Wastewater

CNOOC Limited places great emphasis on wastewater treatment and strictly adheres to standards and regulations, including the Effluent Limitations for Pollutants from Offshore Petroleum Exploration and Production (GB 4914-2008), the Biological Toxicity for Pollutants from Marine Petroleum Exploration and Exploitation (GB 18420.1-2009), the Discharge Standard for Water Pollutants from Ships (GB 3552-2018) and the Sealing Management Regulations for Shipborne Pollution Control Equipment in Coastal Waters. Produced water containing oil and domestic wastewater are treated to meet discharge standards before being discharged, re-injected into formations, or reused, while wastewater generated by operational vessels is comprehensively managed.

Waste Gas

CNOOC Limited strictly complies with environmental regulations and policies in countries and regions where it operates. It actively addresses associated gas treatment in oil fields. In 2024, the Company conducted in-depth inspections on the prevention and control of air pollution in onshore terminals. Following national, local, and industry standards such as the Integrated Emission Standard of Air Pollutants (GB 16297-1996) and the Emission Standards of Air Pollutants for Onshore Oil and Gas Exploitation and Production Industry (GB 39728-2020), it significantly promoted the reduction of VOCs in onshore terminals, effectively fulfilling its environmental protection responsibilities, and playing an important role in coordinating energy development and environmental protection.

Solid Waste

CNOOC Limited strictly adhere to national standards and regulations, including the Technical Specification for the Collection, Storage and Transportation of Hazardous Waste (HJ 2025-2012), the Standard for Pollution Control on Hazardous Waste Storage (GB 18597—2023). We resolutely implement the relevant requirements in the Management Rules for Ecological Protection and Pollution Prevention and Control to effectively minimize the risk of hazardous waste emissions and ensure compliant disposal.

In 2024, we focused on strengthening the data traceability system for solid and hazardous waste transfers. A solid waste full-process management system was launched, comprehensively covering key management elements such as waste-generating units, personnel, marine vessels, land transport units, and disposal entities. This system ensured a seamless digital integration of solid waste management, spanning planning, process tracking, and end-point supervision. It marks a significant step in advancing our transition to intelligent, digital solid waste management.