Chevron Corporation (NYSE:CVX) announced that its Unocal East China Sea Ltd. subsidiary has begun natural gas production from the first stage of its 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, of the San Ramon-based company.

The Chuandongbei Project covers over 800 square. Unocal East China Sea, Ltd. holds a 49% participating interest as the operator, while China National Petroleum Corporation holds a 51% participating interest.

Production is planned to ramp up over coming months, to a 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.

Melody Meyer, president, Chevron Asia Pacific Exploration and Production Company stated, “First gas at Chuandongbei represents the next step in our energy partnership with China.”