China has completed construction of the main structure of its first offshore platform designed to inject carbon dioxide into underground gas reservoirs, marking a step forward in low-carbon natural gas production.

The central platform for the Dongfang 1-1 gas field in south China's Hainan Province entered the commissioning stage on Sunday. Once operational, the project is expected to permanently store more than one million tonnes of CO2 underground each year.

Unlike conventional processing, which sends CO2-rich natural gas ashore for decarbonization, the project captures and purifies CO2 during offshore gas production before pressurizing and injecting it back into the reservoirs. The process both stores the carbon and helps recover hard-to-extract gas, boosting production while cutting emissions.

China's first offshore self-operated gas field, Dongfang 1-1 has produced more than 50 billion cubic metres of natural gas since production began in 2003.