Numerical modeling demonstrates the feasibility of retrofitting oil caverns into lined rock hydrogen storage facilities, highlighting structural trade-offs between cavern configurations.
Key Points
To evaluate the technical feasibility and material costs of retrofitting underground oil storage caverns into lined rock caverns for large-scale hydrogen gas storage.
Conducted numerical simulations evaluating two retrofit configurations—a single-cavern design versus multiple sub-caverns separated by concrete pillars—using operational demonstration parameters.
Calculated ultimate and maximum operating gas pressures with an uplift failure model incorporating cavern burial depth and rock mass mechanical properties.
Performed comparative material cost evaluations alongside static and short-term cyclic thermo-mechanical structural analyses.
Dividing the cavern into sub-caverns reduced maximum steel liner tensile stress at the expense of pillar stress concentrations, whereas the single-cavern scheme offered higher storage capacity with less concrete.
Static modeling overestimated maximum steel liner tensile stress and concrete plastic-zone volume while underestimating rock-mass and total system plastic zones compared to cyclic thermo-mechanical analysis.
Both design schemes maintained low tensile stress in the steel liner, confirming the technical feasibility of repurposing caverns under adequate pressure safety margins.