CO2‐Switchable Foams for Enhanced Oil Recovery and Carbon Sequestration

Abstract Carbon dioxide (CO 2 ) foams have emerged as a promising strategy for enhanced oil recovery (EOR), providing effective gas mobility control. However, challenges in maintaining subsurface stability and enabling surface‐controlled collapse persist, and a comprehensive assessment of their CO 2 storage potential remains unexplored. This study presents an innovative approach using switchable foams stabilized by a CO 2 ‐responsive surfactant, N ‐erucamidopropyl‐ N , N ‐dimethylamine (UC 22 AMPM). Through integrated laboratory experiments under simulated reservoir conditions, the reversible foaming/defoaming, in situ foam generation and transport in porous media, as well as CO 2 storage capacity were systematically evaluated. The results reveal a unique reversible foam modulation mechanism driven by alternating CO 2 and N 2 exposure with CO 2 ‐induced foams displaying distinct pressure‐dependent stability profiles. Microfluidic visualization technique demonstrates efficient in situ foam generation within porous media, further corroborated by core‐flooding experiments revealing resistance factors of up to 14, underscoring their robust conformance control capability. Absorption experiments operating under simulated oil reservoir indicates a 22% increase in CO 2 sequestration efficiency compared to traditional brine flooding. These findings provide a quantitative framework for harnessing the potential of CO 2 ‐responsive foams in both EOR operations and sustainable carbon sequestration.