Sinopec Oilfield Service Corporation (Sinopec SSC) has issued a notice convening its first H Shareholders Meeting for 2026.

Key Meeting Details • Date & Time: Friday, 22 May 2026, 10:15 a.m. • Venue: Conference Room 7, 3rd Floor, Beijing Kuntai Royal Hotel, Chaowai Avenue B12, Chaoyang District, Beijing.

Core Resolution Shareholders will vote on a single special resolution authorising the Board to repurchase the company’s domestic shares and/or overseas-listed foreign shares.

Shareholder Eligibility & Registration • Record Date: Close of business Friday, 15 May 2026. • Register Closure: 15 May 2026–22 May 2026 (both days inclusive). • Share transfer documents must be lodged with Computershare Hong Kong Investor Services no later than 4:30 p.m. on Thursday, 14 May 2026 to qualify for attendance and voting.

Proxy Arrangements • Completed proxy forms, together with notarised powers of attorney where applicable, must be submitted to the company’s business address or to Computershare by 10:15 a.m. on 21 May 2026 (Hong Kong time). • Shareholders may appoint one or more proxies; proxies are not required to be shareholders.

Additional Information • Voting will be conducted by poll, with votes recorded as “for,” “against,” or “abstention.” • The Board encourages shareholder participation and will address questions raised during the meeting. • Attendees are responsible for their own travel and accommodation costs.

Business Contact Sinopec SSC, No. 9 Jishikou Road, Chaoyang District, Beijing, 100728, PRC (Tel: +86-10-5996 5998).