致非登记持有人之通知信函及回条 – 以电子方式发布公司通讯之安排

(Incorporated in Hong Kong with limited liability under the Companies Ordinance) （根据公司条例于香港注册成立的有限公司） Stock Codes: 00883 (HKD Counter) and 80883 (RMB Counter) 股票代号：00883（港币柜台）及80883（人民币柜台） 28 June 2024 Dear non-registered holder(s) of the Hong Kong Shares (as defined below) Arrangement of Electronic Dissemination of Corporate Communications The English and Chinese versions of all Corporate Communications* of CNOOC Limited (the “Company”) are available electronically on the website of the The Stock Exchange of Hong Kong Limited (the “Stock Exchange”) at www.hkexnews.hk and the Company's website at www.cnoocltd.com.As a non-registered holder of Hong Kong Shares if you are interested in receiving the Company's future Corporate Communications you should liaise with your bank(s) broker(s) custodian(s) nominee(s) or HKSCC Nominees Limited through which your Hong Kong Shares are held (the "Intermediaries") and provide your email address to the Intermediaries.The Company will send to you notifications for publication of Corporate Communications on the Stock Exchange's website and the Company’s website by email if the Company has received your functional email address from the Intermediaries or by post if no functional email address is provided and the Company has obtained your postal address.If you wish to receive future Corporate Communications in printed form please complete the enclosed reply form and return it by post or by email to the Company’s Hong Kong share registrar (the “Share Registrar”). Please note that such instruction shall be valid from the date on which such instruction is received until the next time when the Company seeks consent from its registered holders of Hong Kong Shares to receiving the electronic version of all future Corporate Communications or until it is revoked or replaced or you cease to be a holder of Hong Kong Shares whichever is the earliest.Contact details of the Share Registrar: Postal address : 17M Floor Hopewell Centre 183 Queen’s Road East Wanchai Hong Kong Email address : cnooc.ecom@computershare.com.hk Should you have any queries relating to this letter please contact the Share Registrar at (852)2862 8688 during business hours from 9:00 a.m. to 6:00 p.m. (Hong Kong time) Mondays to Fridays excluding Hong Kong public holidays.Yours faithfully By order of the Board CNOOC Limited Mr. Xu Yugao Joint Company Secretary * "Corporate Communications" means any documents issued or to be issued by the Company for the information or action of holders of any of its securities including but not limited to (a) the directors’ report its annual accounts together with a copy of the auditors’ report and where applicable its summary financial report; (b) the interim report and where applicable its summary interim report; (c) a notice of meeting; (d) a listing document; (e) a circular; and (f) a proxy form.各位香港股份（定义如下）非登记持有人： 以电子方式发布公司通讯之安排 中国海洋石油有限公司（「本公司」）之所有公司通讯*的英文版和中文版会在香港联合交易所有限公司（「联交所」）网站www.hkexnews.hk和本公司网站 www.cnoocltd.com上提供。 作为本公司在香港联合交易所有限公司上市股份（「香港股份」）之非登记持有人，如阁下有意收取本公司日后的公司通讯，阁下应联络代阁下持有股份的银行、经纪、托管商、代理人或香港中央结算（代理人）有限公司（统称「中介机构」），并向中介机构提供阁下的电邮地址。 本公司会将有关公司通讯已在联交所网站及本公司网站上发布的通知电邮至阁下的电邮地址（如本公司已从收中介机构到阁下有效的电邮地址）或邮寄至阁下的 邮寄地址（如未提供有效的电邮地址且本公司已获得阁下的邮寄地址）方式发送。 若阁下希望日后收取公司通讯之印刷本，请填妥随附之回条并邮寄或电邮至本公司之香港股份过户处（「股份过户处」）。请注意该指示自收取指示日期起至本公司下一次向香港股份登记持有人寻求其同意以电子版本形式收取日后所有公司通讯之时，或直至该指示被撤回或取代或阁下不再是香港股份持有人为止（以较早者为准）有效。 股份过户处联络资料: 邮寄地址: 香港湾仔皇后大道东 183 号合和中心 17M 楼 电邮地址: cnooc.ecom@computershare.com.hk 如阁下对本函件有任何疑问，请于办公时间星期一至五（香港公众假期除外）上午9时正至下午6时正（香港时间）其间致电股份过户处(852)28628688查询。 承董事会命中国海洋石油有限公司联席公司秘书徐玉高谨启 * 「公司通讯」是指本公司发出或将予发出以供其任何证券的持有人参照或采取行动的任何文件，包括但不限于(a) 董事会报告、年度帐目以及核数师报告副本以及（如适用）财务摘要报告； (b) 中期报告及其中期报告摘要（如适用）； (c) 会议通知； (d) 上市文件； (e) 通函;和 (f) 代表委任表格。 2024 年 6 月 28 日CCS9336 CNOH_NRH REPLY FORM 回条 To: Hong Kong Registrars Limited (The “Share Registrar”) 致： 香港证券登记有限公司（「股份过户处」） 17M Floor Hopewell Centre 香港湾仔皇后大道东 183 号 183 Queen’s Road East Wan Chai Hong Kong 合和中心 17M 楼 (Note 1) 提示(附注 1)REMINDER As a non-registered holder of the Company's shares listed on The Stock Exchange of Hong Kong Limited (the “Hong Kong Shares”) if you wish to receive all future Corporate Communications* from the Company you should liaise with your bank(s) broker(s) custodian(s) nominee(s) or HKSCC Nominees Limited through which your Hong Kong Shares are held (collectively the “Intermediaries”) and provide your email address to your Intermediaries.作为公司在香港联合交易所有限公司上市股份（「香港股份」）之非登记持有人，如阁下有意收取公司日后的公司通讯，阁下应联络代阁下持有香港股份的银行、经纪、托管商、代理人或香港中央结算（代理人）有限公司（统称「中介机构」），并向中介机构提供阁下的电邮地址。 Request for Corporate Communications in printed form / 要求收取公司通讯文件印刷版 (Notes 2 3 & 4 ) (附注2、3及4) (Please mark “?” in the below box if applicable) （如适用，请在以下方格内划上「?」号）Name of the listed company (the “Company”) : CNOOC Limited 上市公司（「公司」）名称：中国海洋石油有限公司 I/we would like to receive the Corporate Communications in printed form. This instruction is valid from the date on which such instruction is received until the next time when the Company seeks consent from its registered holders of Hong Kong Shares to receiving the Electronic Version of all future Corporate Communications or until it is revoked or replaced or I/we cease to be a holder of Hong Kong Shares whichever is the earliest.本人╱我们欲收取公司通讯文件的印刷版。本指示自收取指示日期起至公司下一次向香港股份登记持有人寻求其同意以电子版本形式收取日后所有公司通讯之时，或直至该指示被撤回或取代或本人╱我们不再是香港股份持有人为止（以较早者为准）有效。 Printed English version 英文印刷本 Printed Chinese version 中文印刷本 Printed English and Chinese versions 中、英文印刷本 (Note 3) Name(s) of non-registered holder(s): Signature(s): 非登记股东姓名：(附注3)签名： (Please use ENGLISH BLOCK LETTERS 请用英文正楷填写) Contact number: Date: 联络电话号码： 日期： Notes: 附注： 1. This letter is addressed to non-registered holder(s) of the Hong Kong Shares (“Non-registered holder” means such person or company whose Hong Kong Shares are held in The Central Clearing and Settlement System (CCASS)).此函件乃向公司香港股份之非登记持有人（「非登记持有人」指香港股份存放于中央结算及交收系统的人士或公司）发出。 2. Please complete all your details clearly. 请阁下清楚填妥所有资料。 3. Any form with no box marked “?” with no signature or otherwise incorrectly completed will be void. 如在本回条未有在方格内划上「?」号、或未有签署、或在其他方面填写不正确，则本回条将会作废。 4. For the avoidance of doubt the Company does not accept any other instructions given on this Reply Form. 为免存疑，在本回条上的任何额外指示，公司将不予处理。 * Unless otherwise specified Corporate Communications refer to any documents issued or to be issued by the Company for the information or action of holders of any of its securities including but not limited to (a) the directors’ report its annual accounts together with a copy of the auditors’ report and where applicable its summary financial report; (b) the interim report and where applicable its summary interim report; (c) a notice of meeting; (d) a listing document; (e) a circular and (f) a proxy form.除非另有注明，公司通讯指公司已发出或将予发出以供其任何证券的持有人参照或采取行动的任何文件，包括但不限于(a) 董事会报告、年度帐目以及核数师报告副本以及（如适用）财务摘要报告； (b) 中期报告及其中期报告摘要（如适用）； (c) 会议通知； (d) 上市文件； (e) 通函;和 (f) 代表委任表格。 PERSONAL INFORMATION COLLECTION STATEMENT收集个人资料声明 (i) “Personal Data” in this statement has the same meaning as “personal data” in the Personal Data (Privacy) Ordinance Chapter 486 of the Laws of Hong Kong (“PDPO”).本声明中所指的「个人资料」与香港法例第486章《个人资料（私隐）条例》（「《私隐条例》」）中「个人资料」的涵义相同。 (ii) Your Personal Data provided in this Reply Form will be used in connection with the Company’s electronic dissemination of Corporate Communications. Your supply of Personal Data to the Company is on a voluntary basis.In case of a failure to provide sufficient information the Company may not be able to process your instructions and/or requests as stated in this Reply Form.阁下于本回条所提供的个人资料将用于有关公司以电子方式发布公司通讯的事宜上。阁下是自愿向公司提供个人资料。若阁下未能提供足够资料，公司可能无法处理阁下在本回条上所述的指示及/或要求。 (iii) Your Personal Data may be disclosed or transferred by the Company to its subsidiaries the Share Registrar and/or other companies or bodies for any of the stated purposes or when it is required to do so by law and will be retained for such period as may be necessary for our verification and record purposes.公司可就任何所说明的用途或在法例规定的情况下，将阁下的个人资料披露或转移给公司的附属公司、股份过户处、及/或其他公司或团体，并将在适当期间保留该等个人资料作核实及纪录用途。 (iv) You have the right to request access to and/or correction of your Personal Data in accordance with the provisions of the PDPO. Any such request for access to and/or correction of your Personal Data should be in writing by mail to the Hong Kong Privacy Officer of the Share Registrar at 17M Floor Hopewell Centre 183 Queen’s Road East Wan Chai Hong Kong or by email at PrivacyOfficer@computershare.com.hk.阁下有权根据《私隐条例》的条文查阅及/或修改 阁下的个人资料。任何该等查阅及/或修改个人资料的要求均须以书面方式邮寄至股份过户处（地址为香港湾仔皇后大道东 183 号合和中心 17M 楼）向香港隐私主任提出，或发送电邮至 PrivacyOfficer@computershare.com.hk。 Mailing Label 邮寄标签 Please cut the mailing label and stick it on an envelope to return this form to us.Computershare Hong Kong Investor Services Limited No postage is necessary if posted in Hong Kong.香港中央证券登记有限公司 Freepost No. 简便回邮号码：37 当 阁下寄回此回条时，请将邮寄标签剪贴于信封上。 Hong Kong 香港 如在本港投寄，阁下无需支付邮费或贴上邮票。