Net profit for CNOOC - an offshore oil and gas specialist and listed arm of parent China National Offshore Oil Corp - more than doubled last year from 2017 to 52.7 billion yuan ($7.88 billion), marking its best results since 2014.

The company's realized oil prices were up 28 percent last year to $67 per barrel. Gas prices were up 10 percent to $6.41 percent million cubic feet.

That helped to lift oil and gas revenue last year by 22 percent to 227 billion yuan, also the best level since 2014.

The company has set an ambitious target to boost its reserve and production by increasing spending in the upstream sector.

CNOOC plans to spend 70 billion to 80 billion yuan on exploration and production this year, after capital expenditure rose more than 25 percent in 2018.

Its reserve life, measured in how long its current oil and gas reserve base can last, rebounded to 10.5 years in 2018, CNOOC said.

The company plans to pay a final dividend of HK $0.40 per share.

(Reporting by Meng Meng and Dominique Patton; Editing by Tom Hogue)