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A CO 2 -Responsive Gel System (AM/NVP/DMAEMA) for Plugging High-Permeability Gas Channeling Zones in a CO 2 Flooding Process

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide To address the issue of CO 2 channeling along high-permeability zones during the development of CO 2 flooding in low-permeability reservoirs, this study developed a CO 2 -responsive gel system for gas channeling plugging. Through molecular design, a CO 2 -responsive polymer (AM/NVP/DMAEMA) was synthesized, and its structure was characterized. The results indicated that the successful synthesis of the polymer was confirmed. Constructed based on this CO 2 -responsive polymer (AM/NVP/DMAEMA), the CO 2 -responsive polymer gel system (designated as DKS) has the following formulation: the CO 2 -responsive polymer with a mass fraction of 0.5%, WD-1 with 0.8%, and WD-2 with 0.8%. Performance tests of DKS were conducted under relevant environmental conditions (e.g., different temperatures, salinities, and pressures). The results showed that the gelation strength of the system is above grade H with an elastic modulus ( G ′) > 2 Pa; after 30 days of aging, the gel strength remains above grade H, and the water loss rate after 30 days of aging is <5%. In the CO 2 flooding simulation experiment on artificial cores, DKS exhibited excellent injectability and plugging performance: the injection pressure is below 0.80 MPa, the plugging rate can reach over 95%, and the reduction rate of the CO 2 outlet flow can reach over 95%. In a CO 2 atmosphere, compared with conventional gels, DKS demonstrates outstanding gel strength and stability in CO 2 environments, which holds a significant reference value for the efficient development of CO 2 flooding in low-permeability reservoirs.

Source: ACS Omega

DOI: 10.1021/acsomega.5c11373