FIng Lean - A Natural Development

摘要

Construction of the Shell Prelude FLNG facility is currently well underway. When completed, the facility is expected to export LNG, LPG and condensate from a rich gas stream. Developments with rich gas streams, using similar facilities, may also benefit from the considerable amount of revenue possible from condensate and LPG sales. However, some fields contain gas that is significantly leaner, and will not have the benefit of condensate and LPG revenue streams. Recognising that the world has lots of low liquid content gas, so called ‘lean gas’, Shell saw a strategic opportunity and is developing FLNG Lean. FLNG Lean is an FLNG concept with a nominal LNG production capacity of 6 million tonnes per annum and reduced functionality for other liquids. FLNG Lean is a natural development within the Shell standardised FLNG design approach and it is designed to expand our LNG capabilities. We anticipate it to be cost-competitive for larger, lean gas fields. FLNG Lean has many similarities when compared to the standard FLNG design. We continue to focus on standardisation, with modifications only as required. The substructure design with its utilities, the accommodation, the operating and the safety philosophies, the flare and blow-down system, the LNG containment systems, and the LNG off loading system are all the same thereby enabling repeatability gains. Lessons learnt and the latest technology developments have also been implemented. Some utilities are relocated to the substructure to create sufficient deck space for the liquefaction trains and process equipment. High capacity modern aero-derivative gas turbines will drive the liquefaction compressors and power generators. Process heating requirements will be largely met by waste heat recovery units. This paper will describe the FLNG Lean design and its potential application area. We will highlight the approach followed, explain the main features of FLNG Lean, and compare it with the generic Prelude FLNG design.