Abstract:

Rapid social and economic development requires a steady supply of energy and natural resources. Such resources are markedly abundant in the deep earth. “Marching into the deep earth”, therefore, is an inevitable trend in energy supply such that the current resource exploration and development technology, cost, and financial prospects are compatible with meeting the resources needs. Owing to the “carbon peak and carbon neutrality” campaign, green, low-carbon, high-quality development has become a shared goal for society. To meet the major demands for energy, resource security, and ecological environmental protection, it is particularly important to accelerate the clean energy exploration and development, enhance the carbon storage capacity, and strengthen research on geological energy storage. These tasks are closely related to the study of deep hydrogeological process and such study requires immediate attention. By analyzing several literature reports, a comprehensive comparative study was conducted on the course of research discipline development and its relevant hot issues. This study sought to summarize and assess the current situation and future trends in deep hydrogeological research related to the distribution and circulation of deep groundwater, the accumulation of geothermal and lithium resources under the control of deep groundwater, the development of clean energies such as deep geothermal, hot-dry rock, and shale gas, the geological sequestration of CO₂ in the deep saltwater layers, and geological energy storage in the aquifer. Deep and systematic studies were found to be needed in such areas owing to the dynamic mechanism of groundwater circulation, the material and energy conversion process, water-rock interaction, the thermal accumulation mechanism, and the accuracy and precision of monitoring technology in deep hydrogeology under the conditions of high temperature and high pressure. In addition, the characterization of reservoir heterogeneity, the heat source mechanism, the sustainable development technology of deep resources and energy, the evolution characteristics of deep resources and environment under human intervention, the earthquake induced by hydraulic fracturing, the sensitivity of faults triggered by fluids, and the evolution of the triggering process will continue to remain as key research topics.

Key words: deep hydrogeology, resource accumulation and development, geothermal, hot dry rock, lithium in deep groundwater, CO₂ geological storage, geological energy storage