Ekofisk was the first major discovery in the North Sea.
Phillips Petroleum discovered Ekofisk in December 1969 in the Norwegian sector, about 320 kilometres southwest of Stavanger. The find proved that the North Sea held substantial oil reserves, not merely the gas deposits already known from discoveries such as Groningen and the southern North Sea fields.
Production began in 1971, initially using subsea wells and tankers. Ekofisk crude was valuable because it was relatively light and low in sulphur. The field became the centre of a much larger complex that eventually included nearby fields such as Eldfisk, Embla, Tor and Albuskjell.
Statfjord, Forties and Brent are famous North Sea fields, but they were discovered later. Forties was found in 1970, Brent in 1971 and Statfjord in 1974. Ekofisk’s discovery helped trigger the rapid expansion of offshore exploration and production across both the Norwegian and British sectors.