Abstract
Controlling CO2 channeling in heterogeneous reservoirs remains a major challenge for both enhanced oil recovery (EOR) and secure geological storage. AMPS-HPAM copolymers exhibit high-temperature resistance and brine tolerance compared with conventional HPAM gels, making them well suited for the harsh environments associated with CO2 injection. Chromium-based crosslinkers (CrAc and CrCl3) were investigated because sulfonic acid groups in AMPS can coordinate with trivalent chromium ions, enabling dual ionic crosslinking and the formation of a robust gel network. While organic crosslinked AMPS-HPAM gels have been widely studied, the behavior of chromium-crosslinked AMPS-containing systems, particularly their gelation kinetics under CO2 exposure, remains less explored. This experimental study evaluates the gelation behavior and stability of chromium-crosslinked AMPS-HPAM gels by examining the effects of the polymer concentration, molecular weight, polymer–crosslinker ratio, temperature, pH, salinity, and dissolved CO2. The results clarify the crosslinking behavior across a range of formulations and environmental conditions and establish criteria for designing robust gel systems. Gelation times can be controlled from 5 to 10 h, and the resulting gels maintained structural integrity under CO2 exposure with less than 3.6% dehydration. Long-term thermal testing has shown that the gel remains stable after 10 months at 100 °C, with evaluation still ongoing. These results demonstrate that chromium-crosslinked AMPS-HPAM gels provide both durability and tunability for diverse subsurface conditions.
Recommended Citation
M. Sharifi Paroushi et al., "Evaluation of Chromium-Crosslinked AMPS-HPAM Copolymer Gels: Effects of Key Parameters on Gelation Time and Strength," Gels, vol. 12, no. 1, article no. 87, MDPI, Jan 2026.
The definitive version is available at https://doi.org/10.3390/gels12010087
Department(s)
Geosciences and Geological and Petroleum Engineering
Second Department
Chemical and Biochemical Engineering
Third Department
Chemistry
Fourth Department
Materials Science and Engineering
Publication Status
Open Access
Keywords and Phrases
AMPS-HPAM gel; chromium crosslinkers; CO2 resistance gel; gel strength; gel time; ionic coordination
International Standard Serial Number (ISSN)
2310-2861
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2026 The Authors, All rights reserved.
Creative Commons Licensing
This work is licensed under a Creative Commons Attribution 4.0 License.
Publication Date
01 Jan 2026
Included in
Biochemical and Biomolecular Engineering Commons, Geology Commons, Materials Chemistry Commons, Materials Science and Engineering Commons, Petroleum Engineering Commons
Comments
Missouri University of Science and Technology, Grant None