Latest trends -FSRU and FSU Vikas Singh 2013,Kochi 28 th November
Content Types of LNG carrier & LNG tank Floating Storage Unit Floating Storage Regasification unit FSRU Design & Construction Mooring Arrangement Loading arm Regasification system and Gas transfer Land based terminal vs FSRU Complexities Chartering New Developments Key Players Summary
Moss type LNG Carrier
Moss Tanks Aluminum alloy single spherical tank supported at equatorial ring Insulated with polyurethane foam which is purged with Nitrogen A partial barrier in form of a drip-tray beneath the sphere is fitted Normal operating pressure 22kPa Moss is owned by Norwegian Company Moss Maritime
Membrane type (prismatic) LNG carrier
Membrane tanks by GTT (Gaz Transport & Technigaz) No.96 tanks Primary and secondary 0.7mm membrane made of Invar(36% Ni steel alloy) which has almost no thermal contraction. Primary & secondary insulation is made of plywood boxes filled with perlite.
Mark III tanks Primary barrier corrugated steel about 1.2 mm thick in direct contact with liquid. Secondary barrier called triplex basically a metal foil sandwiched between glass wool sheet and compressed together. The insulation consists of a load-bearing system made of prefabricated panels in reinforced polyurethane foam.
CS1 membrane tanks Combines No 96 & Mark III components Primary barrier 0.7mm membrane made of Invar Secondary barrier is made of triplex Primary & secondary insulation is made of polyurethane foam
Self-supporting Prismatic shape IMO type-b (SPB) containment system Developed by IHI,Japan tank is of stiffened plate structure of aluminum alloy or 9%Ni steel, covered by PUF insulation, supported by tank supports and chocks made of specially reinforced plywood. No chances of Sloshing damage due to subdivision Partial loading is possible Still not much in trade
Floating Storage Unit (FSU) Floating Storage Units are used for temporary storage of LNG before being transferred to the regasification facility FSU concept is typically based on chartering a conventional LNGcarrier (typically 125 150k cbm in capacity) Modifications are minimal and easy May be anchored, moored or idling close to the coast Many older conventional LNG carriers readily available in today s market Can be purchased or chartered, for short or longer periods, greatly adding to flexibility LNG is loaded into the FSU by Ship to Ship Transfer (STS) operation
Floating Storage and Regasification Unit (FSRU) floating ship terminal where LNG is received, stored and regasified before being sent ashore Economic attractiveness, in general FSRU s cost less than land based schemes of a similar size Flexibility as FSRU s can be moved from one demand centre to another or designed to trade as a LNG carrier, Shuttel & Regasification Vessel (SRV) or LNGRV Mitigates fluctuations due to seasonal demand
Construction and Design of FSRU
FSRU construction FSRU may be constructed by Existing LNG carrier conversion or Purpose built FSRU s are used in wide range capacities starting from 125k cbm Excelerate Energy developed first Gasport in 2007/Teesside, UK First converted FSRU Golar Spirit commissioned 2009/Pecem,Brazil Largest FSRU on order(daewoo shipyard, Korea) of 263k cbm, planned to enter into service in Nov 2016 at Port of Montevideo, Uruguay
Typical details of a large purpose built FSRU Length - 345m Breadth- 55.0m Storage capacity- 2,63,000 cbm Regasification capacity-540 MMSCFD (LNG conversion: about 10,900 MT/day) Jetty Mooring with break water
Typical details of a FSRU converted from a LNG carrier Length -289m Breadth -44.6m Depth -26 m Draft -11.4m Tank type -Moss No of tanks -5 Cargo tanks capacity -129k cbm Gas send out -2 MMTPA
LNG carrier conversion No single factor to decide which type of LNG carrier makes the best FSRU. Availability and cost are the prime considerations when seeking candidate. Technically older Moss vessels are favoured especially if intention is to just moor and vessel will not be utilized to trade LNG.
LNG carrier conversion Converting LNG carrier into FSRU is simple in principle but execution is challenge. Risk of suitability and quality of design Quality of construction On time delivery of vessel High level of technical integration Long lead times for special equipments In general time required is upto 18-24 months
LNG carrier conversion Add vaporisers, loading arms and extra pumps to the LNG carrier, upgrade its power, electrical and control systems and you have an FSRU. Older vessels are generally more conservatively designed, more robust and provide easier foundations for major engineering modifications. Modern membrane tank vessel, having efficient propulsion system is favored when intention is to continue using the vessel to trade as LNGC (SRV/LNGRV) The self supporting Moss type tanks have strong structural integrity and do not have operational cargo filling restrictions.
LNG carrier conversion FSRU Storage capacity is dictated by the port and supply logistics. Gas send out capacities, temperatures and pressures will be influenced by maximum and minimum rate demands. Mooring system design will depend on the local environment and the jetty layout. FSRU s communication links and ESD systems are integrated with the onsite LNG and natural gas handling systems.
Side by side(at Jetty) Mooring Primary & Secondary fenders Additional fairleads & capstan arrangements STS
Mooring Across the pier Normal jetty operation for both FSU/FSRU & Shuttle LNGC
Mooring Along the pier Normal jetty operation for both FSU/FSRU & Shuttle LNGC
Turret mooring Mooring Turn table at bow or stern with 360 0 rotation Non rotating platform to support anchors, risers, service lines etc Need modification on vessel Suitable for off shore rough environment STS
Loading Arms Standard loading arms to allow side by side transfer of LNG and vapour return. Loading arms similar to ones used at onshore terminals additionally modified to account for relative motions between shuttle and FSRU. Flexible cryogenic hoses
LNG Regasification System LNG is sent from the tanks to the regasification skid. Which generally comprises of booster pumps and steam heated vaporizers. Few designs also use propane. The booster pumps will increase the pressure to about 85 to 90 bars. High pressure LNG is vaporized. Regasification can be both in open or closed loop mode.
Possible means of LNG vaporization Open Loop Seawater: pumping warm seawater across the vaporizer and discharging cooled seawater Closed Loop Water: pumping fresh water through a closed circuit in which the water is warmed in the FSRU boilers and cooled across the LNG vaporizer Closed Loop Steam: Using steam produced in the FSRU boilers to vaporize the LNG and returning the condensate back to the boilers in a closed loop
Skid Mounted Regasification unit
Gas send out Gas transfer in general has 2 options; 1) through the FSRU s connection with a subsea buoy in the hull of the ship -submerged turret loading (STL) for off shore 2) through a high-pressure gas manifold located forward of the vessel s LNG loading arms for Jetty operation
FSRU vs land terminal Cost comparisons must be treated with caution, as the circumstances surrounding floating and land based developments can affect the cost of both significantly. In general FSRU s may provide a faster return on capital. Attraction for FSRU also lies in the fact that residents tend to favour energy supply solutions that are situated far away from where they live NIMBY syndrome Also in areas of uncertain economic growth with an element of political or economic instability. FSRU is flexible, scalable & movable.
FSRU vs land terminal Onshore terminal development may require extensive planning. Depending on the topography, it may also take more construction time as compared to the FSRU s which may be converted from an existing LNG carrier. In normal LNG carrier, most of the required equipments are already available only minor additions required. FSRUs have limited regulatory issues wrt complex land issues. No generic solution to industry s regasification needs. Each FSRU has to be designed to meet the specific requirements of the charterer for particular project.
Complexities of FSRU Technical specification must be robust capturing all the operational requirements. Vital to spend time with the end user, to make specifications of the FSRU as close as possible to the operational requirements. Converting existing LNG carrier into FSRU: Integration requires extreme efforts. High pressure associated with FSRU operations introduce a new set of risks not present on conventional LNG carriers.
Complexities of FSRU FSRU have upgraded fire and gas detection systems and fire fighting systems. In addition a more sophisticated emergency shut down system based on the rules for offshore oil and gas operations is provided. Operation and maintenance of the vessel. As an FSRU forms part of the shore infrastructure, EIA and assurance of vessels compliance with the local as well as international marine requirements are also central issues.
Chartering FSU Normal LNG carrier may be used as a FSU. Few LNG carriers built by shipowners for speculation remain open on offer most of the time. Shipowners owning old carriers may also remain interested in offering as FSU s in sync with prevailing LNG carrier long term charter rates. Owners of New LNG carriers may not be interested in offering as FSU for longer duration. New carrier not being used entirely on the account of propulsion and auxiliary machinery may generate speed warranty & machinery issues.
Chartering FSRU Unlike FSU, FSRU is newly built or an existing LNG carrier is converted to FSRU when employment is in hand Chartering is for relatively long term. Spot availability is difficult as very few FSRU s are built by owners on speculation basis. Majority of the FSRU s under construction or delivered are already committed.
New developments FSU+FRU This alternative is based on providing two different vessels, one to function as LNG storage and the other as the regasification unit. best suited to calm waters. LNGC as FSU Small floating regas unit
FSU + Regas Structure Normal LNGC as FSU Construction of Piles Construct Regas Module in a yard Transport on a semisubmersible ship Float off on pile support
Gravity Based Structure Large concrete structure resting on sea bed LNG tanks Regas plant Mooring facility Unloading facility Send out line Living space
Key Players Excelerate Energy 4 operational Dockside floating regas Gasport tm (UK,Argentina & Kuwait) 3 more in line First Gasport in Teesside, UK, 2007 Offshore Regas Gateway tm Terminal (in US) First Gateway Terminal in US 2005 & decommissioned in 2012 Energy Bridge FSRU tm Also pioneer in STS more than 500 STS
Golar LNG Key Players 4 operational converted FSRUs 125k 138k cbm (Brazil,Dubai,Indonesia) 5 th under commissioning 3 x 170k cbm on order (Jordan,Kuwait) Hoegh LNG 2 x 145k cbm operational converted FSRUs (US) 4 x 170k cbm on order (Indonesia,Lithuania,Chille) Exmar Has fleet of 8 LNGRVs First LNGRV Excelsior was delivered in 2005 First commercial STS in Aug 2006 Many more LNG ship owners & management company's have ordered for FSRU & exploring opportunities in this sector.
Summary Cost, speed of delivery and flexibility are the main advantages of FSRU s. Concept of FSRU s may provide in general a rapid and competitively priced turnkey alternative to a shore based gas terminal. FSRU business is challenging. It involves sound aggregation of shipping and energy technology, commercial skills and marine operating experience.
Vikas Singh 28 th November 2013,Kochi