PetroChina is one the biggest oil exploration companies in the world.
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Sales = $333.39 Billion
It is in the business of exploration, development, production and sale of natural gas & crude oil, refining of crude oil & petroleum products, transmission of natural gas, crude oil & refined oil products along with sale of natural gas, production & marketing of primary & derivative petrochemical products and marketing of refined products & trading business. The headquarters of the company are in Beijing, China and was founded in the year 1999. It has five business segments which are Exploration & production, refining & chemicals, natural gas & pipeline, marketing and cash management & financing activities. It has approximately 534,652 employees worldwide.