World's deepest hydrogen well confirms natural H₂ in French subsurface

French energy company La Française de l'Énergie (FDE) has successfully completed drilling on the PTH-2 well in Pontpierre, Moselle — making it the deepest well in the world specifically dedicated to natural hydrogen, at 3,655 metres. The milestone is part of the REGALOR II research programme, a collaboration between FDE, the University of Lorraine, CNRS, BRGM and Solexperts.

Natural hydrogen was confirmed across multiple intervals of the sedimentary basin, building on FDE's initial 2023 discovery at Folschviller. During drilling, 58 samples were collected directly at the surface, accompanied by a comprehensive geological data acquisition programme including core sampling and in-depth logging. Technical partners RED Drilling, SLB, Baker Hughes and Weatherford supported the operations.

Natural — or 'gold' — hydrogen occurs naturally in geological formations without any production process, making it potentially one of the lowest-cost, lowest-emission hydrogen sources imaginable. Whether it can be extracted at commercially viable scale remains the key open question, and FDE is candid on this point: the Moselle discovery is not yet factored into the company's financial targets.

What is clear is that FDE is moving fast. Next up are further work on its Trois-Évêchés permit in France and — off the back of this success — new exploration wells planned in Kansas, USA, from the second half of 2026.