A CNOOC oilfield in Bohai Sea Photo: Courtesy of CNOOC

China National Offshore Oil Corp (CNOOC) announced on Wednesday a new discovery of 100 million tons in the shallow Neogene formations of China's Bohai Sea - the Qinhuangdao 29-6 Oilfield.

This is the seventh consecutive oilfield of this size discovered in China's largest crude oil production base, the Bohai Oilfield, since 2019, according to a CNOOC release sent to the Global Times on Wednesday.

The discovery further strengthens China's offshore oil and gas reserves and is of great significance in safeguarding national energy security, said the release.

According to CNOOC, the Qinhuangdao 29-6 Oilfield is located in the central Bohai Sea. It is another lithologic oilfield of 100 million tons discovered in the region following the major discovery of the Qinhuangdao 27-3 Oilfield in recent years. Testing shows that a single well can produce approximately 370 tons of crude oil per day, demonstrating strong exploration potential.

An official of CNOOC said that the company has strengthened innovation in the hydrocarbon migration and accumulation models and technologies for the shallow Neogene slope zones, leading to the recent discovery.

This achievement challenges the conventional understanding that slope areas merely serve as pathways for hydrocarbons rather than sites for substantial accumulation, demonstrating the significant exploration potential of uplifted peripheral slopes, said the official.

"The discovery demonstrates the resilience and innovative potential of domestic oil and gas exploration in China. In the context of the global energy transition, such achievements in increasing reserves and production help balance short-term energy demands with long-term sustainable development," Lin Boqiang, director of the China Center for Energy Economics Research at Xiamen University, told the Global Times on Wednesday.

Lin noted that this also directly enhances domestic oil supply capacity and reduces dependence on imported petroleum. In an environment of geopolitical uncertainty and fluctuations in international oil prices, such a major domestic discovery strengthens energy autonomy and ensures the stability of the industrial chain, he said.

On Sunday, CNOOC announced that the Bohai Oilfield has produced more than 40 million tons of oil equivalent in 2025, setting a new record.

The Bohai Oilfield, which currently includes more than 60 producing oil and gas fields, has yielded a cumulative crude oil output exceeding 600 million tons. Over the past five years, its oil and gas production has grown by 5 percent annually, according to CNOOC.

Data from the National Energy Administration showed that China's crude oil production in 2025 is expected to reach 215 million tons, hitting a historical high.

Lin attributed the achievements in crude oil production to continuous oilfield exploration and technological advancements.

"Discoveries of large oil fields in the Bohai Sea, South China Sea, and other regions have strengthened the country's crude oil reserves. Technological innovations, such as 3D seismic exploration, horizontal well drilling, and enhanced recovery techniques, have improved recovery rates in mature oil fields and the efficiency of discoveries in new areas, serving as the core driving force behind production growth," the expert noted.