The Statfjord field operated by Statoil in the North Sea can celebrate the 20th anniversary of starting production today, 24 November.
Since the first of its three platforms came on stream in 1979, the field has produced oil and gas worth more than NOK 910 billion. Over half this sum has gone directly to the Norwegian state in the form of taxes and royalty.
Statfjord has yielded almost 3.7 billion barrels of oil and nearly 60 billion cubic metres of gas over its first two decades.
This field also provided the basis for building the Statpipe gas trunkline and Statoil's Kårstø treatment complex north of Stavanger.
Meanwhile, offshore loading of oil from Statfjord has made Statoil – and now its Navion subsidiary – the world's largest shuttle tanker operator. More than 5,145 cargoes have been lifted from the field.
Statfjord was developed and initially operated by Mobil, with Statoil taking over the operatorship on 1 January 1987.
"Development work in the 1970s was hit by delays, cost overruns and much media attention," recalls project manager Håkon Lavik in Statfjord's planning and licence department.
"The project was subjected to an official commission of inquiry, but the cost of Statfjord B, for instance, had been recovered after just 11 months of production."
Statfjord accounted for more than 80 per cent of Statoil's operating profit in 1982, and still contributed roughly 40 per cent of this figure in 1998.
Between 1987 and 1993, the field averaged more than 700,000 barrels per day. Production has declined since 1994 to the present daily average of just over 250,000 barrels.
The production record for a single day on Statfjord A was set on 3 December 1985 at 351,235 barrels. Starting up on 1 October 1980, the most stable well – A06 – flowed 121.4 million barrels of oil without a workover or equipment replacement until 10 August 1995.
Statfjord is now producing three times as much water as oil. Almost five-sixths of the reserves in the 160-million-year-old Jurassic sandstone reservoir have been recovered, but it will take 10-15 years to bring up the remaining one-sixth.
Employees on the three platforms and at the operations organisation in Stavanger will celebrate the 20th anniversary with a good dinner. And a model of Statfjord B is due to be presented today to the Norwegian Petroleum Museum in Stavanger.