Cutting well costs

November 8, 2000, 08:00 CET

A Statoil-initiated collaboration on maintaining subsea wells in nine Norwegian offshore licences could yield annual savings of up to NOK 1 billion.

Eighteen companies have joined forces in the efficient well intervention project, which covers Statoil's Statfjord, Gullfaks, Åsgard, Norne and Heidrun fields as well as the Tordis, Vigdis and Borg developments operated by Norsk Hydro.

More than 60 per cent of Norwegian offshore output comes today from subsea wells, says project manager Arne Erichsen.

These are currently maintained with the aid of rigs already at work on drilling assignments in the relevant area.

Wells are still being drilled in most of the licences concerned as part of a field development plan. But this phase is due to be over for most of them by 2003.

The eight fields will have 200 subsea wells between them, and each of these needs a workover about every four years. That gives roughly 50 operations per year.

From 2003, vessels will have to be specially hired for intervention and maintenance. The collaborating companies stand to gain substantially by concluding long-term charters for a combination of light units and rigs.

"Permanent access to rigs and vessels is the best guarantee that the necessary equipment is available at all times to keep the wells in regular production," says Mr Erichsen.

The project has submitted a preliminary report to the operations units, which will now continue to negotiate with the partnership group.