Evaluation and investigation technology of salt cavern resources in China

Under the background of the “carbon peaking and carbon neutrality goals”, the salt cavern is an important place for geological storage and carbon sequestration. The limited knowledge of the quantity and quality of the salt cavern and immature investigation technology constrains the development and utilization of salt cavern. After analyzing the geological exploration reports on major salt mines, reserves reports, enterprise annual reports, and research articles, a scientific understanding and basic judgment of the amount and utilizability of salt caverns in China are obtained; a technical system of salt cavern resource survey is established through a test with comprehensive detection technology in the concentrated area of salt cavern. The results show that salt cavern resources in China are characterized by abundant reserves, wide distribution, feasible burial depth, and convenient utilization on large scale. The most abundant salt cavern resources occur in the east and central regions. The national salt cavern resources are divided into levels I, II, and III by using an availability evaluation method system of salt cavern resource. Level I accounting for about 29.4%, is mainly distributed in Jiangsu, Hubei, Henan, and other provinces in east and central China. Salt cavern resources in level I are preferred for development and utilization. Level II accounting for about 65.4%, is widely distributed in southwest, northwest, and centra China, and can be used as a prospective area for development and utilization. Salt cavern resources in level III accounting for about 5.2%, are not suitable for development and utilization. Ground geophysical exploration, which can identify the characteristics of the regional geology, salt layer geology, hydrogeology, and salt cavity distribution of the salt mining area, guides the site selection on the salt cavern construction; geophysical exploration of high precision, which can obtain the information of salt mine levels and cavity structure, benefit the construction and operation detection of storage. This study provides the basic data and technical support for the planning and development of salt cavern resources in China.