Natural Hydrogen Reservoirs: Reservoir Engineering Principles and Appraisal Strategies

Natural hydrogen has emerged as a promising subsurface energy resource, shifting scientific attention from hydrogen generation mechanisms toward the reservoir conditions required for commercial accumulation and production. This review examines natural hydrogen from a reservoir engineering perspective, emphasizing the geological, petrophysical, and dynamic factors governing storage capacity, containment, and deliverability. Although natural hydrogen systems follow the classical petroleum system framework of source, migration, reservoir, seal, and trap, the unique physical properties of molecular hydrogen including its low viscosity, small molecular size, and high diffusivity introduce additional challenges for long-term retention and reservoir performance. Current field evidence remains limited, with the Bourakebougou field in Mali representing the only sustained producing natural hydrogen accumulation, while exploration programs in Kansas, South Australia, Lorraine, Oman, Brazil, and Spain provide important analogues for evaluating diverse reservoir play types. The review compares the principal geological settings for natural hydrogen accumulation, discusses hydrogen-specific reservoir properties, caprock integrity, fluid-rock interactions, and recharge mechanisms, and identifies the critical uncertainties affecting reserve estimation and production forecasting. It concludes that commercial success will depend less on estimates of global hydrogen resources than on rigorous reservoir appraisal integrating geological characterization, pressure-transient testing, hydrogen-specific petrophysical measurements, geochemical and microbiological analyses, and coupled reservoir simulation. Advancing these capabilities will be essential for transforming natural hydrogen from an emerging geological occurrence into a commercially viable energy resource.

کلیدواژه ها:

Natural Hydrogen Reservoir ، Geologic Hydrogen ، Reservoir Engineering ، Hydrogen Trapping