2025/07/07 by Fabrice Brunet, Benjamin Malvoisin · 3 voices
Earth and Planetary Sciences · Engineering · Environmental Science · #Atmospheric and Environmental Gas Dynamics #Groundwater and Isotope Geochemistry #Hydrocarbon exploration and reservoir analysis
paper · pdf · doi:10.33063/agc.v1i2.738
openalex publication_date 2025/07/07 · openalex created_date 2025/07/08 · openalex updated_date 2026/07/22
The possibility that natural H2, or ‘white H2’, can be of economic interest relies on (1) the occurrence of large H2 gas accumulations similar in size to oil and gas fields and/or on (2) natural H2 production processes that are sufficiently efficient, locally, to lead to recharge rates that are commensurable with economical extraction rates. This latter possibility is investigated in the reference case of a deep aquifer located in an intracratonic sedimentary basin. Various production reactions are considered which involve RedOx reactions among Fe-bearing rock-forming minerals. The production kinetics of radiolytic H2 as a function of depth is also modeled. H2 consumption by microbial activity is implemented. It appears that olivine serpentinisation is the only process capable of generating H2 concentrations high enough to reach H2 gas saturation in the aquifer and thus generate H2-rich gas accumulation. The combination of a deep H2 source (> 7,000 m, i.e., T> 240°C) and a shallow accumulation (< few hundred meters) turns out to be the only possible configuration for such an accumulation. Estimated H2 accumulation rates do not however exceed a few tons of H2 per year, which is far from being an economical value estimated to a few kton per year at least. In conclusion, in the case of a deep aquifer in an intracratonic setting and considering water-rock interactions as the main source process, natural H2 can hardly be considered renewable on an industrial timescale.