Table 2
Some of instability-induced factors (Yang et al., 2013).
| Factor | Results | Example |
|---|---|---|
| Creep closure | Volume loss, introducing lateral pressure on casing | Eminence (USA), Tersanne (France) 40% and 30% of total volume was closed respectively |
| Dissolution | Irregular shape of cavern, not enough spaces for storing, solution of pillar located between caverns | Subsidence and crater induced at surface in Bayou Choctaw |
| Anomaly zones (high and low solubility zones and gaseous zones) | Introducing crack in roof and wall, volume loss resulting from compaction of insoluble sediments | Some space of Kiel was occupied resulting from insoluble zones |
| Week cementation at cavern’s neck | Pipes corrosion, crack generation resulting in production leakage | Gas leakage and accumulation in layers in 22 years cause explosion and fire at Mount Belvieu |
| Cavern located at shallow depth | Nearness to the groundwater cause the roof of cavern to be leached | NGL-Kansas-USA |
| Injection and withdrawn rate | Tensile stress resulting in thermal changes during injection and withdrawn | |
| Thin cap rock | Development the crack in cap rock resulting in leaking | Failure in cap rock of Napoleonville, Louisiana, USA |
| Thin pillar | Failure in pillars located between caverns | Failure in pillar between two cavern at Mineola’s facility in 1995, Texas, USA |
| Human errors | Low feasibility study, overfilling | Cavern damage resulting from overfilling, Petal and Brenham, USA |
| Uncertainty in exploration, over-pressuring |