Floating liquefied natural gas
Encyclopedia
Floating liquefied natural gas (FLNG) refers to water-based liquefied natural gas
(LNG) operations employing technologies designed to enable the development of offshore natural gas resources. While no FLNG facilities currently exist, a facility is in development by Royal Dutch Shell
, and is due to be completed by around 2017. Floating above an offshore natural gas field, the FLNG facility will theoretically produce, liquefy, store and transfer LNG (and potentially LPG and condensate
) at sea before carriers ship it directly to markets.
In 1997, Mobil
developed a FLNG production concept based on a large, square structure with a moon-pool, commonly known as "The Doughnut". In 1999, a major study was commissioned as a joint project by Chevron Corporation
and several other oil and gas companies. This was closely followed by the so-called 'Azure' research project, conducted by the EU and several oil and gas companies. Both projects made great progress in steel concrete hull design
, topside development and LNG
transfer systems.
Since the mid 1990s Royal Dutch Shell has been working on its own FLNG technology. This includes engineering and the optimization of its concept related to specific potential project developments in Namibia
, Timor Leste/Australia, and Nigeria
.
In July 2009, Royal Dutch Shell signed an agreement with Technip
and Samsung
allowing for the design, construction and installation of multiple Shell FLNG facilities.
. Royal Dutch Shell announced their investment in FLNG on 20 May 2011.
In April 2010 Shell's FLNG technology was selected as the Sunrise Joint Venture’s preferred option for developing the Greater Sunrise gas fields in the Timor Sea
. This followed an extensive and rigorous concept-evaluation process during which the merits of the project were weighed up against alternative onshore solutions. The Woodside-operated
JV is now seeking to engage regulators on the concept selection process. Following the decision by Shell to go ahead with its Prelude FLNG development, the Sunrise project would be the second deployment of Shell’s proprietary FLNG design.
In February 2011, Petronas
awarded a FEED contract for an FLNG unit to a consortium of Technip and Daewoo Shipbuilding & Marine Engineering
. The facility will be located in Malaysia, although the specific gas field is unknown.
Petrobras
has invited three consortiums to submit proposals for engineering, procurement and construction contracts for FLNG plants in ultra-deep Santos Basin
waters. A final investment decision is expected in 2011.
Meanwhile, Japan's Inpex
plans to leverage FLNG to develop the Abadi gas field in the Masela block of the Timor Sea, with a final investment decision expected by the end of 2013. Late in 2010, Inpex deferred start-up by two years to 2018 and cut its 'first phase' capacity to 2.5 million tons per year (from a previously proposed capacity of 4.5 million tonnes).
According to a presentation given by their engineers at GASTECH 2011, ConocoPhillips
aims to implement a facility by 2016-19, and has completed the quantitative risk analysis of a design that will undergo pre-FEED study during 2011.
GDF Suez Bonaparte – a joint venture undertaken by the Australian oil and gas exploration company Santos (40%) and the French multi-international energy company GDF Suez
(60%) – has awarded a pre-FEED contract for the Bonaparte FLNG project offshore Northern Australia. The final investment decision is expected in 2014, with startup planned for 2018. The first phase of the project calls for a floating LNG
production facility with a capacity of 2 million mt/year.
Chevron Corporation is currently considering an FLNG facility to develop offshore discoveries in the Exmouth Plateau of Western Australia, while ExxonMobil
is waiting for an appropriate project to launch its FLNG development.
production to an offshore setting presents a demanding set of challenges. In terms of the design and construction of the FLNG facility, every element of a conventional LNG facility needs to fit into an area roughly one quarter the size, whilst maintaining the utmost levels of safety and giving increased flexibility to LNG production.
Once a facility is in operation, wave motion will present another major challenge. LNG containment systems need to be capable of withstanding the damage that can occur when the sea’s wave and current motions cause sloshing in the partly filled tanks. Product transfers also need to deal with the effects of winds, waves and currents in the open seas.
Many solutions to reduce the effect of motion and weather are again to be found in the design, which must be capable of withstanding – and even reducing – the impact of waves. In this area, technological development has been mainly evolutionary rather than revolutionary, leveraging and adapting technologies that are currently applied to offshore oil production or onshore liquefaction
. For example, traditional LNG loading arms have been adapted to enable LNG transfers in open water, and hose-based solutions for both side-by-side transfers in calmer seas and tandem transfers in rougher conditions are nearing fruition.
. It is also abundant and affordable and may be able to meet world energy needs by realising the potential of otherwise unviable gas reserves (several of which can be found offshore North West Australia). FLNG technology also provides a number of environmental and economic advantages:
. When the gas reaches the facility, it will be processed to produce natural gas, LPG, and natural gas condensate. The processed feed gas will be treated to remove impurities, and liquefied through freezing, before being stored in the hull. Ocean-going carriers will offload the LNG, as well as the other liquid by-products, for delivery to markets worldwide. The conventional alternative to this would be to pump gas through pipelines to a shore-based facility for liquefaction, before transferring the gas for delivery.
).
The specifications make Shell's FLNG facility particularly well-suited for fields with high production rates for reserves starting at 2 Tcuft and beyond – less than a tenth the size of the Groningen gas field
off the Netherlands.
in Korea. Some modules may be constructed elsewhere and then transferred to the shipyard for assembly. The facility can remain on station for more than 25 years, and its lifetime can be further extended through overhaul and refurbishment. The hull has a design life of 50 years.
. Potentially, this could result in more uptime for the facility.
Additionally, Shell designers have optimised safety on the facility by locating storage facilities and process equipment as far from crew accommodation as possible. As a result of this, the accommodation areas of visiting LNG carriers are also at maximum distance from critical safety equipment. Safety gaps have been allowed between modules of process equipment so that gas can disperse quickly in the event of a gas leak.
Liquefied natural gas
Liquefied natural gas or LNG is natural gas that has been converted temporarily to liquid form for ease of storage or transport....
(LNG) operations employing technologies designed to enable the development of offshore natural gas resources. While no FLNG facilities currently exist, a facility is in development by Royal Dutch Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...
, and is due to be completed by around 2017. Floating above an offshore natural gas field, the FLNG facility will theoretically produce, liquefy, store and transfer LNG (and potentially LPG and condensate
Natural gas condensate
Natural-gas condensate is a low-density mixture of hydrocarbon liquids that are present as gaseous components in the raw natural gas produced from many natural gas fields....
) at sea before carriers ship it directly to markets.
Background
Studies into offshore LNG production have been conducted since the early 1970s, but it was only in the mid 1990s that significant research backed by experimental development began.In 1997, Mobil
Mobil
Mobil, previously known as the Socony-Vacuum Oil Company, was a major American oil company which merged with Exxon in 1999 to form ExxonMobil. Today Mobil continues as a major brand name within the combined company, as well as still being a gas station sometimes paired with their own store or On...
developed a FLNG production concept based on a large, square structure with a moon-pool, commonly known as "The Doughnut". In 1999, a major study was commissioned as a joint project by Chevron Corporation
Chevron Corporation
Chevron Corporation is an American multinational energy corporation headquartered in San Ramon, California, United States and active in more than 180 countries. It is engaged in every aspect of the oil, gas, and geothermal energy industries, including exploration and production; refining,...
and several other oil and gas companies. This was closely followed by the so-called 'Azure' research project, conducted by the EU and several oil and gas companies. Both projects made great progress in steel concrete hull design
Offshore concrete structure
Offshore concrete structures have been in use successfully for about 30 years. They serve the same purpose as their steel counterparts in the oil and gas production and storage. The first concrete oil platform has been installed in the North Sea in the Ekofisk field in 1973 by Phillips Petroleum...
, topside development and LNG
Liquefied natural gas
Liquefied natural gas or LNG is natural gas that has been converted temporarily to liquid form for ease of storage or transport....
transfer systems.
Since the mid 1990s Royal Dutch Shell has been working on its own FLNG technology. This includes engineering and the optimization of its concept related to specific potential project developments in Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
, Timor Leste/Australia, and Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
.
In July 2009, Royal Dutch Shell signed an agreement with Technip
Technip
Technip is a provider of project management, engineering, and construction services for the oil and gas industry, headquartered in Paris, France....
and Samsung
Samsung
The Samsung Group is a South Korean multinational conglomerate corporation headquartered in Samsung Town, Seoul, South Korea...
allowing for the design, construction and installation of multiple Shell FLNG facilities.
Current projects
A number of major gas and oil companies are still researching and considering FLNG developments, with several initiatives planned for the future. However, the world's first development of FLNG will be Shell's 'Prelude' FLNG project, 200 kilometres (124.3 mi) offshore Western AustraliaWestern Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
. Royal Dutch Shell announced their investment in FLNG on 20 May 2011.
In April 2010 Shell's FLNG technology was selected as the Sunrise Joint Venture’s preferred option for developing the Greater Sunrise gas fields in the Timor Sea
Timor Sea
The Timor Sea is a relatively shallow sea bounded to the north by the island of Timor, to the east by the Arafura Sea, to the south by Australia and to the west by the Indian Ocean....
. This followed an extensive and rigorous concept-evaluation process during which the merits of the project were weighed up against alternative onshore solutions. The Woodside-operated
Woodside Petroleum
Woodside Petroleum Limited is an Australian petroleum exploration and production company. It is a public company listed on the Australian Securities Exchange and has its headquarters in Perth, Western Australia.-History:...
JV is now seeking to engage regulators on the concept selection process. Following the decision by Shell to go ahead with its Prelude FLNG development, the Sunrise project would be the second deployment of Shell’s proprietary FLNG design.
In February 2011, Petronas
Petronas
PETRONAS, short for Petroliam Nasional Berhad, is a Malaysian oil and gas company that was founded on August 17, 1974. Wholly owned by the Government of Malaysia, the corporation is vested with the entire oil and gas resources in Malaysia and is entrusted with the responsibility of developing and...
awarded a FEED contract for an FLNG unit to a consortium of Technip and Daewoo Shipbuilding & Marine Engineering
Daewoo Shipbuilding & Marine Engineering
Daewoo Shipbuilding & Marine Engineering Co., Ltd ' is the second largest shipbuilder in the world and one of the "Big Three" shipbuilders of South Korea.On 21 February 2011, the A. P...
. The facility will be located in Malaysia, although the specific gas field is unknown.
Petrobras
Petrobras
Petróleo Brasileiro or Petrobras is a semi-public Brazilian multinational energy corporation headquartered in Rio de Janeiro, Brazil. It is the largest company in Latin America by market capitalization and revenue, and the largest company headquartered in the Southern Hemisphere by market...
has invited three consortiums to submit proposals for engineering, procurement and construction contracts for FLNG plants in ultra-deep Santos Basin
Santos Basin
The Santos Basin is an offshore pre-salt basin. It is located in the south Atlantic Ocean, some south east of São Paulo, Brazil. One of the largest Brazilian sedimentary basins, it is the site of several recent significant oil fields, including Tupi and Jupiter....
waters. A final investment decision is expected in 2011.
Meanwhile, Japan's Inpex
Inpex
is a Japanese oil company established in 1966 as North Sumatra Offshore Petroleum Exploration Co., Ltd.In 2006, INPEX acquired Japanese oil company Teikoku Oil.- Projects :...
plans to leverage FLNG to develop the Abadi gas field in the Masela block of the Timor Sea, with a final investment decision expected by the end of 2013. Late in 2010, Inpex deferred start-up by two years to 2018 and cut its 'first phase' capacity to 2.5 million tons per year (from a previously proposed capacity of 4.5 million tonnes).
According to a presentation given by their engineers at GASTECH 2011, ConocoPhillips
ConocoPhillips
ConocoPhillips Company is an American multinational energy corporation with its headquarters located in the Energy Corridor district of Houston, Texas in the United States...
aims to implement a facility by 2016-19, and has completed the quantitative risk analysis of a design that will undergo pre-FEED study during 2011.
GDF Suez Bonaparte – a joint venture undertaken by the Australian oil and gas exploration company Santos (40%) and the French multi-international energy company GDF Suez
GDF Suez
GDF Suez S.A. is a French multinational energy company which operates in the fields of electricity generation and distribution, natural gas and renewable energy. The world's largest utility after taking control of Britain's International Power, the company was initially formed by the merger of Gaz...
(60%) – has awarded a pre-FEED contract for the Bonaparte FLNG project offshore Northern Australia. The final investment decision is expected in 2014, with startup planned for 2018. The first phase of the project calls for a floating LNG
Liquefied natural gas
Liquefied natural gas or LNG is natural gas that has been converted temporarily to liquid form for ease of storage or transport....
production facility with a capacity of 2 million mt/year.
Chevron Corporation is currently considering an FLNG facility to develop offshore discoveries in the Exmouth Plateau of Western Australia, while ExxonMobil
ExxonMobil
Exxon Mobil Corporation or ExxonMobil, is an American multinational oil and gas corporation. It is a direct descendant of John D. Rockefeller's Standard Oil company, and was formed on November 30, 1999, by the merger of Exxon and Mobil. Its headquarters are in Irving, Texas...
is waiting for an appropriate project to launch its FLNG development.
Challenges
Moving LNGLiquefied natural gas
Liquefied natural gas or LNG is natural gas that has been converted temporarily to liquid form for ease of storage or transport....
production to an offshore setting presents a demanding set of challenges. In terms of the design and construction of the FLNG facility, every element of a conventional LNG facility needs to fit into an area roughly one quarter the size, whilst maintaining the utmost levels of safety and giving increased flexibility to LNG production.
Once a facility is in operation, wave motion will present another major challenge. LNG containment systems need to be capable of withstanding the damage that can occur when the sea’s wave and current motions cause sloshing in the partly filled tanks. Product transfers also need to deal with the effects of winds, waves and currents in the open seas.
Many solutions to reduce the effect of motion and weather are again to be found in the design, which must be capable of withstanding – and even reducing – the impact of waves. In this area, technological development has been mainly evolutionary rather than revolutionary, leveraging and adapting technologies that are currently applied to offshore oil production or onshore liquefaction
Liquefaction
Liquefaction may refer to:* Liquefaction, the general process of becoming liquid* Soil liquefaction, the process by which sediments become suspended* Liquefaction of gases in physics, chemistry, and thermal engineering* Liquefactive necrosis in pathology...
. For example, traditional LNG loading arms have been adapted to enable LNG transfers in open water, and hose-based solutions for both side-by-side transfers in calmer seas and tandem transfers in rougher conditions are nearing fruition.
Advantages
Natural gas is the cleanest burning fossil fuelFossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
. It is also abundant and affordable and may be able to meet world energy needs by realising the potential of otherwise unviable gas reserves (several of which can be found offshore North West Australia). FLNG technology also provides a number of environmental and economic advantages:
- Environmental - Because all processing is done at the gas field, there is no need to lay long pipelinesPipeline transportPipeline transport is the transportation of goods through a pipe. Most commonly, liquids and gases are sent, but pneumatic tubes that transport solid capsules using compressed air are also used....
all the way to the shore. There is also no requirement for compression units to pump the gas to shore, dredging and jetty construction or the onshore construction of an LNG processing plant, all of which significantly reduce the project's environmental footprint. Avoiding construction also helps preserve marine and coastal environments. Additionally, environmental disturbance would be minimised during the later decommissioning of the facility, because it could be disconnected easily and removed before being refurbished and re-deployed elsewhere.
- Economic – Where pumping gas to shore can be prohibitively expensive, FLNG makes development economically viable. As a result, it will open up new business opportunities for countries to develop offshore gas fields that would otherwise remain stranded, such as those off the coast of East Africa.
Operation
The FLNG facility will be moored directly above the natural gas field. It will route gas from the field to the facility via risersDrilling riser
A drilling riser is a conduit that provides a temporary extension of a subsea oil well to a surface drilling facility. Drilling risers are categorised into two types: marine drilling risers used with subsea blowout preventer and generally used by floating drilling vessels; and tie-back drilling...
. When the gas reaches the facility, it will be processed to produce natural gas, LPG, and natural gas condensate. The processed feed gas will be treated to remove impurities, and liquefied through freezing, before being stored in the hull. Ocean-going carriers will offload the LNG, as well as the other liquid by-products, for delivery to markets worldwide. The conventional alternative to this would be to pump gas through pipelines to a shore-based facility for liquefaction, before transferring the gas for delivery.
Specifications
In the case of Shell’s facility, engineers have managed to fit every component of an LNG plant into an area roughly one quarter the size of a conventional onshore plant. Even so, Shell's facility will be the largest floating offshore facility ever built: longer than four football fields laid end-to-end. It will measure around 488m long and 74m wide, and when fully ballasted will weigh 600,000 tonnes (roughly six times as much as the USS Nimitz aircraft carrierNimitz class aircraft carrier
The Nimitz-class supercarriers are a class of ten nuclear-powered aircraft carriers in service with the United States Navy. With an overall length of and full-load displacements of over 100,000 long tons, they are the largest capital ships in the world...
).
The specifications make Shell's FLNG facility particularly well-suited for fields with high production rates for reserves starting at 2 Tcuft and beyond – less than a tenth the size of the Groningen gas field
Groningen gas field
The Groningen gas field is a giant natural gas field located near Slochteren in Groningen province in the northeastern part of the Netherlands. Discovered in 1959, it is the largest natural gas field in Europe and the tenth largest in the world.-History:...
off the Netherlands.
Construction
The Shell FLNG facility will be constructed at Samsung's Geoje Island shipyardGeoje
Geoje is a city located in South Gyeongsang province, just off the coast of the port city of Busan, South Korea. Daewoo Shipbuilding & Marine Engineering in Okpo and Samsung Heavy Industries in Gohyeon are both located on Geoje Island. The city also offers a wide range of tourist sights...
in Korea. Some modules may be constructed elsewhere and then transferred to the shipyard for assembly. The facility can remain on station for more than 25 years, and its lifetime can be further extended through overhaul and refurbishment. The hull has a design life of 50 years.
Safety
A unique feature of Shell’s FLNG design is its ability to stay safely moored in harsh weather conditions, including category five cyclonesTropical cyclone scales
Tropical systems are officially ranked on one of several tropical cyclone scales according to their maximum sustained winds and in what oceanic basin they are located...
. Potentially, this could result in more uptime for the facility.
Additionally, Shell designers have optimised safety on the facility by locating storage facilities and process equipment as far from crew accommodation as possible. As a result of this, the accommodation areas of visiting LNG carriers are also at maximum distance from critical safety equipment. Safety gaps have been allowed between modules of process equipment so that gas can disperse quickly in the event of a gas leak.