Page 116 - Gas Wettability of Reservoir Rock Surfaces with Porous Media

100 Gas Wettability of Reservoir Rock Surfaces with Porous Media

dichloromethane extract liquor was dried with MgSO 4 and filtered. Finally,
the filtered liquor underwent vacuum distillation before it was precipitated in
ice ether (thevolume of ice ether is 10 times that of concentrated liquor). The
precipitate was filtered and placed in a vacuum over to dry to balance the
weight.

3.2.2.1.2 Synthesis of Fluorine Amphiphilic Polymeremulsion
80 mL deionized water was poured into a 250 mL three-necked flask, 0.2 g
NaHCO 3 and 0.5 g lauryl sodium sulfate (SDS) was added into it, and stirred
intensely until it dissolved. Then, 3 mL Tween-80 was injected and the stirring
speed increased to 300 r/min. It was stirred until it formed micelles, and the
macromolecule initiator was added while constantly stirring. Cupric bromide,
Ligand bipyridine, and fluorinated monomer were mixed and dissolved at
60 C, cooled in an ice-bath, and added to the above emulsified solution and

sheared as a uniform preemulsion with a shear emulsion mixer. The solution
was then moved to an oil-bath at 80 C and nitrogen was injected. Ascorbic

acid was added to start the reaction, and the reaction was stopped after
8 hours to obtain the emulsion.

3.2.2.2 EVALUATION OF PERFORMANCE OF FLUORINE AMPHIPHILIC
BLOCK POLYMER
3.2.2.2.1 Infrared Spectroscopic Analysis
Fluorine-containing methacrylate monomer tridecafluoro-octyl ester and
macro-initiator MPEG-Brwere were synthesized into amphiphilic block poly-
mer with different mole ratio, which was precipitated and then dried. The col-
umn was coated with KBr pellet. After the polymer is spotted and filmed, the
infrared spectrogram is conducted. At a scanning range of 4000B400 cm 21 ,
wave number precision was 0.01 cm 21 and resolution ratio was 1 cm 21 . The
results are shown in Figs. 3.7 and 3.8.

From Fig. 3.7, it can be seen that 2960 cm 21 presents expansion-feature
absorption peak of CH 3 and CH 2 . Peaks in 1460 and 730 cm 21 are
bending vibration peaks of methylene, and the peak at 1700 cm 21 is the
absorption peak of ester group. The ester group is displaced to 1740 and
1750 cm 21 in the figure, as the fluorine atom has a great influence on the
vibration absorption peak of adjacent groups, and it also illustrates that the
ester group has become a saturated ester group. The expansion vibration peak
21 21
of C F bond appears at 1110 cm , and wave number of about 1200 cm is
the characteristic absorption peak of C O C (ether bond). Additionally, the
graphs of the four kinds of polymers have no absorption peak of C 5 Cin
monomer at 1500B1700 cm 21 . It is concluded from the above results that
the monomer has reacted completely during the polymerization process and
the product presents the structure of a copolymer.

Furthermore, fluorine-containing methacrylate monomer tridecafluoro-octyl
ester (F08), Trifluorooctyl acrylate (F07), and dodecafluoroheptyl acrylate