Statoil AS has awarded Coflexip Stena Offshore Norge a contract for the abandonment of Statoil's Tommeliten subsea field on the Norwegian continental shelf. "It is the first time that the Norwegian authorities have given consent for a light well intervention vessel to do work in a live well as an offshore installation," said Coflexip Stena Offshore (CSO), "and it is the first time that such work will be undertaken by a vessel in the North Sea, without the support of divers."
Tommeliten was developed with six subsea trees on a single template in 73 m of water. It produced for 10 years before being shut in by Statoil in 1998.
The scope of work for the abandonment project includes re-entry of all six trees this month with the CSO Seawell vessel. To isolate the reservoir, the vessel will use cement and set mechanical plugs inside the well at a depth of up to 3,000 m below the seabed. Once the wells are secured, the christmas trees will be recovered.
CSO will supply all well engineering and downhole services and all consumables required to perform the work.
"Statoil is the first company to adopt this innovative approach in Norway," said Kevin Wood, CSO's executive vice-president, operations and projects, for North America, the North Sea, and Asia-Pacific. Wood says the CSO Seawell class of monohull vessel's cost-effectiveness, versatility, mobility, and efficiency make it capable of intervening on live subsea wells.
