PetroChina to lead shale gas project in Chongqing

Commercial output from $4 billion joint venture set to start by 2017

PetroChina Co and three partners will invest more than $4 billion to drill for shale gas in China's most productive shale fields.

PetroChina has joined Sinochem Group and two local State-owned enterprises to form the venture in the southwestern municipality of Chongqing, according to a statement on the city's website on Wednesday. The project will start operations by the end of the year and begin commercial production in 2017.