Pilot study on the underground lined rock cavern for LNG storage

This paper reports the background information and the initial results obtained from the pilot underground LNG (liquefied natural gas) storage cavern in Korea, where all natural gas is stored in the condition of liquid phase. Many attempts have been made in the past to store LNG underground in unlined containment, though without success. A new concept for storing LNG in a lined rock cavern has been developed to provide a safe and cost-effective solution. It consists of protecting the host rock against the extremely low temperature and providing a liquid and gas tight liner. One of the most significant problems related to underground storage of cryogenic material is the need to prevent the leakage of liquid and gas from the containment system to the rock mass caused by tensile failures due to shrinkage of the rock mass around the caverns. In order to verify the technical feasibility of this storage concept, a pilot plant was constructed for storing Liquefied Nitrogen and has been in operation since January 2004, though has now been decommissioned. The overall monitored results from the pilot operations confirmed that the construction and operation of underground LNG storage in lined rock caverns is technically feasible for a rock engineering point of view. The results of this study may promote the first ever real scale underground LNG storage system in a rock cavern in the world.