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
1. Context
[Movie]
1. Innovative Design
2. Construction in Arctic conditions
3. Conclusion
OVERVIEW
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.
SAFETY : our SHARED VALUE towards zero accident
We strive for Zero accidents
Risk mitigation as early as design stages
Specific site trainings
Risk analysis of any taskSystematic prestart meeting
Management involvement
1- Context
MOVIE
The project best presented by those who build it
Arctic conditions
Lelu Island
(BC)
Melkøya Island
(hammerfest)
Sabetta
(Russia)
Sabetta : 71° 15' 25" North 72° 5' 46" East
Most extreme arctic conditions ever
Kenai(Alaska)
Useful previous experience
Hammerfest, NORWAY
Design, procurement and construction of :
- 2 full containment LNG tanks of 125,000m3capacity each. Post-tensioned Concreteouter containment and 9% Nickel steelinner 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 : 2002-2005
Dec. 2012 Call for tender
May 2013 Letter of intention & contract award 6 months = very short
Summer 2013 Mobilization at Sabetta
Winter 2013-2014 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. 2016 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
On Yamal LNG, an extremely tense timeline for preparation and execution
Scope of works
CLIENT JSC YAMAL LNG
Type of Contract Engineering, Procurement and Construction (EPC)
Type of LNG tank Above Ground, full containment
Number of tanks 4
Operating capacity 160,000m3 each
Inner tank 9% Nickel Steel
Outer tank Post-tensioned Concrete
Base slab type Elevated base slab
Foundation type Thermostabilized piledfoundation
2- Innovative Design
Pile design in Permafrost
948 steel/concrete 530mm dia. piles
948 pin bearings
Elevated slab
24m piles
1- Imposing deformations to a stiff structure results in high stresses
Pile design in PermafrostThe main issues
Concrete slab
Controlled Sand fill
UnstablePermafrost
Thermal deformations
Limited free height in winter
High shear force
High bending moment
“Siberian Sock” filled with flexible material
Longer free height in winter
Reduced shear
Reduced moment
Thermal deformations
2- Thawing may jeopardize permafrost stability
Thermostabilization of the permafrost
Pile design in PermafrostFast track implementation
Testing of flexible filling material under arctic conditions
“Sock” placing
Finished
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)
Optimization of foundation design in Permafrost
3- Construction in Arctic conditions
Mobilization
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
CONSTRUCTION CONSTRAINTS
PILE INSTALLATION
Piled foundations
Piled foundations
Slip-form for Wall concreting
Roof Sectors Fabrication & Transportation
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)
CONSTRUCTION KEY ISSUES
Roof sectors installationwith central mast
Roof sectors installationwith central mast
Steel Roof in place
Concrete roof construction
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.
CONSTRUCTION KEY ISSUES
Heaters inside the tank
Vapour barrier (steel liner) installation
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)
CONSTRUCTION KEY ISSUES
Erection of Thermal corner protection (TCP)
FABRICATION OF MODULES @ KALININGRAD
TRANSPORTATION OF MODULES
Installation of Modules on the Roof
Installation of Modules on the Roof
Installation of Modules (vertical pipe-rack)
Installation of Modules (vertical pipe-rack)
4- Conclusion
Anticipation
Complementarity
Communication
Control
The Fundamentals of Success
Thank you for your attention !