| Name      of entity                                             |   | Our      interest |   | Jurisdiction      of incorporation |
|-----------------------------------------------------------------|--------|-------------------|--------|------------------------------------|
| CNOOC      China Limited                                        |   | 100%              |   | Tianjin,      PRC             |
| CNOOC      International Limited                                |   | 100%              |   | British      Virgin Islands   |
| China      Offshore Oil (Singapore) International Pte Ltd  |   | 100%              |   | Singapore                     |
| CNOOC      Finance (2002) Limited                               |   | 100%              |   | British      Virgin Islands   |
| CNOOC      Finance (2003) Limited                               |   | 100%              |   | British      Virgin Islands   |
| Malacca      Petroleum Limited                                  |   | 100%              |   | Bermuda                       |
| OOGC      America, Inc.                                         |   | 100%              |   | Delaware,      USA            |
| OOGC      Malacca Limited                                       |   | 100%              |   | Bermuda                       |
| CNOOC      Southeast Asia Limited                               |   | 100%              |   | Bermuda                       |
| CNOOC      Africa Holding Ltd.                                  |   | 100%              |   | British      Virgin Islands   |
| CNOOC      Africa Ltd.                                          |   | 100%              |   | British      Virgin Islands   |
| CNOOC      Africa (UK) Limited                                  |   | 100%              |   | London,      U.K.             |
| CNOOC      ONWJ Ltd.                                            |   | 100%              |   | Labuan,      F.T.,Malaysia    |
| CNOOC      SES Ltd.                                             |   | 100%              |   | Labuan,      F.T.,Malaysia    |
| CNOOC      Poleng Ltd.                                          |   | 100%              |   | Labuan,      F.T.,Malaysia    |
| CNOOC      Madura Ltd.                                          |   | 100%              |   | Labuan,      F.T.,Malaysia    |
| CNOOC      Blora Ltd.                                           |   | 100%              |   | Labuan,      F.T.,Malaysia    |
| CNOOC      NWS Private Limited                                  |   | 100%              |   | Singapore                     |
| CNOOC      Australia E&P Pty Ltd.                           |   | 100%              |   | Australia                     |
| CNOOC      Wiriagar Holding Limited                        |   | 100%              |   | British      Virgin Islands        |

| CNOOC      Muturi Holding Limited                        |   | 100%   |   | British      Virgin Islands       |
|---------------------------------------------------------------|--------|--------|--------|-----------------------------------|
| CNOOC      Muturi Ltd.                                        |   | 100%   |   | The      Isle of Man         |
| CNOOC      Canada Limited                                     |   | 100%   |   | Canada                       |
| CNOOC      Belgium BVBA                                       |   | 100%   |   | Belgium                      |
| CNOOC      Australia Limited                                  |   | 100%   |   | British      Virgin Islands  |
| CNOOC      Exploration & Production Nigeria Limited  |   | 100%   |   | Nigeria                      |
| AERD      PROJECTS NIGERIA Limited                       |   | 92.11% |   | Nigeria                      |
| CNOOC      Hong Kong Holding Limited                     |   | 100%   |   | Hong      Kong                    |
| CNOOC      Myanmar Holding Ltd.                          |   | 100%   |   | British      Virgin Islands       |
| CNOOC      Myanmar Ltd.                                       |   | 100%   |   | British      Virgin Islands  |
| CNOOC      Caspian (Kazakhstan) Ltd.                     |   | 100%   |   | Cayman      Islands               |

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