Research progress on detection-evaluation-utilization technology of deep special space

The safe and efficient development of deep special space represented by the closed underground mined space, salt caverns, porous aquifers and deep coal seams is an important way and a major strategic demand to ensure the safety of national deep resources and energy. This paper focuses on the scientific and technological problems behind the bottleneck of deep special space exploration, evaluation and utilization, systematically combs the research status of deep special space exploration, evaluation and utilization, and summarizes the key technical system that needs to be broken through in deep special space exploration, evaluation and utilization. The results show that: High-precision detection and inversion modeling is the premise to realize the utilization of deep special space, the precise detection and intelligent identification technology of deep spatial structure and disaster is in the stage of transition from single breakthrough to system integration, but the adaptability of complex environment is still the main challenge. Dynamic identification of multi-field and multi-resource and scientific evaluation of development potential are the core challenges of deep space development and utilization, machine learning and intelligent algorithms are triggering technological paradigm changes in the evaluation and utilization of deep underground space. The resource, energy and functional reuse of mine underground space have become the key path to promote the transformation of resource-based cities and implement the “double carbon” strategy, the lack of evaluation model, adaptation system and technical system, and the lack of reuse cases are the biggest obstacles to standard formulation. CO₂ geological storage in deep coal seam, salt cavern hydrogen storage, sediment expansion and compressed air energy storage, aquifer gas storage, abandoned roadway physical energy storage are the main utilization methods of deep special space at this stage; however, due to the lack of systematic and authoritative national standards / industry standards, the construction of demonstration projects is in its infancy. Breaking through the five technical systems of ‘precise detection and storage space fine characterization’, ‘multi-resource and multi-physical field dynamic intelligent identification and evaluation’, ‘full-scene intelligent monitoring and safety guarantee for mine underground space reuse’, ‘full-life cycle safety monitoring and detection of CO₂ storage in deep coal seam’, ‘dynamic sealing evaluation of physical energy storage in deep underground space under multi-field disturbance’ can provide scientific and technological support for the implementation of national deep underground strategy.