Russia was able to rapidly repair some of its key oil refineries hit by Ukrainian drones, reducing capacity slashed by the attacks to about 10 percent from nearly 14 percent in late March, Reuters estimates show.
Ukraine has stepped up drone attacks on Russian energy infrastructure since the start of the year, hitting some major oil refineries in the second-largest oil exporter, sending the price higher
Russia claims drone attacks constitute terrorism. Ukraine says its drone attacks on Russia are justified because it is fighting for survival as Russia has launched a "massive retaliation" strikes on Ukrainian energy infrastructure.
There have been no reports of successful attacks on major Russian refineries since the Taneco plant was hit on April 2.
Russia is renovating its refineries quickly, despite difficulties in obtaining Western know-how.
This includes the "Rosneft" plant in Ryazan, which returned to operation CDU-4 and the main CDU-6 for primary oil refining, as well as the refinery in Kuibyshev, which repaired CDU-4 and CDU-5 of "Sizran".
According to Reuters calculations, total Russian primary oil refining capacity affected by the drones was reduced to 90,500 metric tons per day (660,000 bpd) from about 123,800 tons per day (907,000 bpd ) before that.
However, total cumulative primary oil refining capacity in Russia, excluded due to various outages and maintenance, is expected to reach 4.4 million tonnes in April, up from 4.1 million tonnes in March.
The pause in strikes from Ukraine came after criticism from the United States, the world's biggest energy consumer, where high fuel prices are high on the agenda ahead of the November 5 presidential election.
Replying to Republican US Senator Tom Cotton why the Joe Biden administration is discouraging the Ukrainians from attacking their "war-making capabilities" of Russia, Defense Secretary Lloyd Austin told the Senate Armed Services Committee last week that the attacks could damage global energy markets.
"Of course, these attacks could have an additional effect in terms of the global energy situation and... but frankly, I think Ukraine would do better by pursuing tactical and operational objectives that can to directly affect the current battle," he said.