Ukrainian Drone Attack Halts Core Processing Unit at Russia's Fourth-Largest Ryazan Oil Refinery

Russia's Ryazan oil refinery, the country's fourth-largest and located southeast of Moscow, halted a critical crude oil distillation unit following a Ukrainian drone strike that caused a fire on October 22-23. This unit, CDU-4 or AVT-4, accounts for about 25% of the refinery's capacity, processing roughly 80,000 barrels per day. The attack also forced shutdowns of several adjacent units, including reforming, vacuum hydrotreating, and catalytic cracking facilities, significantly reducing the plant's output though it continues limited operations. Ukraine's General Staff confirmed responsibility for the strike amid their intensified campaign targeting Russian energy infrastructure to disrupt military fuel supplies and reduce oil export revenues. The ongoing attacks have caused motor fuel shortages across several Russian regions, highlighting the broader impact on Russia's energy sector amid stalled peace talks mediated by U.S. President Donald Trump. Rosneft, the refinery's owner, declined to comment on the incident.