He stated that Russia’s deep oil refining units producing Euro-4 and Euro-5 standard fuels sustained the most severe damage.
“Building hydrotreating or catalytic cracking units costs hundreds of millions of dollars. The Euro unit complex at the Moscow Oil Refinery cost over a billion,” Kuyun said.
“That's not something you can quickly recoup.”
The expert noted that because such equipment is manufactured under Western licenses, sanctions make acquiring replacements virtually impossible.
In response, Russian authorities have lowered fuel quality requirements, effectively permitting the production of Euro-3 standard fuels and allowing non-core enterprises to produce gasoline using additives.
A large-scale drone attack targeted the Russian city of Penza on June 1, 2026, causing fires and heavy smoke near a bearing plant. Missile alert was declared in the city. Penza residents reported hearing a series of explosions. Local authorities claimed that air defense systems were intercepting the drones.
Drones struck two oil refineries in the Russian city of Ufa, Bashkortostan – 1,400 kilometers from Ukraine – on the morning of June 25.
President Volodymyr Zelenskyy announced on July 1, 2026, that Ukrainian Defense Forces struck an oil refinery in Ufa, which is one of Russia’s largest producers of lubricants and is located 1,300 kilometers from the frontline.