Reinforcement measures on gas caverns
Since 2006, more than 30 new gas caverns of the Etzel cavern storage facility with a maximum available working gas volume of around 3.3 billion m³ have been handed over to customers from the energy industry.
After technical incidents occurred in 2014 at gas production strings of two new caverns due to incorrectly supplied components of the underground completion, the cavern boreholes were repaired in 2015 and 2016 and returned to regular operation.
Recompletion of the 28 reinforced new-build gas caverns
As a precautionary measure, measures to reinforce the gas production pipe rounds have been carried out on the remaining 28 new caverns since September 2015 and were completed at the end of August 2016. The work to reinforce the gas production pipe rounds took around two weeks per gas cavern. A pressure lock (so-called "snubbing plant") is being used to implement the measures.
STORAG ETZEL provided regular information about this on this website.
In the summer of 2020, the recompletion of the first of 28 reinforced new-build gas caverns was completed by STORAG ETZEL. The recompletion included the replacement of the complete gas production string and the installation of an underground safety valve that can be controlled from above ground in accordance with the Deep Drilling Mining Ordinance (BVOT) in the state of Lower Saxony. This restored this cavern borehole to its original construction condition. As some work processes had to be carried out without interruption, the work was at times carried out in 24-hour operation.
Further gas caverns to be successively converted since 2021
Since spring 2021 and in the following years, further gas caverns will be successively converted. We provide information here at www.storag-etzel.de under "News & Press" on the further status of the work.