Bohai

Bohai is the most important crude oil producing area for the Company. The crude oil produced in this region is mainly heavy oil. The operational area in Bohai is mainly shallow water with a depth of approximately 10 to 30 metres. As of the end of 2021, the reserve and production in Bohai reached 1,536.9 million BOE and 522,084 BOE/day, respectively, representing approximately 26.8% of the Company’s total reserves and approximately 33.3% of its production.

With rich oil and gas resources, Bohai has been one of the Company’s core areas for exploration and development. In 2021, the Company successfully made six discoveries in Bohai, namely Kenli 10-2, Caofeidian 11-3 East, Qinhuangdao 35-5, Jinzhou 25-3, Bozhong 28-1 and Longkou 31-3. In addition, the Company also successfully appraised 19 oil and gas bearing structures, including Bozhong 13-2, Bozhong 19-6, Bozhong 19-2, Bozhong 29-4, Bozhong 19-4, Bozhong 29-1 East, Caofeidian 2-2, Caofeidian 11-3 East, Kenli 10-2, Kenli 20-1, Luda 10-6, Luda 25-1, Luda 27-1, Suizhong 36-2, Jinzhou 25-1 South, Jinzhou 20-5, Qinhuangdao 33-3, Qinhuangdao 27-3 and Longkou 15-2.

In 2021, we efficiently appraised Kenli 10-2 oilfield, and the proven in-place volume exceeded 100 million tons of oil equivalent, which changed the situation that no discovery of lithologic oilfields with 100 million tons of oil equivalent was made in the shallow layers of the sag belt of Bohai oilfields. We continued to explore Luda 10-6 medium-deep lithologic oil and gas reservoirs, which was proved to be light and mid-to-large sized oil and gas fields. We expanded the exploration of Bozhong 13-2 encirclement area, with proven in-place volume exceeding 31 million tons of oil equivalent, another breakthrough in the exploration of hydrocarbon accumulation inside buried hills.

We sped up the capacity construction of new projects. Caofeidian 6-4 oilfield, Luda 29-1 oilfield, Qinhuangdao/Caofeidian oilfields onshore power project, Bozhong 19-4 oilfield adjustment project, Bozhong 26-3 oilfield expansion project, Luda 6-2 oilfield, Caofeidian 11-6 oilfield expansion project and Kenli 16-1 oilfield have all been put into production. Among them, the Qinhuangdao/Caofeidian onshore power project, the world’s largest power-from-shore project to supply offshore oilfields, was put into operation on schedule. It marks that China’s offshore oilfields have achieved historic changes in the way of electricity consumption, and that the transition into low-carbon energy consumption by offshore oilfields has entered the stage of full implementation. In 2021, the crude oil production in Bohai oilfields exceeded 30 million tons, making it the largest crude oil production base in China and providing a solid foundation for the Company to achieve its production growth target in the mid-and-long term.

In 2022, Kenli 6-1 oilfield 10-1 North block development project, Kenli 6-1 oilfield 5-1, 5-2, 6-1 block development project, Bozhong 29-6 oilfield development project and Jinzhou 31-1 gas field development project will be put into production within the year.

Western South China Sea

Western South China Sea is one of the Company’s important crude oil and natural gas production areas. The typical operating water depth in the region ranges from 40 to 1,500 metres. The crude oil produced here is mostly light or medium. As of the end of 2021, the reserves and production in Western South China Sea reached 847.0 million BOE and 195,511 BOE/day, respectively, representing approximately 14.8% of the Company’s total reserves and approximately 12.5% of its production.

In 2021, the Company made 4 discoveries in the Western South China Sea, namely Wushi 16-5, Wushi 1-6, Wushi 22-9 and Baodao 21-1. In addition, the Company successfully appraised 9 structures, namely Weizhou 11-6, Wushi 16-9, Wushi 1-6, Lingshui 17-2, Wenchang 9-3, Wenchang 19-1, Wenchang 8-3, Wenchang 9-7 and Dongfang 13-1. Among them, positive progress was made in the efficient appraisal of Baodao 21-1 gas field, with the proven in-place gas reserves of approximately 30 billion cubic meters, the biggest breakthrough in the Songnan-Baodao sag in more than half a century. Wenchang 9-7 marks the largest discovery made in Wenchang A sag structure in 12 years.

The construction of new projects progressed in an orderly manner. Shenhai-1 gas field and Weizhou 11-2 oilfield were put into production in 2021. The successful production of Shenhai-1 gas field, the first self-operated large deepwater gas field in offshore China, marks a major leap forward of CNOOC Limited’s offshore oil and gas exploration and development to the ultra-deep water depth of 1,500 meters. The gas field will steadily produce 3 billion cubic meters per annum of natural gas for 10 consecutive years, and will become one of the important sources to meet the gas demand in Guangdong, Hong Kong and Hainan area. It will also drive the efficient development of surrounding and follow-up gas fields and help the Company’s progress in its low-carbon transition. In addition, the development projects in the southeast area of Dongfang 1-1 gas field and the south block of Ledong 22-1 gas field are expected to be commissioned in 2022.

Eastern South China Sea

Eastern South China Sea is another important crude oil and natural gas producing area of the Company. The typical operating water depth in the region ranges from 100 to 1,500 metres. The crude oil produced here is mostly light or medium. As of the end of 2021, the reserves and production in Eastern South China Sea reached 665.1 million BOE and 305,828 BOE/day, respectively, representing approximately 11.6% of the Company’s total reserves and approximately 19.5% of its production.

In 2021, the Company made six new discoveries in Eastern South China Sea, namely Xijiang 24-4, Xijiang 30-1, Panyu 11-12, Huizhou 33-4, Huizhou 19-5 and Lufeng 13-8. One oil and gas bearing structure was successfully appraised, namely Lufeng 13-8. The Company has promoted the multi-type, multi-layer exploration in southern Lufeng as a whole, building new and promising bases for increasing reserves in the Eastern South China Sea.

Liuhua 21-2 oilfield, Liuhua 29-2 gas field and Lufeng oilfields regional development project started production in 2021. Enping 15-1/10-2/15-2/20-4 oilfields joint development project is expected to come on stream in 2022.

East China Sea

The typical operating water depth in the East China Sea region is approximately 90 metres. As of the end of 2021, the reserves and production in the region represented approximately 2.7% and approximately 1.2% of the Company’s total reserves and production, respectively.

In 2021, the Company continued to promote pioneering innovation and exploratory experiments in the East China Sea. The technological experiments to enhance oil recovery rate, such as gas reservoir depressurisation extraction, achieved initial results. The unmanned transformation of producing oil and gas fields was completed. We achieved safe and efficient operation of unmanned offshore platforms and significantly reduced production costs.

Onshore China

We mainly engaged in the exploration, development and production of unconventional natural gas resources in onshore China. We have established two major production bases in the Qinshui Basin and the eastern edge of the Erdos Basin. As of the end of 2021, the reserves and production in onshore China represented approximately 1.5% and approximately 2.0% of the Company’s total reserves and production, respectively.

In 2021, the proven in-place volume of onshore unconventional natural gas of the Company increased steadily, with newly added proven in-place volume of approximately 30 billion cubic meters. Linxing gas field implemented the development strategy of “achieving high yield with fewer wells” and positive results had been achieved. High-yield wells accounted for a higher proportion of total well counts. The open flow of fractured wells recorded a new high. In addition, the Shen’an pipeline (Shanxi-Hebei section), the longest coalbed methane pipeline in China led by CUCBM, the wholly owned subsidiary of CNOOC Limited, has been fully commissioned. In the future, the pipeline will supply stable clean energy to North China. It will also further expand onshore sales channels for the Company.

In 2022, Shenfu South gas field development project, Central Linxing 4/5 development project and Panhe thin layer coalbed methane development project are expected to be put into production. In the future, we will step up the development of onshore unconventional natural gas to boost the proportion of natural gas in our production mix.