When gas arrives at a storage facility via a pipeline network it first enters a metering station where it is filtered, and the quantity and quality are measured. Injection to and withdrawal from the reservoir take place via a number of wells. Where necessary, compressors bring the incoming gas (working gas) up to the right injection pressure. Since compression raises the temperature, the gas must then be cooled before being conveyed to the wellhead and injected into the natural rock formations. Care must be taken not to exceed the original reservoir pressure.
Working gas is injected and withdrawn as required. This cuts operating costs and helps maintain high environmental standards.
Whenever the gas is withdrawn it must be reprocessed. It must be dried as it will have absorbed moisture in the reservoir. Once it is on-specification it enters the grid and is transported to the consumer.