Single Point Mooring System (SPM) for an Offshore LNG Terminal

Transcription

1 Single Point Mooring System (SPM) for an Offshore LNG Terminal GASTECH 2005, Session 7 - Technical Bilbao, March 15 th, 2005 Max Krekel Senior Naval Architect Bluewater Offshore Production Systems Neal Prescott Director Subsea Deepwater Technology Fluor Corporation

2 SPM System for Offshore Transfer of LNG Subsea Cryogenic Pipelines DOE/NETL research study to Bishop Process Offshore LNG Receiving Terminals Content

3 Introduction 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

4 LNG Transfer Systems MANIPULATOR HOSES QUICK (DIS)-CONNECTOR In-plane Motion Envelope of Hose Manipulator MANIPULATOR HARD PIPING

5 Cryogenic 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 increase Manipulator works with both options

6 FLNG or FSRU with Big Sweep

7 LNG Terminal in Shallow Water

8 LNG Terminal in Shallow Water

9 Open Terminal - Berthing No. 2 : Approach & Transfer No. 1 : Approach of Mooring Line messenger No. 3 : Mooring line messenger connected No. 4 : Mooring line connected & LNG tanker in position No. 5 : BIG SWEEP dynamically positioned alongside No. 6 : Hoses connected & LNG transfer

10 Dedicated Terminal - Berthing

11 Subsea Cryogenic Pipelines

12 Subsea Cryogenic Pipeline 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

13 Subsea 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

14 Insulated Cryogenic Pipeline Configuration Nanoporous insulation inside annular space. Flexible Aerogel (Aspen Aerogels, Inc. Can Install Below Ground in a trench Can install above ground on sleepers with gimbaled supports Internal cryogenic product pipe for LNG / vapor / LPG service. ASTM 333 Grade 8, 9% Nickel Steel Concrete weight coating if required External casing pipe Carbon Steel with FBE corrosion coating. Note: Inner and outer pipe connected with non-metallic or metallic bulkheads.

15 Cryogenic Subsea Pipeline Metallic Bulkhead Details Cut-Away view of metallic bulkhead at field joint 1 x external split sleeve 3 x prefab transitions Pipe-in in-pipe joint Pipe-in in-pipe joint Prefab transition Split sleeve Prefab transition External insulation at joint, if required

16 Cryogenic Subsea Pipeline Non-metallic Bulkhead Details Non-metallic bulkhead used to transfer thermal contraction and growth loads from inner pipe to outer pipe. Material is installed in annular space to transfer loads by friction and / or shear. A water-stop is incorporated in the design. Pipe-in in-pipe joint Pipe-in in-pipe joint External insulation at joint, if required

17 DoE/NETL cooperative Research Study to Bishop Process

18 Tank Based Terminals LNG Carrier Bishop Process Bishop Process Salt Cavern Terminals F LIQUID Tank Storage Offshore Mooring 2000 psi + 40F LNG Pumps 1000 psi 0.5 to 1.5 Bcf/d Pump to Pipeline Pressure Warm to Vapor Heat Exchanger GAS Cavern Storage 3+ Bcf/d Natural Gas Grid

19 Bishop Process 400 Formations ~ 1,000 Storage Caverns

20 Bishop Process Infrastructure Saturation Gulf Coast Region 30% Capacity Available

21 Bishop Process Bishop Terminal Conceptual Design Big Sweep Mooring System Shallow Water Mooring System Weathervaning Allows non dedicated LNGCs Flexible Design Options Big Sweep Mooring System With Bishop Platform In Background Bishop Platform

22 Model 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

23 Model Basin Tests Model Basin Test Program - Pictures: Survival Waves

24 Model Basin Tests Model Basin Test Program - Pictures: Operational Waves

25 Model 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.

26 Insulated Cryogenic Pipeline Test Configuration

27 Insulated Cryogenic Pipeline Test Configuration

28 Offshore LNG Receiving Terminals

29 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

30 Offshore LNG receiving terminals Courtesy LNG express, Vol. XIV, No. 12 December 1, 2004

31 Offshore 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

32 Offshore LNG receiving terminals Remote SPM type offloading system (1) Improved terminal lay-out: LLC Separation between storage, process and DEEPWATER OIL PORT, U.S.A. LNGC 28 55'23"N 90 00'37"W 28 54'52"N 89 59'36"W 28 54'52"N 89 57'00"W #4 Mitigates escalation in case of incident Allows future expansions (2 nd 28 54'05"N 28 53'50"N 89 56'38"W 90 04'07"W A MARINE TERMINAL SPM) 1 NM 28 53'06"N 90 01'30"W SPM 104 SPM C 28 52'21"N 89 57'47"W ANCHORAGE 28 53'10"N 89 53'42"W B 28 52'04"N 89 52'42"W 28 51'07"N 90 03'06"W # '09"N 90 02'24"W APPROACH SECTION # '20"N 89 53'51"W 28 49'05"N 89 55'54"W # '36"N 89 55'00"W 28 48'15"N 89 54'18"W SAFETY FAIRWAY = NAV-AID BUOY

33 Offshore LNG receiving terminals 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

34 Offshore 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)

35 Cryogenic Pipeline Offshore SPM with Pipeline Cryogenic Site with Tanker Terminal for loading / offloading Offshore LNG Pipeline Gas Plant

36 Cryogenic Pipeline Offshore SPM with Pipeline Cryogenic Site with Tanker Terminal for loading / offloading Remote Offshore LNG Unloading Terminals Offshore LNG Pipelines Offshore GBS with LNG Storage and Regasification Gas Export Pipeline

37 Cryogenic Pipeline Offshore SPM with Pipeline Cryogenic Site with Tanker Terminal for loading / offloading Offshore LNG Pipelines Offshore Platform with Regasification and Salt Cavern storage

38 Table 1: Comparison FPSO and LNG terminal West Africa Large FPSO Gulf of Mexico LNG terminal Arrangement spread moored barge gravity base structure Production: Storage: Im/Export: Transfer: volume energy value (1) dollar value (2) volume days production volume parcel value Carrier value Location to terminal Type frequency Environment: H significant (1-year) H significant (100 years) Notes: (1) (2) (3) (4) (5) (6) Offshore LNG receiving terminals 200,000 bopd 1,100 B Btu/d 7.0 MM us$/d 2,000,000 bbls 5.0 days 1,000,000 bbls 35 MM us$ 70 MM us$ Remote ( ~ 6000 ft) Weathervaning 50~75 (3) parcels/yr 2.4 m (4) / 1.2 m (5) 3.6 m / 1.2 m Assuming oil to be 5.5 MMBtu/bbls and gas 1.1 MBtu/scf Assuming oil at us$ 35 / bbls and gas at us$ 5 / MMBtu At plateau production, will decline in later life Swell conditions Wind waves Non hurricane 1,000 MMscfd 1,100 B Btu/d 5.5 MM us$/d 175,000 m days 135,000 m 3 16 MM us$ 150 MM us$ Close (~ 150 ft) Fixed heading 120~140 parcels/yr 4.3 m (6) 9.4 m

39 Offshore 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 facilities Is this really the right way to go??

40 Conclusions 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 industry Confirmation of feasibility completed: SPM systems for LNG Transfer Offshore Subsea Cryogenic Pipelines