This issue of Deep Underground Science and Engineering (DUSE) publishes 19 high-quality articles. These articles cover a broad range of topics from underground space construction, deep mineral resource mining, and clean energy extraction to rock mechanics, disaster prevention, and artificial intelligence application. These articles highlight emerging challenges and recent advancements in deep underground engineering, certainly reflecting the diversity and current depth of research in deep underground science and engineering.
For this editorial, the editors will discuss the objectives, research contents, current status, future directions, and industrial chain perspectives of the field. Deep underground science and engineering is a strategic discipline that ventures deep into the Earth to secure resources, expand space, and ensure safety. Its core mission is to address resource constraints, unravel the unknowns of the subsurface, and ultimately build a synergistic innovation chain linking science, technology, and practice. Its objectives are strategically significant and urgent in four aspects. First, safeguarding national strategic resource security is the primary driver. As shallow resources become depleted, exploring ultra-deep resources such as oil, gas, geothermal, and critical metal minerals becomes imperative. These engineering requirements drive us to understand the behavior of the deep underground and to pursue its sustainable development. Second, unraveling the mysteries of the Earth system is fundamental. The deep Earth is the planet's engine; studying its internal structure, composition, and dynamic processes is key to understanding Earth's evolution and habitability. This constitutes the fundamental science of the deep underground. Third, expanding underground space for habitation and development is increasingly important. Beyond ground surface resources, the deep underground provides vast space (e.g., abandoned mines, salt caverns) for energy storage, carbon sequestration, and even laboratories or data centers. These underground spaces may be open cavities or porous media. Fourth, enhancing disaster prevention and mitigation is essential. Understanding deep earthquake mechanisms and engineering hazards enables better monitoring, early warning, and control of geohazards.
Deep underground science and engineering provides a highly interdisciplinary frontier. Its main research areas currently include the following. (1) Deep underground science as the foundation: Deep Earth structure, material composition and cycling, energy transport mechanisms, rock mechanics, and rock dynamics should be the central foci. (2) Deep resource exploration and extraction: This area encompasses ultra-deep well construction, efficient extraction (e.g., deep shale gas), in situ preservation coring, and related key technologies. (3) Deep underground space use and storage: This direction includes the utilization of deep space for energy storage (oil, gas, and hydrogen), CO2 sequestration, and deep underground laboratories. (4) Deep engineering and hazard control: Deep rock mechanics, intelligent prevention of engineering disasters (e.g., rockburst), and health monitoring are key directions. (5), Deep environment and ecology present emerging directions for the sustainable development of the deep underground. Examples include deep subsurface microbiology, groundwater accumulation and migration, and the unique ultra-quiet and ultra-clean deep environment.
Deep underground science is at a critical juncture driven by national strategic needs and a technical paradigm shift. Strong national strategic support is a key driving force for the growth of deep underground science and engineering. In 2021, the Key Laboratory of Deep Earth Science and Exploration Technology (Ministry of Natural Resources, China) was established. The “Deep Earth Science in China 2035 Development Strategy” was released in 2025, setting a clear roadmap. These initiatives demonstrate that China has elevated deep underground science to a national strategic priority.
Deep underground engineering has achieved major milestones in well drilling and other areas: (1) Notable milestones in oil and gas drilling include the Shendi Take 1 well, which reached 10 910 m in depth and the Shendi Chuanke 1 well, which reached over 10 000 m in depth. Multiple ultra-deep shale gas reservoirs have also been discovered. (2) Key technologies such as ultra-deep wireline coring and specialized deep-drilling rigs have been mastered. New metal-ceramic composites are now used for high-temperature resistance. It is worth noting that Asia's first salt-cavern hydrogen storage demonstration project has commenced operation. (3) Several advanced research platforms have been established. The Yunlong Lake Laboratory of Deep Underground Science and Engineering is the world's largest underground laboratory. A key laboratory for the geological disposal of nuclear waste was established in the Beishan granite formation. Several innovation consortia have been formed to bridge theory, technology, and engineering applications. (4) A paradigm shift in research is underway. Artificial intelligence (AI) is transforming deep underground science from empirical interpretation to intelligent cognition, establishing a full chain of sensing–modeling–inference–decision–control.
Nevertheless, gaps in research on deep underground science and engineering remain. Compared with global leaders, China's exploration depths (typically <1000 m vs. 2500–4000 m internationally) and extraction cost competitiveness (e.g., shale oil) still lag behind. Based on current trends, the following directions hold great potential: (1) AI-empowered full-chain intelligence: AI can process massive datasets for precise resource prediction, intelligent risk warning, and automated extraction. (2) Deep energy storage and carbon sequestration: Large-scale underground hydrogen storage, compressed air energy storage, and CO2 sequestration are critical for carbon neutrality goals. (3) 10-km-class deep exploration and development: This aims to overcome extreme high-temperature and high-pressure challenges in drilling, extraction, and in-situ sensing. (4) Deep geothermal and clean energy: Hot dry rock resources should be developed and natural hydrogen should be explored as a new clean energy source. (5) Comprehensive utilization of deep underground space: This includes scientifically planning abandoned mines and other underground spaces for data centers, laboratories, and other facilities. (6) Deep environments and extremophiles: Exploring the deep biosphere and studying extremophiles for biotechnological applications are emerging directions for research.
The sustainable development of deep underground science and engineering depends on forming distinct industrial chains. Perspectives on the field can therefore be analyzed as follows. Research, technological breakthroughs, and industrial development are tightly interwoven, forming a potentially vast industrial chain. Considering the deep underground industrial chain as a value-transfer system helps identify bottlenecks at each stage. The upstream comprises equipment and materials. The core question is how to achieve self-reliance under extreme conditions, for example, by developing materials resistant to ultra-high temperature and pressures and high-sensitivity sensors, and by fully localizing key equipment (e.g., intelligent rigs). The midstream concerns resource exploration and extraction. The core question is how to achieve precise, efficient, and green development. Some examples are how to improve deep-ore targeting with AI, how to co-extract multiple resources (oil, gas, and geothermal), and how to efficiently utilize low-grade ores. The downstream involves space utilization and technical services. The core question is how to ensure safe, efficient, and intelligent use of underground space. Some examples are using digital twins for engineering risk early warning to ensure long-term safety of large-scale hydrogen storage or CO2 sequestration.
How research advances generate new industrial chains is a key concern in deep underground science and engineering. In practice, each breakthrough can create or reshape an industry. The main pathways for generating new industrial chains include the following. First, direct industrialization of technological breakthroughs in new materials (e.g., wear- and corrosion-resistant composites) can spawn a high-end drilling tool industry. In addition, new equipment (e.g., superconducting detectors and intelligent rigs) can form a high-end equipment manufacturing sector. Second, research outcomes can create new business models. Mature deep energy storage technologies (e.g., salt-cavern hydrogen storage) can create a new industrial chain integrating energy, chemicals, and equipment. Deep space utilization may give rise to new economies such as underground data centers and laboratories. By forming innovation consortia, basic research from universities and institutes is tightly coupled with corporate R&D and engineering applications, accelerating laboratory-to-market translation. Government–industry–academia–research collaboration is key to the success of deep underground science and engineering projects.
In summary, deep underground science and engineering is not only a fundamental endeavor to explore our planet's unknowns, but also a strategic field critical to national energy security, resource sustainability, and future development. By tackling extreme scientific and engineering challenges, it is continuously generating and will keep generating a vast industrial chain spanning advanced materials, intelligent equipment, resource extraction, and underground space utilization.
