vessels under construction will be the first to enter service has been the subject of some speculation. Shell contracted the first LNG ‘floater’ in May 2011, the 488m-long Prelude vessel which Samsung Heavy Industries (SHI) is building for positioning off Australia’s northwestern coast.
Prelude embraces many groundbreaking technologies and will be the world’s largest floating, man-made structure upon completion. However, such is the scale of the project that it will not be ready to enter into service until early 2017.
A more modest newbuilding is the 300m-long FLNG vessel that Petronas ordered at Daewoo Shipbuilding and Marine Engineering (DSME) in early 2012 for what it terms its PFLNG 1 project. The scheme calls for the vessel to be positioned in shallow water about 180km off the coast of Bintulu in the Malaysian state of Sarawak in order to liquefy gas from the Kanowit field. In contrast to the Prelude LNG production
capacity of 3.6 mta, PFLNG 1 will be able to liquefy 1.2 mta. The Malaysian unit is scheduled to commence LNG production in late 2015.
In February 2014 Petronas sanctioned a second floating LNG project for Malaysian waters. The PFLNG2 vessel will be built at SHI and have a capacity to produce 1.5 mta. It is due to go into service in 2018 off the coast of Sabah, where it will process gas from the Rotan field.
The smallest of the four FLNG vessels under construction is that being developed by Exmar for a 15-year charter with Pacific Rubiales and positioning at Tolú on Colombia’s Caribbean coast. The non-propelled vessel, named FLNG Caribbean and termed a floating liquefaction regasification and storage unit (FLRSU), was ordered at the Wison yard in China in June 2012 and is scheduled to be providing LNG, at a rate of 0.5 mta, by the second quarter of 2015.
The recently announced conversion project involves the fitting of four modular liquefaction trains on Golar LNG’s 1975-built, 125,000m3, spherical tank LNG carrierHilli. The work, which will be carried out at Keppel Shipyard in Singapore, will provide the vessel with a liquefaction capacity of 2.2–2.8 mta. Black & Veatch’s proprietary Prico liquefaction technology will be utilised and the conversion project is due for completion in the first quarter of 2017.
Golar holds options with Keppel covering similar conversions on two
other of its older LNG carriers. The shipowner has not yet finalised a charter deal forHilli in its new role but is in negotiations with several potential customers.
On paper it looks like the Exmar FLRSU will be the first past the finishing line. However, the contenders will not be claiming a place in the history books until the first cargo from their floater is transshipped. Experience has shown that it is best not to take anything for granted when new technologies are being applied.
The five committed FLNG projects look set to be the first batch of many similar initiatives. Floating production is poised to follow in the footsteps established by the LNG industry’s adoption of the floating storage and regasification unit (FSRU) concept over the past decade. Having said that, the technologies involved in LNG regasification are much less complex than those involved in its liquefaction, so FLNG will never match the extent and the pace of the FSRU take-up.
Nevertheless the welcome given by the LNG industry to floating regasification shows how quickly innovative technologies can be adopted and accepted in the modern era. Just as importantly, floating regasification has been quick to prove that major cost savings can accrue from offshore solutions. When the regasification cost element of delivered gas via an FSRU comes in at one-third
Five FLNG vessel
projects are underway
and developers of
upwards of 20 further
such schemes are
working towards final
investment decisions
Time is nigh for floating
LNG production
The technology behind Prelude, a vessel of many superlatives, is set to be replicated in many new FLNG projects
A SIGTTO/GIIGNL commemorative issue LNG shipping at 50I 105I 105
that of gas processed at a shore-based import terminal, the benefits are not difficult to appreciate.
The US has eight and Australia seven FLNG schemes on the drawing board. The developers of the majority of these projects are currently engaged in preliminary engineering work with a view to commissioning full front- end engineering and design (FEED) studies. A successful outcome, along with the necessary permits and gas sales agreements in place, would enable a final investment decision (FID) to be taken in 2015–16 and their projects to transship the first LNG to delivery tankers in 2018–2019.
Most of the US and Australian initiatives are based on floaters with relatively large, single train liquefaction capacities, of 3–4 mta, to enable the export of sizeable quantities of gas. The US projects, for example, are competing with numerous shore- based terminal schemes to export the same shale gas resources.
In Australia the offshore fields targeted by the FLNG community hold significant reserves, and floating production offers a lower cost, fast-track alternative to the construction of a shore- based export terminal and an associated, long-distance, subsea gas pipeline.
Sometimes, however, even an FLNG proposal in Australia is found not to be commercially justified. In summer 2014 GDF Suez and Santos decided to shelve their planned Bonaparte FLNG scheme rather than press on to the FEED stage, citing the questionable economics of the project.
Shell is a partner in a number of Australia’s prospective FLNG developments, and in these cases the energy major’s Prelude technology has been chosen as the route to project realisation. The concept is based on solid foundations, Shell having researched its FLNG options for 15 years and devoted 1.6 million man- hours to work on the engineering challenges before deciding on the Prelude design and equipment.
Prelude will be moored using the world’s largest turret yoke arrangement 200km from the nearest land off Australia’s northwest coast, an area prone to seasonal cyclones. The Prelude FLNG vessel is being designed for not only an uninterrupted service life of 20 years at this location but also a further 20 years at another potential offshore gas field development.
Making the Prelude concept more
widely available will be facilitated by the fact that Shell has entered into a master service agreement with Technip and Samsung covering the design, construction and installation of multiple FLNG facilities over a period of up to 15 years.
Smaller scale units are also well represented amongst the FLNG schemes under development. It is estimated that there are over 650 remote offshore fields with between 0.5 and 5 trillion cubic feet (tcf) of stranded gas that would be ripe for development with small-scale, barge- mounted liquefaction plants.
The combination of liquefaction plants of modular construction and simple barge-shaped hulls, especially when the facility is moored in nearshore waters, helps ensure that the investment cost per tonne of LNG produced is much below the equivalents for both a large-scale FLNG project and a shore- based export terminal. Exmar’s small FLRSU, for example, is expected to cost US$300 million, complete with topsides.
The Exmar FLRSU, which is due to be positioned at a dedicated jetty located 3km off Colombia’s Caribbean coast, is illustrative of the effect such a vessel can have on a region’s LNG supply chain. The FLRSU will work in tandem with a floating storage unit (FSU) also moored at the jetty, transferring LNG to the FSU as it is liquefied.
It is likely that initially the terminal will export full LNGC cargoes of 140,000–160,000m3, depending on the
sizes of the FSU and the delivery tanker, to the international spot market once every six weeks. Eventually, once the region’s customers have their LNG receiving infrastructure in place, the FLRSU will supply the small-scale
power generation markets of Central America and the Caribbean using coastal LNG carriers.
Exmar has established a strategic alliance with Black & Veatch, the supplier of the FLRSU’s liquefaction plant technology, and Wison, the builder of the vessel, to explore further opportunities for the small-scale FLNG technology the partnership has developed.
One of the principal advantages of the FLNG approach to bringing LNG to market is that the entire vessel can be built under controlled conditions by experienced and skilled workers at a dedicated yard. In doing so the cost overruns, construction problems and inclement weather conditions often encountered at shore terminal building sites can be avoided.
Yard construction of an FLNG vessel also enables the building schedule to be accelerated through replication and efficiency shortcuts, again to the benefit of the overall budget. Financing arrangements are usually facilitated by yard construction, and the overall project will benefit from the lessons learned from previous projects of a similar nature.
The FLNG projects involving the vessels under construction are based on the side-by-side method of offloading LNG to the LNG shuttle carrier. The next frontier, for projects in more inhospitable waters, will be the adoption of the tandem offloading method. For the moment, however, the homework has been done, the foundation FLNG vessels are currently under construction and a raft of investment decisions on new projects is imminent. The FLNG era has begun. MC
The FLNG Caribbean project is poised to show what is possible with small, barge- mounted liquefaction units
A SIGTTO/GIIGNL commemorative issue 106 I
106 ILNG shipping at 50
T
he delivery of the 6,500m3Coral Anthelia to Anthony Veder and the2,500m3Kakayu Maru to Tsurumi
in 2013 raised the complement of coastal LNG carriers worldwide to 16 vessels. Another four such ships are on order, all building in China and earmarked for gas distribution duties along the country’s long coastline. Three of the vessels are in the 28–30,000m3 size range and, on
delivery in 2015, will be the largest coastal LNG carriers yet built.
This fleet of small-scale LNG carriers is only a decade old. It has emerged to facilitate the extension of the LNG supply chain and to bring the benefits of this clean-burning, competitively priced fuel to a much wider range of customers. The main market drivers for small-scale LNG are the growing use of gas as marine fuel and the need to supply remote residential communities, power stations and commercial ventures not connected to the pipeline grid.
Predicting the size of the coastal LNG carrier fleet 10 years hence and the pace at which it will grow pose challenges but it is safe to say that the influence being exerted by the current market drivers will continue to strengthen. New delivery routes, terminal facilities, bunker depots and fuelling stations are being developed and naval architects’
drawing boards around the world are filling up with coastal LNGC design concepts. A number of newbuilding projects have been mooted and several are poised to materialise.
All the coastal LNG carriers built to date have IMO Type C insulated, pressure vessel cargo tanks fitted horizontally in the vessel. The Type C tanks are either cylindrical or bilobe in shape and stainless steel and aluminium have been used as tank materials. With Type C tanks there is no need for the cargo containment system to have a secondary barrier. Ship designs with alternative containment systems, including GTT membrane tanks, have been developed but as yet only Type C tanks have been specified.
Various types of propulsion system have been utilised on small-scale LNG carriers, including dual-fuel arrangements which enable the use of cargo boil-off gas as vessel fuel. When dual-fuel plant is specified, back-up arrangements, such as a reliquefaction plant or gas combustion unit, must be in place either to handle excess boil-off gas or for emergencies when there are problems with the propulsion system. While the new reality of an extended LNG supply chain is getting closer, there are still parts of the existing coastal LNG
carrier fleet that are not fully employed in the trade. Eight of the ships are designed as multipurpose gas carriers, with the ability to carry ethylene and LPG as well as LNG. This flexibility has helped the operators achieve high utilisation rates for the vessels until that time they are needed for LNG distribution duties. The current strength of the ethylene trades has been a boon in this respect.
The largest of the coastal LNG carriers currently in service, the 15,600m3Coral Energy, is fully dedicated to the trade. The vessel was built by Neptun Werft of Rostock in Germany, part of the Meyer Group, for Anthony Veder, and Skangass, the vessel’s long-term charterer, worked closely with the principals in the design of the vessel. The ability to load LNG at large terminals and deliver cargoes to all sizes of terminals by means of a dual manifold arrangement was a key design consideration.
Anthony Veder describesCoral Energy as the world’s first direct-drive, dual-fuel, ice-class 1A LNG carrier. The ship’s Wärtsilä dual-fuel engine is linked directly to the propeller, thus avoiding the power losses that can arise with diesel-electric drive systems. The 1A ice class rating means that the vessel will be able to function in the Baltic Sea throughout the winter months.
Coral Energy has been delivering cargoes loaded at the Skangass liquefaction plant in Stavanger’s Risavika harbour to receiving terminals at Fredrikstad in Norway and Nynäshamn in Sweden. Until the European LNG distribution and bunkering markets get up to speed the Risavika plant has spare capacity, and
Coral Energy has also been facilitating product sales by transporting LNG offered by Skangass on the spot market.
IM Skaugen operates four LNG