CNOOC Limited (the “Company”, SEHK: 00883 (HKD Counter) and 80883 (RMB Counter), SSE: 600938) announces that Mero4 Project has commenced production safely on May 24 Brasilia time.

Mero field is located in the Santos Basin pre-salt southeastern offshore Brazil, about 180 kilometers away from Rio de Janeiro, in a water depth of between 1,800 and 2,100 meters. Mero4 Project will be developed by the traditional deep-water Pre-salt development mode, FPSO+Subsea. 12 development wells are planned to be commissioned, including 5 oil producers, 6 water or gas alternate injectors, 1 convertible well. In order to maximize production, the wells are equipped with intelligent well completion technology, which enables the remotely switching between production and injection wells via platform.

The FPSO used in Mero4 is one of the largest FPSOs in the world, which was integrated in China in December 2024 and arrived at the oilfield in March 2025. The FPSO is able to produce up to 180,000 barrels of crude oil, process 12 million cubic meters of natural gas per day and inject 250,000 cubic meters of water, which will increase the installed production capacity of Mero field to 770,000 barrels of crude oil per day.

To implement the concept of green and low carbon development, Mero4 project is also equipped with resources to operate the HISEP (High Pressure Separator), which allows underwater separation between the extracted oil and the associated gas and reinject the gas into the reservoir. The HISEP will simultaneously boost production and reduce emission.

CNOOC Petroleum Brasil Ltda, a wholly-owned subsidiary of CNOOC Limited, holds 9.65% interest. Petrobras is the operator and has 38.6% interest, TotalEnergies holds 19.3% interest, Shell Brasil holds 19.3% interest, CNPC holds 9.65% interest, and Pré-Sal Petróleo S.A –PPSA holds 3.5% as the Federal Union representative in non-contracted areas.

About CNOOC

CNOOC Limited (SEHK: 00883, SSE: 600938) is a listed company on the Shanghai Stock Exchange and the Hong Kong Stock Exchange with stock codes of 600938 and 00883, respectively.
The Company is the largest producer of offshore crude oil and natural gas in China and one of the largest independent oil and gas exploration and production companies in the world. The Company mainly engages in exploration, development, production and sale of crude oil and natural gas.