The INPEX-operated Ichthys LNG Project reached a key milestone this week when it completed the installation of 140 km of rigid subsea flowlines.

The final infield pipelay marked a significant achievement for the project's offshore installation campaign at the Ichthys Field in the Browse Basin, located approximately 220 km offshore Western Australia.

The infield flowlines were installed in a water depth of up to 275 m to carry reservoir fluids from 20 subsea wells to the project’s two massive floating processing facilities—a central processing facility and floating production storage and offloading facility.

All flowlines were installed with in-line structures, weighing up to 220 tonnes, requiring a total of more than 11,000 onshore and offshore flowline welds to be executed.

Ichthys Project Managing Director Louis Bon said the safe completion of the complex subsea network was a major accomplishment. “We are very proud the infield pipelay was successfully completed without a single Lost Time Injury or any harm to the environment,” he said.

“This achievement has marked the end of a 16-month offshore campaign to install 47 kilometres of 6-inch and 8-inch mono-ethylene glycol flowlines, seven kilometres of 12-inch transfer condensate flowlines and 85 kilometers of 18-inch production flowlines.”

In addition to the infield flowlines, the Ichthys LNG Project offshore installation campaign has completed installation of 49 foundation piles, five production manifolds and a 6,500-tonne riser support structure.

Earlier this month, the project team marked another significant achievement, having successfully pressure tested the offshore component of the 42-inch gas export pipeline.