Fiammetta Mondino

The natural hydrogen (also referred to as “white” or “geological” hydrogen) appears as the most promising candidate to achieve economically viable, stable, low-carbon footprint economy, compared to the non-homogeneous cost of synthetically-produced hydrogen. Naturally-occurring free hydrogen gas has been reported in multiple geological contexts since decades, such as serpentinized peridotite massifs, pre-Cambrian cratons, rift zones, geothermal and volcanic regions: these represent the most favorable and economically-viable geological settings for natural hydrogen generation, potential accumulation and preservation. Additionally, sedimentary basins may also be potential for natural hydrogen generation/accumulation when associated with specific geological environments and H2-generation mechanisms. The concept of “Favourability Maps” has been successfully applied in geothermal exploration. Our proposed workflow is based on the generation of “Natural Hydrogen Favourability Maps (NHFMs)”: a tool to support decision making in natural hydrogen exploration. These maps are the result of the overlap between surface and subsurface elements. The surficial indicators for hydrogen generation may include fairy cycles, hyper-alkaline springs in serpentinizied contexts and hydrogen surface measurements, while subsurface parameters involve the main hydrogen play elements. The hydrogen play elements of an area include multi-dimensional interaction of: 1) the geodynamic setting of a region and its controls on the spatial distribution of potential hydrogen-generation rock types (e.g. peridotite lithotypes, radioelement-rich rocks, etc.), 2) the hydrogen-generation rock types (mineralogy, rheology, weathering intensity, petrophysical properties, etc.), 3) the relationship between rock-types and hydrogen generation mechanisms (e.g. water/rock interactions), 4) the stratigraphic setting, 5) the reservoir characterization, 6) the tectonic setting and the link with the presence/absence of privileged migration paths, 7) the caprock characterization, 8) the thermal properties of the region (heat-flow, thermal gradient, etc.), and 9) the hydrogeological setting. The integration of all these key play elements allow the construction of HFMs to assist in the identification and characterization of potential hydrogen prospects, the creation of a project funnel for prospect ranking and providing more informed support for decision making. The concept of HFMs has been applied in several regions and different geological contexts around the globe and has proven to be very effective for locating potential natural hydrogen prospects. Additionally, these prospects were confirmed using highly innovative and advanced TERRA-A proprietary natural resources detection technology (e.g. natural hydrogen, helium, water etc.), thereby providing strong evidence for the efficacy of hydrogen-favorability maps as a promising tool for exploration and evaluation of natural hydrogen prospects.

Co-auteur : Grant Nicholas, Peter Seibert, Mahmoud Leila