Avant-monts franc-comtois
Helium in Franche-Comté: characterization of an accumulation with industrial implications
Avant-Monts franc-comtois exploration license
Drilling surveys were carried out in the Jura foothills between the 1950s and 1970s. These revealed the presence of non-combustible gases in this region of the Doubs department. In similar geological contexts, helium is associated with these non-combustible gases.
In order to push further our geological knowledge of the area and validate the helium and carbon dioxide content, 45-8 ENERGY submitted a exploration license application in April 2021. That license concerns a 306 km² area located in the northwestern part of the Doubs department.
Granted by order of the Minister of Economy, Finance, Industrial and Digital Sovereignty and the Minister of Energy Transition on August 5, 2022, the license was published in the Official Journal on September 29, 2022.
If the geological assumptions are confirmed, we plan to jointly exploit helium, carbon dioxide, and any associated gases to meet growing demand, in line with our local and eco-responsible commitment.
The license was granted for a period of 5 years so that the necessary works may be carried out gradually across the entire license area.
Size of the exploration area
306 km²
Size of the exploration area
Concerned municipalities
58
Concerned municipalities
Granted period
5 years
Granted period
Objectives
Deepen our geological knowledge of the area.
Understanding the origin and migration paths of the gases present in order to target areas prone to accumulation.
Demonstrate the technical and economic viability of a project to recover the gas mix in the area.
A supported project
45-8 ENERGY has received €2.88 million in funding as part of the France 2030 investment plan’s call for expressions of interest in “Russian, Belarusian, or Ukrainian dependency inputs.”
The proposal to produce helium in France by 45-8 ENERGY would contribute to national sovereignty, a hot topic, especially as helium’s position as a strategic resource has been reinforced in the latest list of critical resources of the European Union, published in early 2023.
Assumptions about the gas mix
Helium
Between the 1950s and 1960s, wells were drilled in several municipalities in the Avant-Monts area, which revealed the presence of non-combustible gases.
Although helium was not measured at that time, it has a certain affinity with non-combustible gases, like nitrogen, already associated to each other in similar contexts.
Since then, our initial field measurements confirmed the significant presence of helium in the region.
Nitrogen
High nitrogen levels have been detected in several wells in the region.
Nitrogen is the most abundant element in the Earth’s atmosphere (it accounts for approximately 78% of its composition). Due to the abundance of nitrogen in the air, its appeal is limited and its economic use unlikely.
Its release to the atmosphere has no risks for the population and the environment (does not contribute to the greenhouse effect).
Exploration area
The license covers 306 km² of the Doubs department, spread across 58 municipalities:
Audeux, Avanne-Aveney, Berthelange, Besançon*, Beure, Bonnay, Braillans, Burgille, Busy, Chalezeule, Champagney, Champvans-les-Moulins, Châtillon-le-Duc, Chaucenne, Chemaudin et Vaux, Corcelles-Ferrières, Corcondray, Courchapon, Dannemarie-sur-Crète, Decevey, Ecole-Valentin, Etrabonne, Ferrières-les-Bois, Fontain, Franey, Franois, Geneuille, Grandfontaine, Jallerange, Lantenne-Vertière, Larnod, Lavernay, Le Moutherot, Les Auxons, Mazerolles-le-Salin, Mercey-le-Grand, Mérey-Vieilley, Miserey-Salines, Montferrand-le-Château, Noironte, Pelousey, Pirey, Placey, Pouilley-Français, Pouilley-les-Vignes, Pugey, Rancenay, Recologne, Ruffey-le-Château, Saint-Vit, Serre-les-Sapins, Tallenay, Thise, Thoraise, Torpes, Velesmes-Essarts, Vieilley et Villers-Buzon.
Key steps
Operations
Completed
September 2025
Well Test
The well test is carried out at the drilled well, in Mazerolles-le-Salin.
This step involves measuring the concentration of helium in the gas mixture and assess the size and economic viability of the accumulation.
August 2025
Medium-depth drilling
The drilling campaign is carried out in Mazerolles-le-Salin.
This step involves confirming the presence of helium and to recognize and characterize the geological formations in which helium could be contained.
What's next?
If the drilling campaign proves to be successful and confirms the helium potential, further works may be carried out. Ultimately, the aim is to valorize helium economically, produce this strategic resource in the Doubs region, and supply local industries.
A pilot production unit could be considered in the long term, as it is the case at our Fonts-Bouillants site in Nièvre.
We could consider the same type of unit in the Doubs region. Once the economic and technical potential has been validated, long-term industrial production is the next step. The infrastructure would be very modest in size, equivalent to an agricultural warehouse. It would have to reconcile industrial activity with respect to the environment.
The pilot helium production unit in Nièvre (Fonts-Bouillants Project).
