PetroChina is one of the largest oil and gas companies in the world, based in China. It was established in 1999 and is a subsidiary of China National Petroleum Corporation (CNPC). The company is involved in the exploration, production, and distribution of oil and natural gas, as well as refining and marketing petroleum products. As a publicly traded company, PetroChina is listed on the Hong Kong Stock Exchange and the New York Stock Exchange. It plays a significant role in the global energy market and contributes to China's energy security and economic development through its extensive operations both domestically and internationally.