Geologicaly-sourced H2 exploration: pathfinders, tools, and methods

Recently, the growing demand for carbon-free energy has sparked an unprecedented interest in naturally occurring H2, as it could represent a potential alternative resource to fossil fuels. Throughout the world, and since more than one century, numerous natural H2-bearing geological fluids have been discovered, but to date, there is neither exploration strategy nor any resource assessment, as practical guidelines for hydrogen targeting are still missing. Here, we lay the foundation of a preliminary exploration guide based on a global ‘source-transport-accumulation’ understanding of H2-concentrating process and a combination of techniques and data used for both conventional petroleum and mining exploration. Based on different case studies, belonging to contrasted geological settings, we will provide the first elementary bricks to evaluate the sources, migration and trapping of H2 in the Earth’s crust.