Mined caverns and disused mines
Mined cavern consists of one or more galleries excavated in rock from a vertical shaft or inclined drift.
Sites are selected essentially on the basis of geological criteria:
- rock must be hard enough for the cavern to be stable,
- caverns are unlined.
Stored product is prevented from escaping on the principle of hydraulic containment, whereby the caverns are located at such a depth that the water naturally present in the surrounding rock creates a counterpressure higher than the pressure of the stored product, preventing it from migrating.
The water pressure in the rock can be enhanced artificially by special water supply systems “the water curtains”.
Typical cavern depths vary from 70 to 200 m.
Mined cavern storage technique, with or without a liner, can also be applied to cryogenic storage of all gases having a liquefaction point below 10 °C.
> See also : Lined mined cavern
Products stored:
- Liquid hydrocarbons
- Liquefied hydrocarbons
- Natural gas
- Industrial wastes
- Chemicals