As the Nord Stream 1 and 2 gas pipelines are affected by mysterious leaks, Le Figaro takes stock of the operation of these pipelines at the heart of the news.
While mysterious leaks affect the Nord Stream 1 and 2 gas pipelines, supposed to allow the sending of Russian gas to Europe, Le Figaro takes stock of how these big pipes work.
The gas pipeline is a large steel pipeline used to transport natural gas, in gaseous form, under pressure over long distances, up to 3000 kilometers. Most often, the pipe is buried in the ground, one meter deep, but it can be installed in the open air or under water. “ In France, almost the entire gas pipeline network is buried. This avoids external aggressions and does not damage the landscape. », explains Ludovic Leroy of IFP Energies nouvelles (IFPEN).
In concrete terms, the gas is introduced into the pipeline from the storage areas or the field processing sites. It then circulates under a pressure varying between 80 and 200 bars and at a speed of more than 30 kilometers per hour.
Approximately every 300 kilometres, depending on the networks, the gas is pushed through compressor stations which increase its pressure to allow it to move forward in its progression. These stations are themselves powered by an electric motor or a gas turbine.
Leaks more difficult to manage underwater
The gas then travels to delivery stations, providing gas metering, filtering and even heating functions. Once this stage is over, the gas is finally delivered to large industrialists or to the distribution networks. “ The hose is thinner on arrival because there is less pressure “, says Ludovic Leroy of IFPEN.
In the event of leaks, the situation is easier to manage when the gas pipelines are underground than under water. “For onshore gas pipelines, there are isolation valves that can isolate entire sections in the event of a leak. The defective section will then be replaced by a new one. This work is very heavy, and it becomes extremely complex when it has to be done under the sea. “. This is particularly the case for the Nord Stream 1 and 2 gas pipelines.
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In France, two operators share the role of gas transporters, namely Téréga for the network in south-west France and GRTgaz (a subsidiary of Engie), for the rest of the territory. Note that the gas can also be transported via a liquefaction process. The gas is then transformed into liquefied gas and is transported by sea.