China National Offshore Oil Corp, one of the country's three major oil and gas companies, did major oil-gas exploration during the 13th Five-Year Plan period (2016-20), with oil-gas exploration reaching 1.3 billion metric tons and proved natural gas reserves reaching 500 billion cubic meters, the company said on Friday during a press release in Beijing.

It produced 383 million tons of crude and 116.6 billion cubic meters of natural gas during the five years, with a batch of large- and mid-sized oil and gas fields including Bozhong 19-6 and Kenli 6-1, which further ensured the country's energy security, said the company.

The company's total oil and gas production reached 107.7 million tons of oil equivalent and its total volume of trade in oil products was 128 million tons. Total oil and gas production also hit a record high in 2020 of 65.3 million tons of oil equivalent, it said.

The domestic crude production rose by 2.4 million tons over the previous year and accounted for 80 percent of increase in the country's crude oil production.

According to CNOOC, offshore oil and gas production has become a major pillar of the country's energy growth. The company also imported 29.75 million tons of LNG last year.

CNOOC Limited, a listed arm of CNOOC, said on Thursday that the company has achieved a total net production of 137.7 million barrels of oil equivalent (BOE) for the first quarter of 2021, representing an increase of 4.7 percent year-over-year.

It was mainly attributable to production growth from the commencement of new projects, including the Liuhua 16-2/20-2 and Lvda 16-3/21-2, the company said during its press release of the 2021 first quarter key operational statistics on Thursday.

For new projects planned for this year, the Caofeidian 6-4 oilfield has commenced production, and other projects are progressing as scheduled, it said.

During the first three months, the company made two new discoveries and drilled 18 successful appraisal wells. The Kenli 10-2 and Wenchang 9-7 oil and gas bearing structures were successfully appraised in offshore China too. Kenli 10-2 is expected to be a mid-to-large-sized oilfield that indicates broad exploration prospects for shallow lithology oil and gas reservoirs in Bohai, while Wenchang 9-7 is expected to be a mid-sized oilfield.