Influence of Hydrolyzed Polyacrylamide (HPAM) Molecular
Weight on the Cross-Linking Reaction of the HPAM/Cr<sup>3+</sup> System
and Transportation of the HPAM/Cr<sup>3+</sup> System in Microfractures
Lei Zhang
Liming Zheng
Jingyang Pu
Chunsheng Pu
Shuxia Cui
10.1021/acs.energyfuels.6b02230.s001
https://acs.figshare.com/articles/journal_contribution/Influence_of_Hydrolyzed_Polyacrylamide_HPAM_Molecular_Weight_on_the_Cross-Linking_Reaction_of_the_HPAM_Cr_sup_3_sup_System_and_Transportation_of_the_HPAM_Cr_sup_3_sup_System_in_Microfractures/4204680
The
influence of the molecular weight (<i>M</i><sub>w</sub>)
of hydrolyzed polyacrylamide (HPAM) on the cross-linking reaction
of HPAM/Cr<sup>3+</sup> and the transportation of HPAM/Cr<sup>3+</sup> in microfractures is systematically studied using viscometry, ultraviolet–visible
absorption spectrophotometry, and displacement experiment with a visual
microfractured model. The results show that a high-<i>M</i><sub>w</sub> HPAM is advantageous to the intramolecular cross-linking
reaction of the HPAM/Cr<sup>3+</sup> system but disadvantageous to
the transportation of the HPAM/Cr<sup>3+</sup> system in microfractures.
At the intramolecular cross-linking stage, the injection pressure
of the HPAM/Cr<sup>3+</sup> system in microfractures is almost equal
to that of the HPAM solution, which undergoes no change with the degree
of the cross-linking reaction. The higher the HPAM <i>M</i><sub>w</sub>, the earlier the intramolecular cross-linking ends (thus,
the intermolecular cross-linking reaction of HPAM/Cr<sup>3+</sup> occurs
earlier, which leads to an earlier increase in the injection pressure
of the HPAM/Cr<sup>3+</sup> system). Moreover, there is a matching
relationship between the fracture aperture and the HPAM/Cr<sup>3+</sup> system to minimize the chromatographic separation when the HPAM/Cr<sup>3+</sup> system transports in the microfracture. For the conformance
control of a fractured tight oil reservoir, we conclude that an HPAM/Cr<sup>3+</sup> system with a low-<i>M</i><sub>w</sub> HPAM can
more easily enter the deep reservoir to expand the swept volume on
a larger scale. However, the system with a high-<i>M</i><sub>w</sub> HPAM can form a gel with a higher viscosity to produce
a higher plugging strength.
2016-10-26 00:00:00
HPAM
cross-linking reaction
intramolecular cross-linking ends
intramolecular cross-linking reaction
intramolecular cross-linking stage
injection pressure