Single Point Mooring System (SPM) Single Point Mooring System (SPM) for an Offshore LNG Terminalfor an Offshore LNG Terminal
GASTECH 2005, Session 7 - TechnicalBilbao, March 15th, 2005
Max Krekel Neal PrescottSenior Naval Architect Director Subsea Deepwater TechnologyBluewater Offshore Production Systems Fluor Corporation
• SPM System for Offshore Transfer of LNG • Subsea Cryogenic Pipelines• DOE/NETL research study to ‘Bishop Process’• Offshore LNG Receiving Terminals
ContentContent
Production & Terminals for LNG moving offshore → Need for offshore LNG transfer systems
• High system availability– Weathervaning system– Robust cryogenic flow path
• Suitable for ‘open’ terminals, i.e.– Vessels of opportunity, transfer at existing man.as well as ‘dedicated’ terminals– Dedicated vessels with bow loading facilities
IntroductionIntroduction
In-plane Motion Envelope
of Hose Manipulator
In-plane Motion Envelope
of Hose Manipulator
MANIPULATORHARD PIPING
QUICK (DIS)-CONNECTOR
MANIPULATORHOSES
LNG Transfer SystemsLNG Transfer Systems
Cryogenic hoses vs. loading armsCryogenic hoses vs. loading arms
Large diameter cryogenic hoses promissing:• Most robust option with min. mechanical components• Number of designs ‘technically ready’ (e.g. Technip, BPP-
Dantech, Amnitec..)However…..• Perceived as ‘technology risk’ by some operators• Preference for ‘hard pipe’ loading arms• Dynamic swivels seen as marginal technology increaseManipulator works with both options
FLNG or FSRU with ‘Big Sweep’FLNG or FSRU with ‘Big Sweep’
LNG Terminal in Shallow Water LNG Terminal in Shallow Water
LNG Terminal in Shallow Water LNG Terminal in Shallow Water
No. 1 : ApproachNo. 2 : Approach & Transfer of MooringLine messenger
No. 3 : Mooring line messenger connectedNo. 4 : Mooring line connected & LNGtanker in position
No. 5 : BIG SWEEP dynamically positionedalongside
No. 6 : Hoses connected & LNG transfer
Open Terminal Open Terminal -- BerthingBerthing
Dedicated Terminal Dedicated Terminal -- BerthingBerthing
Subsea Cryogenic Pipelines
Key to Offshore LNG terminals are Sub Sea Cryogenic pipelines:
• Technology based on ‘Bundles’ and ‘Pipe In Pipe’ (PIP) systems used in the GoM and North Sea for ‘hot flows’
• Main design challenge is to acc. thermal contraction:– Use of low expansion materials (e.g. Invar)– Application of bellows (typ. every 50 ft)– Both have major drawbacks for cost & reliability
• Recently new concepts developed
SubseaSubsea Cryogenic PipelineCryogenic Pipeline
Subsea LNG Transfer SystemSubsea LNG Transfer System
Delta– Cost Savings of approximately 20% - 25% over
competing systems
Advantages– Does not use exotic metals (Invar) for product line– Uses standard 9% Ni Steel for product line– Does not use vacuum in annular space– Ease of Fabrication and Welding– Extremely effective insulation - Aspen Aerogels, Inc. – Conventional Bundle Fabrication and Installation
Insulated Cryogenic Pipeline ConfigurationInsulated Cryogenic Pipeline ConfigurationNanoporous insulation inside Nanoporous insulation inside annular space.annular space.
•• Flexible Aerogel (Aspen Flexible Aerogel (Aspen Aerogels, Inc.Aerogels, Inc.
Concrete weight coating Concrete weight coating if required if required
Internal cryogenic Internal cryogenic product pipe for LNG / product pipe for LNG / vapor / LPG service. vapor / LPG service.
•• ASTM 333 Grade 8, 9% ASTM 333 Grade 8, 9% Nickel SteelNickel Steel External casing pipe Carbon External casing pipe Carbon
Steel with FBE corrosion Steel with FBE corrosion coating.coating.
Note: Inner and outer pipe Note: Inner and outer pipe connected with nonconnected with non--metallic or metallic or metallic bulkheads.metallic bulkheads.
• Can Install Below Ground in a trench
• Can install above ground on sleepers with gimbaled supports
Cryogenic Subsea Pipeline – Metallic Bulkhead DetailsCryogenic Subsea Pipeline – Metallic Bulkhead Details
Cut-Away view of metallic bulkhead at field joint– 1 x external split sleeve– 3 x prefab transitions
PipePipe--inin--pipe jointpipe joint
PipePipe--inin--pipe jointpipe joint
Split sleeveSplit sleevePrefab Prefab transitiontransition
Prefab Prefab transitiontransition
External insulation External insulation at joint, if requiredat joint, if required
Cryogenic Subsea Pipeline – Non-metallic Bulkhead DetailsCryogenic Subsea Pipeline – Non-metallic Bulkhead Details
PipePipe--inin--pipe jointpipe joint
PipePipe--inin--pipe jointpipe joint
NonNon--metallic bulkhead used to transfer thermal metallic bulkhead used to transfer thermal contraction and growth loads from inner pipe to outer contraction and growth loads from inner pipe to outer pipe. Material is installed in annular space to transfer pipe. Material is installed in annular space to transfer loads by friction and / or shear. A waterloads by friction and / or shear. A water--stop is stop is incorporated in the design.incorporated in the design.
External insulation External insulation at joint, if requiredat joint, if required
DoE/NETL cooperative Research Study to ‘Bishop Process’
LIQUID Tank Storage
Pump to Pipeline Pressure
Warm to VaporWarm to Vapor
Offshore Mooring
LNG PumpsHeat Exchanger
GAS Cavern Storage
Bishop Process™
Salt CavernTerminals
Natural Gas Grid
LNGLNGCarrierCarrier
- 260° F
1000 psi
0.5 to 1.5 Bcf/d
3+ Bcf/d
2000 psi+ 40F
Tank Based Terminals
Bishop ProcessBishop Process
400 Formations ~ 1,000 Storage Caverns
Bishop ProcessBishop Process
Infrastructure SaturationGulf Coast Region
30% Capacity Available
Bishop ProcessBishop Process
““Big Sweep” Mooring Big Sweep” Mooring SystemSystem
““Big Sweep” Mooring SystemBig Sweep” Mooring SystemWith Bishop PlatformWith Bishop Platform™™In BackgroundIn Background
Bishop Bishop PlatformPlatform™™
• Shallow Water Mooring System
• Weathervaning• Allows non
dedicated LNGCs• Flexible Design
Options
Bishop Terminal™ Conceptual Design
Bishop ProcessBishop Process
Model Basin TestsModel Basin Tests
Model Basin Tests to verify system for:• Survivability in ‘Extreme Hurricane Conditions’
– Structural loads w/o LNG carrier• Operability in ‘Normal Operating Conditions’
– Hawser loads, DP thrust requirements– Overall behavior, relative motions
• Characteristics in ‘Calibration Conditions’– Regular waves to verify and/or calibrate analytical
models
Model Basin Test Program - Pictures:
Survival Waves
Model Basin TestsModel Basin Tests
Model Basin Test Program - Pictures:
Operational Waves
Model Basin TestsModel Basin Tests
Final report by Oceanic Consulting:“Throughout the tests, general observations showed
that the arm and tanker would prove adequate for this type of mooring arrangement.”
And“Overall, nothing observed during the tests indicates
that such a setup will not be able to operate in the conditions tested.”
Model Basin TestsModel Basin Tests
Insulated Cryogenic Pipeline – Test ConfigurationInsulated Cryogenic Pipeline – Test Configuration
Insulated Cryogenic Pipeline – Test ConfigurationInsulated Cryogenic Pipeline – Test Configuration
Offshore LNG Receiving Terminals
CAPEX for total LNG chain significantly more than for ‘traditional’ oil field development
• LNG receiving terminal is only ~10% of total investment• Oil companies plan for proven terminals onshore
Offshore LNG receiving terminalsOffshore LNG receiving terminals
Courtesy LNG express, Vol. XIV, No. 12 – December 1, 2004
Offshore LNG receiving terminalsOffshore LNG receiving terminals
However…• Local community concerns frustrate US onshore terminals• Offshore terminals are considered as ‘fall back’• No ‘technology risks’, only proven onshore technologies:
– Gravity Base Structure– Dolphin mooring arrangement– Loading arms for LNG transfer
Offshore LNG receiving terminalsOffshore LNG receiving terminals
Remote SPM type offloading system (1)• Improved terminal lay-out:
– Separation between storage, process and LNGC
– Mitigates escalation in case of incident– Allows future expansions (2nd SPM)
1 NM
Offshore LNG receiving terminalsOffshore LNG receiving terminals
LLC
DEEPWATER OIL PORT, U.S.A.
MARINE TERMINAL
SECTIONAPPROACH
ANCHORAGE
FAIRWAYSAFETY
102SPM
SPM103
104SPM
28°54'52"N89°59'36"W
28°55'23"N90°00'37"W
28°53'50"N90°04'07"W
89°57'00"W28°54'52"N
89°53'42"W28°53'10"N
89°52'42"W28°52'04"N
89°53'51"W28°50'20"N
89°55'54"W28°49'05"N
90°02'24"W28°50'09"N
90°03'06"W28°51'07"N
89°55'00"W28°48'36"N
28°48'15"N89°54'18"W
28°54'05"N89°56'38"W
28°52'21"N89°57'47"W
28°53'06"N90°01'30"W
#3
= NAV-AID BUOY
#4
A
B
#2
#1
C
Remote SPM type offloading system (2)• Superior marine operations:
– Approach & Berthing: LNGC approach always up weather, abort fail to safe
– Transfer operation with minimal LNGC motions; possibility for roll mitigation
– Easy disconnect under all circumstances
Offshore LNG receiving terminalsOffshore LNG receiving terminals
Remote SPM type offloading system (3)• Therefore increased terminal availability &
regularity of operations– Marine operations can start & continue in
higher seastates– Shorter ‘weather window’ required to start
LNG transfer operations– Will allow ‘catch-up’ after disrupt situations
(e.g. hurricanes)
Offshore LNG receiving terminalsOffshore LNG receiving terminals
Cryogenic Pipeline – Offshore SPM with PipelineCryogenic Pipeline – Offshore SPM with Pipeline
Cryogenic Site with Tanker Terminal for loading / offloading
Gas Plant
Offshore LNG Pipeline
Cryogenic Pipeline – Offshore SPM with PipelineCryogenic Pipeline – Offshore SPM with Pipeline
Cryogenic Site with Tanker Terminal for loading / offloading
Offshore LNG Pipelines
Offshore GBS with LNG Storage and Regasification
Remote Offshore LNG Unloading Terminals
Gas Export Pipeline
Cryogenic Pipeline – Offshore SPM with PipelineCryogenic Pipeline – Offshore SPM with Pipeline
Cryogenic Site with Tanker Terminal for loading / offloading
Offshore LNG Pipelines
Offshore Platform with Regasification and Salt Cavern storage
Table 1: Comparison FPSO and LNG terminal West Africa
Large FPSO Gulf of Mexico LNG terminal
Arrangement spread moored barge gravity base structureProduction: volume energy value(1) dollar value(2)
200,000 bopd 1,100 B Btu/d 7.0 MM us$/d
1,000 MMscfd 1,100 B Btu/d 5.5 MM us$/d
Storage: volume days production
2,000,000 bbls 5.0 days
175,000 m3 3.7 days
Im/Export: volume parcel value Carrier value
1,000,000 bbls 35 MM us$ 70 MM us$
135,000 m3 16 MM us$ 150 MM us$
Transfer: Location to terminal Type frequency
Remote ( ~ 6000 ft) Weathervaning
50~75(3) parcels/yr
Close (~ 150 ft) Fixed heading
120~140 parcels/yr Environment: Hsignificant (1-year) Hsignificant (100 years)
2.4 m(4) / 1.2 m(5) 3.6 m / 1.2 m
4.3 m(6) 9.4 m
Notes: (1) Assuming oil to be 5.5 MMBtu/bbls and gas 1.1 MBtu/scf (2) Assuming oil at us$ 35 / bbls and gas at us$ 5 / MMBtu (3) At plateau production, will decline in later life (4) Swell conditions (5) Wind waves (6) Non hurricane
Offshore LNG receiving terminalsOffshore LNG receiving terminals
Comparing Gulf LNG terminals with WA FPSOs:• With a higher combined value for parcel and carrier• With double the number of transfer operations• In more onerous sea conditions• Moor to a more difficult berth• In close proximity to production & storage facilitiesIs this really the right way to go??
Offshore LNG receiving terminalsOffshore LNG receiving terminals
ConclusionsConclusions
Offshore transfer of LNG can be done safely but:• Avoiding technology risks may in fact incur operation &
safety risks• Lessons learnt in over 40 years of offshore transfer of oil
are valid for LNG industryConfirmation of feasibility completed:• SPM systems for LNG Transfer Offshore• Subsea Cryogenic Pipelines
