The decision was taken in the summer of 1986 to start a waterflood pilot in the Ekofisk formation, the upper of the two reservoir zones.
This was regarded as successful, and the whole project was expanded in 1988 to the lower part of the Ekofisk formation and the Tor zone in the southern part of the field.
It was decided to convert the second support for the bridge to the southern flare stack at the Ekofisk Complex to a wellhead platform with eight slots.
Designated Ekofisk 2/4 W, this facility was installed in November 1989. Necessary changes were made to the 2/4 C and 2/4 A platforms to accommodate eight additional wells from each.
Waterflooding from the 2/4 W module began on 12 September 1990 in the lower part of the Ekofisk formation (Danian) and the southern section of the Tor zone (Cretaceous).
Building the breakwaterStatoil brings Tommeliten on stream