We should take in account that replacing one distillation column unit is sort of doable, but imagine Russia would need to produce 30 of them, transport, hire and assign workers, and assemble on site. Frankly, they don't have such capacity.
It seems that refineries are not properly defended and attempt to do so can overstretch Russian resources beyond breaking point, yet somebody will issue such order anyway. The next logical move would be F-16s arriving to the battlefield equipped with HARM missiles to make Russian front line PVO blind, especially when A-50s were hunted down recently too. Interesting game of chess here.