The fields are Wenchang 19-1 North and Weizhou 12-8 West. The company, in its announcement Thursday, gave no reserve estimate for either production area.
The Wenchang 19-1 North field has three wells producing oil. Weizhou 12-8 West field has five wells.
CNOOC set a net production target for 2013 of 338 million to 348 million barrels of oil equivalent. Last year's net production ranged from 341 million to 343 million barrels.
The company said new net production would derive in part from 10 new oil and natural gas fields offshore.
CNOOC planned 140 exploration wells this year.
The U.S. Energy Information Administration said in an October market report China is the largest net oil importer in the world.