Modeling of hydrogen genesis in ophiolite massif

Natural hydrogen is a promising energy source, but its economic viability remains to be assessed. The present study consists in a modeling methodology applied to hydrogen genesis in Oman ophiolite. With the use of several fluid-rock interactions codes, we modeled groundwaters in fractured harzburgites. The hydrogeological system considered is the following: shallow circulations (above 50m-deep) lead to alkaline springs and fuel deeper flows responsible for serpentinization and hydrogen generation. Numerical results were compared with field data (water compositions, mineralogy, etc.), and a good agreement was obtained. An interesting point evidenced by our model is the major role played by carbonates in this system. Where present, these minerals act as carbon buffers, and lead to formation of methane rather than hydrogen. (C) 2017 The Authors. Published by Elsevier B. V.