The leak occurred in the process module on the Gjøa facility at 20.01 on 21 June. This incident led to gas detection, a general alarm, automatic shutdown of the process plant, pressure blowdown and mustering in accordance with the alarm instructions.
Engie has estimated the leak rate at 1.06kg/s and the total quantity leaked as about 1.25m³. Analyses show that the fluid consisted largely of produced water with small quantities of hydrocarbons in the form of gas and condensate. The condensate did not ignite during the incident. The leak was halted after about 30 minutes.
The direct cause of the leak was a fatigue fracture in a weld on a ½-inch pipe nozzle installed on a condensate pump connected to the gas recompression system.
In connection with the emergency shutdown, it was registered that an emergency shutdown valve (ESV) upstream from the leak site failed to close.
The emergency response command on the facility decided to evacuate 19 people to land. There were 49 personnel on board (POB) before the evacuation. The position on Gjøa was normalised at 22.09.
In its investigation of the incident, the PSA has found that Engie’s maintenance of the ESVs with associated actuators has been inadequate. These problems have been known over a long period, but not dealt with.
The investigation has identified nonconformities from the regulations in the following areas:
- barriers and the barrier management system
- management and maintenance system
- responding to vibration
- organisation and management.
In addition, an improvement point has been identified related to:
- carcinogenic and mutagenic chemicals.
On the basis of the investigation’s findings, Engie has been given notice of the following order.
Pursuant to section 69 of the framework regulations on administrative decisions, see section 5 of the management regulations on barriers, Engie is ordered to take the necessary measures to ensure that safety-critical equipment is operated, tested and maintained in a way which ensures the performance of the barriers at all times. See chapter 7.1 .1 in the report.
The deadline for compliance with this order is set to 16 February 2018. We must be informed when the order has been complied with.