oa Natural Hydrogen Resource Assessment using Down-Whole Dissolved Gas Monitoring and Experimental Organic Geochemistry

Identifying economic hydrogen resources in the underground is a new challenge in gas exploration. In order to predict coalbed methane occurences in the Lorraine Carboniferous basin, artificial maturation was used to document methane isotopic signature from 0.5 to 3.0 %Ro. SysMoG™ , a new technology for monitoring dissolved gases at depth identified methane as major constituent in waters of FOLS1A well (Lorraine, France). Yet, contribution of hydrogen to the dissolved gas mixture increased regularly with depth up to 20% at 1200m. Extrapolation of the hydrogen enrichment profile observed suggests that 76% dissolved hydrogen contribution should be reached at about 3000m depth. In addition, comparison of the isotopic composition of methane present in the dissolved gas of FOLS1A well with artificial maturation indicates composition matching with coal of about 1.4%Ro, a maturity level currently reached at about 3200m depth. This implies that the dissolved methane observed between 800 and 1200m diffuses from coal bearing strata located at about 3200m where methane and hydrogen are mixed. Their sources might be different though. We therefore suggest that this depth should be a privileged target of the drilling campaign planned in the future REGALOR II R&D project.