Chains

Inpex has completed the offshore pre-lay of the 77km chain and cable mooring system for $34bn Ichthys LNG project in the Browse Basin, located off the northern coast of Western Australia.

The company laid 49 chains on the seabed in water depths of up to 250m as part of the mooring system, securing the project’s central processing facility (CPF) and floating production, storage and offloading (FPSO) unit for at least 40 years of operation.

Once located in the field, the CPF will deliver natural gas and some condensate to onshore processing facilities in the Northern Territory using an 890km-long subsea gas export pipeline.

Most condensate is planned to be processed through the FPSO and shipped directly to market from the field.

More than 40,000t of large-scale anchor chains have been provided for the project.

Each chain link weighs more than 700km and the 28 CPF mooring chains required more than 25,000t of mainly 178mm diameter chain.

"An early decision was made to avoid pile driving during the whale calving period where associated underwater noise may have created a disturbance."

The 21 FPSO mooring chains needed more than 15,000t of 161mm diameter chain.

Ichthys project managing director Louis Bon said: "Because the Ichthys field is located just 120km from the main hump back whale migratory routes and calving grounds of north-west Australia, an early decision was made to avoid pile driving during the whale calving period where associated underwater noise may have created a disturbance."

The CPF and FPSO are currently under construction in South Korean ship yards and will be towed 5,600km to the Ichthys field upon completion.

More than 16,000t of subsea structures and 140k of rigid flowlines were also installed across the Ichthys field to extract gas and condensate.

In January, Ale completed the contract awarded by Cuel by loading out the final module for the Ichthys project’s onshore liquefied natural gas facilities in Thailand.


Image: Inpex laid 49 chains on the seabed in water depths of up to 250m as part of the mooring system. Photo: © INPEX.