The Ichthys gas field is a natural gas field located in the Timor Sea, off the northwestern coast of Australia. The field is located 220 km offshore Western Australia and 820 km southwest of Darwin, with an average water depth of approximately 250 metres. 

It was discovered in 2000 and developed by Inpex in partnership with Total, Tokyo Gas, Osaka Gas, Chubu Electric Power, Toho Gas, Kansai Electric Power and CPC.

The Central Processing Facility (CPF), the Ichthys Explorer, is the world's largest Semi-submersible platform weighing approximately 120,000 tonnes and with topsides measuring approximately 130m by 120m. The facility was designed to operate continuously for 40 years, and is built to withstand a 1 in 10,000 year event, which required anchor chains with individual links up to 1m in length.

The CPF is the central hub for initial offshore processing of all well fluids delivered from an extensive, 130-kilometre network of subsea well infrastructure.

Gas from the CPF will be sent though an 890-kilometre subsea pipeline to the onshore LNG facility, at Bladin Point, near Darwin for processing. 

According to en.wikipedia & mastermariners.org.au