SPECIAL REPORT: Three major North Sea decommissioning projects under way

Feb. 11, 2008
There are a number of decommissioning projects currently under way in the North Sea.

There are a number of decommissioning projects currently under way in the North Sea. Three major projects are BP PLC’s North West Hutton platform in the UK sector, Total SA’s Frigg platforms, which straddle the UK-Norwegian boundary, and ConocoPhillips’s Ekofisk-1 platform in Norwegian waters.

North West Hutton

BP’s North West Hutton platform produced 125 million bbl of oil between 1983 and January 2003. A heavy-lift vessel will remove the 20,000-tonne topsides and the 17,000-tonne steel jacket down to the tops of the footings (OGJ, June 20, 2005, p. 51). The units will be moved to the Able yard on Teesside for recycling and disposal and the decommissioning work will be completed next year.

This decommissioning project will use new cutting tool technology to remove a steel jacket structure of this weight, which sits in 140 m of water. After this work is finished, Heerema and subcontractors will decommission the pipeline, clear debris, and inspect the platform site.

BP PLC and its partners have awarded a contract for the removal and disposal of the North West Hutton installation in the UK sector of the North Sea. Photo from BP.
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A BP spokesman told OGJ that it will start decommissioning in the second quarter. “We did the well abandonment phase some years back when the field was still operational. We cleaned up the topsides to make them hydrocarbon free. This project has never been done before and we have estimated £169 million; we haven’t revised it and we’ll have a better idea of costs once we finish it.”

Frigg

The Frigg platforms, whose name refers to the Norse goddess of marriage, fertility, and love, produced 80 million cu m/day of gas at its peak. It stopped production on Oct. 26, 2004.

Total plans to remove the Norwegian steel drilling Platform 2; the steel substructure for drilling Platform 1; the topsides of the concrete installation and compression Platform 2; and the British steel platform of the quarters platform, treatment Platform 1, and the topsides of concrete drilling Platform 1. In addition the field’s internal pipelines and cables and waste on the seabed will be removed and taken to land.

It will leave the behind the concrete substructure for treatment and compression Platform 2 on the Norwegian side and two concrete substructures on the UK side.

Decommissioning was meant to finish last year, but bad weather has meant missing this deadline. The company is optimistic that the Frigg platforms will be decommissioned before the summer.

Ekofisk-1

A ConocoPhillips spokesman told OGJ that its Ekofisk-1 decommissioning plan was on schedule to finish by 2013.

“We have removed the topside of the storage tank weighing 25,000 tonnes of steel. We have removed some light structures on the platforms and the rest of it will go during the contractual process,” he said.

He declined to say, however, when it would award the decommissioning contract or the cost of the entire project.