The largest refinery in Ukraine is in Odessa and it is still working away providing fuel for the Ukrainian military.
The irony is that the Odessa refinery is owned by Gazprom, which is owned by the Russian government. If Putin attacks it he wipes out billions in Russian property.
You are wrong. The Odessa installation is somewhat small. Capacity of about 54K barrels/day. Compared to the Dnipro/Kremenchuk complex that has throughput of 550,000 barrels/day.
And the Odessa facility is owned by Lukoil, not GAZPROM.