Accident cause found

December 17, 1998, 08:00 CET

A locked heave compensator has been confirmed as the cause of an accident on the Deep Sea Trym drilling rig almost two weeks ago.

This emerges from the report of Statoil's inquiry into the incident, which occurred on the Rimfaks field operated by the group in the North Sea.

Substantial material damage was caused when the compensator system, used to offset vessel motion during drilling, locked during tests with a production well on this Gullfaks satellite.

Repairs are currently underway offshore to correct structural damage to Deep Sea Trym. The Norwegian Petroleum Directorate (NPD) has banned further use of the rig until all this work - including corrections to the heave compensator - has been completed.

The NPD has ordered Statoil as operator to ensure that drilling contractor Odfjell Drilling, which owns the rig, implements the measures it is required to carry out. An assessment of and future plans for the vessel must be submitted by the group to the state agency before Deep Sea Trym can return to work.

Together with Odfjell Drilling and Hydralift, which supplied the heave compensator, Statoil has also had a meeting with the NPD to report on action taken in the wake of an incident when the same equipment locked on the rig in August.

The group has decided against deploying a replacement unit until Deep Sea Trym can return to work on the Rimfaks well, which is likely to be in about two months time.