10.1021/acs.energyfuels.6b02230.s001
Lei Zhang
Lei
Zhang
Liming Zheng
Liming
Zheng
Jingyang Pu
Jingyang
Pu
Chunsheng Pu
Chunsheng
Pu
Shuxia Cui
Shuxia
Cui
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
American Chemical Society
2016
HPAM
cross-linking reaction
intramolecular cross-linking ends
intramolecular cross-linking reaction
intramolecular cross-linking stage
injection pressure
2016-10-26 00:00:00
Journal contribution
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.