The discovery well, Caofeidian 6-4-1, was drilled and completed at a depth of about 3100 metres.
The well encountered oil pay zones with a total thickness of about 180 metres, and its production tested at around 5750 barrels per day of light oil.
"The successful appraisal of Caofeidian 6-4 structure not only represents a significant breakthrough after several years of exploration in the west of Bohai, but also provides important guidance in oil and gas exploration in similar areas," CNOOC Ltd said in a release.
"In
