While the global energy giants are struggling with plunging crude prices, Russian oil firms are increasing profits and output as a weak domestic currency protects their business. Russia's oil majors Rosneft, Lukoil and Gazprom Neft are doing better than their Western counterparts Shell, BP or Exxon. This comes on the back of the depreciating Russian currency which cuts costs and taxes for the companies that generate earnings in US dollars but pay most of their expenses in rubles.