The Inpex-operated Ichthys LNG project is moving forward with the installation of a 6500-tonne riser support structure (RSS) tower at the Ichthys Field, marking the beginning of the project’s major installation campaign.
The Ichthys LNG project RSS. From Inpex.
The installation was done by the deepwater construction vessel Aegir at Ichthys, located in the Browse basin, offshore Western Australia.
According to Inpex, the RSS is the largest subsea structure ever laid on the seabed. When the arch is placed, the structure will stand 110m off the seabed. The completed RSS will be a physical, fixed support for flexible risers and dynamic umbilicals that connect subsea gathering systems to the project’s semisubmersible central processing facility (CPF), currently under construction in Korea.
The pipelay campaign and RSS installation began in mid-October, when the Aegir arrived at the Ichthys Field. The campaign includes the installation of the RSS, subsea manifolds, about 41km of flexible risers and pipe, and about 141km of rigid flowlines. The overall offshore installation campaign is estimated to take 12 months.
“The RSS is an integral piece of the subsea field architecture, as all other subsea structures and the CPF mooring system will be installed and oriented relative to its location in the Ichthys gas-condensate field,” says Claude Cahuzac, Ichthys LNG project offshore director. “To give a sense of scale, that’s about 30,000-tonne of subsea equipment that will be installed during the offshore installation campaign in water depths of around 250m.”
The Ichthys LNG project is scheduled to begin production at the end of 2016. It will have an initial capacity to produce 8.4mtpa of LNG, 1.6mtpa of liquefied petroleum gas, and approximately 100,000bbl/d of condensate at peak production.
Several moving pieces have been in the works for the Ichthys LNG project the past two months.
In mid-October, Expro won a US$50 million contract to supply a high rate well testing package and ancillary services for the project in which the company will provide well testing, large bore subsea landing string, well intervention, fluid analysis and surface sampling services for a significant scope of development work with an initial phase encompassing more than 20 high rate gas production wells. The project will continue into 2017 to 2018.
Also in October, McDermott International moved forward with the two-year development process of creating its new forged body specialty valve designed exclusively for the Ichthys LNG project.
In September, Hydro Deck delivered the first modules for the Ichthys LNG project. Over the course of the project, Hydro Deck will offload more than 200 large, pre-fabricated modules from sea to ground, up to 8m tidal variations.
Inpex operates the Ichthys project with 66.7% interest with partners Total (30%), Tokyo Gas (1.575%), Osaka Gas (1.2%), Chubu Electric Power (0.35%), and Toho Gas (0.42%).