Major sites including the Ryazan Volgograd and Astrakhan refineries have shut fuel production and it will take weeks or months to restore it

Drones also attacked Russia's limited oil storage as well as pipelines and pumping stations disrupting flows to export ports and refineries in traders said

There is nowhere to store this oil: there are almost no large storage facilities in Russia, and those that do exist were hit in January. It is also difficult to refine the excess oil at refineries: drone have knocked out around 10% of Russian refining capacity.

Volumes from Russia's western ports of Primorsk, Ust-Luga, and Novorossiisk in January were down 17% from a year earlier, and the cost to transport a cargo from Russia's Pacific port of Kozmino to China up fivefold in January, Reuters calculations based on traders' data showed.