(Hong Kong, September 4, 2011) - CNOOC Limited (the "Company", NYSE: CEO, SEHK:0883) noticed that on September 2, 2011 State Oceanic Administration of People’s Republic of China£¨"SOA"£© announced, through SOA’s official website, that ConocoPhillips China Inc ("COPC")£¬as the Operator of Penglai (PL) 19-3 oil field, has neither completely screened out the oil spill risks nor completely sealed the sources of oil spillage . The SOA also announced that, according to the analysis of the Joint Investigation Team ("JIT"), the JIT had determined that the oil spill incident at PL19-3 oil field is clarified as an accident involving liabilities as COPC did not fulfill its duties as a reasonable and prudent operator.

SOA has ordered COPC to suspend water injection, drilling and oil and gas production operations (the "Three Suspensions") at the entire PL19-3 oil field, and to take effective measures to continue screening out the potential oil spill risks, seal all sources of oil spillage and complete the cleanup work in a timely manner. In addition, as announced by the SOA, it has ordered COPC to recompose the Oceanic Environmental Impact Assessment (the "EIA") for the development of PL19-3 oil field and, upon further approval on the EIA to resume the operations gradually, and further ordered that COPC must revise the Overall Development Plan (the "ODP") and the "Three Suspensions" will only be lifted after the approval on the ODP.

In addition, the SOA also announced it will, on behalf of State, make claims against COPC for the damage to the marine environment caused by PL19-3 oil spill accident in accordance with Marine Environment Protection Law of the People's Republic of China. Currently, the relevant preparation work is underway.

We fully respect the decisions made by SOA. As the non-operator, the Company will continue to assist COPC to execute SOA’s decisions and to inform the public of the work progress as well as to welcome the supervision from the public.

PL19-3 is an oil field operated under a Production Sharing Contract ("PSC"). COPC is the Operator and responsible for the management of daily operations. CNOOC Limited holds 51% of participating interest during the development and production phase under the PSC.

The operations of Platforms B and C of PL19-3 oil field were already suspended on July 13 as required by the SOA. As a result, the Company’s net production has been reduced by approximately 22,000 barrels per day. The suspension of operations of the entire PL19-3 oil field will further reduce the Company's net production by approximately 40,000 barrels per day.