A deep reservoir for hydrogen drives intense degassing in the Bulqizë ophiolite

Abstract

Deep crustal production of hydrogen (H 2 ) is a potential source of primary energy if recoverable accumulations in geological formations are sufficiently large. We report direct measurements of an elevated outgassing rate of 84% (by volume) of H 2 from the deep underground Bulqizë chromite mine in Albania. A minimum of 200 tons of H 2 is vented annually from the mine’s galleries, making it one of the largest recorded H 2 flow rates to date. We cannot attribute the flux solely to the release of paleo-fluids trapped within the rocks or to present-day active and pervasive serpentinization of ultramafic rocks; rather, our results demonstrate the presence of a faulted reservoir deeply rooted in the Jurassic ophiolite massif. This discovery suggests that certain ophiolites may host economically useful accumulations of H 2 gas.

A Review of the Migration of Hydrogen From the Planetary to Basin Scale

“…Notably, this study found no correlation between hydrogen and helium concentrations but did observe substantial organic and crustal contributions (CH 4 and N 2 ). Contrastingly, recent data from South Australia and direct measurements from the Bulqizë chromite mine in Albania report significant hydrogen outgassing, with H 2 concentrations >80% and varying but minor N 2 , CO 2 and CH 4 components (Goh, 2023;Gold Hydrogen, 2023;Truche et al, 2024;Yeo, 2023). Interestingly, whilst the results of Lévy et al (2023a) indicated no a clear connection between hydrogen and helium in the context of serpentinization, Karolytė et al (2022) documented He-rich hydrocarbon gases in South Africa's Witwatersrand Basin, where the scarcity of mafic and ultramafic minerals capable of serpentinization suggests radiolytic hydrogen production as the predominant mechanism.…”

“…The relationship between fluid migration and helium is paradoxical, given that for high He concentrations to be preserved alongside high H 2 concentrations (e.g., Gold Hydrogen, 2023), migration must be rapid enough to prevent dilution whilst the isolation of fluids over billions of years could allow He to accumulate whilst H 2 is lost (e.g., Karolytė et al, 2022). The relationship between surface gas seep compositions and migration pathways is more nuanced, given that microbial methanogenesis (Table 5) is depth-dependent (e.g., Truche et al, 2024). Hydrogen consumption within the shallowest levels of the subsurface (<1 m) may imprint a diurnal variation onto otherwise long-lived high-concentration (>50%) H 2 signals (e.g., Myagkiy, Moretti, & Brunet, 2020).…”

“…Natural Hydrogen is encountered as a free gas (i.e., surface seeps), dissolved in groundwater and within fluid inclusions in rocks. Natural hydrogen migrates through a wide range of mechanisms, including diffusion (e.g., through crystalline lattices) and advection (e.g., dissolution in groundwater, migration along faults) (e.g., Farver, 2010;Lefeuvre et al, 2021Lefeuvre et al, , 2022Strauch et al, 2023;Truche et al, 2024). Whilst laboratory experiments and assessments of specific case studies have shed some light on the complex nature of natural hydrogen migration, large gaps remain in our understanding of the mechanisms responsible for the large-scale migration of hydrogen through the deep Earth and within sedimentary basins.…”

Characterizing Natural Hydrogen Occurrences in the Paris Basin From Historical Drilling Records

“…In light of the global shift toward sustainable energy sources, naturally occurring H 2 has garnered significant attention as a putative carbon-neutral energy alternative to traditional fossil fuels. This interest is reflected in recent research exploring the potential of H 2 in various geological contexts (Donzé et al, 2020;Moretti et al, 2021;Prinzhofer et al, 2018; N. J. P. Smith et al, 2005;Truche et al, 2024). Current exploration methodologies for targeting H 2 in potential geological reservoirs predominantly rely on soil gas analysis at a depth of approximately 1 m. However, this approach is somewhat limited in scope and does not encompass a comprehensive and efficient methodology.…”

Enhancing a Deep Learning Model for the Steam Reforming Process Using Data Augmentation Techniques

“…It can be produced from renewable or non-renewable energy sources [1]. Despite the newest reports indicating possible accumulations of hydrogen in geological formations [2,3], by 2023, 84% of the hydrogen produced came from fossil sources, including 62% from natural gas, according to data from the International Energy Agency (IEA) [4]. The steam reforming of methane is recognized as the predominant technique for hydrogen production.…”