PetroChina is a company providing petroleum-related products, services, and related activities. It operates through Exploration and Production, Refining and Chemicals, Marketing, and Natural Gas and Pipeline segments. The Exploration and Production segment engages in the exploration, development, production, and marketing of crude oil and natural gas. The Refining and Chemicals segment refines crude oil and petroleum products and produces and markets primary petrochemical products, derivative petrochemical products, and other chemical products. The Marketing segment is involved in the marketing of refined products and trading business. The Natural Gas and Pipeline segment engages in the transmission of natural gas, crude oil, and refined products, and the sale of natural gas.