Shell’s Prelude FLNG risked major failure due to power issues

Australia’s offshore security regulator NOPSEMA said Shell’s Prelude FLNG facility risked the “catastrophic failure” in December due to a power outage.

Prelude is a floating liquefied natural gas (FLNG) facility, located offshore, north-northeast of Broome, in Western Australia. It is designed to extract, liquefy and store natural gas at sea before it is transferred and shipped to customers. It arrived at its current location back in mid-2017.

At the beginning of December 2021,  Shell had to temporarily suspend production at the facility because of a fire that occurred at the facility the day before. Previously, the FLNG unit went offline from February 2020 to January 2021 due to an electrical trip.

Later in December, Australian offshore safety regulator NOPSEMA ordered Shell to keep the FLNG shut. They said it is until the facility’s safety systems are fully operational.

At the start of January, WAtoday said it obtained a copy of NOPSEMA’s investigation report into the fire incident and subsequent power failures. According to these sources, the facility was at risk of suffering a “catastrophic failure”.

After the fire incident, the Prelude relied on three diesel backup units that all failed to work properly. The fire was quickly handled. However, for the next couple of days, the facility’s safety systems only operated sporadically due to a lack of reliable power. The crew reported various difficulties, such as temperatures as high as 45 degrees in their living quarters with high humidity.

On the other hand, no power meant there was no heating of the cavity to prevent the temperature of the steel structures supporting the deck from falling to dangerously low levels.

In conclusion, NOPSEMA said the unreliable power produced “significantly higher than normal” risks on the Prelude FLNG. It stressed that “cooling of the substructure in the vicinity of the LNG tanks could lead to catastrophic failure if unmitigated”.

However, NOPSEMA found Shell “appropriately managed” the immediate risks to the crew. When the inspectors visited, the incident was under control. The regulator is not considering the prosecution of Shell at this stage.

The report also states that Shell had not yet determined the root causes of the initial fire or the subsequent power failures.

The Prelude FLNG has the capacity to produce 3.6 mtpa of LNG. In addition, it can produce 1.3 mtpa of condensate, and 0.4 mtpa of LPG. Shell holds a total of 67.5 per cent stake in the facility. There is also Japan’s Inpex (17.5 per cent stake), Korea’s Kogas 10 (per cent), and Taiwan’s CPC (5 per cent).