(Hong Kong, 9?April, 2026) CNOOC Limited?(“the Company”, SEHK: 00883 (HKD counter) and 80883 (RMB counter), SSE: 600938) released its 2025 Environmental, Social and Governance (ESG) Report in Hong Kong?today.

· Adhere to efficient governance and solidify the foundation for development

· Advance green transition?and foster a sustainable ecosystem

· Fulfill social responsibility and share the benefits of development

Faced with profound adjustments in the global energy market and fragmentation of the climate governance landscape, CNOOC Limited adheres to the principle of pursuing progress while maintaining stability, and embeds ESG concepts into development strategy and the entire process of operation. ESG governance has been improved to safeguard the Company's high-quality growth. In 2025, the Company received numerous domestic and international accolades, including the "Corporate Sustainability Leadership Awards – Gold Award" from The Asset?magazine and the "China Listed Company Value Awards ESG" from Securities Times, reflecting broad stakeholder recognition of the Company's high-quality development achievements.?

CNOOC Limited is committed to efficient governance. The Company endeavors to improve decision-making through building a diversified Board of Directors and enhancing the directors' capabilities. ESG-related mechanisms are optimized. Ten key tasks have been completed, including ESG indicator system optimization and climate-related disclosure studies. The Company continues to enhance its risk management and internal compliance systems. Due diligence reviews on ESG issues are conducted. Audits on risk management processes are carried out on a regular basis. All employees have signed the Letter of Commitment on Compliance. Anti-commercial bribery and anti-corruption trainings are arranged to ensure sound corporate governance.

CNOOC Limited is steadily advancing green transition.?The Company continues to optimize its product mix and enhances the capacity of clean energy supply. CNOOC Limited adheres to green and low-carbon production throughout the entire process. Energy efficiency has been improved. The application of shore power has been expanded, driving the consumption of green electricity to 1.08 billion kWh in 2025. Flare gas recovery has also achieved remarkable progress. Integrated development of hydrocarbon and renewable businesses has continued. The Company has made solid progress in offshore wind resource acquisition. Hainan CZ7 wind farm project and the world's first 16-MW Tension Leg Platform (TLP) floating wind power project are advancing in an orderly manner. Carbon-negative sectors are fostered. The Company has led the development of two national offshore CCUS standards, and successfully commissioned China's first offshore CCUS demonstration project at Enping 15-1. Offshore trials for deep-sea CO??hydrate solidification and sequestration have been carried out to explore "shore-to-sea carbon sequestration" potentials. The preliminary research on oil-gas-electricity-hydrogen-carbon comprehensive energy demonstration project has started. CNOOC Limited?adheres to technology-led development.?Its annual R&D expenditure registered?a 22% year-on-year increase.?Digital and intelligent transformation is advanced. The unmanned rate of offshore platforms has been increasing steadily. "Shenhai-1" gas field is selected into China’s first batch of pioneer-class smart factory cultivation list.

CNOOC Limited actively fulfills its social responsibilities.?Upholding the community co-building approach of "EMPOWER-Empowering communities, limitless acts of kindness", the Company?continues to implement public welfare projects in rural revitalization, educational?support, and ecological protection. The?total annual investment exceeds?RMB 134 million, including RMB 74.68 million invested in rural revitalization, which has benefitted approximately 6 million people. In terms of production safety, the Company has been optimizing the accountability system?to reinforce the foundation of "Safe CNOOC". Safety improvement campaigns and hazard inspections and rectifications are carried?out,?to maintain a stable safety performance throughout the year. In line with its?talent-driven strategy, the Company?enhances?employee care and engagement, promoting mutual growth between staff and the Company to improve the?employees' sense of safety, belonging, and fulfillment.?As for supply chain, CNOOC Limited has been deepening reforms and focusing on ESG-related issues. Compliance trainings for suppliers are implemented, to facilitate?a green, win-win, and clean supply chain.?CNOOC Limited?enhances?stakeholder communication and transparency in information disclosure. It has been rated as?A-grade?in the information disclosure assessment conducted by?the Shanghai Stock Exchange for three consecutive years.

Looking ahead, Mr. Zhang Chuanjiang, Chairman of the Company, said:?“CNOOC Limited will foster?new quality productive forces for?marine energy and resources development, and rely on a robust ESG management and disclosure system, to achieve?high-quality and sustainable growth.?We will strive to build a world-class energy and resources group with distinctive marine characteristics.?By pursuing stable development, delivering superior performance, and fulfilling?responsibilities, we aim to share the benefits of growth with all stakeholders. We look forward to joining hands?with you to create a sustainable and prosperous future together.”