Russia’s Ryazan refinery, the country’s fourth-largest oil processing plant, was forced to shut down a critical crude unit after a fire broke out following a drone strike. Reuters reports, citing industry sources, that the AVT-4 (also known as CDU-4) crude distillation unit was urgently halted on 22 October, after it caught fire as a result of the attack.

Key unit offline after fire triggered by drone

Reuters says the AVT-4 unit, which processes 4 million metric tons of crude annually—roughly 80,000 barrels per day—was taken offline after it caught fire on 22 October. Two Russian industry sources told Reuters the shutdown followed the fire damage caused by the drone strike. The unit accounts for about one-quarter of the Ryazan refinery’s overall capacity. The refinery is located southeast of Moscow.

Ukraine’s General Staff confirmed on 23 October that its forces had struck the Ryazan refinery.

Reuters reports that several adjacent units were also shut down after the fire, including a reformer, a vacuum gasoil hydrotreater, and a catalytic cracker. While the plant remains operational, sources said it is now processing oil at a reduced volume.

Fuel output disruption across multiple units

The Ryazan refinery, owned by the Russian state-controlled oil company Rosneft, processed 13.1 million metric tons of crude in 2024. That year, it produced 2.3 million tons of gasoline, 3.4 million tons of diesel, and 4.2 million tons of fuel oil.

The shutdown of AVT-4 and other systems comes as several Russian regions are already experiencing fuel shortages, according to local authorities, who have previously sometimes linked those shortages to Ukrainian attacks on energy infrastructure.

Ukrainian drones struck the Ryazan oil refinery overnight on 23 October, sparking a massive fire at the facility. Ukrainian Telegram channel Exilenova+ and Russian news Telegram channel Astra geolocated the blaze to the Rosneft-owned oil refinery, located about 460 km from Ukraine, which supplies fuel to Moscow and surrounding regions. This marks at least the sixth attack on the refinery since January 2025.

The Ryazan refinery belongs to Rosneft and ranks among Russia's largest petroleum facilities. Its declared capacity reaches 17 million tons of crude oil per year. The plant produces all grades of automotive gasoline, diesel fuel, aviation kerosene, fuel oil, liquefied gases, bitumen and petrochemical feedstock.

Explosions and fire engulf the Ryazan oil facility

According to the reports, eyewitnesses heard approximately 10 explosions around 3:15 a.m. on the outskirts of Ryazan. Locals also heard blasts in the nearby city of Skopin in Ryazan Oblast. Residents described seeing flashes in the sky before fire erupted at the Ryazan facility. Russian channels confirmed the nighttime explosions across the oblast.

Ukrainian Telegram channels, Exilenova+ and Supernova+, both shared video showing flames on the horizon, reportedly filmed in Ryazan. Exilenova+ reported that drones targeted the Ryazan oil refinery and the Dyagilevo military airfield, while Supernova+ initially stated that the target was the airfield, but later leaned to the refinery as the attack's target.

Exilenova+ pinpointed the camera operator coordinates to 54.581845, 39.745340, approximately one kilometer from the refinery, and concluded that the fire is taking place on the refinery's premises.

Russian news Telegram channel Astra's analysis confirmed the attack location. The channel geolocated eyewitness footage to the Southern Industrial District near Etalon gas station in Ryazan.

Ryazan Oblast Governor Pavel Malkov later acknowledged that allegedly falling drone "debris" allegedly caused a fire at an industrial facility. He did not specify which enterprise was hit.

Refinery's "heart" targeted again - the oil cracking unit

Based on its pinpointed geolocation, Supernova+ reported the fire occurred in the area of the refinery's catalytic cracking or hydrotreatment unit.

The facility processed approximately 12-13 million tons annually in recent years. In August, Ukrainian drones forced the plant to temporarily reduce production capacity. The refinery operated with only one major unit at roughly half capacity.

Militarnyi noted that the refinery supplies motor fuel to regions surrounding the Russian capital. The facility sits more than 450 kilometers from the Ukrainian border. It serves as a key fuel provider for the Central Federal District.

Pattern of repeated attacks

This attack continues a sustained campaign against the Ryazan facility. On 5 September, drones hit the ELOU-AVT-6 unit at the refinery. NASA satellites detected a fire at the facility on 22 May. On 24 February, Ukrainian drones damaged the primary oil processing unit.

The refinery also faced attacks overnight on 24 January and again on 26 January.