Chapter 4
from kaolinite surface to make kaolinite more water-wet. Surfactants used here
+ -
are OCtyItrimethyIammonium bromide (CH-N (CH0)0Br, C8TAB), betaine and
amine oxide. C8TAB is used here as a model cationic surfactant. The other two
surfactants exhibit the equilibrium between zwitterionic and cationic forms, which
depends on pH. The cationic form is dominant at lower pH. Tables 4.2 and 4.3
show betaine and amine oxide samples used in wettability test.
Table 4.3 Amine oxide samples used in wettability test
|
Commercial name |
Formula |
Activity |
|
AMMONYX CDO Special |
CHo-(CHo) -CO-NH-(CHo)o-N+(CHo)-O 3 ' 2,x v 2,3 v 3z2 _______________X=6- 16_______________ |
32.5% |
|
AMMONYX DO |
C H -N+(CH)-0^ 10 21 ' 3'2 |
30% |
|
AMMONYX LO |
c1Ak-n(ch,)√0 12 25 ' 3'2 |
30% |
|
AMMONYX MCO |
CH -N+(CHo)-O' _______________x=12-18_______________ |
30% |
4.2.4.1. EffectofC8TAB
Figure 4.6 shows water-wet fraction of 1.0 w.% kaolinite in toluene-brine
mixture (1:1, vlv) with 100 ppm I 200 ppm naphthenate adding different amounts
of C8TAB at pH 8.3 24 hours after preparation. The dashed lines show water-wet
fractions of kaolinite with or without naphthenate as control, without C8TAB added.
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