The Inpex-operated Ichthys LNG project has seen a completion of the offshore pre-lay of the 77 kilometer chain and cable mooring system in the Browse Basin, off the coast of Western Australia.

As part of the mooring system, 49 chains were laid on the seabed in water depths of up to 250 metres and anchored to foundation piles—5.5 meters in diameter and 63 meters long, the company explained.

The mooring system will secure two offshore facilities-the central processing facility (CPF) and floating production, storage and offloading (FPSO) facility-at the Ichthys field seabed for at least 40 years of continuous operation.

Supplying more than 40,000 tonnes of large-scale anchor chains for the project represented nearly 18 months of worldwide chain production. Each chain link weighs more than 700 kilograms, Inpex explained.

The 28 CPF mooring chains required more than 25,000 tonnes of mainly 178 millimeter diameter chain, while the 21 FPSO mooring chains needed more than 15,000 tonnes of mainly 161 millimeter diameter chain.

Ichthys project managing director Louis Bon said: “Despite the difficulty of the task, I’m proud to say that it was successfully completed without a single Lost Time Injury or any harm to the environment.”

“The offshore facilities will operate for decades and the mooring system plays a key role in ensuring their integrity,” he added.

In addition to the mooring system, more than 16,000 tonnes of subsea structures and 140 kilometers of rigid flowlines have been installed across the Ichthys field to safely and efficiently extract gas and condensate.