China National Offshore Oil Corp. made "significant progress" with its exploration program during the first quarter, its chief executive officer said Tuesday.

CNOOC said it made five new discoveries and drilled eight successful appraisal wells off the Chinese coast so far this year.

"In the first quarter, the company made significant progress in exploration, particularly the new discoveries and successful appraisals will lay a solid foundation for the company's sustainable development," CEO Li Fanrong said in a statement.

For first quarter 2014, CNOOC said its 108.1 million barrels of oil equivalent produced a 15.5 percent increase over the same period last year.

In terms of net sales, the company said it generated an unaudited $59.15 billion during the first quarter, a 6.9 percent increase year-on-year. CNOOC attributed the increase in revenue to its increased oil and natural gas production.

In January, the state-owned company -- the third-largest in China -- said it plans to drill more than 150 exploration wells this year and produce more than 422 million barrels of oil equivalent.