Water Treatment


First FLNG facility in the world: the Italian contribution


Artes Ingegneria will contribute with two water treatment plants for the Shell project - Prelude, the first FLNG vessel operating in the Australian's coast from 2016


In the next twenty-five years, demand for energy in the world will grow even further. The increase of the demand for natural gas is supported by the liberalization of some markets, newly found reserves worldwide, the stop to nuclear decided by many countries after Fukushima, and the lower exploitation costs and price than oil. The new natural gas reserves to be exploited are mainly "unconventional" (shale gas) or in offshore fields off the coast. In the second case the use of traditional structures would be technically complex and very expensive, compared to the time of exploitation of the reservoir. The situation has prompted the major Oil&Gas companies in developing LNG plants installed on board of ships, known as Floating Liquefied Natural Gas (FLNG) - in which the extracted gas is treated and directly liquefied and transferred to ocean-going carriers, which will load the LNG as well as other liquid by-products (condensate and LPG) and deliver them to the market.


Conventional LNG Supply Chain


To reduce the assembly time of the plants inside the hull of the ship, the packages will be supplied fully modularized. A major challenge therefore consists in the mechanical design of the structures (size: 15m x 10m x 7m) that will support the weight of the equipments and ensure stability both during lifting and fitting, with an estimated weight of 90 tons, and under operating conditions, with an estimated weight of 150 tons able to withstand multidirectional accelerations. The engineering of Artes has developed specific construction solutions to be able to respect the process guarantees required by the customer even in the presence of significant wave motion that could alterate the regular flows distribution inside the vessels irreparably compromizing the packages performances.


The condensate polishing unit produces 71 m/h of deoiled water through three granular activated carbon filters sized at 100% of capacity; two of them work in series while the other one is on stand-by, according to the "merry-go-round" scheme. An concentration of less than 0.2 mg/l of oils and residual hydrocarbons is guaranteed. The demineralization system that treats the mixture of


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continuous production of 235 m/h of demineralized water, thanks to the presence of three mixed-bed ion exchangers, containing strong cationic and anionic resin, each designed to treat 50% of the total flow rate. Two exchangers work in parallel, while the third one is on stand-by, ready to replace the first one that goes into regeneration. This process guarantees a specific conductivity of the demineralized water of less than 0.2 mS/cm.


recovered condensate and desalinated water ensures a 3


Location Depth


FLNG Supply Chain


FLNG facility production facility


Storage


Workers Weight


The first FLNG facility in the world, owned by Shell and developed by the consortium Technip-France & Samsung Heavy Industries (Korea), will be destinated to satisfy the Asian market and would be operational by 2016, for 25 years. It will be the largest offshore facility in the world, for if its total length (top view) is compared with the height of the commonly known skyscrapers, it would be as high as the Taipei Tower 101, and more than half of the Burj Khalifa in Dubai.


It represents a major engineering project of a high design complexity and very innovative application, the first of its kind to enter the operational phase. The Italian company Artes Ingegneria is extremely proud to provide its contribution: design, construction and supply of two water treatment systems to feed the steam generators. The system consist of a condensate treatment unit that removes traces of hydrocarbons present in the condensed steam to be recovered and a demineralization unit which produces ultrapure deionized water (right). The mechanical and process design have been influenced by the particularly severe conditions of the installation site: a floating vessel that will operate in an area subject to cyclonic events. Thus, the materials selection has to be compatible with the severe conditions of process related to the use of strong acids and bases and with the high humidity and salinity of the environment.


Browse Basin, 200 kilometres off Australia’s -north west coast. ~250 mtrs.


3.6 mtpa of LNG, 1.3 mtpa of condensate and 0.4 mtpa of LPG


Below the deck and with a capacity up to 220,000 m of LNG, 90,000 m of LPG, and 3


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126,000 m of condensate. The total storage capacit y is equivalent to around 175 Olympic swimming pools.


>600 engineers have spent over 1.6 million hours working on the facility’s design options


600,000 ton - roughly six times as much as the largest aircraft carrier. Some 260,000 ton of that weight will consist of steel - around 26 times more than the quantity used to build the Eiffel Tower


Process Condensate


Condensate Polishing Unit


In this FNLG vessel-operating plant built by BONO Artes a condensate treatment unit removes traces of hydrocarbons (present in the condensed steam to be recovered) and a demineralization unit produces ultrapure deionized water


The first unit of Shell FLNG will be followed in the upcoming years by other similar projects for extraction and liquefaction of natural gas in place, especially in Asia-Pacific: always off the coast of northern Western Australia, south of Papua New Guinea and Malaysia. Other projects are related to Guinea Gulf (Africa), Venezuela and Brazil where Petrobras has just begun the construction of a FLNG facility to be dedicated to the exploitation of the deposit of Santos starting from 2017.


Demineralization Unit


Steam Generator


Turbine


Turbine Condensate


Desalinated water 7


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