China BlueChemical Ltd. — Proxy Solicitation & Information Statement 2026

Apr 13, 2026

NOC

中海石油化学股份有限公司 China BlueChemical Ltd.*

(a joint stock limited company incorporated in the People's Republic of China with limited liability)

(Stock Code: 3983)

Reply Slip for Domestic Shareholders' Class Meeting

I/(We) ____________

of (address) ____________

telephone number: ________ and fax number: __________

being the holder(s) of _________ domestic shares (the "Domestic Shares") of China BlueChemical Ltd. (the "Company") hereby confirm that I (We) wish to attend or appoint a proxy to attend (on my/(our) behalf) the class meeting for the shareholders of the Domestic Shares ("Domestic Shareholders' Class Meeting") to be held at the 3rd Floor Meeting Room, Yihai International, Haikou, the PRC on Thursday, 28 May 2026 immediately after the H shares shareholders' class meeting of the Company.

Signature(s): ____________

Date: _______ 2026

Note: Shareholders of Domestic Shares who intend to attend the meeting in person or by proxy should return the reply slip in person, by post or by fax to the Company's Secretary Office of the Board of Directors in China on or before Friday, 8 May 2026. The Company's Secretary Office of the Board of Directors in China is Room 1707, Kaikang CNOOC Mansion, No. 15, Sanqu, Anzhenxili, Chaoyang District, Beijing, the PRC (Tel: 0086-10-84527250, Fax: 0086-10-84527254, Post code: 100029).

• For identification purpose only