Page 104 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

88 Gas Wettability of Reservoir Rock Surfaces with Porous Media

2. Experimental procedure
A certain amount of organic amine is prepared and dissolved in an
appropriate amount of isopropyl ether solvent and poured into a
250 mL three-neck flask, while being stirred with a magnetic stirrer. The
temperature is reduced to below 10 C using an ice bath, and perfluori-

nated sulfonyl fluoride is then dripped into it. Then the temperature is

raised to 60 C; 10% aqueous hydrochloric acid is added to rinse the
solution after the reaction. The layered outcome is separated using a
separating funnel and the upper oil-phase is washed. Finally, N-[3-
(dimethylamino)-propyl group] perfluorinated sulfonyl fluoride is
obtained.

3.1.2.2 SYNTHESIS OF FLUOROCARBON SURFACTANT
1. Chemical equation
The chemical equation for synthesizing fluorocarbon surfactant is
shown as follows:

OH
CH 3
H 2
+ NaSO C CH CH 2 Cl
F C CF 2 SO 2 NH CH 2 N CH 3 3
3
7 3
CH 3 OH
Alkaline environments H 2
+ – + NaCl
F C CF 2 SO 2 NH CH 2 N C CH SO 3
3
3
7
H 3 C
2. Synthesis procedure
NFA is dissolved in an appropriate amount of isopropanol, and
poured into a reaction flask, then heated until it is dissolved (60 C).

Next, an appropriate amount of sodium 2-hydroxy-3-chloro propanesul-
fonate [7] is dissolved in distilled water and poured into the same reac-
tion flask. It is heated and refluxed at 85 C for 2 hours. When the

reactant is cooled to 50 C, an appropriate amount of anhydrous sodium

carbonate is added, and it is continually heated at 85 C for 4 hours. The

reactant is then poured into a flask submerged in a water bath and dried
until it loses liquidity, before acetone is finally added to obtain the fluo-
rocarbon surfactant.

3.1.2.3 EVALUATION OF GAS-WETTING ALTERATION EFFECT
The core piece was first treated with 0.2% OP-10 for 48 hours, then treated
with the fluorocarbon surfactant for 10 hours, and then dried and taken out.
The core surface wettability was measured using contact angle method, as
shown in Table 3.1.