As its name suggests, PetroChina Company Ltd is the listed arm of state-owned China National Petroleum Corporation (CNPC). It is China's biggest oil producer, and is listed in Hong Kong, New York, and Shanghai.

PetroChina taps Chevron for Sichuan gas field development

PetroChina, the nation's largest oil and gas producer, will partner United States-based energy major Chevron Corp to develop high-sulphur gas fields in northeastern Sichuan province, a project that has proved difficult and accident-prone in the past.