Shell Prelude: Classification, certification & verification

Project scope: Classification, certification, verification, validation across multiple contractors.

Clients:Shell Australia (Operator), Technip (France), Samsung Heavy Industries (Korea), Single Buoy Moorings (Monaco).

Application: Floating Liquefied Natural Gas (FLNG) unit.

The Prelude FLNG project was given the final go ahead in May 2011. Prelude comprises the largest floating offshore facility in the world, at 488 metres long, 74 metres wide, and displacing about 600,000 tonnes of water. It requires about 260,000 tonnes of steel to build and its turret is the largest ever built. It will be moored at a depth of 250 metres for 25 years without dry docking, in the Browse Basin, offshore northwest Australia. Prelude has been designed to withstand category five cyclones and its technology has generated over 150 patents.

  • Production capacity: 5.3 million tonnes per annum (mtpa): 3.6 mtpa LNG, 1.3 mtpa condensate, 0.4 mtpa LPG (propane, ethane, butane).
  • LNG chilled to -162C, shrinking volume 600-fold.

Shell Prelude - Classification certification and verification - facts and figures - 962x329

Our services to Prelude include:

  • Classification of the substructure (hull) and turret.
  • Certification of the topsides, turret and equipment (expect to issue at least 924 LR certificates covering in excess of  e 1,100 tagged items) against project and international codes and standards.
  • Verification and Validation of the overall unit against performance standards within a safety case regime.

These services to Prelude were applied across multiple contracts, with:

  • Technip France (Paris), for topsides design appraisal and construction and commissioning surveys in Korea.
  • Samsung Heavy Industries (Geoje, Korea), for substructure design appraisal and survey.
  • Shell Australia for validation of the overall unit and of the subsea and risers (involving Shell and FMC in Malaysia).
  • Single Buoy Moorings for turret design appraisal (Monaco) and construction surveys (Dubai).
  • Multiple vendors (in Europe, Asia and North America) for classification and certification of equipment packages.
Computer graphic of Shell's Prelude FLNG facility. Image courtesy of Shell plc.

Prelude to sustainable technology

A workforce of more than 5,000 are helping to build the world’s largest floating offshore facility, Prelude FLNG, at South Korea’s Geoje shipyard for the energy multinational Shell.