Ekofisk is a field in the southern part of the Norwegian sector in the North Sea. The water depth is 70 metres. Ekofisk was discovered in 1969, and the initial plan for development and operation (PDO) was approved in 1972. Test production was initiated in 1971 and ordinary production started in 1972. Production was initially routed to tankships until a concrete storage tank was installed in 1973. Since then, the field has been further developed with many facilities, including facilities for associated fields and export pipelines. Several of the initial facilities have already been removed or are awaiting decommissioning. The initial field development started with three production platforms: Ekofisk A, Ekofisk B and Ekofisk C. Wellhead platform Ekofisk X and process platform Ekofisk J were installed in 1996 and 1998, respectively, as part of the Ekofisk II project. In 2005, wellhead platform Ekofisk M was installed as part of the Ekofisk Growth Project. A plan for water injection at Ekofisk was approved in 1983. Ekofisk K, which is the main injection facility, started water injection in 1987 and is still in operation. There had also been water injection at Ekofisk W from 1989 until 2009, when Ekofisk W was shut down and replaced by a subsea template, Ekofisk VA. A PDO for the development of Ekofisk South was approved in 2011. The project included two new installations in the southern part of the field: production platform Ekofisk Z and a subsea template for water injection, Ekofisk VB. Injection from Ekofisk VB and production from Ekofisk Z started in 2013. The accommodation facilities Ekofisk H and Ekofisk Q were replaced by Ekofisk L in 2014. An amended PDO for an additional water injection template, Ekofisk VC, was approved in 2017.