Comparative Study of Oilfield Chemicals, Polymers, and Nanoparticles for Hydrogen Gas Foam Formation in Subsurface Storage Applications

Subsurface storage of hydrogen gas presents a promising solution for large-scale energy storage, but conformance control remains a critical challenge to prevent gas migration and improve storage efficiency. One of the key mechanisms for enhancing hydrogen containment is using hydrogen gas foams, which can block and divert gas flow in porous media. This study investigates the efficacy of various chemical agent- sodium dodecyl sulfate (SDS), polyacrylamide (PAM), and nanoparticles—as foaming agents to stabilize hydrogen gas foams for improved conformance control in subsurface reservoirs. The behaviour of these agents was compared in terms of foam stability, mobility control, and their interaction with subsurface conditions such as temperature, pressure, and salinity. Experimental results showed that SDS, as a surfactant, facilitates rapid foam formation but suffers from instability in high- temperature and high-salinity environments. PAM, a polymer, enhances the viscosity of the foam, resulting in improved foam strength and mobility control; however, its performance is sensitive to salinity variations. Silica Nanoparticles (0.1 wt% and 30 nm average particle size), when incorporated into the foam system, improved foam longevity, mitigating the collapse observed with surfactants alone. These nanoparticles contributed to forming stable, rigid films within the foam structure, which resisted breakdown under harsh reservoir conditions. In addition to foam stability, viscosity measurements highlighted that 1000 ppm PAM-based foams exhibited significantly higher viscosity (up to 150% increase compared to SDS-based foams) and superior viscoelastic nature, offering better resistance to gas migration through permeable rock formations. Nanoparticle-infused foams demonstrated an optimal balance between foam strength and stability, resisting shear-induced breakdown while maintaining sufficient viscosity for effective mobility control. A critical aspect of the hydrogen foam system is its ability to sustain uniform surfactant films, which forestall hydrogen ingress into water-bearing zones. This is particularly important for preventing unwanted hydrogen-water interactions that can reduce the storage efficiency. By maintaining a stable foam front, the selected agents provide a barrier that slows hydrogen diffusion, ensuring higher gas retention within the desired reservoir zone. The findings from this comparative analysis are critical for optimizing chemical formulations for hydrogen storage and ensuring long-term stability of subsurface hydrogen reservoirs, making it a viable energy storage solution. KEYWORDS Foam Stability; Gas Conformance Control; Geological Storage Challenges; Premature Gas Breakthrough; Subsurface Hydrogen Storage.