天然氢气的成因机制、赋存状态及成藏机制OA

As the global energy system transitions toward low-carbon and clean development,geological hydro-gen has emerged as a promising energy carrier because of its high calorific value and zero carbon emissions.As a sustainable underground resource generated by geological processes,natural hydrogen has attracted increas-ing attention for its potential contribution to resource exploration,energy security,and carbon neutrality.Through a comprehensive review and analysis of the existing literature,this study systematically examines the classification of hydrogen,the genesis and source identification of natural hydrogen,and its phase states and modes of occurrence.It further summarizes the geological conditions and enrichment mechanisms responsible for hydrogen reservoir formation and proposes a"generation-transportation-accumulation"theoretical frame-work.Natural hydrogen is predominantly generated through inorganic processes,including deep-source degas-sing and water-rock reactions,with additional contributions from organic processes,such as the decomposition of organic matter and microbial activity.It occurs as free gas,dissolved gas,and adsorbed hydrogen in the shal-low subsurface,whereas metal hydrides represent its principal occurrence in the deep subsurface.Trans-sphere structures and major deep faults provide the primary migration pathways,while clay minerals,coal-bearing strata,and dense water-bearing caprocks constitute the key geological conditions for hydrogen preserva-tion.To address the limitations of existing identification methods,this study proposes a"three-in-one system-atic genesis discrimination system"that integrates isotopic,geochemical,and geological evidence.This work provides a scientific basis for the exploration of natural hydrogen resources and contributes to advancing the energy transition and achieving carbon neutrality.