Largest Chinese oil and gas producer and distributor and one of the largest global oil companies, whose core business includes exploration, development, production and marketing of crude oil and natural gas; refining, transportation, storage and marketing of crude oil and oil products; production and marketing of primary petrochemical products, derivative chemicals and other chemicals; transportation of natural gas, crude oil and refined oil, and marketing of natural gas. PetroChina is the company with the largest market value, being the first company with a market cap of $1 trillion.