Geomechanical and Geochemical Considerations for Hydrogen Storage in Shale and Tight Reservoirs

Underground hydrogen storage (UHS) in shale and tight reservoirs represents a promising solution for large-scale energy storage, playing a critical role in the transition to a hydrogen-based economy. However, the successful implementation of UHS in these low-permeability formations is contingent on a thorough understanding of the geomechanical and geochemical factors that influence storage integrity, injectivity, and long-term stability. This review critically examines the geomechanical aspects, including stress distribution, rock deformation, fracture propagation, and caprock integrity, which govern the containment of hydrogen under subsurface conditions. Additionally, key geochemical challenges, such as hydrogen-induced mineral alterations, adsorption effects, microbial activity, and potential reactivity with formation fluids, are explored to assess their impact on storage feasibility. A comprehensive analysis of experimental studies, numerical modeling approaches, and field-scale applications is provided to identify existing knowledge gaps and future research directions. By integrating geomechanical and geochemical perspectives, this review contributes to the development of effective strategies for optimizing hydrogen storage in unconventional reservoirs, ensuring long-term sustainability and operational safety.