By Ma Dongwei

China National Offshore Oil Corporation (CNOOC) recently announced that the Deep Sea No.1 gas field, the largest offshore gas field in the country, completed its 100th shipment. Oil and gas production from the field in 2025 exceeded 4.5 mil tons of oil equivalent.

Located about 150km southeast of Hainan Island, the Deep Sea No.1 produces 15 mil cubic meters of natural gas and over 1,600 tons of condensate per day. Since its startup in 2021, upgrading and modification works have been carried out, unleashing the maximum potential of the deep sea gas field. In 2025, natural gas production reached 5 billion cubic meters for the first time, exceeding its designed peak capacity. Total production from gas fields around Hainan Island exceeded 10 mil tons of oil equivalent in 2025.