The 25th anniversary of Statoil's first exploration well, spudded by Ross Rig in the Sleipner area of the North Sea, falls today, 4 July.
"Esso was nominally our technical assistant for this 15/12-1 well," recalls Idar Johnsen. "But it actually did the job. We were only apprentices."
Now operations vice president in the new areas cluster of Exploration & Production Norway, he was one of Statoil's two "learners" on Ross Rig in the summer of 1975.
Although this first attempt failed to find hydrocarbons, Mr Johnsen remembers that the group learnt fast.
The following year, it stood on its own two feet for the exploration well which discovered the Tommeliten field in block 1/9 at the southern end of Norway's sector.
"In reality, the 1/9 well was the first we operated ourselves, but we had representatives from partner Phillips Petroleum on the rig," says Mr Johnsen.
"Everyone thought the oil business and Americans were synonymous. It took us a little time to overcome that myth."
In retrospect, many steps have followed over the subsequent 25 years. The most important is increased knowledge about and awareness of safety and the working environment, Mr Johnsen believes.
"We've naturally made many crucial advances on the technical side as well, but the lessons we've learnt about the importance of the working environment and good relationships for a good and safe job are more important."
The brand new Ross Rig was chartered in 1975 by owner Ross Drilling to a consortium of Esso, Amoco, Conoco and Statoil.
Training was part of the cooperation agreement between these companies, and Statoil posted sub-surface and drilling personnel to its partners for two years.
Drilled in 95 metres of water, 15/12-1 was Ross Rig's first operation and reached a vertical depth of 3,269 metres below ground.
This rig handled most of Statoil's drilling operations up to 1981.
Since 1975, the group has drilled horizontal wells with a total length of almost 9,000 metres and – at 7,385 metres – the longest well so far carried out from a floater.
Statoil has also secured deepwater drilling experience, and was responsible last year for a well in more than 2,000 metres of water in the Gulf of Mexico.
A total of 15 mobile rigs are working for Statoil in the summer of 2000.