Ichthys Offshore Flowlines Complete
The INPEX-operated Ichthys LNG Project announced a key milestone this week when it successfully completed the installation of 140 kilometers (87 miles) 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 kilometers (137 miles) offshore Western Australia.
The infield flowlines were installed in a water depth of up to 275 meters (900 feet) 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 tons, 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.”
The milestone has marked the end of a 16-month offshore campaign to install 47 kilometers (29 miles) of 6-inch and 8-inch mono-ethylene glycol flowlines, seven kilometers (four miles) of 12-inch transfer condensate flowlines and 85 kilometers (53 miles) 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 ton 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.
The 890 kilometer (553 mile) gas export pipeline will ultimately connect the offshore facilities to the onshore plant being constructed within schedule at Bladin Point, near Darwin.
The two floating processing facilities currently under construction in South Korea will be towed to the Ichthys Field once completed and will remain moored offshore for the project’s 40-year operational life.
The infield flowlines work was led by Heerema Marine Contractors (HMC) Australia—under subcontract to the lead contractor McDermott Australia—using the deepwater construction vessel DCV Aegir.
The Ichthys field has reserves estimates from two geological horizons of around twelve trillion cubic feet of gas and five hundred million barrels of condensate. This makes it the largest discovery of hydrocarbon liquids in Australia in more than 40 years.
When operational, the project is expected to produce 8.4 million tons of LNG and 1.6 million tons of LPG per annum, along with approximately 100,000 barrels of condensate per day at peak.
The project includes some of the world's biggest and most advanced offshore facilities, massive onshore processing facilities near Darwin in the Northern Territory and an 889 kilometer gas export pipeline to unite them. Each of these three components is itself a mega-project and work is progressing for all, with production scheduled for the end of 2016.