CNOOC Ltd and Sinopec Jointly Acquire 20% Interests of Block 32 in Angola

HONG KONG, July 17 /PRNewswire-Asia/ — CNOOC Limited (the “Company” or
“CNOOC Ltd.”, NYSE: CEO; SEHK: 0883) is pleased to announce today that the
Company through a 50:50 joint venture with Sinopec International Petroleum
Exploration and Production Corporation (“SINOPEC”), has signed a Sale and
Purchase Agreement with Marathon International Petroleum Angola Block 32
Limited, a subsidiary of Marathon Oil Corporation, to acquire a 20% working
interest in the Production Sharing Contract and Joint Operating Agreement
under Block 32, offshore Angola. The transaction has a total value of US$1.3
billion, excluding any purchase price adjustments at closing, and will be
effective from Jan.1, 2009.

(Logo: http://www.prnasia.com/xprn/sa/200701301659.jpg )

Block 32, with an acreage of 5,090 square kilometers, is an oil rich
deepwater exploration block with 12 oil discoveries. The block is located
about 150 kilometers off the coast in a water depth of 1400 to 2200 meters.

The parties involved expect to close the transaction by year-end 2009,
subject to government and regulatory approvals and the pre-emption rights of
the other parties to the Production Sharing Contract and Joint Operating
Agreement.

Twelve previously announced discoveries in Block 32 include: Gindungo,
Canela, Cola, Gengibre, Mostarda, Salsa, Caril, Manjericao, Louro, Cominhos,
Colorau and Alho. Conceptual development studies are underway in order to
identify the feasibility of a first development area in the central
southeastern part of Block 32.

Mr. Yang Hua, President of the Company said: “I am glad that we seize the
opportunity to acquire this asset. Since our listing, we have stuck to a value
driven acquisition strategy to take opportunities. This transaction is a good
example of such strategy.”

Marathon will retain a 10% interests in the block after the transaction.
Block 32 is operated by Total SA of France, which owns a 30% stake and acts as
the operator. Sonangol, Angola’s state-owned oil company owns 20%, while Exxon
Mobil Corp. holds 15% and Galp 5%.

Credit Suisse services as a financial advisor to both CNOOC Ltd. and
SINOPEC.

Notes to Editors:

More information about the Company is available at
http://www.cnoocltd.com .

This press release includes “forward-looking statements” within the
meaning of the United States Private Securities Litigation Reform Act of 1995,
including statements regarding expected future events, business prospectus or
financial results. The words “believe”, “intend”, “expect”, “anticipate”,
“project”, “estimate”, “plan”, “predict” and similar expressions are intended
to identify such forward-looking statements. These statements are based on
assumptions and analyses made by us that we believe are reasonable under the
circumstances. However, whether actual results and developments will meet our
expectations and predictions depend on a number of risks and uncertainties
which could cause our actual results, performance and financial condition to
differ materially from our expectations. For a description of these and other
risks and uncertainties, please see the documents we file from time to time
with the United States Securities and Exchange Commission, including our 2008
Annual Report on Form 20-F filed on May 8, 2009.

    For further enquiries, please contact:

     Mr. Xiao Zongwei
     Joint Company Secretary
     and General Manager of Investor Relations Department
     CNOOC Limited
     Tel:   +86-10-8452-1646
     Fax:   +86-10-8452-1441
     Email: xiaozw@cnooc.com.cn

     Ms. Sharon Fung
     Ketchum Newscan Public Relations Ltd
     Tel:   +852-3141-8082
     Fax:   +852-2510-8199
     Email: Sharon.fung@knprhk.com

SOURCE CNOOC Limited