| 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 (2003) Limited                               |   | 100%         |   | British Virgin Islands   |
| Malacca Petroleum Limited                                  |   | 100%         |   | Bermuda                  |
| OOGC America LLC                                           |   | 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 SES Ltd.                                        |   | 100%         |   | Labuan, F.T., Malaysia        |
| CNOOC Poleng Ltd.                                     |   | 100%         |   | Labuan, F.T., Malaysia        |
| CNOOC Madura 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%         |   | Labuan, F.T., Malaysia        |
| CNOOC Muturi Holding Limited                          |   | 100%         |   | Labuan, F.T., Malaysia        |
| CNOOC Muturi Limited                                       |   | 100%         |   | The Isle of Man          |
| CNOOC Belgium BVBA                                         |   | 100%         |   | Belgium                  |
| CNOOC Australia Limited                                    |   | 100%         |   | British Virgin Islands   |
| CNOOC Exploration & Production Nigeria Limited    |   | 100%         |   | Nigeria                  |

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| CNOOC Hong Kong Holding Limited                         |   | 100% |   | Hong Kong                    |
|--------------------------------------------------------------|--------|------|--------|------------------------------|
| CNOOC Myanmar Holding Ltd.                              |   | 100% |   | British Virgin Islands       |
| CNOOC Myanmar Ltd.                                           |   | 100% |   | British Virgin Islands  |
| CNOOC Middle East (Qatar) Limited                       |   | 100% |   | British Virgin Islands  |
| CNOOC Congo SA                                          |   | 100% |   | Republic of Congo            |
| CNOOC Caspian (Kazakhstan) Ltd.                         |   | 100% |   | Cayman Islands               |
| CNOOC Singapore Private Limited                         |   | 100% |   | Singapore                    |
| CNOOC Australia Energy Pty Ltd                          |   | 100% |   | Australia                    |
| CNOOC Batanghari Ltd.                                   |   | 100% |   | Labuan, F.T., Malaysia       |
| CNOOC Palung Aru Ltd.                                   |   | 100% |   | Labuan, F.T., Malaysia       |
| CNOOC FPSO Holding Limited                              |   | 100% |   | Liberia                      |
| CNOOC Liberia Limited                                   |   | 100% |   | Liberia                      |
| CNOOC Uganda (BVI) Ltd                                  |   | 100% |   | British Virgin Islands       |
| De coöperatieve vereniging CNOOC Netherlands U.A.  |   | 100% |   | The Netherlands              |
| CNOOC Netherlands B.V.                                  |   | 100% |   | The Netherlands              |
| CNOOC Uganda Ltd                                        |   | 100% |   | Uganda                       |
| CNOOC Deepwater Development Limited                          |   | 100% |   | Zhuhai, PRC             |
| CNOOC Hainan Dock Limited                                    |   | 100% |   | Hainan, PRC             |
| CNOOC Iraq Limited                                      |   | 100% |   | British Virgin Islands       |
| CNOOC Finance (2011) Limited                            |   | 100% |   | British Virgin Islands       |
| CNOOC Algeria (BVI) Limited                             |   | 100% |   | British Virgin Islands       |
| CNOOC Reserves Fund I, Ltd.                             |   | 100% |   | Cayman Islands               |
| CNOOC Luxembourg S.à r.l.                          |   | 100% |   | Luxembourg                   |
| CNOOC Investment Canada Inc                                  |   | 100% |   | Alberta, Canada              |

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| CNOOC Canada Inc.                                                 |   | 100%      |   | Alberta, Canada         |
|-------------------------------------------------------------------|--------|-----------|--------|------------------------------|
| CNOOC Finance (2012) Limited                                 |   | 100%      |   | British Virgin Islands       |
| CNOOC Finance (2013) Limited                                 |   | 100%      |   | British Virgin Islands       |
| Tainan-Chaoshan Petroleum Operating Company Limited*         |   | 50%       |   | British Virgin Islands       |
| Husky - CNOOC Madura Limited *                                    |   | 40%  |   | British Virgin Islands  |
| Chaoyang Petroleum (BVI) Limited*                            |   | 50%       |   | British Virgin Islands  |
| Chaoyang Petroleum (Trinidad) Block 3A Limited*              |   | 50%       |   | Barbados                     |
| Chaoyang Petroleum (Trinidad) Block 2C Limited*              |   | 50%       |   | Barbados                     |
| Bridas Corporation*                                          |   | 50%       |   | British Virgin Islands       |
| PNG Energy Limited                                           |   | 70%       |   | British Virgin Islands       |
| GINI Energy Ltd                                              |   | 70%       |   | Papua New Guinea             |
| CNOOC Iceland ehf.                                           |   | 100%      |   | Iceland                      |
| CNOOC Luxembourg Holding S.à r.l.                       |   | 100%      |   | Luxembourg                   |
| CNOOC Petroleum Brasil LTDA                                  |   | 100%      |   | Brazil                       |
| CNOOC International Energy Services (Beijing) Limited   |   | 100%      |   | Beijing, PRC                 |
| Aurora Liquefied Natural Gas Ltd.                            |   | 60%       |   | Alberta, Canada         |
| Canadian Nexen Petroleum East Al Hajr Ltd.                   |   | 100%      |   | Alberta, Canada         |
| Canadian Petroleum Yemen Limited                             |   | 100%      |   | Jersey                  |
| CanadianOxy Offshore Production Co.                          |   | 100%      |   | Delaware, USA           |
| CNOOC UK Limited                                             |   | 100%      |   | England and Wales       |
| ICH Capital Funding Zurich Limited                           |   | 100%      |   | Switzerland             |
| ICH Capital Management Hungary Limited Liability Company          |   | 100%      |   | Hungary                 |

----

| ICM Assurance Ltd.                                     |   | 100% |   | Barbados                  |
|-------------------------------------------------------------|--------|------|--------|--------------------------------|
| ICM Capital Limited                                    |   | 100% |   | Barbados                  |
| ICM Holdings Limited                                   |   | 100% |   | Jersey                    |
| International Capital Holdings Limited                 |   | 100% |   | Malta                     |
| Long Lake Finance Management Ltd.                      |   | 100% |   | Alberta, Canada           |
| Nexen Brasil Exploração Petróleo Ltda.  |   | 100% |   | Brazil                    |
| Nexen E & P Services Nigeria Limited               |   | 100% |   | Nigeria                   |
| Nexen Energy Acquisitions Holdings Limited             |   | 100% |   | Jersey                    |
| Nexen Energy Holdings International Limited            |   | 100% |   | Jersey                    |
| Nexen Energy Holdings U.S.A. Inc.                      |   | 100% |   | Delaware, USA             |
| Nexen Energy Marketing Europe Limited                  |   | 100% |   | England and Wales         |
| Nexen Energy Marketing Nigeria Limited                 |   | 100% |   | Nigeria                   |
| Nexen Energy Marketing U.S.A. Inc.                     |   | 100% |   | Delaware, USA             |
| Nexen Energy Services International Ltd.               |   | 100% |   | England and Wales         |
| Nexen Energy Services U.S.A. Inc.                      |   | 100% |   | Delaware, USA             |
| Nexen Energy ULC                                       |   | 100% |   | British Columbia, Canada  |
| Nexen Ettrick U.K. Limited                             |   | 100% |   | England and Wales         |
| Nexen Exploration Norge AS                             |   | 100% |   | Norway                    |
| Nexen Field Services Nigeria Limited                   |   | 100% |   | Nigeria                   |
| Nexen Holdings U.S.A. Inc.                             |   | 100% |   | Delaware, USA             |

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| Nexen Holdings West Africa Limited                          |   | 100% |   | Jersey             |
|------------------------------------------------------------------|--------|------|--------|-------------------------|
| Nexen Marketing International Ltd.                          |   | 100% |   | Barbados           |
| Nexen Marketing Singapore Pte Ltd.                          |   | 100% |   | Singapore          |
| Nexen New Venture Jersey Limited                            |   | 100% |   | Jersey             |
| Nexen Oil & Gas Holdings U.S.A. Inc.                    |   | 100% |   | Delaware, USA      |
| Nexen Oilfield Services Nigeria Limited                     |   | 100% |   | Jersey             |
| Nexen Petroleum Capital Management U.S.A. Inc.              |   | 100% |   | Delaware, USA      |
| Nexen Petroleum Colombia Limited                            |   | 100% |   | Jersey             |
| Nexen Petroleum Deepwater Nigeria Limited                   |   | 100% |   | Nigeria            |
| Nexen Petroleum Dragon U.K. Limited                         |   | 100% |   | England and Wales  |
| Nexen Petroleum Exploration and Production Nigeria Limited  |   | 100% |   | Nigeria            |
| Nexen Petroleum Holdings U.S.A. Inc.                        |   | 100% |   | Delaware, USA      |
| Nexen Petroleum International (U.S.A.) Inc.                 |   | 100% |   | Delaware, USA      |
| Nexen Petroleum Nigeria Limited                             |   | 100% |   | Nigeria            |
| Nexen Petroleum Offshore U.S.A. Inc.                        |   | 100% |   | Delaware, USA      |
| Nexen Petroleum Operations Yemen Limited                    |   | 100% |   | Jersey             |
| Nexen Petroleum Poland Sp. zo.o.                            |   | 100% |   | Poland             |
| Nexen Petroleum Sales U.S.A. Inc.                           |   | 100% |   | Texas, USA         |
| Nexen Petroleum U.K. Holdings Limited                       |   | 100% |   | England and Wales  |

----

| Nexen Petroleum U.K. Limited                  |   | 100% |   | England and Wales     |
|----------------------------------------------------|--------|------|--------|----------------------------|
| Nexen Petroleum U.S.A. Inc.                   |   | 100% |   | Delaware, USA         |
| Nexen Resource Holdings U.K. Limited          |   | 100% |   | England and Wales     |
| Nexen Services Jersey Limited                 |   | 100% |   | Jersey                |
| Wascana Energy 2001 Ltd.                      |   | 100% |   | Saskatchewan, Canada  |
| Canadian Nexen Petroleum Yemen                |   | 100% |   | Alberta, Canada       |
| Nexen Crossfield Partnership                  |   | 100% |   | Alberta, Canada       |
| Nexen Energy U.K. LLP                         |   | 100% |   | England and Wales     |
| Nexen Marketing                               |   | 100% |   | Alberta, Canada       |
| Nexen Med Hat-Hatton Partnership              |   | 100% |   | Alberta, Canada       |
| Nexen Nigerian Holdings Coöperatief U.A  |   | 100% |   | Netherlands           |
| Nexen Oil Sands Partnership                   |   | 100% |   | Alberta, Canada       |

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