biggest oil companies in world
No of employees (2014): 544083. With around half a million employees, Petrochina, the listed arm of state owned China National Petroleum Corp. (CNPC) is easily one of the biggest oil and gas companies in the world. The company operates in four segments: Exploration and Production, Refining and Chemicals, Marketing and Natural Gas and pipeline.
Within 20 years, Royal Dutch Shell became the leading oil company in the world. The company restructured itself in 2005 when it dissolved the original partnership of Shell Transport and Royal Dutch Petroleum to officially unify the two as Royal Dutch Shell plc.