CHINA has discovered a major oilfield in the central and northern parts of the Bohai Sea, with proven reserves of 104 million tons of oil, marking a monumental find in the region following a decade of search efforts, state-owned oil giant CNOOC announced on Monday.

The Qinhuangdao 27-3 oilfield, located 200 kilometers west of North China's Tianjin, is a 48.9-meter-thick oil layer in a 1,570-meter-deep well. With reserves exceeding 100 million tons of oil equivalent, testing has shown that the oilfield can produce about 110 tons of crude oil per day, showing promising exploration prospects.