Updated 30 November at 0700 hrs
On Sunday evening, 28 November, all crews without emergency response responsibilities were evacuated from the Statoil-operated installation after a major gas leak was discovered.
The PSA was notified at 19:23 hours on Sunday and immediately mobilized its emergency response organization to follow up Statoil's work to secure the safety of personnel and handle the well problems.
Although the developments on Snorre A on Monday morning were satisfactory, the risk of further leaks has not yet been averted as some challenges remain in connection with re-establishing the barriers in the well.
The PSA demobilized its emergency response center at 15:45 hours, but preparedness remains high so that the organization can be remobilized at short notice, if needed.
The gas leak, which was probably the result of a well kick in a water/gas injection well, was discovered at about 19:00 hours on Sunday, 28 November.
A well kick entails an instability in the well as a consequence of the well taking in gas, oil or water. If the barriers fail, a well kick can lead to a blowout.
No one was injured in the incident. However, of a crew of 216 people, 141 were evacuated early in the incident - 90 people to Snorre B and 50 people to the mobile rig Stena Don, which is moored at the Visund field. At about 02:10 hours the PSA was notified that an additional 40 people had been evacuated to Statfjord C.
A crew of 36 remained on the installation to shut down and re-establish the necessary barriers and control over the well. Manning on Snorre A will increase somewhat in the course of the day on Monday in connection with remaining work to re-establish the well barriers.
According to Statoil, the well problems occurred in connection with well workover and pulling of production tubing on the field.
The PSA is monitoring Statoil's assessments of safety for the crew remaining on the installation and the company's efforts to regain control over the well.
The Snorre field was proven in 1979 and is the eighth largest field on the Norwegian shelf.
Snorre is located east of the Statfjord field. Water depths in the area are 300-350 meters.
Snorre is an oil field developed in two phases. Phase 1 encompasses a floating steel installation with living quarters and a process facility (Snorre A) to the south, and a subsea template with ten well slots (Snorre SPS) centrally located on the field, tied in to Snorre A.
Snorre TLP is also developed with a separate process facility for production from the Vigdis field.
Phase 2 encompasses a semi-submersible integrated drilling, process and living quarters installation (Snorre B) on the northern part of the field.
Press spokesperson in the Petroleum Safety Authority Norway:
Press spokesperson Inger Anda
Tel. +47 970 54 064