When engineers at Russian oil firm Lukoil discovered a turbine had broken at their largest refinery on January 4, they quickly realised the problem was far from trivial. There was only one company that knew how to repair the gasoline-producing unit at the NORSI refinery, located on the Volga River, some 430 km (270 miles) east of Moscow. The firm, petroleum engineering multinational UOP, had withdrawn from Russia after the country invaded Ukraine in February 2022.