Interim net income rose 116% to 71.89 billion yuan ($10.50 billion) while revenue rose 75.6% to 176.7 billion.

Oil prices have soared this year, with prices coming close to $147 in March after Russia's February 24 invasion of Ukraine - which Moscow calls a "special military operation" - spurred supply fears.

CNOOC's net oil and gas production hit a record high 304.8 million barrels of oil equivalent (boe), up 9.6% on the year, 71% of which came from domestic operations.

The firm is a top contributor to China's domestic oil production as national giants tackle geologically more complex and more costly resources to counter a steep decline at mature basins.

Its domestic net output rose 12.5% to 216.8 million boe, thanks to large projects such as deepwater gas field

Shenhai-1 in the South China Sea, Bozhong 19-4 in Bohai Bay in northern China, as well as coalseam gas development in northern China.

First-half capital expenditure rose 15.4% to 41.6 billion yuan while the year's plan stands at 90-100 billion yuan.

Its overseas production, including operations such as in Guyana and Brazil, grew 3% at 88 million boe.

Net proven reserve stood at 5.73 billion boe by end-2021, maintaining reserve life of more than 10 years for the last five consecutive years.

Its Hong Kong-listed shares have gained 48% this year versus the benchmark Hang Seng Index which has fallen 14%. Its Shanghai listed shares have risen 28% since their debut in April.

($1 = 6.8490 Chinese yuan renminbi)

(Editing by Jason Neely)

By Chen Aizhu