Current status and development trend of safety and emergency support technology for energy storage in deep underground spaces

With the scientific and technological goals of “Three Deeps Leading”, China’s oil and gas resource exploration is advancing from shallow strata to deep strata, and the construction of kilometer level deep underground engineering has become the norm. With the exploration of deep ground engineering, available deep underground spaces such as depleted oil and gas reservoirs, salt caverns, and goafs have emerged. Deep underground spaces have been proven to have advantages in large-scale energy storage and utilization, such as large reserves, wide distribution, high safety, low economic costs, and environmental friendliness. The industrial energy storage application of deep underground spaces is a powerful means to optimize China’s energy storage structure and ensure the national energy storage strategy needs. However, China started relatively late in the research of safety and emergency guarantee technology for energy storage safety in deep underground spaces. Currently, commonly used surface oil and gas storage methods are limited by geographical environment, construction conditions, and transportation methods. At the same time, accidents in surface oil and gas storage facilities face challenges such as complex causal factors, strong correlation, and wide disaster coverage. Therefore, the safe storage of energy in deep underground spaces is urgent. At present, China’s utilization of deep underground space energy storage focuses on the redevelopment of depleted oil and gas reservoirs, and the existing deep ground safety protection technology lags behind the practical needs of deep ground energy storage infrastructure safety protection. Therefore, this article systematically summarized the current research status of deep ground energy storage technologies such as deep gas storage, hydrogen storage, carbon sequestration, and compressed air energy storage. The goal was to achieve green transformation in the energy industry with strategic energy security storage. It emphasized the integration of energy storage, carbon sequestration, and deep resource extraction, and proposes a dual carbon cycle architecture for deep space energy storage and utilization. At the same time, the risks faced by deep ground energy storage equipment and facilities were systematically identified, covering the entire life cycle of deep ground energy storage design, construction, operation, and abandonment. The development needs, difficulties, and suggestions for China’s deep ground energy storage safety and emergency support technology were revealed, and a technical framework for the full life cycle safety and emergency support of deep ground energy storage was constructed. The development suggestions for China’s deep underground space safety and emergency support technology from 2024 to 2050 were proposed, providing reference for improving China’s deep underground space energy storage safety and emergency support technology system.