Debris from the drone, which was shot down, caused a fire at the refinery, which is owned by oil major Rosneft, the officials said.
Russia's SHOT and Mash Telegram news channels reported that a series of blasts were heard near the refinery early on Monday, Reuters reported.
There were no casualties, officials said. However, it was unable to immediately verify whether the refinery was operational or to establish the extent of the damage it had sustained.
Ukraine has been systematically targeting Russian energy infrastructure in an attempt to disrupt Russia's economy and its ability to fund what the Kremlin calls its special military operation in Ukraine.
MA/PR