Chevron Corp. (NYSE: CVX) fully-owned subsidiary Unocal East China Sea Ltd. began natural gas production from the first stage of the Chuandongbei project in southwest China. Chuandongbei is one of the largest onshore gas projects developed by an international oil company and a national oil company in China.

“First gas for the Chuandongbei Project represents a significant milestone and highlights Chevron’s leadership in the development of sour gas resources,” said Jay Johnson, executive vice president, upstream, Chevron “The project will be an important supplier of clean and affordable energy to the rapidly growing economy in southwest China.”

The Chuandongbei project covers more than 800 sq km in Sichuan Province and the Chongqing Municipality. Unocal East China Sea Ltd. holds a 49 percent participating interest as the operator and China National Petroleum Corp. holds a 51 participating percent interest.

The start-up of the first train commences stage one of the project. Production is planned to ramp up over coming months as all three trains come online. The three trains have a combined design outlet capacity of 258 million cubic feet of natural gas per day. The Chuandongbei Project is estimated to contain potentially recoverable natural gas resources of 3 trillion cubic feet.