China National Offshore Oil Corporation (CNOOC) announced a major oilfield discovery in the Bohai Sea, adding over 100 million tonnes of oil equivalent proved in-place, according to the company on Monday.

The field has been tested to produce about 110 tonnes of crude oil per day from a single well. Through continued exploration, the proved in-place volume of Qinhuangdao 27-3 Oilfield has reached 104 million tonnes of oil equivalent.

It marks a significant discovery in the central-northern region of the Bohai Sea after a decade.

Zhou Jiaxiong, deputy general manager of CNOOC's Tianjin Branch, said the oilfield is located in one of the main areas for early-stage oilfield exploration in the Bohai Sea. "It represents another significant milestone in the exploration strategy for rock formations on the shallow part of the Bohai Sea," Zhou said.

The researchers identified the complex strike-slip fault zone that was enriched with oil and gas by leveraging extensive drilling data, experiments and foundational studies.

Xu Changgui, deputy chief exploration officer of CNOOC said the Qinhuangdao 27-3 oilfield is the sixth one with a proved-in place volume over 100 million tonnes in Bohai Sea since 2019.

Qinhuangdao 27-3 is located in the central-northern region of the Bohai Sea, approximately 200 kilometers west of Tianjin, with an average water depth of about 25 meters.