Advances in the Mechanisms, Influencing Factors, and Control of Hydrogen Loss during Underground Hydrogen Storage in Depleted Reservoirs

Abstract

Underground hydrogen storage is key to achieving large-scale energy storage, managing the intermittency of renewable energy, and promoting the global energy structure’s transition to low carbon. This paper reviews various hydrogen losses occurring during hydrogen storage in depleted gas reservoirs, categorizing hydrogen loss into chemical reactions, hydrogen flow, and hydrogen capture. It deeply discusses the loss mechanisms and key influencing factors of each type of loss. The results show: (1) Chemical reactions of hydrogen in the reservoir lead to permanent hydrogen loss, mainly influenced by reservoir mineralogy and microbial sensitivity; (2) Diffusion, viscous fingering, and leakage are the main factors of hydrogen flow loss, with attention needed on the integrity of the caprock and production facilities during storage; (3) Hydrogen loss due to dissolution capture is minor, but residual and adsorption capture can cause significant hydrogen loss under the influence of wettability, interfacial tension, capillary pressure, and phase trapping. Based on this, specific recommendations are provided to reduce hydrogen loss, and future research directions are outlined.