- A letter with notification of the order was sent to Equinor on 17 December 2020.
- The order was issued on 12 January 2021.
This facility stands on the Statfjord field in the North Sea, which is operated by Equinor.
The PSA investigation has covered not only Equinor but also Archer as the drilling contractor for Statfjord B.
A short circuit and arc flash occurred while replacing a defective circuit breaker in an electrical switchboard for drilling on Statfjord B on 18 August 2020, and resulted in a fire.
Actual and potential consequences
The incident caused a production shutdown and material damage from the fire.
Personnel directly involved in the incident while extinguishing the fire were exposed to harmful smoke and received treatment for this. It will not be possible to identify any possible latent effects until some time after the exposure.
Exposure to harmful smoke from the fire in the switchboard room could have had serious toxic effects or fatal consequences.
In slightly different circumstances, the arc flash generated by the short circuit had the potential to cause serious burns for one person.
Direct and underlying causes
The direct cause of the incident was very probably a conductive foreign body which caused a short circuit when the breaker was inserted, with a consequent arc flash and fire.
A number of underlying causes of the incident on Statfjord B have been identified by the investigation. These relate primarily to:
- technical deficiencies
- expertise and capacity
- decision-making and information-sharing processes
- roles, responsibilities and conduct of analyses
- coordination of collaboration between operator and contractor
- planning and executing the work of replacing the breaker.
The investigation has identified 11 nonconformities in relation to the incident:
- risk management in Equinor
- barrier management
- lack of expertise and training
- conducting maintenance work at night
- inadequate information-sharing and use of information systems
- failure by Equinor to see to it that Archer complies with requirements in the HSE legislation
- deficiencies in the maintenance programme and in improving such work
- deficiencies in the arc flash analysis and communicating necessary information
- lack of protection against thermal effects
- lack of protection against interruptions and of adequate selectivity between protection devices in the event of faults in the installation
- deficiencies in handling hazard and accident situations.
The nonconformities relating to lack of expertise and training (section 9.3 in the investigation report) and deficiencies in the maintenance programme and in improving such work (section 9.7) are directed at Archer. The other nonconformities are directed at Equinor.
On the basis of the investigation’s findings, Equinor has been given the following order.
Pursuant to section 69 of the framework regulations on administrative decisions, see sections 4, 15, 21 and 16 of the management regulations on risk reduction, on information, on follow-up and on general requirements for analyses respectively, and section 18 of the framework regulations on qualification and follow-up of other participants, Equinor is ordered to take the following action with regard to the electrical installations on its facilities.
- Identify and implement measures which ensure adequate technical, operational and organisational solutions to reduce the probability of damage, faults and hazard and accident situations occurring in connection with operation and maintenance of the electrical installations. See section 9.1 of the report.
- Identify and implement measures which ensure the necessary information transfer internally and to relevant contractors in order to plan and execute activities with the electrical installations in a prudent manner. See section 9.5 of the report.
- Review the company’s follow-up of drilling contractors and ensure that the correct parameters and preconditions are provided, as well as seeing to it that they carry out their work in compliance with the regulations. See section 9.6 of the report.
- Review arc-flash studies to ensure that these are representative for the actual conditions. See section 9.8 of the report.
The deadline for reporting how the order will be complied with is 1 February 2021. The deadline for complying with the order is 5 April 2021. We must be notified when the order has been complied with.
The PSA report contains descriptions of identified nonconformities in addition to those which form the basis for the notice of an order, and the PSA has requested that Equinor provides an explanation of how these will be dealt with. It has also requested that Archer explain how nonconformities 9.3 and 9.7 will be dealt with, and that Equinor coordinates a collective response.