Performance assessment of an underground gas storage cavern using water-shed scale groundwater flow modeling with large grid spacing

In this study, we simulated the water-shed scale groundwater flow near an underground LPG storage cavern system to assess its performance. To consider the effects of the storage cavern system on groundwater flow with large grid spacing, we proposed a mathematical model of a head-dependent flux boundary condition for a storage cavern system. Then, we examined its applicability by comparing the simulation results from assigning head-dependent flux boundary conditions, to those from assigning constant head boundary conditions for a hypothetical storage cavern system. Then, we applied this new simulation to the performance assessment of a real underground LPG storage cavern system. The results show that the influence of a storage cavern system on groundwater flow can be modeled in a 3-D water-shed scale with large cells by applying the proposed head-dependent flux boundary condition. The proposed model for a head-dependent flux boundary condition was used for performance assessment of the storage cavern systems and discussion of future works for their performance.