Although significant progress has been made in the development of shallow natural gas, the exploitation of deep shale gas continues to face numerous challenges. Therefore, conducting research on deep shale gas extraction is crucial. The efficient exploitation is contingent upon a comprehensive understanding of the mechanical properties, fracturing behaviors, and transformation processes of deep reservoir formations. This paper initially delineates the geo-mechanical characteristics and key development challenges associated with deep shale gas reservoirs. It subsequently reviews recent advancements in laboratory experiments, numerical simulations, and field technologies. Finally, suggestions and strategies are proposed to enhance the efficiency of deep shale gas development. The perspectives offered in this paper aim to provide new insights into optimizing exploration and production in deep and complex geological environments.

Hydrogen is a low-carbon and clean energy source that can be produced from a wide range of sources, and the vigorous development of hydrogen energy industry is an important measure to achieve the dual-carbon goal and cope with the global energy transition. In the whole industry chain of "preparation–storage–transportation–application" of hydrogen energy, the difficulty of hydrogen storage has long been a constraint to the high-quality development of hydrogen energy industry. Salt cavern hydrogen storage has outstanding advantages such as low cost, large scale, high safety, and high hydrogen storage purity, which is an important development direction of large-scale hydrogen storage in the future, and also a major strategic demand during China's low-carbon energy transition. The current situations of hydrogen production industry and hydrogen energy consumption in China were comprehensively investigated, and the demand for salt cavern hydrogen storage in China was further analyzed. The technology and engineering status of using salt caverns to store natural gas and hydrogen in foreign countries were investigated, and the development and construction history of salt cavern storage in China were summarized. The similarities and differences of using salt caverns to store natural gas, helium, compressed air, and hydrogen were compared, and three major scientific and technological challenges that salt cavern hydrogen storage in Chin faces were proposed: hydrogen seepage and biochemical reaction in bedded salt rock, wellbore integrity control in salt cavern hydrogen storage, and pregnancy and prevention of disaster in hydrogen storage groups. The research results clearly define the rapid growth trend of hydrogen storage demand and the key research directions of large-scale salt cavern hydrogen storage in China.