Krystian Wójcik

Natural accumulations of hydrogen occur in different geological horizons in Poland. For example, hydrogen occurs as admixtures (together with e.g. methane, nitrogen, and helium) in at least 70 gas fields, reaching up to 10% vol. Moreover, the occurrences of hydrogen – as a free gas or gas dissolved in formation waters/brines – were observed in many deep wells drilled during exploration of hydrocarbons  since the 60s. Natural hydrogen accumulations occur in Cambrian, Carboniferous, Permian Rotliegend and Main Dolomite horizons, basement of the Carpathian units, Miocene of the Carpathian Foredeep, and Carpathian flysch deposits. The appearances of hydrogen cannot be excluded also in other layers, such as Triassic or Jurassic on the Polish Lowland, although those layers have never been tested as not prospective in terms of oil and gas exploration.

Since 2023 the Polish Geological Survey recognizes natural accumulations of hydrogen investigating over 320 documented and historical oil and gas fields in Poland, as well collecting data from over 20 000 deep wells. The result will be a detailed map of hydrogen concentrations for specific geological horizons. These enable calculation of hydrogen geological resources, as well as indication of the most promising places, where economic exploration will be possible. From the other side, there still remains the questions related to the origin of hydrogen accumulations. Among many discussed ideas, the migration from Earth mantle along deep faults, serpentinization of ultramaphic rocks, hydrolyses in Fe-rich rocks, as well as Variscan volcanism or coal beds metamorphism are possible in different regions of Poland.