Job description

-- Who we are
We are Mantle 8, a clean-tech start-up revolutionizing natural hydrogen exploration with cutting-edge technology and geologic strategies. Backed by leading clean-tech investors including Breakthrough Energy Ventures and Kiko Ventures, we're scaling up affordable natural hydrogen exploration — and you could be a key part of this journey!
Natural hydrogen offers an affordable, abundant energy source with significant potential in Europe. At Mantle 8, we integrate cutting-edge geoscience, novel seismic gathering and interpretation through 4D imaging, big data analytics, and AI-driven methodologies to systematically identify prospective areas worldwide

– What the role is about
As a Maturation Lead, you will play a critical role in advancing Mantle8’s most strategic exploration assets from permit acquisition into drill-ready projects and beyond. You will be responsible for a selected portfolio of high-potential projects that have entered the maturation phase — typically following the granting of a maturation permit and/or the decision to deploy advanced and capital-intensive components of our technology stack such as HOREX.
Your role is to design, integrate, and execute the full technical maturation program, ensuring that each project is optimally prepared for exploration drilling. This includes orchestrating multidisciplinary workflows across geology, geochemistry, and geophysics, and continuously refining our technology stack through feedback loops from field and drilling results.
You will act as a highly transversal technical leader, bridging disciplines and ensuring that all subsurface insights are integrated into a coherent and decision-oriented exploration strategy. Your work directly impacts the success rate of our drilling campaigns and the continuous improvement of Mantle8’s proprietary technologies.

– What you’ll be doing
1. Lead the full technical maturation strategy for selected projects:
• Define and execute the end-to-end maturation workflow from permit acquisition to drill readiness.
• Translate early-stage prospectivity into robust, drillable targets through integrated subsurface analysis.
• Prioritize and sequence technical activities to maximize value creation and de-risking ahead of drilling.
2. Orchestrate multidisciplinary subsurface integration:
• Lead the integration of geology, geochemistry, and geophysics into a unified interpretation framework.
• Ensure consistency and coherence across datasets, models, and interpretations.
• Drive collaboration across internal teams and external partners contributing to the maturation program and preparing for the exploration drilling campaign.
3. Design and manage advanced exploration programs:
• Define and oversee the deployment of advanced technologies (e.g., HOREX) as part of the maturation process.
• Specify technical programs, data acquisition strategies, and interpretation workflows.
• Ensure optimal balance between cost, risk, and information gain in all technical decisions.
• Refine & assess Prospect assessment & ranking based on P50 estimate, PPPs, techno-economic modelling.
4. Prepare and support exploration drilling:
• Deliver fully integrated subsurface models and target definitions to support drilling decisions.
• Contribute to well design, drilling strategy, and pre-drill risk assessment.
• Support operations during drilling campaigns from a subsurface perspective.
5. Build feedback loops to improve Mantle8’s technology stack:
• Analyse drilling results and post-mortem data to assess model accuracy and assumptions.
• Feed insights back into GeoLogix, APoGeH, HOREX and broader internal methodologies & exploration strategies.
• Continuously refine exploration workflows to improve success rates and efficiency.

Profile required

– What we’re looking for
Essential Requirements:
• Strong experience in subsurface exploration within Oil & Gas, Mining, or related resource industries.
• Proven track record in advancing projects from early-stage prospectivity to drill-ready targets.
• Deep expertise in at least one core discipline (geology, geophysics, or geochemistry) with strong working knowledge across the others.
• Demonstrated ability to integrate multidisciplinary datasets into coherent exploration models.
• Experience designing and managing complex exploration or appraisal programs.
• Strong understanding of uncertainty, risk assessment, and decision-making in subsurface exploration.
• Ability to operate in a hands-on manner, combining strategic thinking with execution.
Highly Valued:
• Experience with advanced exploration techniques and high-resolution subsurface imaging methods.
• Prior involvement in drilling campaigns and post-drill evaluation.
• Familiarity with hydrogen systems, unconventional resources, or frontier exploration contexts.
• Willingness to partly relocate to the Grenoble area, French Alps.
• Adaptable and thriving in a dynamic start-up environment.
• Passionate about contributing to clean-tech innovations.

– What we offer
Competitive Package:
• Corporate welfare plan & supplementary health insurance.
• Indefinite contract with full French employment protections.
Unique Opportunity:
• Have a meaningful contribution in the energy revolution of our lifetime by enabling successful exploration drilling of a new clean, affordable, and sovereign energy source.
• Work at the forefront of natural hydrogen exploration, bridging cutting-edge science with real-world impact.
• Significant impact in a high-profile fast-growing clean-tech start-up.
• Collaborative, dynamic, and diverse work environment in the stunning French Alps.

Ready to help turn subsurface insights into successful drilling campaigns? Join us in building the future of natural hydrogen exploration!
Mantle8 is an equal opportunity employer committed to diversity and inclusion. We welcome applications from individuals of all backgrounds.

Company description

🇬🇧 Mantle8 is a deep-tech exploration company dedicated to unlocking the potential of natural hydrogen as a new clean energy resource.

By combining advanced geoscience, subsurface modeling and cutting-edge simulation technologies, Mantle8 develops innovative exploration methods to identify and evaluate natural hydrogen systems deep within the Earth.
Our multidisciplinary team brings together geoscientists, engineers, data scientists and explorers who share a common ambition: advancing scientific understanding while building the foundations of a new energy frontier.
From regional exploration concepts to prospect generation and technological development, Mantle8 works at the intersection of research, innovation and industrial application to accelerate the emergence of natural hydrogen as part of the global energy transition.
At Mantle8, exploration is not only about discovering new resources — it is about expanding knowledge, challenging assumptions and building solutions for the future of energy.

Why is everything in English if Mantle8 is based in the heart of the French Alps?
Because Mantle8 is an international adventure.
As of March 2026, our team includes 21 people representing 9 different nationalities. This diversity is one of our greatest strengths, and English is the language that allows everyone to collaborate, debate ideas and build things together.
We love our home in the French Alps, but inside Mantle8 our common ground is English — from meetings and technical discussions to emails and, yes, even our jokes.
So if you’re thinking about joining us, English is not just helpful — it’s essential to be part of the conversation.



🇫🇷 À propos de Mantle8

Mantle8 est une entreprise deep-tech d’exploration dédiée à révéler le potentiel de l’hydrogène naturel comme nouvelle ressource d’énergie propre.
En combinant géosciences avancées, modélisation du sous-sol et technologies de simulation de pointe, Mantle8 développe des méthodes d’exploration innovantes permettant d’identifier et d’évaluer les systèmes d’hydrogène naturel présents en profondeur dans la Terre.
Notre équipe pluridisciplinaire réunit géoscientifiques, ingénieurs, data scientists et explorateurs partageant une ambition commune : faire progresser la connaissance scientifique tout en construisant les bases d’une nouvelle frontière énergétique.
De la génération de concepts d’exploration régionaux à l’identification de prospects et au développement technologique, Mantle8 opère à l’interface entre recherche, innovation et application industrielle afin d’accélérer l’émergence de l’hydrogène naturel dans la transition énergétique mondiale.
Chez Mantle8, l’exploration ne consiste pas seulement à découvrir de nouvelles ressources — il s’agit aussi d’élargir la connaissance, de remettre en question les certitudes et de construire des solutions pour l’énergie de demain.

Pourquoi tout est-il en anglais alors que Mantle8 est basée au cœur des Alpes françaises ?
Parce que Mantle8 est avant tout une aventure internationale.
Début mars 2026, notre équipe compte 21 personnes représentant 9 nationalités différentes. Cette diversité est l’une de nos plus grandes forces, et l’anglais est la langue qui nous permet de collaborer, de débattre d’idées et de construire ensemble.
Nous sommes très attachés à notre ancrage dans les Alpes françaises, mais chez Mantle8 notre langue commune est l’anglais — que ce soit pour les réunions, les discussions techniques, les e-mails et, oui, même nos blagues.
Donc si vous envisagez de nous rejoindre, l’anglais n’est pas seulement utile : il est essentiel pour faire partie de l’aventure.

On 6/1/2026