In an important step, Shell has laid the keel for Prelude FLNG, the world’s first floating liquefied natural gas (FLNG) project. When complete, Prelude is expected to be the largest offshore floating facility ever built. The hull will now be assembled in the dry dock, before the turret and the topsides are fitted at Samsung Heavy Industries’ Geoje shipyard in South Korea.
“This is a key milestone in Prelude’s story,” said Rob Kretzers, Shell executive vice president projects. “Innovative thinking and leading edge technology, as well as hard work from those at Shell and our partners, have helped us reach this significant point in construction. Prelude’s size and scale is unprecedented and I look forward to seeing this enormous structure take shape. Shell is pioneering FLNG which has the potential to revolutionise the way natural gas resources are developed."
FLNG will allow Shell to produce natural gas at sea, turn it into liquefied natural gas and then transfer it directly to the ships that will transport it to customers. It will open up new opportunities for countries looking to develop their gas resources and bring more natural gas to market.
Large steel sections known as “blocks” that will form the hull are being manufactured in the Geoje shipyard, with more than 1,600 already complete. One section can be the size of a large house. The 93 m high turret mooring system is under construction in Dubai and will be transported to Geoje in five parts. The turret will run vertically through one end of the facility and will be anchored to the seabed by four groups of mooring lines. It will allow the facility to rotate with the direction of the wind.
Once complete, the 600,000 tonne facility will be almost half a kilometer in length (488 m or 1,601 ft), which is longer than four soccer fields, and will displace six times as much water as the largest aircraft carrier. It will be moored and hooked up to the undersea infrastructure, around 475 kilometres north-east of Broome, Western Australia.
Despite its huge dimensions, the facility is only one-quarter the size of an equivalent plant on land. Shell’s technology has been adapted for floating LNG, and engineers designed components that will stack vertically to save space. The cooling plant, for example, will be placed above the vast storage tanks that have a capacity equivalent to around 175 Olympic swimming pools. Specially designed tubes, known as risers, will draw 50 million l of cold water from the ocean every hour to help cool the natural gas.
Shell has started to build the organizational capacity in Australia to support the installation and operational phases. Deliveries of equipment to support the drilling operations are under way and Shell has awarded the contract for the Prelude supply base in Darwin, while the recruitment of operations staff began in March 2013.
Shell is leading the delivery of this mega project, working with long-term strategic partners Technip and Samsung Heavy Industries (the Technip Samsung Consortium). Prelude is the first of what is expected to be multiple Shell FLNG projects. The expertise gained from the Prelude project will help develop potential future floating facilities.