CNOOC Ltd (NYSE: CEO, HKG: 0883), China's biggest offshore energy explorer, said that ConocoPhillips (NYSE: COP) operated Penglai 19-3 oilfield in Shandong province has been approved for resuming production. The field was shut in 2011 following an oil spill, causing CNOOC to lose at least 62,000 barrels per day of oil production. Credit Suisse estimates the field will increase CNOOC's daily oil production by 30,000 to 40,000 barrels, which can be translated into a 4-5% increase in oil production and a 3-4% increase in overall production.