The Inpex Corp.-operated Ichthys LNG project has reached another milestone with completion of the prelaying of the 77-km chain and mooring system near Ichthys gas-condensate field in the Browse basin offshore Western Australia.
This mooring system will be used to secure the project’s two major offshore facilities—the central processing facility (CFP) and the nearby floating production, storage, and offloading vessel—for at least 40 years of continuous operation.
Some 49 chains have been laid on the seabed in water as deep as 250 m and anchored to foundation piles. The total weight of the large-scale anchor chains is in excess of 40,000 tonnes—each link weigh more than 700 kg.
Specifically the CPF required 28 mooring chains weighing 25,000 tonnes of 178-mm chain. The FPSO needed 21 chains weighing more than 15,000 tonnes of 161-mm chain.
The 5.5-m piles are each 63 m long. The pile driving operation took place outside the humpback whale carving season.
In addition to the mooring systems, there are more than 16,000 tonnes of subsea structures and 140 km of rigid flowlines installed across Ichthys field.
The CPF with function as a gathering and production center that will feed gas and some minor amounts of condensate into the 890-km undersea export pipeline to onshore processing facilities in Darwin. The bulk of the condensate from the field will be processed through the FPSO and shipped to market directly from the field.