Effective solutions for the safe and reliable delivery of large LNG Storage Tanks in the severe conditions of Northern Siberia

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Vivian Barber
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1 Effective solutions for the safe and reliable delivery of large LNG Storage Tanks in the severe conditions of Northern Siberia Patrick Genoud, Julien Castres Saint Martin, TOKYO, 05 APRIL 2017

2 OVERVIEW 1. Context [Movie] 1. Innovative Design 2. Construction in Arctic conditions 3. Conclusion

3 SAFETY : our SHARED VALUE towards zero accident We strive for Zero accidents We reject the idea that workplace accidents are unavoidable. Our management has a responsibility to do its utmost to ensure the physical integrity and the health of everyone on our worksites and in the facilities we operate. We are committed to zero accident objectives. Risk mitigation as early as design stages Specific site trainings Risk analysis of any task Systematic prestart meeting Management involvement

4 1- Context

5 MOVIE The project best presented by those who build it

6 Arctic conditions Kenai (Alaska) Lelu Island (BC) Sabetta : 71 15' 25" North 72 5' 46" East Sabetta (Russia) Most extreme arctic conditions ever Melkøya Island (hammerfest)

Post-tensioned Concrete outer containment and 9% Nickel steel inner tank.

7 Useful previous experience Hammerfest, NORWAY Design, procurement and construction of : - 2 full containment LNG tanks of 125,000m3 capacity each. Post-tensioned Concrete outer containment and 9% Nickel steel inner tank. - 1 full containment LPG tank of 45,000m3 capacity. - 1 full containment condensate tank of 75,000m3 capacity. Client : SNØHVIT Venture (Statoil, TOTAL, ENGIE, etc.) Execution :

8 On Yamal LNG, an extremely tense timeline for preparation and execution Dec Call for tender May 2013 Letter of intention & contract award 6 months = very short Summer 2013 Mobilization at Sabetta Winter Start foundation works Summer 2014 Concrete slab and wall slipforming for tanks T1 & T2 crucial summer windows Summer 2015 Concrete slab and wall slipforming for tanks T3 & T4 Oct Erection of modules for externals on tanks T1 & T2 critical works in winter also Summer 2017 Erection of modules for externals on tanks T3 & T4 Mid 2017 Ready for cool down (RFCD) for tanks T1 & T2 End 2017 Ready for cool down (RFCD) for tanks T3 & T4

Scope of works CLIENT Type of Contract JSC YAMAL LNG Engineering, Procurement and Construction (EPC) Type of LNG tank Number of tanks 4 Operating capacity Inner tank Outer

9 Scope of works CLIENT Type of Contract JSC YAMAL LNG Engineering, Procurement and Construction (EPC) Type of LNG tank Number of tanks 4 Operating capacity Inner tank Outer tank Base slab type Above Ground, full containment 160,000m3 each 9% Nickel Steel Post-tensioned Concrete Elevated base slab Foundation type Thermostabilized piled foundation

10 2- Innovative Design

11 Pile design in Permafrost 948 steel/concrete 530mm dia. piles Elevated slab 24m piles 948 pin bearings

12 Pile design in Permafrost The main issues Thermal deformations 1- Imposing deformations to a stiff structure results in high stresses Thermal deformations High shear force Concrete slab Reduced shear High bending moment Limited free height in winter Controlled Sand fill Longer free height in winter Siberian Sock filled with flexible material Thermostab ilization of the permafrost Unstable Permafrost 2- Thawing may jeopardize permafrost stability Reduced moment

13 Pile design in Permafrost Fast track implementation Testing of flexible filling material under arctic conditions Sock placing Finished

14 Optimization of foundation design in Permafrost Steel piles installed & filled with concrete Number & length of piles reduced vs FEED base case Simplified bearings (low seismic hazard) Steel Sock on top of pile heads with special bitumen-based filling material in annular space Thermo-stabilization system on each pile (for stabilization of permafrost)

15 3- Construction in Arctic conditions

16 Mobilization

17 CONSTRUCTION CONSTRAINTS Maximization of external works during favorable weather window Double shift (2 x 10 hours) Rebars: cutting and bending in remote workshop / prefabrication on site Slipforming (concrete wall) Prefabrication of roof sectors Assembly of roof sectors directly on top of the walls (full/concrete) Modularization of external structures and piping

18 PILE INSTALLATION

19 Piled foundations

20 Piled foundations

21 Slip-form for Wall concreting

22 Roof Sectors Fabrication & Transportation

23 CONSTRUCTION KEY ISSUES Protection against harsh weather conditions (for external works which cannot be performed within the favorable weather window) Mobile heated sheds (base slab concreting / roof sectors welding / external steel tank plates welding) Winterized batching plant / warehouse for concrete materials storage Early supply of construction materials and equipment Use of mobile cranes in lieu of tower cranes (severe blizzards)

24 Roof sectors installation with central mast

25 Roof sectors installation with central mast

26 Steel Roof in place

27 Concrete roof construction

28 CONSTRUCTION KEY ISSUES Installation of electrical heaters Two heaters by tank have been installed at temporary doors location; With this system, temperature inside the tanks has been maintained at 5 C during winter time and permitted to avoid any welding problems and to have good working conditions.

29 Heaters inside the tank

30 Vapour barrier (steel liner) installation

31 CONSTRUCTION KEY ISSUES Protected environment work (external envelope completion) Hot air blowers Automatic ultrasonic testing (AUT) for inner tank welds inspection allows welding on double shift basis. Maximized use of automatic welding process (submerged arc welding- SAW and Flux-cored arc welding - FCAW)