Single Point Mooring System (SPM) for an Offshore LNG … Conferences/2005/SDS... · Single Point...

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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

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

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

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

Infrastructure SaturationGulf Coast Region

30% Capacity Available

““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

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 Test Program - Pictures:

Operational Waves

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.”

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

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

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)

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

= NAV-AID BUOY

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

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)

Cryogenic Pipeline – Offshore SPM with PipelineCryogenic Pipeline – Offshore SPM with Pipeline

Cryogenic Site with Tanker Terminal for loading / offloading

Gas Plant

Offshore LNG Pipeline

Offshore LNG Pipelines

Offshore GBS with LNG Storage and Regasification

Remote Offshore LNG Unloading Terminals

Gas Export Pipeline

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

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??

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

Single Point Mooring System (SPM) for an Offshore LNG … Conferences/2005/SDS... · Single Point...

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