PetroChina is a Chinese oil and gas company and is the listed arm of state-owned China National Petroleum Corporation. It is China's second biggest oil producer. It engages in wide range of activities related to oil and natural gas, including: exploration, development, production and marketing of crude oil and natural gas, refining, transportation, storage and marketing of crude oil and oil products, the 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.