Implications of the helium-rich basin accumulation model in China for helium enrichment and exploration of coal-bearing gas resources

Background Helium is a scarce strategic resource in China, and enhancing its exploration is crucial for ensuring national resource security. While China's coal-bearing strata are rich in gas resources with significant helium accumulation potential, related research remains in its infancy. Methods This study systematically investigates the enrichment mechanisms and exploration strategies for coal-derived helium by integrating theories of helium generation, migration, and accumulation in natural gas reservoirs. Results and Conclusions Key findings include: (1) China's helium resources exhibit a “north-south zonal and east-west banded” distribution pattern, categorized into eastern mantle-derived enrichment zones, central crust-derived enrichment zones, and western crust-mantle mixed enrichment zones, with spatial differentiation controlled by basin tectonic types and regional evolutionary backgrounds; (2) Helium accumulation follows a dynamic process of source rock exsolution, cross-strata migration, and trap accumulation, governed by helium source confinement, migration pathway effectiveness (fault systems and microporous capillary interactions), hydrodynamic fields, and reservoir-caprock configurations. Trap conditions dominate accumulation processes, with vertical migration primarily facilitated by fault systems, assisted by lithological reservoir-caprock combinations, and supplemented by dissolution-exsolution mechanisms for localized enrichment; (3) Helium generation in coal-bearing basins significantly predates hydrocarbon generation but shares spatiotemporal coupling during peak accumulation periods. Coal measures demonstrate dual helium sourcing (self-generation and storage), forming vertically stacked configurations with natural gas reservoirs; (4) Coal-derived helium exhibits multi-source mixing, widespread symbiosis, three-dimensional enrichment, and low-concentration characteristics. Critical scientific challenges involve multi-source helium contributions, cross-system diffusion dynamics, structural controls on accumulation, and low-abundance resource evaluation. Future exploration should prioritize microstructural systems in tectonic zones, multi-type coal measure reservoirs, deep reservoirs, and basin-margin gas accumulations; (5) It is contended that for coal-derived helium, the concept of “compensating quality with quantity” should be firmly adhered to. Exploration efforts with potential risks should be preferentially carried out in representative potential regions such as the Ordos Basin and the western part of Guizhou and the eastern part of Yunnan. A comprehensive technical system encompassing “target area optimization-coordinated development of multiple coal-derived reservoirs” and the entire chain of “exploration-development-utilization” needs to be constructed. Integrate helium purification technologies and the collaborative development model of “helium-coal-gas” multi-resources, so as to achieve the efficient exploitation of coal-derived helium resources. The research results offer robust theoretical references and clear technical pathways for helium exploration in coal-bearing systems, thereby contributing significantly to the achievement of national helium resource security objectives.