Investigating CO2 and hydrogen flow dynamics and efficiency optimization for underground storage and production: An experimental and simulation-based study

This study uses an experimental and simulation-based approach to investigate hydrogen flow behavior and efficiency optimization during underground hydrogen storage and production (UHSP). Laboratory-scale sandbox experiments were conducted under low pressure to assess the dynamics of H₂, H 2 , and CO 2 mixtures in porous sandstone media. The sandbox experiments revealed that sandstone formations, with high permeability, are effective for both H₂ and H 2 and CO 2 mixtures for gas storage, showing minimal leakage when combined with impermeable cap rocks, which were represented by a clay layer in the sandbox experiment. Further, a 2D mechanistic model was developed and simulated using tNavigator to validate the experimental results, simulating gas migration and reproducing the phenomenon seen in the sandbox modeling experiment. Subsequently, a scaleup study was also conducted, where various optimization scenarios were explored to enhance UHSP efficiency, which includes optimization based on injection duration, injection rates, and model heterogeneity.