Unable to match Putin’s military might, Ukraine is engaging in ‘smart warfare’ to attack the enemy’s oil and gas supply lines
By last week, the evidence of a new and sustained attack against a crucial part of Russia’s economy was impossible to ignore. On Wednesday, a drone hit the Tuapse oil refinery in southern Russia on the Black Sea. Flames from the burning refinery were visible above an inky skyline. Nearby, the airport in Sochi – Putin’s favourite resort, famed for its pebble beaches – was forced to close.
So far this year, Ukrainian drones have struck at least four Russian oil and gas terminals across the country. The attacks are part of a growing asymmetrical campaign by Kyiv to cripple the industry and to deprive Moscow of the billions of dollars in global revenue it uses to fund its war. About half of Russia’s $420bn export earnings last year came from oil.
Sergey Vakulenko, an oil expert at the Washington-based Carnegie Endowment for International Peace, said drones could not destroy a whole Russian refinery because modern firefighting equipment was available and so far the fires had been put out in a few hours.
Modern equipment was available this time. Besides, I'm willing to bet those drones cost a lot less than replacement refinery parts when you have to avoid the sanctions.
And adding to your argument; I believe most refinaries were maintened by Western expertise and replacements were supplied by Western firms, but both aren't happening anymore (like with the airplanes)
So yeah, I agree, these drones are doing damage for sure.