What are the key design considerations driving the successful delivery of the world’s largest semi-submersible Central Processing Facility (CPF), to be installed at the Ichthys gas field in the Browse Basin, 200 km offshore North West Australia? Extreme cyclonic weather conditions, separating condensate from the gas stream, accommodating 150 personnel, and the sheer size of the gas processing unit at 110,000 tonnes, have created unprecedented challenges for the Ichthys design team.
This extended abstract explores the design and planned construction of this massive piece of equipment. The CPF, measuring 110 m x 110 m, will be anchored to the seabed in about 250 m of water using 28 mooring chains. During the 40-year life of the project, the unit will collect gas from a network of up to 50 subsea production wells drilled into reservoirs 4,000–4,500 m beneath the seabed. From the CPF, condensate will be sent to a Floating Production Storage Offtake (FPSO) vessel moored nearby.
The gas will be compressed and sent by an 885-km subsea pipeline to Darwin for processing into LNG, LPG and residual condensate. INPEX with its Ichthys joint venturer, Total, will be shipping 8.4 million tonnes of LNG and 1.6 million tonnes of LPG a year, as well as 100,000 barrels of condensate a day at peak. Successful delivery of the Ichthys Project will ensure INPEX achieves its goal of becoming the operator of a major LNG facility, while helping reach its target of producing 800,000 boe/d by 2020.