Special Issue on Geological Hydrogen and Helium: Geological Processes, Resource Assessment, and Subsurface Storage

Introduction:

Geological hydrogen and helium are attracting attention as potential contributors to a more diverse and resilient global energy system. Natural hydrogen is generated and accumulated through a range of geological processes, while helium is an important resource with applications in advanced technologies, scientific research, and industry. Understanding how these gases originate, migrate, accumulate, and are preserved in the subsurface is essential for evaluating their resource potential and developing reliable exploration strategies.

Recent progress in geochemistry, isotope analysis, basin modeling, geophysical imaging, and subsurface characterization has expanded understanding of hydrogen and helium systems. At the same time, emerging exploration activity has highlighted important questions concerning source mechanisms, geological controls, migration pathways, trapping conditions, resource estimation, and the interaction between hydrogen and noble gases. Integrating geological observations, laboratory experiments, geochemical evidence, and numerical modeling offers opportunities to improve conceptual models and guide exploration.

Despite these advances, uncertainties remain in distinguishing hydrogen sources, identifying prospective geological settings, quantifying resource potential, and assessing accumulation, preservation, and production risks. For helium, improved understanding of source rocks, radiogenic production, migration, and trapping is likewise needed to support resource assessment. Further work is also required to evaluate subsurface storage options, reservoir integrity, gas behavior, and the technical and economic feasibility of development.

This Special Issue aims to bring together the latest research and insights into geological hydrogen and helium systems, from fundamental geological processes to exploration, resource assessment, production, and subsurface storage. It welcomes studies that advance scientific understanding, present robust methods, and provide field, laboratory, or modeling evidence relevant to the responsible assessment and utilization of these resources.

Topics of interest include but are not limited to:

1. Geological Origins and Generation Mechanisms

• Geological, geochemical, and biological processes generating natural hydrogen
• Helium generation, including radiogenic sources and crustal evolution
• Co-occurrence and geochemical relationships between hydrogen, helium, and other gases

2. Migration, Accumulation, and Preservation

• Migration pathways, seals, traps, and controls on subsurface accumulation
• Faults, fractures, lithology, and basin evolution in hydrogen and helium systems
• Gas–rock–fluid interactions and processes affecting preservation

3. Exploration Methods and Resource Assessment

• Geochemical and isotopic indicators, geophysical methods, and integrated exploration workflows
• Prospective geological settings, play concepts, and basin-scale evaluation
• Resource estimation, uncertainty analysis, and exploration risk assessment

4. Reservoir Characterization and Production

• Reservoir properties, deliverability, and production behavior of hydrogen- and helium-bearing systems
• Laboratory experiments, field investigations, and numerical modeling
• Monitoring, well integrity, and technical challenges in exploration and production

5. Subsurface Storage and Engineering

• Geological storage of hydrogen and associated geomechanical and geochemical processes
• Reservoir integrity, leakage pathways, and risk assessment
• Coupled flow, geochemical, and geomechanical modeling for subsurface gas systems

6. Emerging Directions and Integrated Perspectives

• Data integration, machine learning, and advanced characterization techniques
• Environmental impacts, techno-economic assessment, and resource development strategies
• Comparative studies linking natural hydrogen, helium, and broader energy geoscience

We invite contributions that provide new insights, methods, datasets, and case studies on geological hydrogen and helium. By bringing together fundamental research and applied experience, this Special Issue seeks to advance understanding of these resources and support more robust exploration, evaluation, and subsurface management.

Important deadlines:

Submission deadline: May 31,2027

Submission instructions:

Please read the Guide for Authors before submitting. All articles should be submitted online; authors should select “SI: Hydrogen and Helium”on submission. All submissions will undergo the journal’s standard peer-review process.

Guest Editors:

• Chunhe Yang, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, China. Email: chyang@whrsm.ac.cn
• Geoffrey S. Ellis, Stanford University, USA. Email: gsellis@stanford.edu
• Steven A. Tedesco, Running Foxes, USA. Email: s.a.tedesco14@gmail.com
• Quanyou Liu, Peking University, China. Email: liuqy@pku.edu.cn
• Jianfa Chen, China University of Petroleum (Beijing), China. Email: jfchen@cup.edu.cn