CNOOC said production has started from its Enping 18-1 oilfield off the South China Sea.
The oilfield is located in the Pearl River Mouth Basin.
There are currently three wells producing 2,010 barrels of crude oil per day.
The project is expected to reach its designed peak production of 11,800 barrels of crude oil per day within the year.
The Enping 18-1 is an independent oilfield in which the company holds 100% interest and acts as the operator.