Storage and brine extraction
In 1999, the construction of a gas storage facility in Carriço, 200km north of Lisbon, started in order to strengthen the national natural gas supply system. As the head of a European consortium Kavernen Bau- und Betriebs-GmbH was assigned with planning and construction of the facility. Since 2004, KBB Underground Technologies GmbH has been the general contractor for the project.
So far, six wells have been drilled and leached. At present, five caverns are used for gas storage, a sixth is being leached and will start gas storage operations in 2014.
Most of the brine produced is transported to a nearby salt production plant where the water is evaporated using excess heat and the sun.
The caverns are located in a salt structure which belongs to the Dagorda formation at depths of 1,000 m to 1,500 m and have volumes ranging from 350,000 m³ to 750,000 m³.
The complex, challenging tasks in this project include building the cavern sites and roads, drilling the cavern wells, connecting media pipelines for fresh water, brine and natural gas, the EMSR installations for the cavern sites, completion for leaching and gas operations, workover of cavern wells, plant operation, and technical consultancy during initial gas filling.