Update: Shell’s Prelude FLNG on way to Australia

Prelude FLNG on its way to Australia (Image courtesy of Shell)

Shell’s giant Prelude FLNG facility has recently left the Samsung Heavy Industries’ Geoje shipyard in South Korea where it was built, bound for waters offshore Western Australia.

The FLNG, said to be the biggest floating production facility in the world, is expected to arrive at the Prelude gas field in Browse Basin around July 30, according to the marine data provider VesselsValue.

Prelude, with 488m in length and 74m in width, was being towed by POSH Terasea’s vessels Terasea Hawk, Tereasea Falcon and Terasea Osprey, each more than 75m long. A fourth tug acts as an escort. The offshore service contractor won the job back in 2016.

Prelude left Geoje at the end of June and moved into the East China Sea, across the Korea Straits.

The most difficult part of the journey was at the beginning, when nine additional tugs carefully coaxed Prelude from the harbour through a narrow U-shaped channel into open waters, according to Shell.

After the FLNG leaves the East China Sea, Prelude will then go through the Philippine Sea, past the islands of Indonesia and across the Timor Sea.

At the Indonesian archipelago, a fifth vessel will meet the convoy to help refuel, replenish supplies and replace the crew, Shell said, adding that 160 crew members will be on board Prelude during the journey.

At top speed, Prelude will be traveling at around five knots, about the same pace as a fast walk. Along the way, the convoy may encounter small fishing boats and other vessels that Prelude will need to safely avoid.

Once Prelude reaches its final destination at the Prelude gas field, 475 kilometers northeast of Broome, work will start to plug it into the undersea infrastructure.

As 16 pre-laid mooring chains are lifted from the seabed and attached to Prelude’s 93-metre high turret, a sixth towing vessel will join the five boats to keep the facility in place, Shell said.

Because Prelude sits in an area of cyclones and strong ocean movements, the turret will allow the facility to pivot safely with the prevailing current and the wind. Once operational, this ability to act like a weathervane means Prelude can ride out storms without having to disconnect the flexible pipelines that feed in gas from deep below the waves.

When all 16 chains are in place, Prelude will be considered storm-safe and the work of the tugboats will be officially complete.

Shell’s Chief Financial Officer Jessica Uhl said in May that the FLNG facility would come on stream offshore Western Australia in 2018.

It is expected to stay moored at the Prelude gas field for 25 years and to produce 3.6 mtpa of LNG, 1.3 mtpa of condensate and 0.4 mtpa of LPG for export.

(Article updated on July 3 to include additional details of the journey from South Korea to Australia)

LNG World News Staff