Page 50 - Reservoir Formation Damage

34 Reservoir Formation Damage

e..\3
»
• Brown en data
o
tion of the lx
BrowneO data
1 S ;
X
,
/
n t\ . ^
ft .x" *

4 6 8 10 12
in
t 1/2 (hr )
Figure 2-21. Correlation of water pickup during swelling (after Civan, ©1999
SPE; reprinted by permission of the Society of Petroleum Engineers).

= k as(v t-v) (2-19)
subject to

(2-20)
A: is a rate constant. Thus, solving Eqs. 2-19 and 20 yields:

V = V t-(V t-V 0)exp(-k aS) (2-21)
from which the expansion coefficient of a unit clay volume is determined
as:

(2-22)

is the terminal expansion coefficient at saturation. k a is the rate
where a t
coefficient of expansion.
Seed et al. (1962), Blomquist and Portigo (1962), Chenevert (1970),
and Wild et al. (1996) measured the rates of expansion of the samples
of compacted sandy clay, hydrogen soil, typical shales, and lime-stabi-
lized kaolinite cylinders containing gypsum and ground granulated blast
furnace slag, respectively. Figures 2-22 and 2-23 show the correlation
of their data with Eq. 2-22 using Eq. 2-6. The best matches of the data