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Mid to Large Scale Floating LNG Plant -Technology Development and JGC Contribution

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[Author]: Naoyuki Takezawa Project Manager, LNG Projects JGC Corporation e-mail Address: [email protected] 2-3-1, Minato Mirai, Nishi-ku, Yokohama 220-6001, Japan http://www.jgc.co.jp/ [Abstract] Floating LNG Plant (FLNG) is a ‘real’ alternative for land-based LNG Plant. Since completion of initial floating LNG studies in the 1990’s, JGC has developed technical studies and considerations, conducted project-specific FEED and is conducting EPCIC of Floating LNG plants. As a pioneer for Floating LNG plants, JGC who introduced the FLNG concept to the industry, would present the history, technical developments, and insights of on-going EPCIC and FEED projects for both mid-scale (1 - 2 MTPA) and large scale (2 – 8 MTPA) FLNG. Technical developments and studies specifically tailored for FLNG taking account for limited footprints included to: - Selection of Process technology and type of Refrigerant - Motion movement and Equipment design - Selection of refrigerant compressor and its driver - Plot layout and piping design and modularization - HSSE studies - Approach study for LNGC to FLNG - Loading facilities

And so on. Some of FLNG Projects experienced to date are also presented.

http://www.jgc.co.jp/


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1. Introduction

LNG demand is increasing and timely LNG supply is required, especially for power generation in Japan after the earthquake in 2011. Recent oil price reduction becomes stable, and gas demand may increase. Floating LNG Plant (FLNG) is a ‘real’ alternative for land-based LNG Plant. Since completion of initial floating LNG studies in the 1990’s, JGC has led advanced studies and project-specific FEED, and is conducting the Engineering, Procurement, Construction, Integration and Commissioning (EPCIC) of FLNG projects. JGC is securing a unique position as a Contractor for both, Onshore and FLNG Projects. In fact, JGC has vast experiences for On-shore LNG Plant projects and such experiences and knowledge have been applied to the FLNG plants with specific technical developments and considerations. If the gas field to be developed is Offshore, FLNG will be one of the alternatives, which has all of functions on the hull, as illustrated in the following.

2. Background of Development

In early 1990’s the concept of FLNG was developed based on technical feasibility and commercial studies. JGC as a pioneer of FLNG, developed concepts and conducted studies for the installation of LNG facilities on the ship hull with ship builders. Such study involved to visit major LNG related companies including process licensors, equipment suppliers i.e. compressor and driver vendor, mooring facilities supplier, loading facility vendors and Flare supplier and ship classification authorities. Through the visit, Floating LNG concept was propagated to LNG related industry, which should be a trigger to commence their own studies and empirical development for their equipment and facilities.

Fig.3 Concept of FLNG in 1990’s

Fig.2 History of FLNG Projects Fig.1 Concept of FLNG for Offshore Gas Field


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In late 1990’s and early 2000’s, JGC conducted the preliminary FLNG Concept Studies for major oil companies with shipbuilders. In 2000’s, JGC conducted the EPCIC for Floating LPG Plants for Indonesia and Angola, obtaining technical feedback for the design, movement effects, integration, fabrication, towing, installation and operation. In parallel, Pre-FEED and FEED work for ranges of 2 to 5 MTPA FLNG were conducted for Indonesia, Australia, and Brazil. JGC conducted further technology development for movements, cooling methodology, equipment design, piping and control design, interfaces between Subsea and Hull, including HSSE considerations. In 2010’s, JGC conducted the EPCIC of 1.5 MTPA Floating LNG plant for Malaysia, which is the 3rd FLNG EPCIC project in the world with1st deep water (deeper than 500 m) FLNG. JGC has conducted FEED for FLNG for Indonesia and Mozambique. JGC also conducting the construction and commissioning serves to the Prelude FLNG. 3. Technical Developments and Studies Technical developments and studies specifically tailored for FLNG taking account for limited footprints included to: - Selection of Process technology and type of Refrigerant - Study of Motion Effect and Equipment design - Selection of refrigerant compressor and its driver - Plot layout and Piping design and Modularization - HSSE studies including, Quantative Risk Assessment (QRA), Explosion Risk

Assessment (ERA), Fire Risk Assessment (FRA) and so on - Application of Codes and Standards, including requirements by Ship Classification

Authorities

Fig.3 LPG FPSO for Angola

Fig.6 FLNG for Malaysia

Fig.5 LPG FPSO for Indonesia

Fig.4 LPG FPSO for Angola


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- Subsea interface, mooring, flow lines, umbilical and flow stabilities - Approach study for LNG Carrier (LNGC) to FLNG - Loading facilities 3.1 Process Selection

The following will be considered for selection of Liquefaction technology for FLNG, which should be remarkably different to Onshore LNG plant: 1) Robustness to the motion movement 2) Safety considerations including inventory and type of Refrigerant 3) Suitable for plant capacity 4) Efficiency 5) Simplicity The following figure shows the sample of selection of Liquefaction technology for FLNG.

From mid to large scale FLNG, N2 Expansion Processes, Single MR Process, DMR Process were selected to date, due to limited area and difficulty in escape route, if disasters occur on FLNG. Refrigerant type shall be selected considering less hydrocarbon content, especially less propane inventory.

Process Capacity Efficiency Motion Movement

DMR Large (> 2 MTPA) High Mid

SMR Mid (1-2 MTPA) Mid Mid

N2 Expander Small (less than1.5 MTPA) Low Good

Table 1 Comparison of Liquefaction Technology for FLNG

Fig 7 Sample of Selection of Liquefaction Technology


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3.2 Motion Effect Based on enveronmental data, oceanological and meteological information of planned area for installation, motion characteristics of FLNG will be estimated. Forces by wave, wind and current are considered for heading of FLNG and motion movement. Significant wave hight,peak period of wind wave and swell, cyclone also considered.

Sample of Response Amplitude Operators (RAO) of roll motion and heading are shown.

3.3 Equipment Selection against Motion Movement Motion movement will affect equipment performances, both mechanical and process. 1) Tower internals

Distillation columns, Absorbers, liquid-gas contactors will be selected to packing rather than tray.

Fig.10 Pilot Plant (Sulzer Chemtek)

Fig.9 Comparison of Internals

Fig.8 Sample of RAO and Heading Study


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Packing supplier (Sulzer Chemtek) conducted the pilot test for motion movement. Static inclination will also affect to the performance of equipment; which will be estimated considering hull design and equipment installation.

2) Heat Exchangers

Heat exchangers and Reboilers which have liquid surface need to be re-considered to minimize effects by motion movement. 3) Compressor Due to motion movement, nozzle force and moment of rotating equipment should be larger than Onshore application. Refrigerant compressors which have large bore nozzles need to have increased strength of nozzles with reduced piping mass so as to increase flexibility. 4) Compressor Driver Selection of compressor driver is one of the important technical decisions for FLNG, considering power demand, safety, plot space, utility, robustness to motion movement, availability, maintainability and durability for offshore application.

Type of Driver Pros Cons Judge Steam Turbine Not ignition source, less

operation & Maintenance Complicate utility system Fair

Gas Turbine (Aero derivative) Light & Compact Safety Good Electrical Motor (e-LNG) Compact, Operability Large Electrical Power

system Fair

Fig.11 Kettle Type vs. Vertical Thermo siphon type Reboiler (Typical)

Fig.12 Piping around Compressor

Table 2 Comparison of Compressor Driver


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3.4 Topside Layout and Module Locations Topside layout will be conducted basically along with process flow and consideration of safety / hazard and risk mitigations. The following will be key points to be considered for Layout study: 1. Define swivel turret to be external or internal. 2. Define location of Living quarters and Warehouse, aft or fore. 3. Define type of LNG storage tank so as to allow processing facilities installed on the

topsides over the LNG storage tanks. 4. Define product load out system, side by side or tandem LNG offloading. 5. Location of Flare boom. 6. Utility facility location. 7. Helideck and helicopter operations. 8. Supply boat operations.

Following are sample of layout:

In this sample, living quarters are located in aft area, with safe distance to process area. Process modules are plotted as per process flow and utility facilities are located between process area and living quarters.

Fig.13 Sample of Layout of FLNG with External Turret


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3.5 LNG Container LNG Cotainer will be installed in the Hull of FLNG. The following are currently available types of LNG Containers: Apart from LNG Carrier (LNGC) whose operation is full cargo or empty in laden voyage, FLNG will be located at installed Offshore and the level of LNG varies from full to empty, which may be suffered by sloshing occurred by motion movement.

SPB (Self Supporting Prismatic Shape IMO Type-B) and Spherical containers can be withstanding in the harsh marine environment, whereas membrane type container will be used for mild marine environment. Recently membrane type is adopted for FLNG projects by cost advantages and topside utilization.

Fig.14 Type of LNG Container


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3.6 Module Due to work space limitation and fabrication schedule, modules as part of process facilities are designed and fabricated in parallel to the hull construction. Combined structure and piping design modeling method was developed. Support location shall be well coordinated with hull beam, so as to distribute load to hull. Module Weight and center of gravity need to be confirmed with shipbuilder.

3.7 LNG and Condensate Offloading Loading method from FLNG to LNG Carrier (LNGC) should be one of study items. Several methods were proposed, i.e. side by side using loading arms, tandem loading using flexible hoses, tandem loading using swivel system, etc. TechnipFMC as a major loading arm supplier developed the targeting system for side by side loading system using guide wire. Another method is the tandem loading using swivel system which was adopted for Brunei LNG plant, or flexible hose withstanding cryogenic temperature. For condensate, tandem loading system can be available as shown below.

Fig.15 Sample of Module Design

Fig.16 Side by Side Loading (World Maritime News)

Fig.18 Targeting System (FMC HP) Fig.17 Tandem Loading for Condensate


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3.8 LNGC Approaching Study Simulations of approaching the LNG Carrier (LNGC) to FLNG were conducted to ensure that the LNGC can safely approach and aboardage to FLNG. The following shows the sample of study results:

3.9 Safety Studies Since FLNG has limited space for escape if any disease occur. Safety studies are inevitable to ensure safety of crews and facilities. Safety studies include:

- Quantitative Risks Analysis (QRA) - Explosion Risks Analysis (ERA) - Cryogenic Spill Risks Analysis (CRA) - Evacuation, Temporary Refuge, Escape and Rescue

analysis (ETRERA) - Emergency System Survivability (ESSA )

Countermeasures will be considered such as safe distance between fire zones, active and passive fire protection, escape routing, temporary refuge, totally enclosed motor propelled survival craft (TEMPSC), helicopter etc.

Fig.19 Approach of LNGC to FLNG

Fig.20 Sample of ERA

Fig.21 Sample of TEMPSC


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3.10 Water Intake

Cooling media study was conducted so as to define cooling media and its conditions. As a final heat sink, air, sea water, circulating cooling water, were considered. The following table shows pros and cons of cooling media:

Air Cooling Water Cooling

SW Direct Cooling SW Indirect cooling

Effect of high Ambient Temp High Low Low

(Effect to Comp Power) Increase NA NA

Initial Investment Cheaper Relatively high High

Corrosion No High Less than Direct SW

Maintenance Duration Short Long Shorter than Direct SW

Plot Area Large Small Small

Water cooling either direct cooling or indirect cooling was selected for FLNG. Considering efficiency of LNG plant, lower intake temperature should be better for overall efficiency of LNG process, therefore deep sea water utilization will be one of the options. Benefit of lower water temperature can be utilized for reduction of driver power or reduction of intake water amount.

Table 3 Comparison of Cooling Media

-600

-500

-400

-300

-200

-100

00 10 20 30 40

020406080

100

Base case 5 deg DOW

020406080

100

Base case 5 deg DOW

Sea Water Temperature Driver Power (MW) or

Amount of Cooling Water

Wat

er D

epth

( m

)

Fig.22. Water Depth vs. Temperature Profile


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4. FLNG for Mid-scale LNG Plant 4.1 Standard Design FLNG for Mid

Scale FLNG Standard design FLNG was announced by Shell as g-FLNG concept in early 2000’s. In parallel, JGC conducted its own internal development for FLNG both technical and commercial of standard FLNG for range of 1 to 2 MTPA production capacities, assuming utilization of stranded gas fields in South-East Asia and Oceania area. The following are the major features of standard design FLNG.

1 MTPA Model 2 MTPA Model

Hull Size (m) 293 x 60 x 36 365 x 65 x 36

LNG Tank (m3) 155,000 (SPB Alum.) 200,000 (SPB Alum.)

Condensate Tank (m3) 16,000-20,000

Offloading Side by side

Liquefaction Technology APCI SMR APCI DMR

Driver Aero-derivative gas turbine

Due to generic design, cold section such as Liquefaction, LNG storage and Loading systems to be remain unchanged, whereas hot section, such as MEG, Acid Gas Removal, Dehydration and Fractionation systems can be modified by characteristics of feed gas from each gas fields.

Table 4. Major Feature of Standard Design of FLNG

Fig.23 Standard Design Mid-Scale FLNG


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4.2 EPCIC of PFLNG-2 Project Engineering, Procurement, Construction, Integration and Commissioning (EPCIC) of Petronas FLNG 2 Project was awarded to JGC/SHI consortium, to utilize the gas from Rotan Gas Field in offshore of Sabah Province of Malaysia. This project is the 3rd FLNG project in EPCIC, 1st deep water FLNG project of 1500m, and 1st Lump sum contract for FLNG project. Due to reduced oil price and economic circumstances, the Project was once slowdown in progress, but recently resumed. The following shows the major feature of PFLNG 2 Project.

Client Petronas

Contractor JGC-SHI Consortium (JSC)

Contract Award 1Q-2014

Plant Capacity 1.5 MTPA

Liquefaction Technology APCI N2 Expansion Process

(due to safety measures ; Less HC Inventory in the Facilities)

Sea Water Temperature About 15 deg C

Hull Dimension 333L x 64W x 31H

LNG Tank 177,000m3

Dry Weight: Topside/Hull 60,000 ton/ 90,000 ton

Fig.24 PFLNG2

Fig.25 Location of PFLNG 2

Table 5. Major Feature of PFLNG 2


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5. FLNG for Large-scale LNG Plant

5.1 Coral FLNG Project in Mozambique Coral FLNG project is planned to utilize the recently discovered large gas field offshore of Mozambique to LNG. FEED and bid proposal of EPCIC was conducted by Technip-JGC-SHI consortium, which Final Investment Decision (FID) is expected. This project is 1st FLNG in East Africa and utilizing Rovuma Basin Gas Field.

Client Eni East Africa spa.

Contractor Technip-JGC-SHI Consortium

FEED Conducted 2014 – 2015

Plant Capacity 3.5 MTPA

Liquefaction Technology APCI DMR Process

Hull Dimension 414m(L) x 66m(B) x 38.5m(D)

LNG Tank Membrane type 234,600m3

Mooring Internal Turret

Table 6. Major Feature of Coral FLNG (TJS)

Fig.26 Coral FLNG

Fig.27 Topside Layout of Coral FLNG (TJS)


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5.2 Masela FLNG Project Masela FLNG project is intended to utilize gas from Abadi Gas Field in Arafura Sea, Indonesia by INPEX. Pre-FEED and FEED work were conducted in 2008-2009 and 2013-2014, respectively. Plant capacity was changed from 4.5 MTPA to 2.3 MTPA, and further to7.5 MTPA. Due to political reason, the plant may change from FLNG to Onshore LNG plant.

Client INPEX

Contractor JGC-Technip

Pre-FEED Period 2008 - 2009

Capacity 4.5 MTPA

Liquefaction Technology APCI DMR

Hull Dimension 500m(L) x 82m(B) x 38m(D)

LNG Tank SPB (300,000 m3)

Mooring External Turret

Fig.28 Concept of Masela FLNG

Table 7. Major Feature of Masela FLNG－PreFEED Phase

Fig.29 Layout of Masela FLNG


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6. Module Fabrication, Construction and Integration 6.1 Module fabrication and Installation Module fabrication has been conducted by fabrication yards in Korea, China, Singapore, Indonesia and so on. Hull construction is conducted shipyard. Installation and integration of modules on the Hull will be conducted at quay side of shipyard.

6.2 Towing Towing will be conducted by tug boats to the installing area.

Then hock-up with mooring system, connect the risers and umbilical with the turret at the site. Crews and workers will be stay in Flotel near by the installation site. A part of pre-commissioning and commissioning work will be conducted at module yards and integration yard in shipyard before towing. At the offshore, pre-commissioning and commissioning of mainly hydrocarbon related parts and overall facility as Gas Trial will be conducted.

Fig.30 Module Installation at Shipyard

Fig.31 Towing and Installation of FLNG to Site


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7. Way Forward Base on technical development and actual execution of FEED and EPCIC, JGC has accumulated information and design methodologies, and will further apply to the future FLNG projects, as well as assisting and supporting to the currently conducting FLNG project. In future, economic development within deep water area of Exclusive Economic Zone (EEZ), and subsea systems will be one of the expected area.

8. Finally Based on recent Shale Gas utilization to LNG and reduced oil price, the investment circumstances for gas monetization should be effected. For example, some of planned base load onshore LNG projects in Australia thought twice to proceed onshore, but consider FLNG option due to economic and HSSE reason. For stranded gas field in offshore, the FLNG has still a possible option and, may compete to conventional onshore LNG plant using plat form and long subsea pipelines. FLNG concept is still a final option to onshore LNG, however technology development and cost reduction effort may lead the bright future for FLNG.

Fig.32 Expectation to Offshore Business

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