Prelude FLNG Float Out - Time Lapse Video

The 488 meter long hull of Shell’s Prelude floating liquefied natural gas (FLNG) plant has been floated out of the dry dock at the Samsung Heavy Industries (SHI) yard in Geoje, South Korea, where it has been under construction for just over a year.

At 600,000 tons fully loaded, the vessel will be the largest floating structure ever constructed. To put that in perspective, the Prelude FLNG will displace nearly six times as much as water the largest aircraft carrier. At 488 meters long (1601 feet), the hull is almost 300 feet longer than Maersk’s new Triple-E containerships. The facility itself will be constructed with 260,000 tons of solid steel, or more than three times more steel than in the Golden Gate Bridge. It’s LNG tanks can store up to 220,000 m3 of LNG, 90,000 m3 of LPG, and 126,000 m3 of condensate, or a total capacity equivalent to approximately 175 Olympic swimming pools.

Shell plans to moor the Prelude FLNG some 200 kilometers off western Australia at the Prelude gas field for 25 years, where it is expected to produce the equivalent of 110,000 BOE per day.

In addition to its impressive size, the Prelude FLNG facility will be able to withstand Category 5 cyclones, secured in place by one of the largest mooring systems in the world. A 93-meter (305-foot) high turret will run through the facility while four groups of mooring lines will anchor it to the seabed. Three 6,700-horsepower stern thrusters, two of which will operate at any one time, will be used to pivot the facility either out of the wind or to allow LNG carriers to pull safely alongside to load.

Shell says that more than 600 people spent over 1.6 million hours working on different design options for the facility. Eight one-meter diameter pipes will extend about 150 meters below the facility and be used to pump cool seawater (50,000 m3 per hour) to chill the gas to -162° Celsius (-260°F), shrinking it by 600 times in volume and allowing it to be shipped directly from the facility itself.

“This is revolutionary technology developed by Shell,” says Neil Gilmour, Shell Vice President Integrated Gas Development. “It has the potential to change the way we produce natural gas.”

The Prelude FLNG, which analysts says may cost over $12 billion to build, is due to be producing by 2017.