The Etzel cavern site:
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One of the largest cavern sites for ensuring supply
In 1970, the German government decided to store oil for use in a crisis – the so-called federal oil reserve. The salt cavern in Etzel near Wilhelmshaven is one of the locations selected for this purpose.
In early 1971, the mining companies Salzgitter AG/Deutsche Schachtbau- und Tiefbohr-GmbH and Preussag AG founded Kavernen Bau- und Betriebs-GmbH (KBB). The then government-owned industry management company IVG asked KBB to build and run caverns for storing 10 million tonnes of crude oil underground at the Etzel location as part of the federal crude oil reserve.
In autumn of 1973, solution mining operations began in 33 caverns in the Etzel salt dome. Oil filling was completed in 1977. Between 1989 and 1992, nine oil caverns were modified for gas storage and between 1994 and 2004, seven additional oil storage caverns were built. KBB Underground Technologies GmbH played a key role in converting ten additional oil storage caverns for gas storage and subsequent initial gas filling (2006 to 2010).
Since 2006, the Etzel location has become one of the largest gas storage sites in Europe due to the construction of new caverns. The existing infrastructure allows up to 30 caverns to be leached simultaneously. It is expected that 130 caverns will exist in the salt dome by 2022. In this expansion project, KBB UT is responsible for completion, gas tightness testing, and initial gas filling. In 2010, KBB UT has completed ten new caverns for gas storage operations. This means that IVG is operating 23 oil and 29 gas storage caverns with a total volume of 29 million cubic metres (as of May 2011).
