PetroChina Company Limited, together with its subsidiaries, engages in a range of petroleum related products, services, and activities in Mainland China and internationally. It operates through the Oil and Gas and New Energy, Refining Chemicals and New Materials, Sales, and Natural Gas Sales Segments. The Oil, Gas and New Energy Resource segment engages in the exploration, development, transportation, production, and marketing of crude oil and natural gas, as well as is involved in the new energy resource business. The Refining, Chemicals and New Materials segment refines crude oil and petroleum products; and produces and markets primary petrochemical products, derivative chemical products, and other chemical products; as well as engages in new materials business. The Marketing segment is involved in the marketing of refined and non-oil products, and trading business. The Natural Gas Sales segment engages in the transmission and sale of natural gas. The company is also involved in the exploration, development, and production of oil sands and coalbed methane; trading of crude oil and petrochemical products; investment in refining; storage, chemical engineering, storage facilities, service station, and transportation facilities and related businesses; chemical technology development; and provision of technology transfer and technical services. The company was incorporated in 1999 and is headquartered in Beijing, the People's Republic of China. PetroChina Company Limited operates as a subsidiary of China National Petroleum Corporation.