World’s largest offshore facility enters LR class

World’s largest offshore facility ever built, Shell’s Prelude FLNG, has officially entered into Lloyd’s Register class.

The unit measuring 488 meters in length, 74 meters wide, and displacing about 600,000 tonnes of water, in July reached its operating location in the Browse Basin, offshore northwest Australia, having been delivered earlier from Samsung Heavy Industries yard in South Korea.

The unit will be moored at a depth of 250 meters and will not be dry-docked for the first 25 years of its expected 50-year operational life. The facility required around 260,000 tonnes of steel to build and its turret is the largest ever built. It has been designed to withstand category five cyclones and its technology has generated over 150 patents.

LR says it has been actively has been involved with the project from the start, helping to ensure it will operate safely by applying FLNG expertise through classification, equipment certification, validation and verification against performance standards.

Prelude’s substructure and turret have been designed and constructed in accordance with LR’s Rules for Floating Offshore Installations at a Fixed Location and its topsides certified to an agreed set of industry codes and standards. LR also confirmed compliance of the facility with Shell’s design and engineering practices, where applicable, and the performance standards specified by Prelude’s safety case.

Daryl Attwood, LR’s Prelude Project Director, said: “It has been a great honor for us all to participate in this world class project, collaborating with an excellent group of clients represented by the best managers and technical experts from Shell, Technip, SBM, and SHI. LR project managers, design appraisal specialists and surveyors from Aberdeen, London, Dubai, Perth and Korea have contributed significantly to getting the facility to this stage, ably supported by colleagues certifying equipment packages literally around the world.”

The intended risk based classification scheme is expected to benefit from use of the latest in remote inspection technologies to gather accurate and repeatable survey data to allow a predictive and focused approach, LR said. The LR team in Perth will be welcoming colleagues from LR’s Geoje office in the coming months to assist in the transition from the yard through offshore commissioning to the operations phase.

Jeff Baker, LR’s Offshore Business Development Manager for Australasia, said: “The LR Perth team is privileged to support this exciting, huge and complex project going ahead and to continue the strong business relationship between Shell and LR globally. By using the latest in ROV and AUV deployed equipment, we see big opportunities for improvement in the safety, accuracy and manner of offshore facility inspection in service and we anticipate that this will flow on to a new way of approaching classification.”

Shell last week said it had connected all 16 mooring lines of the Prelude floating LNG (FLNG) at the Prelude field.

The 16 mooring chains were pre-positioned on the seabed and then lifted and secured to the facility. Once secure, the hook-up and commissioning phase of the whole production system can start, which is expected to take between 9-12 months.

The largest floating facility ever built will unlock new energy resources offshore and produce approximately 3.6 million tonnes of liquefied natural gas (LNG) per year. It will remain onsite during all weather events, having been designed to withstand a category 5 cyclone.

The Prelude FLNG project is operated by Shell in joint venture with Inpex (17.5%), KOGAS (10%) and OPIC (5%).