Offshore LNG receiving terminals,
new architectures
Gastech 2005
March 15th, Bilbao
Nicolas Jestin, Saipem SA
Andreas Kyriacou, SN Technigaz
15/03/2005
Presentation overview
Gravity Base Structures: new architectures
Large capacity FSRU an alternate to onshore
receiving terminals
15/03/2005
Presentation overview
Gravity Base Structures: new architectures
15/03/2005
LNG receiving terminal: main functions at a glance
LNG carriers berthing
and unloading
LNG regasification plant
& utilities
Metering and export to
the grid
LNG buffer storage
Bilbao LNG receiving
terminal
15/03/2005
Terminal design basis
Functional requirements
Net storage volume 250,000 m3
Design throughput 0.8 bcfd
Peak throughput 1 bcfd
Site characteristics
Area Gulf of Mexico
Water depth 20m (MSL)
100-yr wave Hs = 7.0 m, Tp = 11.2 s
Constructability
Tow out draft (max.) 13.0m
Concrete grade C60 (60 MPa cube strength)
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The prismatic GBS receiving terminal design
Process equipment LQ & Utilities
Prismatic storage tanks
& Containment system
Berthing / Loading
Concrete structure
& Foundations
Terminals functions are integrated Reference design
One single support structure
One single offshore installation operation Footprint - 2xGBS 197 x 68 x 37 m
A long shelter is provided to LNG carriers berthing LNG storage tank 160 x 40 x 28.5m
Concrete structure is: Double slab height 8m
Repetitive Concrete volume 115,000 m3
Modular
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Topside design & reference case layout
Main equipment
Power
Nb x % Total Unit capacity Gas return Fuel gas generation
NG
LNG unloading arms 3 x 33% 100% 4,030 m3/hr Export /
Boil-off Metering
NG return arm 1 x 100% 100% compressors
In-tank pumps 6 x 33% 200% 550 m3/hr
Recondenser
BOG compressor 1 x 100% 100% 12,000 m3/hr
In-tank HP
Recondenser 1 x 100% 100% Storage pumps pumps Vaporisers
HP pumps 6 x 20% 120% 320 m3/hr
Unloading Seawater
ORV Vaporizers 6 x 20% 120% 150 t/hr Seawater pumps
Seawater pumps 6 x 20% 120% 4500 m3/hr
LNG
Gas turbines 3 x 50% 150%
Reference design
deck layout principles
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Re-thinking the GBS architecture
LNG containment system
Self-supporting: 9%Ni Full Containment,
Overall terminal layout
SPB
Integrate functions (one support)
Membrane-type
Spread functions on multiple elements
Topsides arrangement Evaluate combinations: LNG storage tanks
Technically Prismatic with flat deck
Stick-built
Cost wise Cylindrical with domes
Module-type
Foundations
Skirts
Piling/soil preparation Offloading + Elements not varying
Topsides equipment selection
Need of long breakwater
Unloading system (arms)
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LNG storage tanks & Containment systems
Cylindrical tanks enable to take the best of onshore LNG experience
Full Containment tank Membrane tank
Technologies are in use
today
Optimal in terms of
surface / volume ratio
Well known cost-wise
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Solution #1 outline
Tanks on a rectangular slab with independent topsides
Nb of (main) structures 4
Footprint 170 x 97m (GBS)
63 x 47m (topsides)
LNG storage tank = 36m, H = 40m
Bottom caisson height 8m
Concrete volume 73,000 m3
Additional structural steel * 7,000 T
Tanks are protected from environment
by a concrete belt
97m
Provides smaller sheltering to LNGC
Requires offshore hook-up and
50m 170m
interconnecting
50m
100m
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* Compared to reference case
Solution #1 topsides arrangement
Two-leveled compact arrangement
Distinct areas are segregated:
Equipment dealing with gas on one side of the deck,
Separated by a blast & fire wall from utilities equipment (in
particular Power Generation),
Emergency equipment and living quarters are installed
away from the process platform, on separate structures.
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Solution #2 outline
Independent tanks with independent topsides
Nb of (main) structures 6
Footprint = 100m (tanks)
63 x 47m (topsides)
30m x 20m (unloading)
LNG storage tank = 37m, H = 37.5m
Bottom caisson height 6m
Concrete volume 69,000 m3
Additional structural steel * 7,500 T
80m
Further segregation of functions
120m
Reduced protection of LNGC
Increased offshore hook-up
50m
60m
Diameter = 100m
100m
50m
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* Compared to reference case
Solution #3:Going one step further
Tanks on a rectangular slab with integrated topsides
Enhanced bill of quantities
compared to #1 and #2
Reduced offshore hook-up
Needs further refinements in
terms of safety analyses
100m
50m
200m
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Comparison of solutions
Cost estimate have been performed, in terms of delta with reference case
Main cost elements impacted: Reference Solution #1 Solution #2
Civil works
115,000 m3 73,000 m3 69,000 m3
Concrete volume
Structural complexity Cylindrical tanks => Lower volume & easier construction methods
Construction site development Slightly enhanced due to smaller GBS
Graving docks dimensions
Containment system Enhanced BoQ - FC and
membrane are possible
Structural steel:
5,000 T 12,000 T 12,500 T
Decks, jackets, bridges
Offshore installation & hook-up Fully integrated & Requires offshore deck installation
precom. onshore + marine structures (dolphins, etc)
Other parameters evaluated:
Fully acceptable Enhanced due to increased
Safety separation between functions
Schedule Offshore installation yields schedule risks
Operational downtime Effective sheltering if Can be acceptable if small day-to-
directional environment day environment 15/03/2005
Presentation overview
Large capacity FSRU an alternate to onshore
receiving terminals
15/03/2005
Terminal capacities are scaling up
Nominal throughput
MTPA
12 Fos Cavaou, 2007 (prev.)
Freeport
10 Cameron
South Hook
8 Costa Azul
Fos Cavaou
Bilbao final
6 expansion *
Bilbao, 2003
Hazira
4 Dragon Guangdong
Altamira
2 Bilbao
Revithoussa
0
100 200 300 400 500
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Storage capacities (103 m3)
hence the large size FSRU design
Nominal throughput
MTPA
FSRU 320 K
12
10
0
100 200 300 400 500
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Storage capacities (103 m3)
Design basis
Functional requirements
Buffer storage equivalent to 5.3 days of
Net storage volume 320,000 m3 average sendout
Design throughput 1.35 bcfd (10.5 MTPA) Uses one 140,000 m3 LNGC every 2.3
Peak throughput 1.5 bcfd (11.8 MTPA) days
Availability > 99%
350000
storage volume (m^3)
300000
Site characteristics 250000
Area Gulf of Mexico 200000 Autonomy
150000 Volume variation
100000
Wave data 10 yr 100 yr
50000
Hs (m) 8 12.6 0
0 1 2 3 4 5 6 7 8 9 10 11 12
Tp (s) 12.8 14.6
days
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Hull general arrangement
Loa Length overall m 345
B Breadth m 56
C Depth m 27
Displacement - full load condition T 222,000
Draft - full load condition m 12.3
Displacement - full ballast condition T 203,000
Draft full ballast condition m 11.1
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LNG storage and containment system
6 membrane storage tanks
Length m 44
Breadth m 44
Height m 32
Upper chamfer m 10.5
Lower chamfer m 3.5
Membrane surface m2 8500
INVAR membrane NO 96 Corrugated Membrane Mark III
Invar primary barrier Stainless steel corrugated primary barrier
Plywood boxes filled with perlite Sandwich panels with reinforced PU Foam
Invar secondary barrier Triplex secondary barrier
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GAZTRANSPORT & TECHNIGAZ GAZTRANSPORT & TECHNIGAZ
FSRU large capacity Hull design
Draft, GM, GZ curve for identified loading cases Hull structure 36 700 t
Checking of IGC rules for all cases Secondary structure 2 000 t
Intact and damaged stability Marine equipment 1 600 t
Preliminary longitudinal analysis Painting 400 t
Midship section outline Contengencies 4070 t
Preliminary hydrodynamic study Total floater part weight 44 770 t
Process 9 400 t
Turret 1 500 t
Power generation 870 t
Accommodation 900 t
Light ship total weight 57 140 t
Weight report
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Seakeeping analysis
Cross influence cargo / motion behavior expected
RAO curves computed with code DIODORE V3R3 (developed by Principia)
Two filling configurations studied:
97% of LNG in each tank (0 tons of ballast)
30% of LNG in each tank (47000 tons of ballast)
Main influenced motions
At 30% filling ratio: surge, sway and roll
At 97% filling ratio: roll
Surge RAO - 30% loaded tanks Roll RAO - 97% loaded tanks
2 2
1.5 1.5
ampl. (m/m)
ampl. (/m)
1 1
0.5 0.5
0, without coupling effect
0 0 0, with coupling effect
0 5 10 15 20 25 30 0 5 10 15 20 25 30
T (s) T (s) 45 without coupling effect
Roll RAO - 30% loaded tanks Sway RAO - 30% loaded tanks
45 with coupling effect
3 1.5 90 without coupling effect
2.5
90 with coupling effect
ampl. (m/m)
ampl. (/m)
2 1
1.5
Damping coefficient: 10% of
1 0.5
the critical damping
0.5
0 0
0 5 10 15 20 25 30 35 0 5 10 15 20 25 30
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T (s) T (s)
Topsides layout principles
Safety philosophy
Level of risk
Living Quarter
Utilities
Power Generation Process Flare and gas export lines
Living quarter and emergency power generator in a safe area (not above a tank of LNG)
Power generator and utilities above tanks between living quarters and process
Process and all HP natural gas lines located in the fore half of the FSRU
Export lines on the turret at the bow
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Large capacity FSRU Topsides layout
HP pumps
Electric station Gas recovery module
(recondender, BOG
compressor, fuel gas Flare system
LQ system)
Vaporizers modules Send-out &
Utilities module
Offloading platform metering
Emergency diesel (diesel oil, air
generator plant & air
instrument, N2)
Power generation
module 15/03/2005
FSRU mooring and gas export
FSRU is turret moored
Six mooring lines maintain the FSRU
Export lines
Two gas risers transfer gas from FSRU through the turret
Subsea gas pipeline exports the gas to onshore facilities
Risers and pipeline connected in a riser base
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Conclusion
Offshore receiving facilities are close to reality
Final selection of a configuration is to be done according to:
Some key design / engineering parameters
Required throughput
Storage capacity
Terminal availability
Terminal flexibility
No absolute best solution exists
Site constraints A case by case best compromise can
Water depth
be found out when mixing:
Soil characteristics
Customer needs
Execution capabilities
Civil works costs Design capabilities
Offshore operations cost
Construction solutions
15/03/2005
