Floating and float-in LNG solutions for Australian and international locations
The costs of LNG projects have increased worldwide. FLNG and float-in near-shore facilities reduce the total amount of infrastructure required for an offshore gas field development. Woodside has developed a range of FLNG and float-in/near-shore facility concepts. In the process key lessons from more than a dozen potential applications were obtained. The optimisation of process efficiency and availability versus operability and maintainability ends up in a different balance to onshore LNG or FPSO. Knowledge of LNG and FPSO operations and maintenance is required to design FLNG. Quantitative risk assessment (QRA) does not fully define the safety of the facilities. The application of proven philosophies, simplicity, and management of concurrent operations drives inherent safety. The choice of refrigerants for the liquefaction process on an offshore facility is not straightforward (e.g. nitrogen does not necessarily offer as big a safety advantage as often assumed). The design-one-build-many strategy can offer significant advantages if a number of similar facilities can be sanctioned in quick succession; however, this is not generally available and a bespoke solution will generally be optimum. Concrete near-shore facilities have superior durability and potentially lower maintenance but require significant pre-FID decisions and investment for graving docks, etc. FLNG offers greater certainty of execution outcome because of the fabrication and construction in the controlled shipyard environment; however, experience and management processes are required to manage the novelty aspects. Earlier contracting and execution decisions are required for floating LNG than for onshore LNG or standard FPSOs.