UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

of the Securities Exchange Act of 1934

For the month of December 2018

Commission File Number 1-14966

CNOOC Limited

(Translation of registrant’s name into English)

65th Floor

Bank of China Tower

One Garden Road

Central, Hong Kong

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F x    Form 40-F ¨ 

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ¨ 

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ¨ 

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes ¨    No x

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): Not applicable 

Signature 

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. 

	CNOOC Limited
By:	/s/ Xiaonan Wu
Name:	Xiaonan Wu
Title:	Joint Company Secretary

Date: December 18, 2018

EXHIBIT INDEX

Exhibit No.	Description
99.1	Press release entitled “CNOOC Signs Strategic Cooperation Agreements with 9 International Oil Companies”

Exhibit 99.1

中国海洋石油有限公司 

CNOOC LIMITED

Press Release - For Immediate Release

CNOOC Signs Strategic Cooperation Agreements with 9 International Oil Companies

(Hong Kong, December 18, 2018) - CNOOC Limited (the “Company”, SEHK: 00883, NYSE: CEO, TSX: CNU) announced today that its parent company, China National Offshore Oil Corporation (CNOOC), has signed Strategic Cooperation Agreements with 9 international oil companies including: Chevron, ConocoPhillips, Equinor, Husky, KUFPEC, Roc Oil, Shell, SK Innovation and TOTAL (in alphabetical order).

According to the agreements, the Strategic Cooperation Areas are located in the Pearl River Mouth Basin offshore China, including Area A and Area B (existing mining license areas and the contract areas are not included). Area A is approximately 15,300 square kilometers, with a water depth of 80-120 meters and only open for the deep layers below Enping Formation of Paleogene. Area B is approximately 48,700 square kilometers, with a water depth of 500-3,000 meters and open for all the layers.

The agreements will facilitate the establishment of a long term and stable cooperation and share the development opportunities to a certain extent in the Strategic Cooperation Areas, creating conditions for the final signing of contracts. CNOOC Limited, as an independent oil and gas exploration and production company, is the only vehicle through which CNOOC engages in exploration, development, production and sale of crude oil and natural gas.

- End -

Notes to Editors:

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

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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 “expect”, “anticipate”, “continue”, “estimate”, “objective”, “ongoing”, “may”, “will”,

“project”, “should”, “believe”, “plans”, “intends” and similar expressions are intended to identify such forward-looking statements. These statements are based on assumptions and analyses made by the Company in light of its experience and its perception of historical trends, current conditions and expected future developments, as well as other factors the Company believes are appropriate under the circumstances. However, whether actual results and developments will meet the expectations and predictions of the Company depends on a number of risks and uncertainties which could cause the actual results, performance and financial condition to differ materially from the Company’s expectations, including but not limited to those associated with fluctuations in crude oil and natural gas prices, the exploration or development activities, the capital expenditure requirements, the business strategy, whether the transactions entered into by the Group can complete on schedule pursuant to their terms and timetable or at all, the highly competitive nature of the oil and natural gas industries, the foreign operations, environmental liabilities and compliance requirements, and economic and political conditions in the People’s Republic of China. For a description of these and other risks and uncertainties, please see the documents the Company files from time to time with the United States Securities and Exchange Commission, including the Annual Report on Form 20-F filed in April of the latest fiscal year.

Consequently, all of the forward-looking statements made in this press release are qualified by these cautionary statements. The Company cannot assure that the results or developments anticipated will be realised or, even if substantially realised, that they will have the expected effect on the Company, its business or operations.

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For further enquiries, please contact:

Ms. Jing Liu 

Manager, Media & Public Relations 

CNOOC Limited 

Tel: +86-10-8452-3404 

Fax: +86-10-8452-1441 

E-mail: mr@cnooc.com.cn

Ms. Iris Wong 

Hill+Knowlton Strategies Asia 

Tel: +852-2894-6263 

Fax: +852-2576-1990 

E-mail: cnooc@hkstrategies.com