Inorganic nanoparticle-stabilized nitrogen foam systems for enhanced heavy oil recovery: Mechanisms, performance, and field-scale prospects

In heavy oil thermal recovery, repeated steam stimulation cycles commonly lead to operational challenges, including high water cut, severe steam channeling, and declining recovery rates. Conventional nitrogen foam systems, employed for conformance control, are often limited by inadequate thermal stability and insufficient plugging strength under these harsh conditions. To address these limitations, the mechanisms and performance of nitrogen foam technology enhanced by inorganic nanoparticles (NPs) are systematically analyzed herein. NPs markedly improve foam stability and blocking capacity via interfacial adsorption and structural reinforcement, while also conferring enhanced tolerance to high-temperature and high-salinity environments. Looking forward, efforts should prioritize the development of a new generation of nanoparticle-enhanced foams capable of ultra-high-temperature performance and high strength. Furthermore, establishing quantitative relationships between foam system performance and reservoir pore-throat characteristics is essential to enable precise application in complex reservoirs. Beyond synthesizing the current technical landscape, a reservoir-specific compatibility screening workflow and a cross-scale performance prediction framework are innovatively proposed herein. These tools aim to bridge the gap between laboratory research and precise field implementation. Ultimately, nanoparticle-enhanced foam technology presents an innovative pathway for the efficient development of heavy oil resources, offering significant theoretical and practical engineering value.