China National Offshore Oil Company Limited announced Friday that two of its oil fields in the South China Sea have started production.

CNOOC, China's largest offshore oil and gas producer, said in a statement that both oil fields are located in the Pearl River Estuary Basin in the South China Sea.

The Panyu 4-2/5-1 field, one of the two oil fields, is expected to reach its peak output level in 2014, the statement said. CNOOC owns 75.5 percent of the field, while Burlington Resources China Llc owns the remainder.

The other field was identified as Liuhua 4-1. The company owns it completely and expects the field's production to peak next year.