China National Offshore Oil Corp has commenced production at the Bozhong 26-6 oilfield development project (Phase I), the world's largest metamorphic buried hill oilfield, marking a major milestone in offshore energy development and carbon capture initiatives, the company announced on Friday.

Located in central Bohai Bay with an average water depth of about 20 meters, the project boasts cumulative proven oil and gas reserves exceeding 200 million cubic meters. It is expected to reach peak production of approximately 22,300 barrels of oil equivalent per day (boe/d) by the end of 2025, it said.

The commencement of production is being viewed by industry analysts as a critical step in enhancing China's offshore energy security while advancing its low-carbon ambitions.

"This project is significant not just because of its size, but because it demonstrates CNOOC's ability to unlock complex offshore reserves efficiently," said Wang Lining, director of the oil market department under the economics and technology research institute of China National Petroleum Corp.

"With peak production expected at over 22,000 barrels of oil equivalent per day, it will play an important role in reducing China's reliance on imported crude, particularly for the energy-intensive Beijing-Tianjin-Hebei region," he said.

China's marine economy has emerged as a key driver in boosting energy reserves, with over 60 percent of China's new crude oil output coming from offshore production last year, reinforcing the ocean's role as the backbone of the country's energy expansion, according to the Ministry of Natural Resources.

Offshore natural gas discovery remains an area of significant untapped potential, said Wang Zhen, head of the CNOOC Energy Economics Institute, a think tank under the corporation.

As global offshore crude oil contributes over 70 percent of new discoveries, Wang believes China's offshore resources are set to play a more significant role than ever in energy security.

According to CNOOC, the main production facilities include a new central processing platform and an unmanned wellhead platform. A total of 33 development wells are planned to be commissioned, including 22 production wells, 10 gas injection wells and a water source well.

As one of the demonstration carbon capture, utilization and storage projects of the company in Bohai, it adopts advanced technology to capture and separate the associated carbon dioxide from crude oil extraction and reinject back into the formation to drive the oil, thereby increasing production while reducing emissions. The project is expected to bury approximately 1.5 million metric tons of carbon dioxide throughout its life cycle.

CNOOC holds 100 percent interest in this project and is the operator.