CNOOC Limited Western South China Sea — project

The Western South China Sea is one of the Company's important natural gas production areas. In 2025 the Company made two new discoveries there, Weizhou 10-5 and Weizhou 10-5 South, in the buried-hill area of the Beibu Gulf Basin, made breakthroughs in the multi-type buried hills of the Weixiannan Depression, and successfully appraised 13 oil and gas bearing structures, including Lingshui 17-2 and Lingshui 25-1. Dongfang 29-1 Gas Field Development Project, Wenchang 19-1 Oilfield Phase II Project, Wenchang 9-7 Oilfield Development Project, Weizhou 5-3 Oilfield Development Project, Dongfang 1-1 Gas Field Block 13-3 Development Project, Wenchang 16-2 Oilfield Development Project and Weizhou 11-4 Oilfield Adjustment and Satellite Fields Development Project were put into operation during the year.