The floating out of a Korean dry dock of a 1,600 foot hull may not have hit the world headlines as much as Neil Armstrong’s famous first step off the Eagle’s ladder, but was, in its own way, just as significant. The hull is for Shell’s Prelude FLNG (Floating Liquified Natural Gas) facility that will enable Shell to produce from offshore gas fields that would otherwise be inaccessible and is an engineer’s dream that also signifies a revolution in gas production.

For a start there’s the sheer size of the beast - at over 1,600 ft, it’s longer than four football fields and will displace the same amount of water as six of the world’s largest aircraft carriers. It draws in 50,000 cubic metres an hour of cold water from 150m below the ocean surface to help cool the natural gas it holds - and its storage tanks will hold the same amount of liquid as 175 Olympic-sized swimming pools except that this is Liquified natural gas kept at a cool -162° Celsius and shrunk in volume by some 600% allowing it to be shipped off to cites by conventional LNG tankers

Then there’s the incredible construction project – it took more than 600 people around the world 1.6m man hours for the front end engineering and design stage of development for the Prelude FLNG project. The first steel for the seven wellheads was cut in September 2011. The keels were only laid in May 2103 and the hull was built in two massive drydocks at Samsung Heavy Industries’ Geoje Island shipyards in South Korea, one of only a few facilities that could handle projects of this size. The two halves were then joined prior to the float out on December 3rd. The huge vessel is turret moored allowing it to slowly turn into whichever direction the prevailling weather comes from - the turret alone is 305m high, spacious enough to house the Arc de Triomphe.

But all this pales into insignificance when the imaginative scope and purpose of the project is considered. The FLNG will be located at the Prelude gas field, some 300 miles offshore Western Australia where it will extract gas from a field estimated to contain approximately three trillion cubic feet and convert it to LNG - Operator Shell expects the project to produce around 3.6million tons of LNG per year.

Moving the production and processing of natural gas out to sea will revolutionise the way natural gas resources are developed and unlock fields which were previously thought economically unviable. The new technology will avoid pipelines and other infrastructure and lessen the environmental impact of offshore gas developments.

So, congratulations to Shell’s engineers for the imagination and determination to change the way we produce our gas - the Prelude FLNG may be the first such vessel but it definitely won’t be the last.

John Dias

Managing Director, Silver Bullet Marketing Ltd