China’s largest offshore oil and gas hub, the Bohai Oilfield, has recorded its highest annual production level, strengthening the country’s energy supply, the China National Offshore Oil Corporation (CNOOC) has announced.

According to CNOOC, total output from the offshore field exceeded 40 million tonnes of oil equivalent in 2025, marking a new historical high. The company said the achievement highlights the growing importance of the Bohai Oilfield in supporting national energy security and economic development.

The Bohai Oilfield, located in the Bohai Sea, is China’s biggest offshore oilfield in terms of both scale and production capacity. It currently operates more than 60 oil and gas fields and has produced over 600 million tonnes of crude oil since development began.

CNOOC noted that production at the oilfield has continued to rise steadily, with oil and gas output growing at an average rate of about 5 percent each year over the past five years.

Beyond increased production, the company said the oilfield is undergoing major upgrades focused on digital operations and environmentally friendly practices. Progress has been made in the use of locally manufactured equipment, including the successful deployment of China’s first domestically developed shallow-water subsea production system.

In addition, more than 80 percent of the Bohai Oilfield’s facilities have now been connected to electricity supplied from onshore power sources, a move aimed at improving efficiency and reducing carbon emissions.

CNOOC said the latest milestone further positions the Bohai Oilfield as a key pillar of China’s offshore energy industry and a major contributor to long-term, high-quality growth.