Norway’s offshore safety watchdog, the Petroleum Safety Authority (PSA), has completed its investigation of the fire which broke out on Statoil’s Statfjord A platform offshore Norway in October 2016 and identified breaches of regulations.
Statfjord A is a North Sea production platform that has a concrete substructure and storage cells. The Norwegian part of the Statfjord field is located in blocks 33/9 and 33/12 in license 037 and contains both oil and gas.
The fire on the platform began in the utility shaft during transfer of oil from the platform’s storage cells to a shuttle tanker. One of the loading pumps continued to operate because a shaft in the circuit breaker intended to shut off power to its motor suffered a fatigue fracture.
However, displays in the control room indicated that the pump had stopped and, as a result, crude oil was pumped for 51 minutes against a closed valve and its temperature rose from 33°C to 344°C.
According to the PSA, the high temperature combined with powerful vibration in the pump meant that crude oil eventually leaked through the pump seals and ignited. Also, a fire broke out in the oil which leaked into an insulation box connected to the seal oil system.
The fire was confined to the quantity of oil which leaked out. It was initially detected by a flame detector on the loading pump deck and eventually extinguished through activation of the deluge system in the room, the safety body said.
Although there were no injuries during the incident and regardless of the fact that the fire was limited to a confined ignited hydrocarbon leak, 20 people had been moved to Statfjord B by SAR helicopter with production being shut down as well. For safety measures, Statoil had two SAR helicopters and an emergency response vessel standing by after the incident.
At the time of the incident there were 67 people on the platform.
The PSA concluded in its report on Tuesday that the fire would not have escalated even with a long-lasting leak, given that the fire extinguishing system functioned properly and that the incident had no major accident potential.
The safety body added that it identified three non-conformities and four improvement points. The non-conformities were related to investigations and improvement measures after earlier incidents, maintenance of shutdown valves, and blocking of safety systems.
On the other hand, the identified improvement points were in regards to alarm texts, conflict of roles in the emergency response organization, expertise and training, and general alarm and establishing of the emergency response organization.
The PSA has asked Statfjord A operator, Statoil, to explain how the non-conformities will be dealt with, and for an assessment of the identified improvement points.