The rig, Seven Driller, can sink wells 40,000 feet deep and store 150,000 barrels of crude oil, Xinhua News Agency reported in its Web site www.xinhuanet.com, quoting a COSCO official.
The Norwegian firm, which has contracted the rig to Brazil's Petrobras , said earlier this month that it had secured options to build six more drilling units at a Chinese shipyard.