Enhancing Oil Recovery with Nanoparticle-Enhanced Colloidal Gas Aphron: Mechanisms, Research Progress, and Future Perspectives

The development of complex and unconventional reservoirs places higher demands on enhanced oil recovery (EOR) technologies. To address issues such as insufficient control of gas flow rate and chemical agent loss, colloidal gas aphron (CGA) has attracted attention for its potential for microbubble plugging and flow-rate regulation. The introduction of nanoparticles has opened new avenues of research for modulating the interfacial properties, rheological behavior, and stability of CGA systems. However, relevant studies are scattered across fields such as CGA drilling fluids, nanofluid displacement, and nanoparticle-stabilized foams, creating an urgent need for a systematic review of research progress, mechanisms of action, and application prospects for nanoparticle-enhanced CGA. As a comprehensive review, this paper examines 126 relevant publications from 1987 to 2026, including 72 experimental studies and 54 reviews, numerical simulations, field applications, and other types of literature. It provides a comprehensive summary of CGA structure and applications, research progress on nanoparticle-enhanced CGA, and existing mechanisms. It discusses the potential mechanisms of nanoparticle action in CGA systems. Existing research indicates that CGA consists of micron-sized bubbles surrounded by a multilayer shell structure and can regulate flow and seal pores in porous media. Building on this, researchers have introduced nanoparticles into the CGA system to modulate its stability, interfacial properties, and continuous-phase rheological behavior; their effects depend on factors such as particle properties, surfactant–polymer formulations, and reservoir conditions. Existing studies have explored the microscopic mechanisms of nanoparticle-enhanced CGA from the perspectives of gas–liquid interface stability, synergistic interactions between nanoparticles and surfactants/polymers, and pore-scale displacement. Additionally, drawing on nanoparticle applications in other EOR systems, relevant research has proposed potential mechanisms of action for nanoparticles in CGA systems, providing a basis for subsequent mechanism validation and formulation optimization.