A 2D stability analysis of the rock surrounding underground liquified natural gas storage cavern based on COMSOL Multiphysics

Underground liquified natural gas (LNG) storage is essential in guaranteeing national energy strategic reserves, and its construction is being accelerated. The stability of surrounding rock of underground LNG storage caverns under stress-low temperature coupling effect is the key factor determining the feasibility of LNG storage. First, a mathematical model used for controlling the stress-low temperature coupling and the processes of rock damage evolution is given, followed by a 2-D numerical execution process of the mathematical model mentioned above described based on Comsol Multiphysics and Matlab code. Finally, a series of 2-D simulations are performed to study the influence of LNG storage cavern layout, burial depth, temperature and internal pressure on the stability of surrounding rocks of these underground storage caverns. The results indicate that all the factors mentioned above affect the evolution of deformation and plastic zone of surrounding rocks. The research results contribute to the engineering design of underground LNG storage caverns.