The Prelude floating LNG facility will continue to burn, or flare, unwanted gas during an extended shutdown of many months adding to its incredibly high initial carbon footprint.

Production from Shell's 488m-long showpiece off the Kimberley coast shut down in February and is not expected to recommence until the third quarter of 2020.

Boiling Cold understands that Shell has shut-in most of the subsea wells to reduce gas flow, but the Prelude is still receiving more gas than it can consume.

The Prelude emitted 2.32 million tonnes of greenhouse gases in the 12 months to June 2019 for just one shipment of LNG. The Prelude first received gas from its subsea wells in December 2019 but has been powered by gas from as early as June 2018 when it received a load of LNG.

Boiling Cold asked Shell why the Prelude could not be powered by diesel during the shutdown, as it was before June 2018, to stop flaring. A response was not received.

LNG plants are expected to flare more gas than average in the early stages of operation. Still, new facilities generally do not operate for as long as Prelude while producing so little.

The excess gas is burnt safely from a flare tower. The carbon dioxide released has a much lower greenhouse gas effect than unburnt methane but reducing flaring as much as possible is regarded as oil and gas industry best practice.

The LNG industry's case that its product is a net benefit to climate change rests the emissions saved by consumers burning gas instead of the dirtier fossil fuel coal exceeding the significant carbon emissions from LNG production.

A Shell spokesperson said the amount of gas flared each month was now 60% less than when the Prelude commenced operations.

"We are committed to further improving performance over time," the spokesperson said.

"Shell's policies aim to minimise all types of flaring, managed through annually updated greenhouse gas and energy management plans."


Main Picture: Prelude floating LNG facility off the Kimberley coast. Source: Shell