In China, we conduct oil and gas exploration and development primarily through independent operations and cooperation projects.

Independent operations: We have been increasing our reserves and production mainly through independent exploration and development. As of the end of 2023, approximately 85.7% of our net proved reserves and approximately 86.2% of our net production in China were from our self-operated oil and gas fields.

Cooperation projects: We cooperate with partners through product sharing contracts (“PSCs”) in oil and gas resources (including crude oil and natural gas) exploitations. China National Offshore Oil Corporation (“CNOOC Group”), our controlling shareholder, has the exclusive right to enter into PSCs with foreign contractors to cooperate in the exploration, development and production of oil and gas resources in offshore China where acreage is open to foreign cooperation. CNOOC Group has transferred to the Company all its rights and obligations under the existing and future PSCs (except those rights and obligations related to the management and supervision that should be implemented by a State Corporation).

Bohai

Bohai is the largest crude oil production site in China and also 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 meters. As of the end of 2023, the reserves and production in Bohai reached 1,968.4 million BOE and 599,847 BOE/ day, respectively, representing approximately 29.0% of the Company’s total reserves and approximately 32.3% of its production.

With rich oil and gas resources, Bohai is one of the Company’s core areas for exploration and development. In 2023, the Company successfully made two discoveries in Bohai, namely Qinhuangdao 27-3 and Bozhong 26-2 North. In addition, the Company also successfully appraised 9 oil and gas bearing structures, including Qinhuangdao 27-3, Bozhong 26-6, Bozhong 19-2, Bozhong 34-1 West, Luda 16-3 South, Jinzhou 14-6, Longkou 25-1, Caofeidian 28-1 and Caofeidian 23-6.

In 2023, we successfully re-appraised Bozhong 26-6, adding over 40 million cubic meters of oil and gas proved in-place volume, with a total proved in-place volume exceeding 200 million cubic meters, and confirmed it the largest metamorphic buried hill oilfield in the world. Significant discoveries continued to be made in shallow strata exploration in Bohai, with Qinhuangdao 27-3 contributing new proved in-place volume of over 100 million tons.

Bohai is also an important source of growth for the Company’s natural gas reserves and production. Currently, Bohai has over 500 billion cubic meters of proved in-place volume of natural gas. In the future, we will focus on shallow water deep/ultra-deep play exploration and solidly push forward the exploration project for the trillion-cubic- meter gas area in Bohai.

In terms of development and production, Bozhong 28-2 South oilfield secondary adjustment development project, Bozhong 19-6 condensate gas field phase I development project and Penglai 19-3 oilfield 5/10 zone development project have all been put into production in 2023. Among them, Bozhong 19-6 condensate gas field phase I development project is the first 100 billion-cubic- meter condensate gas field in Bohai Bay to be put into production relying on the Bozhong-Kenli oilfields onshore power project, which will provide Beijing-Tianjin-Hebei and Bohai Rim regions with a more stable and reliable supply of clean energy and strongly promote the green and low- carbon development of the Company.

In 2023, the Company completed the construction of onshore power project for Bohai oilfields to promote the green and low-carbon development of oil and gas fields in Bohai. This is the world’s largest onshore power application base for offshore oilfield with the highest voltage of AC power transmission, with a total capacity of 980 megawatts, covering 75% of the existing Bohai facilities, and expected to reduce carbon emission by 1 million tons per year.

In the future, Bohai will still be one of the main sources of production growth for the Company. In 2024, Bozhong 19-6 Gas Field 13-2 Block 5 Well Site Development Project, Suizhong 36-2 Oilfied 36-2 Block Development Project and Bozhong 19-2 Oilfield Development Project will be put into production.

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 meters. The crude oil produced here is mostly light or medium. As of the end of 2023, the reserves and production in Western South China Sea reached 861.9 million BOE and 221,573 BOE/day, respectively, representing approximately 12.7% of the Company’s total reserves and approximately 11.9% of its production.

The Company made a new discovery in Western South China Sea, namely Wenchang 15-1 North, in 2023. 8 oil and gas bearing structures were successfully appraised, namely Wushi 16-5, Weizhou 6-3, Weizhou 11-6, Weizhou 11-10, Wenchang 19-3, Dongfang 11-2, Ledong 16-2 and Yacheng 13-10. The Company made breakthroughs in mid deep-play exploration in Songnan-baodao Sag, opening a new exploration frontier in this area.

Currently, proved in-place volume of natural gas of Western South China Sea has reached nearly one trillion cubic meters. In the future, the Company will focus on deep-water deep-play and deep-water ultra-shallow-play exploration, and solidly push forward the construction of the trillion-cubic-meter gas area in the South China Sea.

In 2024, Shenhai-1 Phase II Natural Gas Development Project and Wushi 23-5 Oilfields Development Project are expected to come on stream.

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 meters. The crude oil produced here is mostly light or medium. As of the end of 2023, the reserves and production in Eastern South China Sea reached 892.6 million BOE and 375,232 BOE/day, respectively, representing approximately 13.2% of the Company’s total reserves and approximately 20.2% of its production.

In 2023, the Company made four new discoveries in Eastern South China Sea, namely Huizhou 26-6 North, Panyu 10-6, Kaiping 18-1 and Xijiang 24-2. In addition, four oil and gas bearing structures were successfully appraised, namely Huizhou 26-6 North, Panyu 10-6, Kaiping 18-1 and Huizhou 25-11. We continued to conduct deep-water and deep-play exploration in the Eastern South China Sea, and Kaiping 18-1 made Kaiping South formation the first deep-water and deep-play 100-million-ton grade oilfield discovery in the South China Sea. In addition, mid-to- large sized oil and gas fields discoveries were made in the deeper layers of Huizhou Sag and Panyu Sag, namely Huizhou 26-6 North and Panyu 10-6, respectively.

In 2023, Enping 18-6 oilfield development project, Lufeng 12-3 oilfield development project and Lufeng oilfields phase II development project had all been put into production. In 2024, Enping 21-4 Oilfield Development Project, Liuhua 11-1/4-1 Oilfield Secondary Development Project and Huizhou 26-6 Oilfield Development Project are expected to come on stream.

East China Sea

The typical operating water depth in the East China Sea region is approximately 90 meters. As of the end of 2023, the reserves and production in the region represented approximately 2.9% of the Company’s total reserves and approximately 1.7% of its production.

In 2023, the Company optimized the adjustment well deployment in the East China Sea, and implemented equipment and facility upgrade and renovation. Meanwhile, the construction of offshore smart oil and gas fields made positive progress.

Onshore China

We mainly engaged in the exploration, development and production of unconventional natural gas resources onshore China. We have established three major production bases, namely Shenfu, Linxing and Panhe in the Qinshui Basin and the eastern edge of the Ordos Basin. As of the end of 2023, the reserves and production onshore China represented approximately 2.0% of the Company’s total reserves and approximately 2.7% of its production.

In 2023, the Company made China’s first major discovery of 100-billion-cubic-meter deep coalbed methane gas field in the Shenfu area of the Ordos Basin and successfully appraised the gas field, demonstrating promising exploration prospects for deep coalbed methane in the eastern edge of this basin. We have accelerated the strategic resource layout, successfully expanded our coalbed methane business to Xinjiang, and obtained new onshore unconventional oil and gas resources.

Currently, proved in-place volume of natural gas has exceeded 400 billion cubic meters onshore China. In the future, we will actively promote the exploration of tight gas and deep coalbed methane in order to effectively push forward the exploration and construction of the onshore trillion-cubic-meter gas areas.

In 2023, the Company carried out technological research around internal tapping of gas reservoirs, fracturing of low-permeability gas reservoir, etc., implemented refined management and multiple measures mainly based on dewatering gas recovery and extraction and depressurizing exploitation, to increase unconventional natural gas production. Onshore China has become one of the important sources of natural gas production growth for the company.

In 2024, demonstration projects of Linxing deep-play coalbed methane exploration and development, as well as Shenfu deep-play coalbed methane exploration and development, are expected to be put into production.

Asia (excluding China)

Asia (excluding China) is the first overseas region the Company entered into. Currently, the Company owns oil and gas assets mainly in Indonesia, Iraq and the United Arab Emirates. As of the end of 2023, the reserves and production in Asia (excluding China) reached 264.0 million BOE and 95,725 BOE/day, respectively, representing approximately 3.9% of the Company’s total reserves and approximately 5.2% of its production.

Indonesia

As of the end of 2023, the Company’s asset portfolio in Indonesia comprises mainly two oil and gas development and production blocks, namely the Madura Strait and Tangguh.

Among them, the Madura Strait block is a joint operation block. As of the end of 2023, the Company had built a gas production base in the Madura Strait with an annual capacity of 3.13 billion cubic meters, became the largest gas supplier in East Java. In addition, the development of the MDK and MBF gas fields is also in preparation.

The Company owns approximately 13.9% interest in the Tangguh LNG project in Indonesia. In 2023, phase I project achieved stable production. The first stage of phase II project, which is the third LNG production train of the Tangguh project, has been put into production, which has become the largest LNG production center in Indonesia, and the development plan for second stage of phase II project has been approved and is currently at the FEED design stage. The Company will work with its partners to promote the development of the Tangguh project as planned.

Iraq

The Company owns a 63.75% participating interest in the technical service contract of Missan oilfields in Iraq and acts as the lead contractor.

In 2023, favourable progress was made in stabilizing the production of Missan oilfields. The Company continuously adjusted and optimized the production enhancement project program, resulting in a sustained steady gross production of 300,000 BOE per day. Average daily net production was increased to approximately 32,000 BOE due to increased cost recovery and the contract model.

United Arab Emirates

The Company indirectly holds 4% interest in each of the two oilfield contract areas, namely the Lower Zakum Shallow Water Oilfield and Umm Shaif & Nasr Oilfield in Abu Dhabi. In 2023, the projects maintained stable production with an average daily net production of approximately 29,000 BOE.

Oceania

Currently, the Company’s oil and gas assets in Oceania are mainly located in Australia. As of the end of 2023, the reserves and production from Oceania reached 27.6 million BOE and 32,454 BOE/day, respectively, representing approximately 0.4% of the Company’s total reserves and approximately 1.7% of its production.

Australia

The Company owns a 5.3% interest in the North West Shelf LNG Project in Australia. The producing project supplies gas to the end-users including the Dapeng LNG Regasification Terminal in Guangdong, China and implements sales of the incremental gas and spot LNG independently.

In 2023, the NWS project operation remained stable, with the daily net production of approximately 32,000 barrels. The incremental gas production exceeded target and generated favourable economic returns.

Other Regions in Oceania

In 2023, the Company exited one exploration block in Papua New Guinea when due.

Africa

Africa is an important source of oil and gas for the Company overseas. The Company’s assets in Africa are primarily located in Nigeria and Uganda. As of the end of 2023, the reserves and production in Africa reached

104.2 million BOE and 57,586 BOE/day, respectively, representing approximately 1.5% of the Company’s total reserves and approximately 3.1% of its production.

Nigeria

The Company owns a 45% interest in the PML2/3/4 and PPL261 blocks (Original OML130 block) in Nigeria. Such block is a deepwater block covering four oilfields, namely Akpo, Egina, Egina South and Preowei. In 2023, the original OML 130 block contract was extended and the block was renamed as PML2/3/4 and PPL261 blocks.

In 2023, the production of Akpo oilfield and Egina oilfield has decreased due to natural decline. The daily net productions of Akpo oilfield and Egina oilfield were approximately 27,000 barrels and 25,000 barrels respectively.

In addition, the Company holds a 20% non-operating interest in the OML138 block offshore Nigeria, and an 18% non-operating interest in the OML139/154 Blocks.

The Company will deepen our regional integration to establish an oil and gas production base in West Africa centred around Nigeria.

Uganda

The Company owns a 28.3333% interest in each of EA 1, EA 2 and EA 3A blocks in Uganda. These blocks are located at the Lake Albert Basin in Uganda, which is one of the most promising basins in terms of oil and gas resources onshore Africa.

In 2023, the well site construction of Kingfisher project was completed and is now undergoing the pipeline laying operation. The infrastructure construction of Tilenga project is currently underway. The Company will continue to work actively with its partners and the local government to facilitate commencement of operation of the projects.

Other Regions in Africa

Apart from Nigeria and Uganda, the Company also owns interests in exploration blocks in countries and regions such as Gabon, Congo-Brazzaville and the Senegal- Guinea-Bissau Joint Economic Zone.

North America

North America is one of the Company’s major overseas oil and gas reserves regions. The Company holds interests in oil and gas blocks in the U.S., Canada, Mexico and Trinidad and Tobago in North America. As of the end of 2023, the reserves and production in North America reached 1,132.2 million BOE and 158,880 BOE/day, respectively, representing approximately 16.7% of the Company’s total reserves and approximately 8.6% of its production.

The U.S.

The Company holds 26.0% and 12.6% interests in Eagle Ford and Rockies, respectively, which are two onshore shale oil and gas projects in the U.S. Productions from the Eagle Ford and Rockies projects increased in 2023 and the daily net production from the Eagle Ford project was 35,000 BOE.

The Company owns 25% and 21% interests in two important deepwater projects, namely Stampede and Appomattox, respectively, in the U.S. Gulf of Mexico. In 2023, the daily net production of Appomattox project reached approximately 19,000 BOE. In addition, the Company also owns interests in several other exploration blocks in the U.S. Gulf of Mexico.

Canada

Canada is one of the areas rich in oil sands resources in the world. The Company owns 100% working interest in Long Lake and three other oil sands projects in the Athabasca region of northeastern Alberta in Canada.

In 2023, production of the Long Lake project was better than expected, with daily net production increased significantly to approximately 61,000 BOE as a result of more effective adjustment wells workloads and the rapid ramping up of Long Lake Southwest.

The Company holds a 7.23% interest in the Syncrude project and its daily net production in 2023 was approximately 19,000 BOE. The Company also holds a 25% interest in the Hangingstone oil sands project and non-operating interests under several other exploration and development licenses.

Long Lake NW Project will commence production in 2024, bringing new production growth to the region.

Other Regions in North America

The Company owns a 12.5% interest in the 2C block in Trinidad and Tobago, which is a producing asset with stable output and favourable economic returns in 2023.

In addition, the Company also owns 100% operating interest in block 1 and a 40% operating interest in block 4 of the Cinturon Plegado Perdido deepwater exploration blocks in Mexico, respectively.

South America

South America has become the region with the largest overseas oil and gas production of the Company and is a significant source of production growth for the Company. The Company holds interests in oil and gas blocks in Brazil, Guyana and Colombia in South America, as well as a 50% interest in BC ENERGY INVESTMENTS CORP. (“BC”) in Argentina. As of the end of 2023, the reserves and production in South America reached 1,155.9 million BOE and 203,632 BOE/day, respectively, representing approximately 17.0% of the Company’s total reserves and approximately 11.0% of its production.

Brazil

Brazil deepwater area is one of the world’s most important oil and gas development regions. CNOOC Limited holds a 10% interest in Libra block and a 7.34% interest in Buzios project in Brazil, respectively, both of which are in the Santos Basin.

The deepwater pre-salt Libra project in Brazil is divided into west, east and central zones, of which the west zone was commercially discovered in 2017 and named the Mero oilfield. The Mero oilfield consists of four phases, namely Mero 1, Mero 2, Mero 3 and Mero 4. Mero 1 project is a producing oilfield, with a daily net production of approximately 14,000 BOE. Currently, Mero 2 has successfully commenced production, and is expected to achieve peak production by mid-2024. The final investment decisions for Mero 3 and Mero 4 oilfields have been made, and Mero 3 is expected to commence production in 2024.

The Buzios oilfield is the world’s largest producing deepwater oilfield. The Buzios oilfield consists of 11 development units, and units 1, 2, 3 and 4 have been already in production with a daily net production of approximately 43,000 BOE. Buzios5 commenced production in 2023 and achieved its peak production target within five months, setting a record for the fastest construction of a large-scale ultra-deepwater pre-salt oilfield. The Company will work closely with its partners to facilitate project construction.

Libra block and Buzios oilfield have become new drivers for the growth of overseas oil and gas production of the Company, bringing new momentum to the Company’s production growth.

The Company also holds a 100% interest in ES-M-592 block in offshore Brazil, a 20% interest in the ACF Oeste block and a 30% interest in the Pau Brasil block.

Guyana

The Stabroek block in offshore Guyana is located in northeastern Guyana with a water depth of 1,600 to 2,000 meters. It is one of the world’s largest exploration discoveries in recent years and CNOOC Limited holds a 25% interest in the block.

In 2023, the discovery of Lancetfish was made in the Stabroek block through ultra-deep-water and deep-play exploration. Currently, a total of over 30 new discoveries have been made in the block and the total recoverable resources in the block amounted to approximately 11 billion BOE as disclosed by the operator.

The Phase I and Phase II of the Liza oilfield in the block has been put into production. As of the end of 2023, these two phases of the project were producing steadily above the designed peak daily production, with a daily net production of approximately 81,000 BOE. The Payara project in this block has been put into production in 2023. In the future, Guyana will remain as one of the Company’s main sources of reserve and production growth.

Argentina

CNOOC Limited holds a 50% equity interest in BC and makes joint decisions on its management. BC holds a 50% equity interest in Pan American Energy Group.

In 2023, BC’s overall production was stable with better- than-expected development performance and net production of approximately 55,000 BOE per day.

Other Regions in South America

The Company also holds rolling exploration rights in Boqueron block in Colombia.

Europe

In Europe, CNOOC Limited holds interests in oil and gas fields such as Buzzard and Golden Eagle in the U.K. North Sea, and holds a 10% equity interest in Arctic LNG 2 LLC in Russia. As of the end of 2023, the reserves and production in Europe reached 49.5 million BOE and 30,510 BOE/day, respectively, representing approximately 0.7% of the Company’s total reserves and approximately 1.6% of its production.

The U.K.

The Company’s asset portfolio in the U.K. North Sea comprises producing projects and exploration projects, which mainly include a 43.21% interest in the Buzzard oilfield, one of the largest oilfields in the North Sea, and a 36.5% interest in the Golden Eagle oilfield. The Company also holds 41.9%, 80.4%, and 79.3% interests in Scott, Telford, and Rochelle oilfields of STaR production blocks, respectively.

In 2023, Buzzard oilfield maintained stable production with an average daily net production of approximately 22,000 BOE. The Company also holds a 66.67% drilling operation interest in P2215 exploration block in the U.K. North Sea.

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Other Regions Of Europe

The Company owns a 10% interest in Arctic LNG 2 LLC in Russia. The project is in the Gydan Peninsula in the Arctic region of Russia.