Looking for natural hydrogen in Albania and Kosova

Abstract

A regional geochemistry field study was conducted in Albania and Kosova to spot natural H2 occurrences related to ophiolite massifs. A total of 21 sites, mainly consisting of natural springs, were studied, and nine were sampled for analyzing associated free gas and C and H isotopes of CH4 and H2 when possible. Four springs showed gas with H2 occurrence, one particularly reaching 16% of H2 in the north of Kosova in a location named Vuçe, which makes it the fifth gas seep most enriched in H2 in the Dinarides, after H2-rich gas seeps in Serbia and Bosnia and Herzegovina. This gas seep is associated with hyperalkaline water having a pH of about 10.7. This would favor the assumption that H2 is derived from the serpentinization of peridotites, a process which is likely still ongoing. H2 is associated mainly with N2 and CH4, like the other H2-rich gas springs in the Dinarides. Based on C and H isotopes, CH4 is abiotic or microbial. H isotopes suggest a formation of H2 at about a 2-km depth. Another hyperalkaline spring was found in the south of Albania, at the border of the Korça Basin, with less than 200 ppm of H2. No relation between H2 and He was identified at the scale of Albania and Kosova, nor at the scale of the whole Dinarides. This work provides a completed map of the H2 occurrences in the Dinarides and allows to highlight some hot spots for H2 exploration, mainly located inside the ophiolite massifs like in other ophiolites (such as Oman, New Caledonia, and The Philippines), and not on major faults like in the Pyrenees.

Natural H2 exploration: tools and workflows to characterize a play

“…The isotopic signature of CH 4 can be useful to trace its origin. Using the abacus of Etiope et al (2017), we observe that continental data are consistent with the different (Coveney et al, 1987;Etiope et al, 2017;Guélard et al, 2017;Lévy et al, 2023;Nivin 2019;Potter et al, 2013;Randazzo et al, 2021;Salvi and Williams-Jones, 1997;Sherwood Lollar et al, 2006;Vacquand et al, 2018).…”

“…This is observed for instance in the ophiolitic contexts that currently get serpentinized. H 2 -rich bubbling is reported in New Caledonia (up to 36 vol.%), Oman (up to 87 vol.%), the Philippines (up to 59 vol.%), and the Balkans (up to 84%) (Lévy et al, 2023;Randazzo et al, 2021;Vacquand et al, 2018). In this kind of spring, the water is usually hyperalkaline, with a pH higher than 9 often related to the serpentinization process.…”

“…Caledonia (Deville and Prinzhofer, 2016), and in the Balkans (Lévy et al, 2023). Even if the ophiolites represent small areas on the land scale compared to MORs, they represent a huge potential for serpentinization and therefore H 2 generation.…”

“…Over the last years, the portable instruments GA2000 and then GA5000 or BIOGAS5000 from Geotech Ò became the norm (Fig. 10a) (Frery et al, 2021;Leila et al, 2021;Lévy et al, 2023;Moretti et al, 2022;Pasquet et al, 2021;Prinzhofer et al, 2019). However, sampling the gas within the first meters of soil could be challenging and frustrating due to the very large air content in the close-to-surface soil, usually more than 95 vol.% with, depending on the cases, few vol.% of CH 4 or CO 2 .…”

“…17. Isotopic data of H 2 -rich gas from ophiolitic, intracontinental represented in different graphs (Abrajano et al, 1988;Etiope et al, 2011;Lévy et al, 2023;Prinzhofer et al, 2018;Randazzo et al, 2021;Sherwood et al, 1988;Sherwood Lollar et al, 1993, 2007Truche et al, 2018Vacquand et al, 2018 compared to MOR (Charlou et al, 1996;Proskurowski et al, 2006Proskurowski et al, , 2008 and volcanic/geothermal data (Arnason, 1977;Caliro et al, 2015;Darling and Talbot, 2003;Kiyosu, 1983;Ricci et al, 2022;Taran et al, 2010). areas are worth targeting for H 2 exploration.…”