Modeling of Hydrogen Genesis in Ophiolite Massif

Bachaud, Pierre; Meiller, Clémentine; Brosse, É.; Durand, Isabelle; Beaumont, Valérie

doi:10.1016/j.proeps.2016.12.051

Cited by 7 publications

(3 citation statements)

References 10 publications

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“…Results show that the solubility of hydrogen tends to increase with depth, to rapidly become significant. As an illustration, H 2 solubility calculated at 1000 m in pure water (about 0.07 mol/kg H2O ) can be compared with the maximum concentration of about 0.01 mol/kg H2O calculated by fluid-rock interactions modeling in Oman ophiolite (Bachaud et al, 2017). This indicates that, in such systems, transport of hydrogen would occur mostly in the aqueous phase and that formation of gaseous H 2 would be a quite shallow process.…”

Section: Natural Continental Hydrogen Emissionsmentioning

confidence: 90%

“…Accumulations have even been found in Kansas (Guélard et al, 2017) or Mali (Prinzhofer et al, 2018), where natural hydrogen is used to produce electricity since 2015. The sources of H 2 and the mechanisms responsible for its formation remain to be clearly identified, even if some chemical reactions are already known to be efficient H 2 producers, such as serpentinization or oxidation of iron-rich rocks (Bachaud et al, 2017;Deville and Prinzhofer 2016;Vacquand et al, 2018). The behavior of this molecule along its migration path is another aspect that needs to be better constrained.…”

Section: Introductionmentioning

confidence: 99%

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Predicting the phase behavior of hydrogen in NaCl brines by molecular simulation for geological applications

Lopez-Lazaro

Bachaud

Moretti

et al. 2019

BSGF - Earth Sci. Bull.

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Hydrogen is targeted to have a significant influence on the energy mix in the upcoming years. Its underground injection is an efficient solution for large-scale and long-term storage. Furthermore, natural hydrogen emissions have been proven in several locations of the world, and the potential underground accumulations constitute exciting carbon-free energy sources. In this context, comprehensive models are necessary to better constrain hydrogen behavior in geological formations. In particular, solubility in brines is a key-parameter, as it directly impacts hydrogen reactivity and migration in porous media. In this work, Monte Carlo simulations have been carried out to generate new simulated data of hydrogen solubility in aqueous NaCl solutions in temperature and salinity ranges of interest for geological applications, and for which no experimental data are currently available. For these simulations, molecular models have been selected for hydrogen, water and Na+ and Cl− to reproduce phase properties of pure components and brine densities. To model solvent-solutes and solutes-solutes interactions, it was shown that the Lorentz-Berthelot mixing rules with a constant interaction binary parameter are the most appropriate to reproduce the experimental hydrogen Henry constants in salted water. With this force field, simulation results match measured solubilities with an average deviation of 6%. Additionally, simulation reproduced the expected behaviors of the H2O + H2 + NaCl system, such as the salting-out effect, a minimum hydrogen solubility close to 57 °C, and a decrease of the Henry constant with increasing temperature. The force field was then used in extrapolation to determine hydrogen Henry constants for temperatures up to 300 °C and salinities up to 2 mol/kgH2O. Using the experimental measures and these new simulated data generated by molecular simulation, a binary interaction parameter of the Soreide and Whiston equation of state has been fitted. The obtained model allows fast and reliable phase equilibrium calculations, and it was applied to illustrative cases relevant for hydrogen geological storage or H2 natural emissions.

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Section: Natural Continental Hydrogen Emissionsmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Predicting the phase behavior of hydrogen in NaCl brines by molecular simulation for geological applications

Lopez-Lazaro

Bachaud

Moretti

et al. 2019

BSGF - Earth Sci. Bull.

Self Cite

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“…In case of H 2 coming from H 2 O, O_1, if the serpentinization at moderate to high temperatures has been largely studied in the field as in laboratory [10,11], the global assessment remains debated and is highly variable depending of the authors [12] for a review of the various estimates). Serpentinization at lower temperatures is observed in the ophiolitic contexts [13], tested in laboratory [14] and through models [15,16]. However, the overall assessment and the kinetic of this redox equation (roughly 3[FeO] + H 2 O => Fe 3 O 4 + H 2 ) remain also poorly known.…”

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confidence: 99%

Hydrogen Emanations in Intracratonic Areas: New Guide Lines for Early Exploration Basin Screening

et al. 2021

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Offshore the emissions of dihydrogen are highlighted by the smokers along the oceanic ridges. Onshore in situ measurements in ophiolitic contexts and in old cratons have also proven the existence of numerous H2 emissive areas. When H2 emanations affect the soils, small depressions and vegetation gaps are observed. These depressions, called fairy circles, have similarities with the pockmark and vent structures recognized for long time in the sea floor when natural gas escapes but also differences. In this paper we present a statistic approach of the density, size, and shape of the fairy circles in various basins. New data from Brazil and Australia are compared to the existing database already gathered in Russia, USA, and again Brazil. The comparison suggests that Australia could be one of the most promising areas for H2 exploration, de facto a couple of wells already found H2, whereas they were drilled to look for hydrocarbons. The sum of areas from where H2 is seeping overpasses 45 km2 in Kangaroo Island as in the Yorke Peninsula. The size of the emitting structures, expressed in average diameter, varies from few meters to kilometers and the footprint expressed in % of the ground within the structures varies from 1 to 17%. However, globally the sets of fairy circles in the various basins are rather similar and one may consider that their characteristics are homogeneous and may help to characterize these H2 emitting zones. Two kinds of size repartitions are observed, one with two maxima (25 m and between 220 m ± 25%) one with a simple Gaussian shape with a single maximum around 175 m ± 20%. Various geomorphological characteristics allow us to differentiate depressions of the ground due to gas emissions from karstic dolines. The more relevant ones are their slope and the ratio diameter vs. depth. At the opposite of the pockmark structures observed on the seafloor for which exclusion zones have been described, the H2 emitting structures may intersect and they often growth by coalescence. These H2 emitting structures are always observed, up to now, above Archean or Neoproterozoic cratons; it suggests that anoxia at the time the sedimentation and iron content play a key role in the H2 sourcing.

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Abiotic hydrogen generation from biotite-rich granite: A case study of the Soultz-sous-Forêts geothermal site, France

Murray

Clément

Fritz

et al. 2020

Applied Geochemistry

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Modeling of Hydrogen Genesis in Ophiolite Massif

Cited by 7 publications

References 10 publications

Predicting the phase behavior of hydrogen in NaCl brines by molecular simulation for geological applications

Predicting the phase behavior of hydrogen in NaCl brines by molecular simulation for geological applications

Hydrogen Emanations in Intracratonic Areas: New Guide Lines for Early Exploration Basin Screening

Abiotic hydrogen generation from biotite-rich granite: A case study of the Soultz-sous-Forêts geothermal site, France

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