Sinopec Oilfield Service : ANNOUNCEMENT ON PROPOSED REDUCTION OF SHAREHOLDING

Hong Kong Exchanges and Clearing Limited and The Stock Exchange of Hong Kong Limited takes no responsibility for the contents of this announcement, makes 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.

Sinopec Oilfield Service Corporation

(a joint stock limited company established in the People's Republic of China)

(Stock code: 1033)

OVERSEAS REGULATORY ANNOUNCEMENT

ANNOUNCEMENT ON PROPOSED REDUCTION OF SHAREHOLDING

This announcement is made pursuant to the Inside Information Provision under Part XIVA of the Securities and Futures Ordinance and Rule 13.09(2) and Rule 13.10B of the Rules Governing the Listing of Securities on The Stock Exchange of Hong Kong Limited.

The board of directors of the Company and all directors warrant that there are no false representations, misleading statements and material omissions in this announcement, and are severally and jointly responsible for the truthfulness, accuracy and completeness of the content herein.

Significant contents reminder:

• • Basic information on the shareholding of shareholder: As at the date of this announcement, CITIC

  Corporation Limited* ( 中國中信有限公司 ) ("CITIC Corporation") was interested in 1,035,000,000 shares of Sinopec Oilfield Service Corporation (the "Company"), representing 5.45% of the total share capital of the Company. The above shares are acquired by CITIC Corporation prior to the initial public offering of A shares of the Company. Such portion of shares have been released from selling restrictions and qualified for listing and trading on 22 August 2016.

• • Main contents of the proposed reduction of shareholding: CITIC Corporation proposed to reduce shares in aggregate of no more than 1% of the total number of shares of the Company (i.e. no more than 189,843,400 shares) by way of centralised bidding and/or commodity trading within six months after 15 trading days from the date of this announcement based on the market price. During the implementation of the proposed reduction of shareholding, CITIC Corporation shall make corresponding adjustment to the number of shares subject to the aforesaid reduction in the event of ex-dividend matters including distribution of dividend, bonus issue, capitalisation of reserves, placing of shares, etc.

• I. BASIC INFORMATION SHAREHOLDING

OFTHEENTITYSUBJECTTOREDUCTIONOFName of shareholderCapacity of shareholderNumber of shares heldShareholding percentage

Source of shares held currently

CITIC Corporation

Shareholder holding more than 5% interest other than the largest shareholder

1,035,000,000

5.45% Acquired prior to the initial public offering of A shares

The entity subject to the aforesaid reduction of shareholding has not party acting in concert and no reduction of shareholding has been taken place since the A Share listing of the Company.

• II. MAIN CONTENTS OF THE PROPOSED REDUCTION OF SHAREHOLDING

  Reason(s) for
  Number of	Percentage of	Mean of	Duration of	Source of	the proposed
  Name of	shares proposed	reduction of	reduction of	reduction of	Reasonable	shares proposed	reduction of
  shareholder	to be reduced	shareholding	shareholding	shareholding	price range	to be reduced	shareholding
  CITIC	No more than	No more than 1% of	Centralised	22 April	market price	Shares acquired prior to	For its own
  Corporation	189,843,400	the total share	bidding or	2021-18	the initial public	operational
  shares	capital of	commodity	October 2021	offering of A shares	needs
  the Company	trading

  • (1) Does the relevant shareholder have other arrangements □Yes √ No

  • (2) Has the shareholder made any prior undertaking with respect to the shareholding percentage, number of shares held, duration of shareholding, means of reduction of shareholding, number of shares to be reduced and price of reduction of shareholding □Yes √ No

• III. RELEVANT RISK REMINDER:

  • (1) The proposed reduction of shareholding is conducted based on CITIC Corporation's own operational needs and will have no material impact on the corporate structure and business development of the Company. During the reduction of shareholding, CITIC Corporation will decide whether or not to implement and how to implement the proposed reduction of shareholding based on factors including the market conditions and share price of the Company. Uncertainties exist in the number of shares to be reduced and the relevant pricing.

  • (2) Whether the implementation of the proposed reduction of shareholding will be associated with the risk of change of control of the listed company □Yes √ No

  • (3) Other risk reminder

    The proposed reduction of shareholding is in compliance with the relevant requirements of the applicable laws and regulations including the Several Provisions on the Reduction of Shares Held in a Listed Company by Shareholders, Directors, Supervisors and Senior Management promulgated by China Securities Regulatory Commission, the Rules Governing the Listing of Stocks on Shanghai Stock Exchange and the Implementation Measures on the Reduction of Shares Held in a Listed Company by Shareholders, Directors, Supervisors and Senior Management issued by the Shanghai Stock Exchange. During the implementation of the proposed reduction of shareholding, CITIC Corporation will be in strict compliance with the requirements of the applicable laws and regulations and timely perform its obligations of information disclosure.

By Order of the Board

Shen Zehong Company Secretary

Beijing, the PRC, 30 March 2021

As at the date of this announcement, the Board of Directors comprises Mr. Chen Xikun#, Mr. Yuan Jianqiang#, Mr. Lu Baoping+, Mr. Fan Zhonghai+, Mr. Wei Ran+, Mr. Zhou Meiyun+, Mr. Chen Wei-dong*, Mr. Dong Xiucheng* and Mr. Zheng Weijun*.

# Executive Director + Non-Executive Director

* Independent Non-Executive Director