Stability and availability evaluation of underground strategic petroleum reserve (SPR) caverns in bedded rock salt of Jintan, China

- Stability and availability of China's first SPR salt caverns are investigated.
- Jintan salt mine has a good feasibility for the SPR caverns construction.
- Operating parameters are proposed to ensure the safety of SPR salt caverns.
- Many abandoned salt caverns of China can be rebuilt as the SPR caverns.
- Interlayers are beneficial for the stability of SPR caverns in Jintan bedded salt formation.

Due to the rock salt resources in China mainly being bedded salt, it brings great challenges for the strategic petroleum reserve (SPR) cavern construction and safety evaluation. A series of investigations are presented to analyze the stability and availability of the China's first underground SPR salt cavern facilities, located in bedded rock of Jintan, China. Systematic mechanics experiments of rocks surrounding SPR cavern were carried out to determine their properties. A 3D-geomechanical model is developed based on the mechanical test results and the characteristics of the target formation. Results show that the bedded rock salts in Jintan salt mine are suitable to construct underground SPR facilities. The interlayers in the bedded rock salt are beneficial to the stability of the underground SPR salt caverns because of their 'Reinforcement Effect'. The results also demonstrate that a number of existing abandoned salt caverns in Jintan salt mine which are unsuitable for gas storage can be rebuilt for SPR in the future. The results can also provide a reference for the implementation of similar projects in other places.