50 years since the discoveryOpening of Ekofisk, 1971. Source: Erik Thorberg

50 years since the discovery

The decision to drill one last hole at the Ekofisk-prospect proved to be extremely rewarding, leading to the first commercial oil discovery (2/4-1) on the NCS and the first giant oil field in Western Europe.

In 1969, Phillips Petroleum Co. was in the doldrums. Earnings were in a slump, management had laid off more than 1,000 employees, and dry holes were hurting the bottom line. Company geologists were excited about prospects in the North Sea, but the company and its partners had drilled a number of dry holes offshore Norway in a two-year span.

After careful consideration, Phillips and the Ekofisk licensees fulfilled their commitment and drilled the last hole.

Ekofisk produces oil from naturally fractured chalk of Late Cretaceous age in the Tor Formation and early Paleocene age in the Ekofisk Formation. The reservoir rock has high porosity, but low permeability. The reservoir has an oil column of more than 300 m and lies at 3,000 m depth.

To learn more about Ekofisk, click here.

Geological model of Ekofisk. Source: Cultural Heritage Ekofisk