Exxon floats offshore LNG plan ExxonMobil has submitted plans for a liquefied natural gas project off the north-western coast of Australia that would enter the record books as the largest offshore floating facility ever built. It is the second supermajor after Royal Dutch Shell to move ahead with plans to produce LNG at sea. Exxon lodged documents with Australia's federal environment department on Tuesday detailing its plans to develop the Scarborough gasfield using floating LNG, or FLNG, technology. But Exxon said it and its partner BHP Billiton would not make a final investment decision on the project until 2014 at the earliest. With FLNG, offshore gas reserves are exploited in situ, rather than being piped to onshore liquefaction plants. As such, it can be used to unlock "stranded" gasfields that are too small or remote to justify the construction of a pipeline to the coast. It is seen as extremely well-suited to Australia, whose gasfields are often close to environmentally sensitive coastal areas unsuited to big onshore LNG plants. In a FLNG project, gas is pumped out of the seabed and transferred to a large ship permanently moored above the field, where it is treated, liquefied, stored and later transferred to special tankers for delivery to international markets. The announcement of Exxon's plans come at a time of growing global demand for LNG. Bernstein Research expects the world's appetite for the clean-burning fuel to almost double during the next decade. Australia will replace Qatar as the world's largest LNG exporter by the end of the decade. Discovered in 1979, Exxon's Scarborough gasfield is in the Carnarvon Basin off the coast of Western Australia and contains 8tn-10tn cubic feet of reserves. The nearest port, Exmouth, is about 220km away. Exxon said the FLNG facility it would build to exploit the Scarborough field would be about 495m long - longer than New York's Empire State Building is tall - and 75m wide. That would make it larger than Prelude, Shell's planned FLNG project in Australia, which will be 488m long and 74m wide and could cost about $11.5bn according to one estimate. Shell's venture, however, is far more advanced than that of Exxon. The company announced last October that it had cut the first steel for Prelude, a facility that will ultimately weigh more than 600,000 tonnes. Exxon said it planned to drill its first wells at Scarborough between 2018 and 2019, with production expected to start during 2020-21. The project would produce 6m-7m tonnes of LNG per annum and ship between six and nine LNG cargoes a month, Exxon said. Prelude, in contrast, would produce 3.6 mtpa of the fuel.