Environmental Protection

CNOOC Limited supports green production by strictly controlling pollutant emissions, conducting pollutant and waste management and monitoring throughout the operation processes, thereby reducing waste.

We abide by the Environmental Protection Law, the Marine Environmental Protection Law, other laws and regulations of the People's Republic of China, and relevant laws and regulations of the host countries. In 2022, we issued the Measures for Ecological Environmental Protection, and formulated and revised six environment management rules, including the Management Rules for Ecological Protection and Pollution Prevention and Control. Its supporting documents, such as the Solid Waste Management Guidelines and the Management Framework for the Whole Process of Soil and Groundwater Pollution Prevention and Control, which cover environmental protection management of construction projects, pollution prevention and control, risk management, capability building, informationalization, special inspections, etc., further clarify our requirements on ecological, environmental protection in project construction and operation.

In 2022, to further enhance the pollutants treatment capacity of major waste-producing units, we set up a special pollutant management team to upgrade the management of volatile organic compounds (VOCs), marine sewage, and solid waste. The team will identify hidden dangers in discharging "waste gas, wastewater, and solid waste", and study advanced treatment technologies, so as to lay a solid foundation for high-standard transformation.

Waste Water:

CNOOC Limited stringently implements laws, regulations and policies released by China and the host countries, and puts more effort into marine environmental protection and control.;

•   Oil-containing Waste Water from Exploitation of Oil and Gas Fields. Strictly abiding by relevant standards for pollutants in offshore oil exploration and development as well as the Water Quality Standard and Practice for Analysis of Oilfield Injecting Waters in Clastic Reservoirs, we will discharge or reinject the waste water only when it has met the standards after treatment.

•   Oil-containing Waste Water from Vessels. We discharge the up-to-standard water or transport back to land for disposal in accordance with the Discharge Standard for Water Pollutants from Ships, the International Convention for the Prevention of Pollution from Ships, 73/78 and the Regulations on the Administration of Sealing for Discharge Equipment on Ships in Coastal Waters.

•   Domestic Sewage. We discharge the sewage after reaching standards in accordance with the Effluent Limitations for Pollutants from Offshore Petroleum Exploration and Production; Domestic sewage from part of the oilfields in the Bohai Sea is reused/discharged, or reinjected into the stratum after treatment.

•   Drilling Fluids and Cuttings. The Company strictly implements the standard requirements CNOOC Emission Concentration Limits of Pollutants from Exploration and CNOOC Biological Toxicity of Pollutants for Exploration and Development; Oil-based drilling fluids and synthetic-based drilling fluids are not discharged into the sea. In the Bohai Sea area, non-water-based drilling fluid drilling cuttings, water-based drilling fluid and its drilling cuttings in drilling oil layers are not discharged, but are all recovered; When it is really difficult to recover water-based drilling fluid, water-based drilling fluid cuttings and non water-based drilling fluid cuttings in other sea areas, after approval by the competent department of the sea area, it will be discharged meeting standards, and the parts that do not meet standards will be transported back to land and handed over to qualified units for compliance disposal.

Waste Gas

The Company conscientiously implements China and the host countries' laws, regulations, and policy documents. In 2022, CNOOC Limited issued the Work Plan for the Control of Total Volatile Organic Compounds (VOCs) and Emission Reduction in the Seventh Term of CNOOC Limited (2022-2024), which stipulated the treatment requirements of VOCs at all fronts during the seventh term, and promoted each branch and subsidiary to summarize the VOCs challenges and formulate special rectification plans.

Solid Waste

Pursuant to the Technical Specification for the Collection, Storage and Transportation of Hazardous Waste, the Measures for Management of Joint Transfer Bills for Hazardous Waste and other norms in China, as well as the Implementation Plan for Comprehensively Strengthening Solid Waste Management and other internal requirements for the compliant disposal of hazardous waste, CNOOC Limited chooses enterprises with appropriate qualifications and capabilities to carry out the storage, transportation and disposal of hazardous waste. We have also established the offshore solid waste information platform and a special solid waste management team to further standardize the handling and disposal of drilling fluid, cutting, production waste, and informationization management.

Environmental Supervision and Inspection

Adhering to the principle of problem-oriented and goals-oriented, CNOOC Limited deepens regular top-down eco-environment protection and inspection and requires the Environmental Protection Department to lead specialists from multiple sectors to conduct special inspections on each branch and subsidiary. In 2022, we completed inspections on four branches and subsidiaries, which, together with what had been done in 2021, covered all subunits, helping each unit to identify and rectify potential environmental vulnerabilities and continuously improve environmental management.

Besides, we commissioned qualified monitoring units to monitor offshore pollutant discharge and determined the discharge of offshore production and domestic sewage. In 2022, we carried out environmental supervision for 10 offshore platforms, 2 land-based terminals, and 2 coalbed operation areas, where we checked the compliance of on-site discharge and facilitated the rectification and upgrading of pollutant-discharging units.

Emission and Waste Reduction Targets:

•   Waste gas emission from onshore terminals is discharged after being treated up to standard: The emission of air pollutants like SO2 and NOX is mainly subject to the Integrated Emission Standard of Air Pollutants (GB 16297-1996). However, if any, stricter environmental protection requirements from local authorities shall prevail.

•   100% of hazardous waste is entrusted to qualified third party for compliant disposal: Hazardous waste management is mainly subject to the National Hazardous Waste List (2021) and the Standard for Pollution Control on Hazardous Waste Storage (GB 18597-2001).

•   100% of non-hazardous waste is entrusted to licensed third party for compliant disposal.

Oil Content in Discharged Water(Platform + Terminal)Tons3,4243,4913,864
Chemical Oxygen Demand (COD)(Platform + Terminal)Tons117.1131.2171.4
Sulfur Dioxide(SO₂) (Terminal)Tons28.521.612.9
Nitrogen Oxides (NOx) (Terminal)Tons417.8317.8179.4
Non-hazardous Waste(Platform + Terminal)Tons30,70351,49573,411
Hazardous Waste(Platform + Terminal)Tons28,01140,91850,979

We strictly follow the requirements of China's laws and regulations and always adhere to the principle of minimizing and recycling solid/hazardous waste, and realizing the harmless disposal of solid/hazardous waste. The solid waste/hazardous waste or the production intensity of solid waste/hazardous waste is not disclosed for the time being as no relevant description has been found in domestic industry regulatory requirements and it is not a key performance indicator for the daily management of enterprises.

The Company's sulfur dioxide and nitrogen oxides emissions are collected and calculated based on the measured data of pollutants’ concentration.