State-owned China National Offshore Oil Corporation (CNOOC), one of China's three major state-owned oil companies, announced on April 17 that its Penglai 9-1 oilfield has been appraised as the largest found in Bohai Bay in recent years.

Discovered in 2010, Penglai 9-1 is located in the Miaoxibei uplift in the eastern part of Bohai Bay, located in the Bohai Sea east of Tianjin. Tests conducted by CNOOC have found that one of Penglai 9-1's appraisal wells encountered oil pay zones with a total thickness of more than 200 meters and produced a daily yield of around 700 barrels, making it one of the largest oilfields — in terms of scale — discovered in the bay in recent years.

"I believe the assessment of (Penglai 9-1) will open up new prospects for exploration and development in the eastern Bohai Sea and contribute to stable production in the whole region," said Li Fanrong, CNOOC's chief executive.

CNOOC also announced the discovery Penglai 15-2, an oilfield located just 8 kilometers south of Penglai 9-1. One of Penglai 15-2's test wells encountered oil pay zones with total thickness of 83 meters and averaging output of around 1,200 barrels a day, making it a medium-sized discovery.

Prior to the discovery of Penglai 9-1, the largest Bohai oilfield was Penglai 19-3, situated about 40km southwest of Penglai 9-1. Penglai 19-3 has been closed since last September following two oil spills that have caused the company's yearly production to slow.

Last week, a number of high-level CNOOC executives offered to forgo their 2011 salaries, a move some say is their way of taking responsibility for damage caused by the spill. Others, however, claim that the offer was made merely to protect the reputations of executives and the company.