A novel dispersed particle gel (DPG) suspension has been developed by researchers from Chengdu University of Technology and University of Alberta, offering enhanced profile control in high-temperature carbon capture, utilization, and storage (CCUS) applications. The study, published in Engineering, details the creation of a DPG suspension that exhibits significant improvements in thermal stability and plugging efficiency compared to traditional CO₂-responsive gels.

CCUS is a crucial strategy for mitigating climate change by capturing CO₂ from industrial sources and injecting it into geological formations such as saline aquifers and oil reservoirs. However, the effectiveness of CO₂ injection can be compromised by early breakthrough and fingering through high-permeability channels in reservoirs. Profile control, which involves injecting plugging agents to block these channels, is a key method to enhance both oil recovery and CO₂ storage efficiency. Traditional CO₂-responsive gels, while effective at ambient temperatures, suffer from reversible swelling and thermal degradation at elevated temperatures, limiting their applicability in high-temperature CCUS operations.

To address these limitations, the researchers synthesized a double-network hydrogel composed of crosslinked polyacrylamide (PAAm) and sodium alginate (SA) networks. This hydrogel was then sheared in water to form a pre-prepared DPG suspension. The innovation lies in the modification of these gel particles using potassium methylsilanetriolate (PMS) and CO₂ exposure, which results in significant and irreversible swelling of the particles. The modified DPG suspension, coded as PAAm/SA-PMS₂/SA₃-mDPG, demonstrated particle sizes over twice their original dimensions and maintained this size even after exposure to 100 °C for 24 hours.

Thermogravimetric analysis revealed that the modified DPG particles exhibited improved thermal stability, with a higher decomposition onset temperature and reduced mass loss compared to the unmodified particles. Core flooding experiments further validated the enhanced performance of the new DPG suspension, achieving a plugging efficiency of 95.3% in ultra-high permeability sandpacks, significantly higher than the 82.8% efficiency of the unmodified DPG suspension.

The study’s findings highlight the potential of the newly developed DPG suspension for effective profile control in high-temperature CCUS applications. The irreversible swelling and enhanced thermal stability of the modified gel particles make them a promising solution for improving the efficiency of CO₂ injection and storage in challenging reservoir conditions. Future research may focus on optimizing the formulation and exploring the long-term performance of the DPG suspension in field-scale operations.

The paper “High-Temperature Stable Dispersed Particle Gel for Enhanced Profile Control in Carbon Capture, Utilization, and Storage (CCUS) Applications,” is authored by Lin Du, Yao-Yu Xiao, Zhi-Chao Jiang, Hongbo Zeng, Huazhou Li. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.04.002. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.