Ship for transporting gas. Gas Voyage. Container ship CSCL Globe
Supertankers gas carriers transport liquefied natural gas equivalent to the energy of 55 atomic bombs. The liquid from these becomes a means of cooking and heating your home, but creating seaborne gas transportation was extremely difficult, although these ships owe their existence to several amazing ideas. Let's look at them.
Transporting natural gas around the world is big business. Supertankers much larger than the Titanic and designed to transport natural gas anywhere in the world. Everything connected with him is of a gigantic scale, but to realize this, you need to be close to him. How do these ships move huge volumes of gas around the world?
There are huge tanks inside. There is enough space for 34 million liters of liquefied gas, the same volume of water that would be enough for an ordinary family to flush the toilet for 1,200 years. And there are four such tanks on the ship, and the temperature inside each is minus 160 degrees Celsius.
Like oil, natural gas is a fossil fuel that was formed by the decomposition of ancient organisms. It can be transmitted through pipelines, but this is very expensive and not practical when crossing oceans; instead, engineers had to come up with transporting gas on ships and the difficulty was that natural gas ignites at any temperature encountered on Earth. A gas leak can be a serious disaster and fortunately there have never been any major incidents and tanker shipping line operators plan to continue in the same spirit.
supertanker tank
There is a very simple solution to turn gas into liquid. In this state, it is not able to ignite and, moreover, takes up much less space. If the cargo were in gaseous form, the tanker would have to be incredibly huge - ten times longer than any existing tanker or 2500 meters long.
To turn a gas into a liquid, it is cooled to a temperature of minus 162 degrees Celsius, but if it is heated enough, the substance immediately turns into a flammable gas. For this purpose, there is a second line of defense - nitrogen. This is an inert gas, of which there is a lot in the air. Under normal conditions, nitrogen does not react with anything and more importantly it prevents the fuel from combining with oxygen in the presence of any spark. In short, ignition is impossible if there is enough nitrogen around. On supertankers, potentially toxic nitrogen is safely sealed within the insulation of the gas tank. In the event of a leak, the nitrogen prevents the dangerous cargo from reacting with oxygen, and the insulation keeps it in liquid form. Supertankers They are jokingly called the largest freezers in the world, because they are the equivalent of three hundred thousand home freezers, only ten times colder.
The gas is cooled onshore and pumped in liquid form onto a supertanker, but these ultra-low temperatures pose great engineering challenges. You simply cannot use standard steel pipes for this job. Transporting this ultra-cold liquid through a ship's pipelines presented shipbuilders with a new set of problems, the solution to which was found using stainless steel to which a little chromium was added. This metal is capable of making ordinary brittle steel withstand ultra-low temperatures.
Shipbuilders who created supertankers liquefied natural gas transporters have ensured that not only the hulls of these ships are ready to cross rough seas, but that thousands of meters of intricate pipelines, with all their vulnerable bends, connections and valves, are made of a material that will withstand low temperatures - alloy stainless steel.
Transporting liquids on supertankers leads to another problem - how to prevent it from sloshing around. Shipbuilders of such ships had to take care of two types of liquid. When moving in one direction supertanker it carries liquefied natural gas, and on the way back, when the tanks are empty, they carry water as ballast to give the ship stability. One problem in two different forms.
Wind and waves will rock the supertanker and cause the liquid to splash from side to side in the tanks. This movement can increase, increasing the rocking of the ship itself, and lead to catastrophic consequences. This effect is called the influence of the free surface of the liquid. Literally, this is the area available for the free splashing of water. This is indeed the problem leading to . Supertankers have an amazing solution. To reduce the influence of the free surface of liquid gas, tanks are made in the form of a sphere. Thus, there is much less space for liquid to splash while the tank is full or almost empty. The tanks are filled with cargo by 98 percent and set off on long voyages, arriving at the tankers' destination completely, leaving as much fuel as needed for the return journey. Therefore, under normal conditions, containers are either filled to capacity or almost empty.
supertanker systems diagram
Without draft load supertanker has decreased significantly, and to reduce it, water is pumped into the ballast tanks in the ship’s hull directly below the gas tanks. However, space does not allow making these compartments spherical, so to prevent water from splashing in them, another solution is required - cargo separator partitions. These are physical barriers first introduced in the 1980s to prevent oil tankers from capsizing. Bulkheads protect tankers from overkill.
The LNG industry is a very promising growth industry for valve manufacturers around the world, but since LNG valves must meet the most stringent requirements, they represent the highest level of engineering challenges.
What is liquefied natural gas?
Liquefied natural gas, or LNG, is ordinary natural gas liquefied by cooling it to −160 °C. In this state, it is an odorless and colorless liquid, the density of which is half that of water. Liquefied gas is non-toxic, boils at a temperature of −158...−163 °C, consists of 95% methane, and the remaining 5% includes ethane, propane, butane, nitrogen.
- The first is the extraction, preparation and transportation of natural gas through a gas pipeline to a liquefaction plant;
- The second is the processing, liquefaction of natural gas and storage of LNG in the terminal.
- Third - loading LNG into gas tankers and sea transportation to consumers
- Fourth - LNG unloading at the receiving terminal, storage, regasification and delivery to end consumers
Gas liquefaction technologies.
As mentioned above, LNG is produced by compressing and cooling natural gas. In this case, the gas decreases in volume by almost 600 times. This process is complex, multi-stage, and very energy-intensive - liquefaction costs can account for about 25% of the energy contained in the final product. In other words, you need to burn one ton of LNG to get three more.
Seven different natural gas liquefaction technologies have been used around the world at different times. Air Products is currently leading the way in technology for producing large volumes of LNG for export. Its AP-SMR™, AP-C3MR™ and AP-X™ processes account for 82% of the total market. A competitor to these processes is the Optimized Cascade technology developed by ConocoPhillips.
At the same time, small-sized liquefaction plants intended for internal use in industrial enterprises have great development potential. Installations of this type can already be found in Norway, Finland and Russia.
In addition, local LNG production plants can find wide application in China, where today the production of cars powered by LNG is actively developing. The introduction of small-scale units could allow China to scale up its existing LNG vehicle transport network.
Along with stationary systems, floating natural gas liquefaction plants have been actively developing in recent years. Floating plants provide access to gas fields that are inaccessible to infrastructure (pipelines, marine terminals, etc.).
To date, the most ambitious project in this area is the floating LNG platform, which is being built by Shell 25 km away. from the west coast of Australia (the launch of the platform is scheduled for 2016).
Construction of an LNG production plant
Typically, a natural gas liquefaction plant consists of:
- gas pre-treatment and liquefaction installations;
- technological lines for LNG production;
- storage tanks;
- equipment for loading onto tankers;
- additional services to provide the plant with electricity and water for cooling.
Where did it all start?
In 1912, the first experimental plant was built, which, however, was not yet used for commercial purposes. But already in 1941, in Cleveland, USA, large-scale production of liquefied natural gas was established for the first time.
In 1959, the first delivery of liquefied natural gas from the USA to the UK and Japan was carried out. In 1964, a plant was built in Algeria, from where regular tanker transportation began, in particular to France, where the first regasification terminal began operating.
In 1969, long-term supplies began from the USA to Japan, and two years later - from Libya to Spain and Italy. In the 70s, LNG production began in Brunei and Indonesia; in the 80s, Malaysia and Australia entered the LNG market. In the 1990s, Indonesia became one of the main producers and exporters of LNG in the Asia-Pacific region - 22 million tons per year. In 1997, Qatar became one of the LNG exporters.
Consumer properties
Pure LNG does not burn, does not ignite or explode on its own. In an open space at normal temperatures, LNG returns to a gaseous state and quickly mixes with air. When evaporating, natural gas can ignite if it comes into contact with a flame source.
For ignition it is necessary to have a gas concentration in the air of 5% to 15% (volume). If the concentration is less than 5%, then there will not be enough gas to start a fire, and if more than 15%, then there will be too little oxygen in the mixture. To be used, LNG undergoes regasification - evaporation without the presence of air.
LNG is considered a priority or important natural gas import technology by a number of countries, including France, Belgium, Spain, South Korea and the United States. The largest consumer of LNG is Japan, where almost 100% of gas needs are covered by LNG imports.
Motor fuel
Since the 1990s, various projects have emerged for the use of LNG as a motor fuel in water, rail and even road transport, most often using converted gas-diesel engines.
There are already real working examples of the operation of sea and river vessels using LNG. In Russia, serial production of the TEM19-001 diesel locomotive running on LNG is being established. In the United States and Europe, projects are emerging to convert road freight transport to LNG. And there is even a project to develop a rocket engine that will use LNG + liquid oxygen as fuel.
Engines running on LNG
One of the main challenges associated with the development of the LNG market for the transport sector is to increase the number of vehicles and ships using LNG as fuel. The main technical issues in this area are related to the development and improvement of various types of engines running on LNG.
Currently, three technologies of LNG engines used for marine vessels can be distinguished: 1) spark ignition engine with a lean fuel-air mixture; 2) dual-fuel engine with ignition diesel fuel and low-pressure working gas; 3) dual fuel engine with ignition diesel fuel and high pressure working gas.
Spark ignition engines only run on natural gas, while dual-fuel diesel-gas engines can run on diesel, CNG and heavy fuel oil. Today there are three main manufacturers in this market: Wärtsila, Rolls-Royce and Mitsubishi Heavy Industries.
In many cases, existing diesel engines can be converted to dual-fuel diesel/gas engines. Such conversion of existing engines may be an economically feasible solution for converting marine vessels to LNG.
Speaking about the development of engines for the automotive sector, it is worth noting the American company Cummins Westport, which has developed a line of LNG engines designed for heavy trucks. In Europe, Volvo has launched a new 13-liter dual-fuel engine running on diesel and CNG.
Notable CNG engine innovations include the Compact Compression Ignition (CCI) Engine developed by Motiv Engines. This engine has a number of advantages, the main one of which is a significantly higher thermal efficiency than existing analogues.
According to the company, the thermal efficiency of the developed engine can reach 50%, while the thermal efficiency of traditional gas engines is about 27%. (Using US fuel prices as an example, a truck with a diesel engine costs $0.17 per horsepower/hour to operate, a conventional CNG engine costs $0.14, and a CCEI engine costs $0.07).
It's also worth noting that, as with marine applications, many diesel truck engines can be converted to dual-fuel diesel-LNG engines.
LNG producing countries
According to 2009 data, the main countries producing liquefied natural gas were distributed in the market as follows:
The first place was occupied by Qatar (49.4 billion m³); followed by Malaysia (29.5 billion m³); Indonesia (26.0 billion m³); Australia (24.2 billion m³); Algeria (20.9 billion m³). Last on this list was Trinidad and Tobago (19.7 billion m³).
The main importers of LNG in 2009 were: Japan (85.9 billion m³); Republic of Korea (34.3 billion m³); Spain (27.0 billion m³); France (13.1 billion m³); USA (12.8 billion m³); India (12.6 billion m³).
Russia is just beginning to enter the LNG market. Currently, there is only one LNG plant operating in the Russian Federation, Sakhalin-2 (launched in 2009, the controlling stake belongs to Gazprom, Shell has 27.5%, Japanese Mitsui and Mitsubishi - 12.5% and 10%, respectively). At the end of 2015, production amounted to 10.8 million tons, exceeding the design capacity by 1.2 million tons. However, due to falling prices on the world market, revenues from LNG exports in dollar terms decreased by 13.3% year-on-year to $4.5 billion.
There are no prerequisites for an improvement in the situation on the gas market: prices will continue to fall. By 2020, five LNG export terminals with a total capacity of 57.8 million tons will be put into operation in the United States. A price war will begin on the European gas market.
The second major player in the Russian LNG market is Novatek. Novatek-Yurkharovneftegaz (a subsidiary of Novatek) won the auction for the right to use the Nyakhartinsky site in the Yamal-Nenets Autonomous Okrug.
The company needs the Nyakhartinsky site for the development of the Arctic LNG project (Novatek’s second project focused on the export of liquefied natural gas, the first is Yamal LNG): it is located in close proximity to the Yurkharovskoye field, which is being developed by Novatek-Yurkharovneftegaz. The area of the plot is about 3 thousand square meters. kilometers. As of January 1, 2016, its reserves were estimated at 8.9 million tons of oil and 104.2 billion cubic meters of gas.
In March, the company began preliminary negotiations with potential partners about the sale of LNG. The company's management considers Thailand to be the most promising market.
Transportation of liquefied gas
Delivery of liquefied gas to the consumer is a very complex and labor-intensive process. After liquefying the gas at plants, LNG enters storage facilities. Further transportation is carried out using special vessels - gas carriers equipped with cryocankers. It is also possible to use special vehicles. Gas from gas carriers arrives at regasification points and is then transported via pipelines .
Tankers are gas carriers.
A gas tanker, or methane carrier, is a purpose-built vessel for transporting LNG in tanks. In addition to gas tanks, such vessels are equipped with refrigeration units for cooling LNG.
The largest manufacturers of vessels for transporting liquefied natural gas are Japanese and Korean shipyards: Mitsui, Daewoo, Hyundai, Mitsubishi, Samsung, Kawasaki. It was at Korean shipyards that more than two-thirds of the world's gas carriers were built. Modern tankers of the Q-Flex and Q-Max series capable of transporting up to 210-266 thousand m3 of LNG.
The first information about the transportation of liquefied gases by sea dates back to 1929-1931, when the Shell company temporarily converted the tanker Megara into a vessel for transporting liquefied gas and built the vessel Agnita in Holland with a deadweight of 4.5 thousand tons, intended for simultaneous transportation oil, liquefied gas and sulfuric acid. Shell tankers were named after seashells- they were traded by the father of the company founder Marcus Samuel
Maritime transportation of liquefied gases became widespread only after the end of the Second World War. Initially, ships converted from tankers or dry cargo ships were used for transportation. The accumulated experience in the design, construction and operation of the first gas carriers allowed us to move on to the search for the most profitable methods of transporting these gases.
Modern standard LNG tanker (methane carrier) can transport 145-155 thousand m3 of liquefied gas, from which about 89-95 million m3 of natural gas can be obtained as a result of regasification. Due to the fact that methane carriers are extremely capital intensive, their downtime is unacceptable. They are fast, the speed of a sea vessel transporting liquefied natural gas reaches 18-20 knots, compared to 14 knots for a standard oil tanker.
In addition, LNG loading and unloading operations do not take much time (on average 12-18 hours). In the event of an accident, LNG tankers have a double-hull structure specifically designed to prevent leaks and ruptures. The cargo (LNG) is transported at atmospheric pressure and a temperature of -162°C in special thermally insulated tanks inside the internal hull of the gas carrier vessel.
A cargo storage system consists of a primary container or reservoir for storing liquid, a layer of insulation, a secondary containment designed to prevent leakage, and another layer of insulation. If the primary tank is damaged, the secondary casing will prevent leakage. All surfaces in contact with LNG are made of materials resistant to extremely low temperatures.
Therefore, the materials typically used are stainless steel, aluminum or Invar (an iron-based alloy with a nickel content of 36%).
A distinctive feature of Moss-type gas carriers, which currently make up 41% of the world's methane carrier fleet, are self-supporting spherical tanks, which are usually made of aluminum and attached to the ship's hull using a cuff along the equator of the tank.
57% of gas tankers use triple membrane tank systems (GazTransport system, Technigaz system and CS1 system). Membrane designs use a much thinner membrane that is supported by the walls of the housing. The GazTransport system includes primary and secondary membranes in the form of flat Invar panels, while in the Technigaz system the primary membrane is made of corrugated stainless steel.
In the CS1 system, invar panels from the GazTransport system, which act as the primary membrane, are combined with three-layer Technigaz membranes (sheet aluminum placed between two layers of fiberglass) as secondary insulation.
Unlike LPG (liquefied petroleum gas) ships, gas carriers are not equipped with a deck liquefaction unit, and their engines run on fluidized bed gas. Given that part of the cargo (liquefied natural gas) supplements the fuel oil, LNG tankers do not arrive at their destination port with the same amount of LNG that was loaded on them at the liquefaction plant.
The maximum permissible value of the evaporation rate in a fluidized bed is about 0.15% of the cargo volume per day. Steam turbines are mainly used as a propulsion system on methane carriers. Despite their low fuel efficiency, steam turbines can be easily adapted to run on fluidized bed gas.
Another unique feature of LNG tankers is that they typically retain a small portion of their cargo to cool the tanks to the required temperature before loading.
The next generation of LNG tankers is characterized by new features. Despite the higher cargo capacity (200-250 thousand m3), the vessels have the same draft - today, for a ship with a cargo capacity of 140 thousand m3, a draft of 12 meters is typical due to the restrictions applied in the Suez Canal and at most LNG terminals.
However, their body will be wider and longer. The power of steam turbines will not allow these larger vessels to develop sufficient speed, so they will use a dual-fuel gas-oil diesel engine developed in the 1980s. In addition, many LNG carriers currently on order will be equipped with an onboard regasification unit.
Gas evaporation on methane carriers of this type will be controlled in the same way as on ships carrying liquefied petroleum gas (LPG), which will avoid cargo losses during the voyage.
Market for maritime transportation of liquefied gas
LNG transportation involves its sea transportation from gas liquefaction plants to regasification terminals. As of November 2007, there were 247 LNG tankers in the world with a cargo capacity of over 30.8 million m3. The boom in LNG trade has ensured that all vessels are now fully occupied, compared to the mid-1980s when there were 22 vessels idled.
In addition, about 100 vessels should be put into operation by the end of the decade. The average age of the world's LNG fleet is about seven years. 110 vessels are four years or less in age, while 35 vessels range in age from five to nine years.
About 70 tankers have been in operation for 20 years or more. However, they still have a long useful life ahead of them, as LNG tankers typically have a service life of 40 years due to their corrosion-resistant characteristics. These include up to 23 tankers (small, older vessels serving the Mediterranean LNG trade) that are due to be replaced or significantly upgraded over the next three years.
Of the 247 tankers currently in operation, more than 120 serve Japan, South Korea and Chinese Taipei, 80 serve Europe, and the remaining vessels serve North America. The last few years have seen phenomenal growth in the number of vessels serving trade in Europe and North America, while the Far East has seen only a slight increase due to stagnant demand in Japan.
Regasification of liquefied natural gas
After natural gas is delivered to its destination, the process of regasification occurs, that is, its transformation from a liquid state back into a gaseous state.
The tanker delivers LNG to special regasification terminals, which consist of a berth, a discharge rack, storage tanks, an evaporation system, installations for processing evaporation gases from tanks and a metering unit.
Upon arrival at the terminal, LNG is pumped from tankers into storage tanks in liquefied form, then the LNG is converted into a gaseous state as needed. Conversion into gas occurs in an evaporation system using heat.
In terms of capacity of LNG terminals, as well as in the volume of LNG imports, Japan is the leader - 246 billion cubic meters per year according to 2010 data. In second place is the United States, more than 180 billion cubic meters per year (2010 data).
Thus, the main task in the development of receiving terminals is primarily the construction of new units in various countries. Today, 62% of receiving capacity comes from Japan, the USA and South Korea. Together with the UK and Spain, the receiving capacity of the first 5 countries is 74%. The remaining 26% is distributed among 23 countries. Consequently, the construction of new terminals will open up new and increase existing markets for LNG.
Prospects for the development of LNG markets in the world
Why is the liquefied gas industry developing at an ever-increasing pace in the world? First, in some geographic regions, such as Asia, transporting gas by tanker is more profitable. At a distance of more than 2,500 kilometers, liquefied gas can already compete in price with pipeline gas. Compared to pipelines, LNG also has the advantages of modular expansion of supplies, and also eliminates border crossing problems in some cases.
However, there are also pitfalls. The LNG industry occupies its niche in remote regions that do not have their own gas reserves. Most LNG volumes are contracted at the design and production stage. The industry is dominated by a system of long-term contracts (from 20 to 25 years), which requires developed and complex coordination of production participants, exporters, importers and carriers. All this is seen by some analysts as a possible barrier to the growth of liquefied gas trade.
Overall, in order for liquefied gas to become a more affordable source of energy, the cost of LNG supplies must compete successfully in price with alternative fuel sources. Today the situation is the opposite, which does not negate the development of this market in the future.
Continuation:
- Part 3: Butterfly valves for cryogenic temperatures
When preparing the material, data from the following sites was used:
- lngas.ru/transportation-lng/istoriya-razvitiya-gazovozov.html
- lngas.ru/transportation-lng/morskie-perevozki-spg.html
- innodigest.com/liquefied-natural-gas-LNG-as-alta/?lang=ru
- expert.ru/ural/2016/16/novyij-uchastok-dlya-spg/
The efficiency of maritime transport of Russian LNG can be significantly increased through the use of the latest technological developments.
Russia's entry into the global LNG market coincided with the advent of improved technologies for sea transportation of liquefied gas. The first gas carriers and new generation receiving terminals, which can significantly reduce the cost of LNG transportation, have entered service. Gazprom has a unique opportunity to create its own liquefied gas transportation system using the latest achievements in this area and gain advantages over competitors who will require a long time for technical re-equipment.
Take into account advanced trends
The launch of Russia's first LNG plant on Sakhalin, preparations for the construction of an even larger production facility based on the Shtokman field and the development of a project for an LNG plant in Yamal include sea transportation of liquefied gas in the list of technologies critical for our country. This makes it relevant to analyze the latest trends in the development of LNG maritime transport, so that not only existing but also promising technologies are incorporated into the development of domestic projects.
Among the projects implemented in recent years, the following areas can be highlighted in increasing the efficiency of LNG maritime transportation:
1. Increasing the capacity of LNG tankers;
2. Increasing the share of ships with membrane-type tanks;
3. Use of diesel engines as a marine power plant;
4. Emergence of deep-sea LNG terminals.
Increasing the capacity of LNG tankers
For more than 30 years, the maximum capacity of LNG tankers did not exceed 140-145 thousand cubic meters. m, which is equivalent to a carrying capacity of 60 thousand tons of LNG. In December 2008, the LNG tanker Mozah (Fig. 1), Q-Max type, was put into operation, the lead in a series of 14 vessels with a capacity of 266 thousand cubic meters. m. Compared to the largest existing ships, its capacity is 80% greater. Simultaneously with the construction of Q-Max type tankers, orders were placed at South Korean shipyards for the construction of the 31st Q-Flex type vessel, with a capacity of 210-216 thousand cubic meters. m, which is almost 50% more than existing vessels. 
According to information from Samsung Heavy Industries, at whose shipyard Mozah was built, in the foreseeable future the capacity of LNG tankers will not exceed 300 thousand cubic meters. m, which is due to the technological difficulties of their construction. However, an increase in the capacity of vessels of the Q-Max and Q-Flex types was achieved only by increasing the length and width of the hull, while maintaining the standard draft of 12 meters for large LNG tankers, which is determined by the depths at existing terminals. In the next decade, it will be possible to operate gas carriers with a draft of 20-25 m, which will increase the capacity to 350 thousand cubic meters. m and improve driving performance by improving the hydrodynamic contours of the hull. This will also reduce construction costs, since larger tankers can be built without increasing the size of docks and slipways.
When organizing LNG exports from Russia, it is necessary to evaluate the possibility of using vessels of increased capacity. Construction of ships with a capacity of 250-350 thousand cubic meters. m will reduce the unit costs of transporting Russian gas and gain a competitive advantage in foreign markets.
U increasing the share of membrane tankers
Currently, two main types of cargo tanks (tanks in which LNG is transported) are used on LNG tankers: inset spherical (Kvaerner-Moss system) and built-in prismatic membrane (Gas Transport - Technigas system). Insertable spherical tanks have a thickness of 30-70 mm (equatorial belt - 200 mm) and are made of aluminum alloys. They are installed (“nested”) into the tanker hull without connection to the hull structures, resting on the bottom of the ship through special support cylinders. Prismatic membrane tanks have a shape close to rectangular. The membranes are made of a thin (0.5-1.2 mm) sheet of alloy steel or Invar (iron-nickel alloy) and are only a shell into which liquefied gas is loaded. All static and dynamic loads are transferred through the thermal insulation layer to the ship’s hull. Safety requires the presence of a main and secondary membrane, ensuring the safety of LNG in case of damage to the main one, as well as a double layer of thermal insulation - between the membranes and between the secondary membrane and the ship's hull.
With a tanker capacity of up to 130 thousand cubic meters. meters, the use of spherical tanks is more effective than membrane tanks, in the range of 130-165 thousand cubic meters. m, their technical and economic characteristics are approximately equal; with a further increase in capacity, the use of membrane tanks becomes preferable.
Membrane tanks are approximately half the weight of spherical tanks; their shape allows the ship's hull space to be used with maximum efficiency. Due to this, membrane tankers have smaller dimensions and displacement per unit of carrying capacity. They are cheaper to build and more economical to operate, in particular due to lower port charges and fees for passage through the Suez and Panama Canals.
Currently, there are approximately equal numbers of tankers with spherical and membrane tanks. Due to the increase in capacity, in the near future membrane tankers will predominate; their share of vessels under construction and planned for construction is about 80%.
In relation to Russian conditions, an important feature of the vessels is the ability to operate in Arctic seas. According to experts, compression and shock loads that occur when crossing ice fields are dangerous for membrane tankers, which makes their operation in difficult ice conditions risky. Manufacturers of membrane tankers claim the opposite, citing calculations that membranes, especially corrugated ones, have high deformational flexibility, which prevents their rupture even with significant damage to hull structures. However, it cannot be guaranteed that the membrane will not be pierced by elements of these same structures. In addition, a ship with deformed tanks, even if they remain sealed, cannot be allowed for further operation, and replacing part of the membranes requires lengthy and expensive repairs. Therefore, designs for ice LNG tankers involve the use of inserted spherical tanks, the lower part of which is located at a considerable distance from the waterline and the underwater part of the side.
It is necessary to consider the possibility of building membrane tankers for exporting LNG from the Kola Peninsula (Teriberka). For the LNG plant in Yamal, apparently, only ships with spherical tanks can be used.
Application of diesel engines and on-board gas liquefaction units
A feature of new project ships is the use of diesel and diesel-electric units as main engines, which are more compact and economical than steam turbines. This made it possible to significantly reduce fuel consumption and reduce the size of the engine room. Until recently, LNG tankers were equipped exclusively with steam turbine units capable of utilizing natural gas evaporating from the tanks. By burning evaporated gas in steam boilers, turbine LNG tankers cover up to 70% of fuel demand.
On many vessels, including the Q-Max and Q-Flex types, the problem of LNG evaporation is solved by installing a gas liquefaction plant on board. The evaporated gas is liquefied again and returned to the tanks. An on-board installation for gas re-liquefaction significantly increases the cost of an LNG tanker, but on lines of considerable length its use is considered justified.
In the future, the problem can be solved by reducing evaporation. If for ships built in the 1980s, losses due to LNG evaporation amounted to 0.2-0.35% of the cargo volume per day, then on modern ships this figure is approximately half as much - 0.1-0.15%. It can be expected that in the next decade the level of losses due to evaporation will be reduced by another half.
It can be assumed that in conditions of ice navigation of an LNG tanker equipped with a diesel engine, the presence of an on-board gas liquefaction unit is necessary, even with a reduced level of volatility. When sailing in ice conditions, the full power of the propulsion system will be used only for part of the route, and in this case the volume of gas evaporated from the tanks will exceed the ability of the engines to utilize it.
New LNG tankers must be equipped with diesel engines. The presence of an on-board gas liquefaction unit will most likely be advisable both when operating on the longest routes, for example, to the east coast of the United States, and when operating shuttle flights from the Yamal Peninsula.
Emergence of deep-sea LNG terminals
The world's first offshore LNG reception and regassing terminal, Gulf Gateway, came into operation in 2005, also becoming the first terminal built in the United States in the last 20 years. Offshore terminals are located on floating structures or artificial islands, at a considerable distance from the coastline, often outside the territorial waters (the so-called offshore terminals). This makes it possible to reduce construction time, as well as ensure that the terminals are located at a safe distance from onshore facilities. It can be expected that the creation of offshore terminals in the next decade will significantly expand North America's LNG import capabilities. There are five terminals in the USA and there are construction projects for about 40 more, 1/3 of which are road terminals. 
Offshore terminals can accommodate vessels with significant draft. Deep-water terminals, for example, Gulf Gateway, have no restrictions on vessel draft at all; other projects provide for a draft of up to 21-25 m. As an example, the BroadWater terminal project can be cited. The terminal is proposed to be located 150 km northeast of New York, in the Long Island Sound, protected from waves. The terminal will consist of a small frame-pile platform installed at a depth of 27 meters and a floating storage and regasification unit (FSRU), 370 meters long and 61 meters wide, which will simultaneously serve as a berth for LNG tankers with draft up to 25 meters (Fig. 2 and 3). Projects of a number of coastal terminals also provide for the processing of vessels with increased draft and a capacity of 250-350 thousand cubic meters. m. 
Although not all new terminal projects will be implemented, in the foreseeable future the majority of LNG will be imported into America through terminals capable of handling LNG tankers with a draft of more than 20 m. In the longer term, similar terminals will play a prominent role in Western Europe and Japan.
The construction of shipping terminals in Teriberka capable of receiving vessels with a draft of up to 25 m will allow us to gain a competitive advantage when exporting LNG to North America, and in the future to Europe. If the LNG plant project is implemented in Yamal, the shallow waters of the Kara Sea off the coast of the peninsula preclude the use of vessels with a draft of more than 10-12 meters.
conclusions
The immediate order of 45 ultra-large LNG tankers of the Q-Max and Q-Flex types changed the prevailing ideas about the efficiency of LNG sea transportation. According to the customer of these vessels, Qatar Gas Transport Company, an increase in the unit capacity of tankers, as well as a number of technical improvements, will reduce LNG transportation costs by 40%. The cost of building ships, per unit of carrying capacity, is 25% lower. These vessels have not yet implemented the full range of promising technical solutions, in particular increased draft and improved thermal insulation of tanks.
What will the “ideal” LNG tanker of the near future be like? This will be a vessel with a capacity of 250-350 thousand cubic meters. m of LNG and a draft of more than 20 m. Membrane tanks with improved thermal insulation will reduce evaporation to 0.05-0.08% of the volume of transported LNG per day, and an on-board gas liquefaction unit will almost completely eliminate cargo losses. The diesel power plant will provide a speed of about 20 knots (37 km/h). The construction of even larger ships, equipped with a full range of advanced technical solutions, will reduce the cost of LNG transportation by half compared to the existing level, and the cost of building ships by 1/3.
Reducing the cost of LNG maritime transport will have the following consequences:
1. LNG will receive additional advantages over “pipe” gas. The distance at which LNG is more effective than a pipeline will be reduced by another 30-40%, from 2500-3000 km to 1500-2000 km, and for subsea pipelines - to 750-1000 km.
2. The distances for sea transportation of LNG will increase, and logistics schemes will become more complex and varied.
3. Consumers will have the opportunity to diversify sources of LNG, which will increase competition in this market.
This will be a significant step towards the formation of a single global gas market, instead of the two existing local LNG markets - Asia-Pacific and Atlantic. An additional impetus for this will be given by the modernization of the Panama Canal, which is planned to be completed by 2014-2015. Increasing the size of the lock chambers in the canal from 305x33.5 m to 420x60 m will allow the largest LNG tankers to move freely between the two oceans.
Increasing competition requires Russia to make maximum use of the latest technologies. The cost of a mistake in this matter will be extremely high. LNG tankers, due to their high cost, have been in operation for 40 years or more. By incorporating obsolete technical solutions into transport schemes, Gazprom will undermine its position in the competitive struggle in the LNG market for decades to come. On the contrary, by providing transportation between the deep-water shipping terminal in Teriberka and offshore terminals in the United States using large-tonnage vessels with increased draft, the Russian company will surpass its competitors from the Persian Gulf in terms of delivery efficiency.
The LNG plant in Yamal will not be able to use the most efficient LNG tankers due to the shallow water area and ice conditions. The best solution will probably be a feeder transportation system, with LNG transshipment through Teriberka.
The prospects for the widespread use of sea transportation for gas exports puts on the agenda the issue of organizing the construction of LNG tankers in Russia, or at least the participation of Russian enterprises in their construction. Currently, none of the domestic shipbuilding enterprises has designs, technologies and experience in constructing such ships. Moreover, there is not a single shipyard in Russia capable of building large-tonnage ships. A breakthrough in this direction could be the acquisition by a group of Russian investors of part of the assets of the Aker Yards company, which has technologies for the construction of LNG tankers, including ice-class ones, as well as shipyards in Germany and Ukraine capable of building large-tonnage vessels.
|
Grand Elena |
Al Gattara (Q-Flex type) |
Mozah (Q-Max type) |
|
|
Year of construction |
|||
|
Capacity (gross register tons) |
|||
|
Width (m) |
|||
|
Side height (m) |
|||
|
Draft (m) |
|||
|
Tank volume (cubic m) |
|||
|
Type of tanks |
spherical |
membrane |
membrane |
|
Number of tanks |
|||
|
Propulsion system |
steam turbine |
diesel |
Vessels over 300 meters long to transport liquefied natural gas will be able to cut through ice up to 2 meters thick. Until factories are built on the Moon or Mars, it will be difficult to find a less hospitable industrial enterprise than Yamal LNG is a $27 billion natural gas processing plant located in Russia 600 kilometers north of the Arctic Circle. In winter, when the sun does not appear for more than two months, temperatures here reach -25 on land and -50 in the blinding fog of the sea. But this desert contains a lot of fossil fuels, about 13 trillion cubic meters, which is equivalent to about 8 billion barrels of oil.
Conventional tankers are still unable to break through the Arctic ice of the Kara Sea, despite its melting due to global warming. Using small icebreaking vessels as tanker escorts remains extremely costly and labor intensive. That's why an international collaboration of ship designers, engineers, builders and owners plan to spend $320 million to create at least 15 300-meter tankers capable of breaking through ice on their own. The ship will have to perform its tasks in extremely harsh conditions,” Bloomberg said Mika Hovilainen, icebreaker specialist in Aker Arctic Technology Inc., a Helsinki-based company engaged in ship design. “Its systems must operate correctly over a very wide temperature range. These tankers are the largest gas carriers ever built, measuring 50 meters in width. When fully loaded, each can carry just over 1 million barrels of oil. All 15 will be able to transport 16.5 million tons of liquefied natural gas per year - enough to supply half of South Korea's annual consumption and close to the capabilities of Yamal LNG. They will travel west to Europe in winter and east to Asia in summer, passing through two meters of ice. Icebreakers do not break ice, as many people think. Ship hulls are designed to bend the edge of the ice cap and distribute the weight evenly across its entire surface. When moving in ice, the tanker uses its stern section, which is specially adapted for grinding thick ice.
Building such ships is part of a much larger game. “This is perhaps the biggest step forward in the development of the Arctic,” said the Russian President Vladimir Putin in December at the launch of the first gas tanker at the Yamal LNG plant. Talking about the 18th century poet's prediction Mikhail Lomonosov On the expansion of Russia and Siberia, Putin emphasized: “Now we can safely say that Russia will expand through the Arctic in this and the next century. The largest mineral reserves are located here. This is the site of the future transport artery - the Northern Sea Route, which, I am sure, will become very effective.”
To avoid excessive work of generators, a special thruster produced by the Swedish-Swiss engineering giant ABB Ltd., disconnects the engines from the propellers. That is, the propellers can spin faster or slower without causing the engine to howl, says Peter Terwiesch, President of ABB's Industrial Automation Division. Separating the engine and propeller workload improves fuel efficiency by 20 percent, he said. As a bonus, “you get much better maneuverability,” Terwiesch says. Operating a supertanker has never been so easy. Although liquefied natural gas tankers have been sailing for about half a century, ferrying fuel from the arid Middle East, until the last decade there was no need for special "ice" models, when the Norwegian Snohvit and Russian project "Sakhalin-2" for the first time began gas production in colder climates. Yamal LNG Port, Sabetta, was designed and built in tandem with the ships that would serve it. The oil and gas industry is rightfully considered one of the most high-tech industries in the world. Equipment used for oil and gas production numbers hundreds of thousands of items, and includes a variety of devices - from elements shut-off valves, weighing several kilograms, to gigantic structures - drilling platforms and tankers, of gigantic size, and costing many billions of dollars. In this article we will look at the offshore giants of the oil and gas industry. Gas tankers of Q-max typeThe largest gas tankers in the history of mankind can rightfully be called tankers of the Q-max type. "Q" here stands for Qatar, and "max"- maximum. A whole family of these floating giants was created specifically for the delivery of liquefied gas from Qatar by sea. Ships of this type began to be built in 2005 at the company's shipyards Samsung Heavy Industries- shipbuilding division of Samsung. The first ship was launched in November 2007. He was named "Moza", in honor of the wife of Sheikh Moza bint Nasser al-Misned. In January 2009, having loaded 266,000 cubic meters of LNG in the port of Bilbao, a vessel of this type crossed the Suez Canal for the first time. Q-max type gas carriers are operated by the company STASCo, but are owned by the Qatar Gas Transmission Company (Nakilat), and are chartered primarily by Qatari LNG producing companies. In total, contracts for the construction of 14 such vessels have been signed. The dimensions of such a vessel are 345 meters (1,132 feet) long and 53.8 meters (177 feet) wide. The ship is 34.7 m (114 ft) tall and has a draft of about 12 meters (39 ft). At the same time, the vessel can accommodate a maximum volume of LNG equal to 266,000 cubic meters. m (9,400,000 cubic meters). Here are photographs of the largest ships in this series:
Tanker "Moza"- the first ship in this series. Named after the wife of Sheikh Moza bint Nasser al-Misned. The naming ceremony took place on July 11, 2008 at the shipyard Samsung Heavy Industries in South Korea.
tanker« BU Samra»
Tanker« Mekaines» Pipe-laying vessel “Pioneering spirit”In June 2010, a Swiss company Allseas Marine Contractors entered into a contract for the construction of a vessel designed to transport drilling platforms and lay pipelines along the bottom of the sea. The ship named "Pieter Schelte", but later renamed , was built at the company's shipyard DSME (Daewoo Shipbuilding & Marine Engineering) and in November 2014 departed from South Korea to Europe. The vessel was supposed to be used for laying pipes South Stream in the Black Sea.
The ship is 382 m long and 124 m wide. Let us remind you that the height of the Empire State Building in the USA is 381 m (up to the roof). The side height is 30 m. The vessel is also unique in that its equipment allows laying pipelines at record depths - up to 3500 m.
in the process of completion afloat, July 2013
at the Daewoo shipyard in Geoje, March 2014
in the final stage of completion, July 2014 Comparative sizes (upper deck area) of giant ships, from top to bottom:
Photo source - ocean-media.su Floating liquefied natural gas plant "Prelude"The following giant has comparable dimensions to the floating pipe layer - "Prelude FLNG"(from English - “floating plant for the production of liquefied natural gas “ Prelude"") - the world's first plant for the production liquefied natural gas (LNG) placed on a floating base and intended for the production, treatment, liquefaction of natural gas, storage and shipment of LNG at sea. To date "Prelude" is the largest floating object on Earth. The closest ship in size until 2010 was an oil supertanker "Knock Nevis" 458 meters long and 69 meters wide. In 2010, it was cut into scrap metal, and the laurels of the largest floating object went to the pipelayer "Pieter Schelte", later renamed to In contrast, the platform length "Prelude" 106 meters less. But it is larger in tonnage (403,342 tons), width (124 m) and displacement (900,000 tons).
Besides "Prelude" is not a ship in the exact sense of the word, because does not have engines, having on board only a few water pumps used for maneuvering The decision to build a plant "Prelude" was taken Royal Dutch Shell May 20, 2011, and construction was completed in 2013. According to the project, the floating structure will produce 5.3 million tons of liquid hydrocarbons per year: 3.6 million tons of LNG, 1.3 million tons of condensate and 0.4 million tons of LPG. The weight of the structure is 260 thousand tons. Displacement when fully loaded is 600,000 tons, which is 6 times more than the displacement of the largest aircraft carrier.
The floating plant will be located off the coast of Australia. This unusual decision to locate an LNG plant at sea was caused by the position of the Australian government. It allowed gas production on the shelf, but categorically refused to locate a plant on the shores of the continent, fearing that such proximity would adversely affect the development of tourism. Related posts: |
