Coupled microbial-geochemical reactions in underground hydrogen storage systems: From hydrogen loss to a cyclically perturbed reactive system

Abstract

Underground hydrogen storage involves repeated cycles of hydrogen injection and withdrawal, which change how formation fluids, minerals and microorganisms interact. Microbial hydrogen consumption and abiotic geochemical reactions are often treated separately, but in a storage reservoir they are connected through substrate supply, solution chemistry and mineral interfaces. Although direct reactions between hydrogen and formation minerals are slow at reservoir temperatures, fluid-mineral interaction can alter the fluid chemistry, the availability of microbial substrates, and the stability of secondary minerals associated with microbial activity. Because chemical and biological changes carry over from one storage cycle to the next, reservoir reactivity can change cumulatively: hydrogen consumption may decline, persist or recover as substrates, pH and microbial communities change. Cycle frequency, shut-in duration, cushion gas composition and fluid chemistry give operators some control over this evolution, but the conditions that minimize hydrogen loss do not necessarily minimize gas contamination or formation damage. Assessing these effects requires distinguishing among hydrogen loss pathways, multi-cycle experiments, in situ characterization and long-term monitoring to identify cumulative changes and help define operating limits.

Document Type: Perspective

Cited as: Lin, J., Li, H., Zhao, Z., Wang, Y., Ali, M. Coupled microbial-geochemical reactions in underground hydrogen storage systems: From hydrogen loss to a cyclically perturbed reactive system. Advances in Geo-Energy Research, 2026, 22(1): 91-94. https://doi.org/10.46690/ager.2026.10.08