Australia's offshore energy regulator NOPSEMA has ordered Shell Australia to keep its giant Prelude FLNG unit shut down until it can show the facility can recover from any future loss of power and keep its employees safe.
NOPSEMA has published a report following a small fire on the 3.6 million tonne per annum capacity floating LNG production unit — the world's largest floating structure — off northwest Australia on 2 December.
The safety body, which sent its inspectors to Prelude on 8 December, said this resulted in a loss of power on the unit, which led to intermittent electrical supply over the following three days as efforts were made to restore the power supply.
- Vessel type: Floating LNG unit
- LNG production capacity: 3.6 mtpa
- Condensate production capacity: 1.3 mtpa
- LPG production capacity: 0.4 mtpa
- Builder: Samsung Heavy Industries
- Topsides: Technip
- Overall length: 488 metres
- Beam: 74 metres
NOPSEMA said that the power failures had impacted the habitability of the facility for the personnel on board, essential services, working conditions and by 6 December this was posing a risk to their health and safety.
The loss of power also affected emergency response capability, the operation of safety equipment and the ability to evacuate personnel by helicopter or boat.
Insufficient understanding
NOPSEMA said seven people on the unit were treated for heat-related conditions.
It said that the power outages also affected the functionality of the process equipment required to effectively manage the LNG inventory.
NOPSEMA said: "The inspectors concluded that the operator did not have a sufficient understanding of the risks of the power system on the facility, including failure mechanisms, interdependencies and recovery."
The regulator rejected Shell's own plan to investigate the incident.
"NOPSEMA is aware that a Shell investigation is planned to determine the cause(s) of the power system issues that led to this incident, " it said.
But it said the proposed scope of the investigation does not provide for a thorough review of the evidence and root cause analysis of the entire series of events experienced during the 2 December incident. The body said it also did not allow for a review of the risks for future similar incidents and actions to mitigate them.
NOPSEMA ordered Shell Australia to conduct a review of the incident and its consequences for the 2 to 6 December period, including those identified in its report.
The major's Australian arm then has to present these to the regulator along with a detailed plan and schedule for the necessary corrective action.
Reporting in
It said that before hydrocarbon production can resume Shell will need to "demonstrate to NOPSEMA's satisfaction that the facility can safely recover essential power and associated essential services following a loss of power and that the safety systems and essential support systems operate to maintain the safety of personnel".
On the first day of the month, starting from March 2022, Shell has to provide an update to NOPSEMA detailing the progress made under the orders made by the regulator.
This latest enforced shutdown will come as a fresh blow to Shell which had only restarted production at Prelude in late 2020 following an 11-month shutdown after an electrical trip led to a series of extensive investigations and repairs.
It also comes at a time of sky-high gas prices where LNG is in demand.
Prelude LNG discharged its first cargo in June 2019.
