The leak occurred in connection with maintenance on a valve. The leak was estimated at 26 kg/s, while the total volume of hydrocarbons was estimated at 1500 kg. Next to the Visund incident on January 2006, this is the largest gas leak to occur in process areas on the Norwegian shelf in recent years.
The gas detection on Oseberg C (photo) system triggered an automatic shutdown. Crew members without emergency response tasks mustered at the lifeboats. No one was injured in the incident, but there were four people present in the area. These people would have died if an explosion had occurred.
The underlying causes of the incident revealed in the investigation include inadequate risk assessments in connection with planning of the work, as well as deficient competence regarding the hydraulics system on the part of the personnel involved.
The PSA has identified five nonconformities in relation to regulatory requirements:
- Deficient competence and inadequate practical experience on the part of personnel working with hydraulic systems.
- Deficient instructions for the work to be performed
- Deficient risk assessment and understanding of risk
- Deficient engineering
- Deficient emergency training. No training had been conducted for scenarios involving the loss of main power and thus loss of power to the control system and telephones.
See Chapter 5.1 of the investigation report for more detailed information.
The PSA has requested that StatoilHydro provide an account of how these nonconformities will be handled, and a reply to the dispatch letter by 16 March.
