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 April 2020

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.

Date: April 29, 2020

EXHIBIT INDEX

Exhibit 99.1

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited take no responsibility for the contents of this announcement, make no representation as to its accuracy or completeness and expressly disclaim any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement.

(Incorporated in Hong Kong with limited liability under the Companies Ordinance)

(Stock Code: 00883)

ANNOUNCEMENT

The board of directors (the “Board”) of CNOOC Limited (the “Company”) hereby announces certain selected unaudited key operational statistics of the Company and its subsidiaries (together the “Group”) for the first quarter of 2020 (ended 31 March 2020). The comparative statistics of the Group for the first quarter of 2019 (ended 31 March 2019) are also disclosed in this announcement.

The Company achieved a total net production of 131.5 million barrels of oil equivalent (“BOE”) for the first quarter of 2020, representing an increase of 9.5% year over year (“YoY”). Production from China increased by 9.7% YoY to 87.1 million BOE, mainly attributable to commencement of new projects and the acquisition of China United Coalbed Methane Corporation Limited (“CUCBM”). Overseas production increased by 9.0% YoY to 44.5 million BOE, mainly due to production contribution from new projects including Egina oilfield in Nigeria and Appomattox oilfield in the US Gulf of Mexico.

For the first quarter of 2020, the Company made two new discoveries and drilled 21 successful appraisal wells. In offshore China, Kenli 6-1 oil and gas bearing structure was successfully appraised and became the first large-sized oilfield in Laibei lower uplift, which further proved the huge exploration potential of the Neogene lithologic reservoir in Laizhou Bay. In Guyana, the sixteenth new discovery of Uaru was made in the Stabroek block.

For the new projects planned to commence production this year, Liza oilfield phase 1 in Guyana has commenced production ahead of schedule in December 2019, and other projects progressed as scheduled.

The unaudited oil and gas sales revenue of the Company reached approximately RMB 39.95 billion for the first quarter of 2020, representing a decline of 5.5% YoY, mainly due to the combined effect of lower realised oil price and increased oil and gas sales volume. During the period, the Company’s average realised oil price decreased 19.3% YoY to US$49.03 per barrel, which was in line with the trend of international oil prices. The Company’s average realised gas price was US$6.38 per thousand cubic feet, representing a decrease of 7.3% YoY, primarily due to the declined gas price in North America.

For the first quarter of 2020, the Company's capital expenditure reached approximately RMB 16.90 billion, up 20.1% YoY as a result of the increased workloads.

Under the current low oil price environment, the Company has adjusted its operating strategy promptly and implemented more prudent investment decision-making to ensure its long-term sustainable development. The Company has reduced its annual net production target for 2020 from 520-530 million BOE to 505-515 million BOE and total capital expenditures for 2020 from RMB 85-95 billion to RMB 75-85 billion.

First Quarter and Year-to-Date Net Production Summary (Unaudited)

* Including our interest in equity method investees, which is approximately 5.0 mmboe in Q1 2020 and approximately 5.1 mmboe in Q1 2019.

First Quarter and Year-to-Date Revenue and Capital Expenditures (Unaudited)*

* Capitalised interests were not included. Capitalised interests for Q1 2020 and Q1 2019 were RMB699 million and RMB784 million, respectively.

For the purpose of this announcement, certain comparative financial data for the first quarter of 2019 have been restated as a results of the acquisition of CUCBM. Unless otherwise indicated, an exchange rate of US$1 = RMB6.9750 has been used for the financial data of the first quarter of 2020, and an exchange rate of US$1 = RMB6.7303 has been used for the financial data of the first quarter of 2019, where applicable. The usage of these exchange rates is for illustration only and does not constitute a representation that any amount has been, could have been or may be exchanged or converted at the above rates or at any other rate at all.

This announcement is published on the website of The Stock Exchange of Hong Kong Limited (http://www.hkex.com.hk) and on the Company’s website (http://www.cnoocltd.com).

Hong Kong, 29 April 2020

Exhibit 99.2

CNOOC LIMITED

For Immediate Release

CNOOC Limited Announces Key Operational Statistics for Q1 2020

(Hong Kong, April 29, 2020) - CNOOC Limited (the “Company”, SEHK: 00883, NYSE: CEO, TSX: CNU) today announced its key operational statistics for the first quarter of 2020.

The Company achieved a total net production of 131.5 million barrels of oil equivalent (“BOE”) for the first quarter of 2020, representing an increase of 9.5% year-over-year (“YoY”). Production from China increased by 9.7% YoY to 87.1 million BOE, mainly attributable to commencement of new projects and the acquisition of China United Coalbed Methane Corporation Limited. Overseas production increased by 9.0% YoY to 44.5 million BOE, mainly due to production contribution from new projects including Egina oilfield in Nigeria and Appomattox oilfield in the US Gulf of Mexico. For the new projects planned this year, Liza oilfield phase 1 in Guyana came on stream ahead of schedule in December 2019, and other projects progressed as scheduled.

During the period, the Company made two new discoveries and drilled 21 successful appraisal wells. In offshore China, Kenli 6-1 oil and gas bearing structure was successfully appraised and became the first large-sized oilfield in Laibei lower uplift, which further proved the huge exploration potential of the Neogene lithologic reservoir in Laizhou Bay. In Guyana, the 16^th new discovery of Uaru was made in the Stabroek block.

For the first quarter of 2020, the Company’s average realised oil price decreased by 19.3% YoY to US$49.03 per barrel, which was in line with the trend of international oil prices. The Company’s average realised gas price was US$6.38 per thousand cubic feet, decreased by 7.3% YoY, primarily due to the declined gas price in North America. The unaudited oil and gas sales revenue of the Company reached approximately RMB 39.95 billion during the period, down only 5.5% YoY, mainly due to the combined effect of lower realised oil price and increased oil and gas sales volume.

The Company's capital expenditure reached approximately RMB 16.90 billion for the first quarter of 2020, up 20.1% YoY, as a result of the increased workloads.

Under the current low oil price environment, the Company has adjusted its operating strategy promptly and implemented more prudent investment decision to ensure its long-term sustainable development. The Company has reduced its annual net production target for 2020 from 520-530 million BOE to 505-515 million BOE and total capital expenditures for 2020 from RMB 85-95 billion to RMB 75-85 billion.

Mr. Xu Keqiang, CEO of the Company, said, “The global oil and gas market was facing an unprecedented situation in the first quarter of 2020 as impacted by the COVID-19 pandemic and sharp drop of international oil prices. In response to an increasingly complex external environment, CNOOC Limited took proactive measures to face the challenges and strived to mitigate the impact. For the rest of the year, we will continue to implement more stringent cost controls, and further strengthen our cash flow management. ”

- End -

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 “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, macro-political and economic factors, changes in the tax and fiscal regimes of the host countries in which we operate, the highly competitive nature of the oil and natural gas industry, the exploration and development activities, mergers, acquisitions and divestments activities, environmental responsibility and compliance requirements, foreign operations and cyber system attacks.  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.