
s -
I
0
E

o 0.1 0.2 0.3 0.4 0.5 0.6 a7 a8 0.9 1.0
[C,),, mho-cm‘l
Pigure 4.39. EIechtcal conductivity of a shaly sand us. equilibrating brine
conductivity at various temperatures 1311.

0.01 0.1 1 10
R,., at Tempertaure, ohmrn
Figure 4.40. Equivalent counterion conductance us. resistivity of equilibrating brine
at uarious temperatures 1311.

The C,, vs. Rw curve at T = 25°C can be represented by:

C,, = 3.83 (1 - 0.83e0.5/Rw) (4.1 39)

This correlation is slightly different, but more accurate, than
Equation 4.138.
The effect of temperature on the relationship between the resistivity
index IR and water saturation S, also was investigated assuming both