franc-comtois exploration license

Avant-Monts franc-comtois in brief

Drilling was carried out in the French Jura "Avant-Monts" region between the 1950s and 1970s. They revealed the presence of non-combustible gas in this region of the Doubs (25).

In similar geological contexts, helium is associated with these non-combustible gases. 45-8 ENERGY is assessing a significant prospective interest in helium.

Based on bibliographic research data and initial field measurements, 45-8 ENERGY has been active in the area since September 2022, after obtaining an exploration license. Issued by the French Ministry of Ecological Transition and the French Ministry of the Economy, Finance and Industrial and Digital Sovereignty, the "Avant-Monts franc-comtois" exploration license covers an area of 306 km² and concerns helium and its related gases.
The permit covers 58 municipalities in the Doubs region, where geological and geophysical data acquisitions have been carried out since summer 2023. These acquisitions have enabled us to better image the subsurface and gain a better understanding of its geological structure.

In 2024, a new phase is getting closer: a medium-depth drilling campaign. This operation will enable 45-8 ENERGY to validate and precisely quantify the presence of helium in the area.

If the drilling and well tests are positive, further acquisitions could follow. Ultimately, the aim would be to extract economic value from helium through industrial production in the Doubs region. This would enable industries with significant helium requirements to be satisfied locally, in an eco-responsible way.

Valorise localy the strategic resources of franche-comté


The Avant-Monts franc-comtois project

Following bibliographic research and encouraging preliminary field measurements, 45-8 ENERGY is considering that the Jura foreland area, located in the Doubs department (25), is a promising prospective area for helium, in association with non-combustible gases highlighted by several drillings carried out in the 1960s and 1970s.

In order to deepen the geological knowledge of the area and precise the helium and carbon dioxide contents, 45-8 ENERGY applied for the Avant-Monts franc-comtois exploration license to the French Ministry of Ecological Transition for a 306 km² area located in the North-West of the Doubs.

This license was awarded by decree signed by the Minister for the Economy, Finance and Industrial and Digital Sovereignty and the Minister for Energy Transition dated August 5, 2022.

License perimeter is voluntarily large in order to comprehensively understand the geology of this particular region with the objective to reduce it at later stage once most promising areas have been spotted. If geological hypotheses are validated, a joint valorisation of helium, carbon dioxide and any other valuable resource is targeted in order to produce them and supply locally and in an eco-responsible way two high demand markets, through small size production units.

The license was awarded for a period of 5 years in order to progressively deploy the exploration program on the entire permit.

Exploration area size

0 km²

306 km²

Exploration area size




Valid period of the license
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5 years

Valid period of the license


The license goals

Deepen our geological knowledge of the area

Assess the origin and the migration paths of the gases to locate the most promising areas.

Demonstrate the technical and economic viability of a joint gases valuation project in the area


Our hypotheses about the gases involved

Between the 1950s and 1960s, wells were drilled in several communes in the “Avant-Monts” area, and found to contain non-combustible gas.

Although helium was not measured at that time, we do know that helium has a certain affinity with the non-combustible gases found. In similar geological contexts, they were associated with helium.

Our first field measurements confirmed the significant presence of helium in the region.

High nitrogen levels have been recorded in several wells in the region. Nitrogen is the most abundant element in the earth’s atmosphere (representing around 78% of its composition). Because nitrogen is so abundant in the air, its appeal is limited and its economic use unlikely. However, its release into the atmosphere poses no risk to people (inert, odorless, invisible) or the environment (it does not contribute to the greenhouse effect, already present in high concentrations in the earth’s atmosphere).

Helium and nitrogen have a strong affinity, which is why it is very likely that a fraction of the helium is associated with it.

Several nearby wells in similar geological formations have reported the presence (2-5%) of a natural hydrogen fraction in combination with the main gas. A similar fraction of natural hydrogen is therefore possible in the “Avant-Monts franc comtois” exploration license.


The exploration area

The exploration license area covers 306 km² of the French Doubs region, spread over 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.

* The Besançon urban area is not directly targeted. It has been included in application permiter for the sake of integration and communication with all stakeholders. This urban and economix area represents in particular a possible outlet for the resources that can be produced.


The work program

The planned work program is of limited extent and will have a very limited and strictly temporary impact on the environment. It mainly involves data acquisitions carried out with portable, indirect equipment, aiming at caracterising the subsurface without any risk for the surrounding populations.


Ongoing operations

Medium-depth drilling

4 concerned municipalities: Berthelange, Mazerolles-le-Salin, Pirey and Pouilley-les-Vigne.

Operations will start from summer 2024 and for 6 months.

45-8 ENERGY is working with FORAGES MASSE, a French expert company. 

A multi-phase drilling campaign
  1. Integration and interpretation of newly acquired geological and geophysical data;
  2. Preparing and carrying out exploratory drilling to confirm the presence of helium and characterize the geological formations in which the helium could be contained.
  3. Carry out withdrawal tests to accurately measure helium concentration and assess the economic and technical viability of the project.

With regard to drilling, a temporary platform will be set up to accommodate the operations. At the end of the work, everything will be returned to its original state, in agreement with the owners and operators of the plots concerned.

Wells that have shown encouraging results will be subject to racking tests. This involves partially opening the well several times to measure its production rate, then closing it again and recording the pressure build-up.


Key steps

Application for an exploration license
Granting of the Avant-Monts franc-comtois exploration license
July - October
Data acquisition (gravimetry, electromagnetism, ERT, passive seismic, 2D seismic reflection, etc.)
July - December*
Medium-depth drilling


What's next?

If the drilling campaign proves positive and confirms the helium potential, further work may be carried out. Ultimately, the aim is to develop the economic value of helium, to produce this strategic resource in the French Doubs region and to supply local industries.

A pilot production unit could eventually be envisaged, as is the case at our Fonts-Bouillants site in the French Nièvre region, with commercial production scheduled to start in September 2024.

We could envisage the same type of unit for the Avant-Monts franc-comtois project. Once the economic and technical potential has been validated, long-term industrial production could be envisaged. The infrastructure would then be very modest in size, equivalent to a farm shed. They would have to reconcile industrial activity with respect for the environment.

The Fonts-Bouillants helium production pilot unit in the Nièvre region (France) is nearing completion.

A supported project

45-8 ENERGY has received €2,88M in funding as part of the France 2030 investment plan’s “Russian, Belarusian or Ukrainian dependence” call for expressions of interest. 

45-8 ENERGY’s proposal to produce helium in France would contribute to national sovereignty, a highly topical issue given that helium’s position as a strategic resource has been reinforced in the European Union’s latest list of critical resources, published in early 2023.

Find out more about 45-8 ENERGY