Page 115 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

Gas-wetting Alteration Agent and Gas-wetting CHAPTER 3 99

FIGURE 3.6
Flushing resistance analysis of core surfaces treated with polymer.

It can be seen from Fig. 3.6 that there is no obvious distinction of the contact
angle of distilled water on core surface with different treatment methods. The
measured contact angles are all over 120 degrees on the core surfaces that are
flushed before drying, flushed after drying, and on the ones that are not
flushed. Thus, flushing resistance of dopamine-containing polymers is very
good due to extremely strong adhesive properties of dopamine.

3.2.2 Fluorine Amphiphilic Block Polymer
3.2.2.1 PREPARING FLUORINE AMPHIPHILIC BLOCK POLYMER
3.2.2.1.1 Preparing Macroinitiator MPEG-Br
In this section, the macromolecule initiator is synthesized with methoxy poly-
ethylene glycol (MPEG). First, 15 g methoxy polyethylene glycol was heated
and dissolved in 250 mL methylbenzene. It was then dehydrated in a dehydra-

tor at 130 C. Thereafter, 2 mL triethylamine was added under thermostatic

water bath at 25 C. Then, 1.9 mL initiator, 2-isobutyryl bromide was injected
below the liquid surface with injectors. Nitrogen was administered constantly
for 10 minutes with electromagnetic stirring and then stopped. The reaction

system was closed for 48 hours at constant temperature (25 C). After the reac-
tion was completed, the reaction mixture was filtered using a glass sand funnel
to remove salt generated during the reaction process. The vacuum distillation
of filtered liquor was then conducted at 75 C to remove most of the methyl-

benzene to get a concentrated liquor, which was then precipitated in ice ether
(the volume of ice ether is 10 times that of concentrated liquor), before the
coarse product was finally filtered.

The coarse product was vacuum dried and then dissolved in water with
pH value of 8-9 and extracted with dichloromethane. The collected