The first phase of Bozhong 26-6 oilfield, by far the largest metamorphic rock oilfield in the world, commenced production on Friday, according to its developer, the China National Offshore Oil Corporation (CNOOC) Tianjin branch.

The development project of the Bozhong 26-6 oilfield is divided into two phases. Phase one encompasses a central processing platform and an unmanned wellhead platform. The goal of this phase is to bring 33 development wells into production, with an expected peak daily output exceeding 3,500 cubic meters of oil and gas equivalent.

The reservoir of the Bozhong 26-6 oilfield is buried in metamorphic rocks beneath the seabed at a depth of over 4,500 meters, and its formation temperature can reach 178 degrees Celsius, making its exploitation extremely challenging, according to the CNOOC Tianjin Branch.

In response, the research team has developed and improved the drilling equipment and created a technical system tailored for deep-sea drilling, noted Tang Baisong, a project manager at CNOOC Tianjin Branch.

The Bozhong 26-6 oilfield is located in the Bohai Sea, about 170 km from north China's Tianjin Municipality, with an average water depth of about 20 meters. Discovered in 2022, its cumulative proven oil and gas reserves has exceeded 200 million cubic meters.