Shell Prelude FLNG

The client

Shell is constructing the world’s first Floating Natural Gas (FLNG) vessel. This project will have the potential to unlock new energy resources and revolutionise the way gas resources are developed.

The background

Babcock completed the concept and basic design of this world-first generic FLNG production, storage and off-loading platform for operation on remote offshore ‘stranded gas’ fields. On completion, this FLNG vessel will be the largest of its kind in the world and a benchmark vessel for the offshore oil and gas industry.

Design concept

The internal turret of the floating production platform will store, process and export LNG, LPG and condensate. LNG and LPG storage will utilise a membrane containment system and is off-loaded using a side-by-side arrangement. Condensate is off-loaded via a stern floating hose.

Designed to remain on station for extended periods and built to class regulations as well as for safe operation in the harshest of wind and wave environments, it has the potential for redeployment.

Technical specification

The vessel is 488m long, 74m wide and 43m deep and displaces in excess of 600,000t. The topsides weigh over 80,000 tonnes and can process a range of gas compositions.

The facility will be capable of an LNG production rate of 3,500,000tpa. Additional capacity for LPG and condensate take the total liquid production potential above 5,000,000tpa. The system design is a global first and has redefined ship based power generation capacity.

Marine design

• Machinery arrangements
• Equipment lists and specifications
• Design of IMS and OMS system Process Flow Diagrams
• Main deck piping layout
• Topside cooling water, piping and manifold layout
• HVAC design and layout

Naval architecture

• Dimensions and hull form
• Lightship and trim, intact and damaged stability analysis
• Hydrodynamic analyses for operational to extreme
• General arrangements
• Topsides/hull interfaces and access/maintenance
• Accommodation, LSA, helideck, navigation and mooring arrangements
• Fire, safety and hazardous area plans

Structural design

• Midship section, profile and decks, shell expansion and fore/aft end construction
• Topside support structure turret integration, riser caisson integration, off-take integration and LSA structure
• Deckhouse scantlings, uptake/exhaust supports and helideck structure

Electrical system design

• HV and LV generating and distribution system design
• Short circuit and load analyses

Cost estimating

• CAPEX budgeting