The China National Offshore Oil Corporation (CNOOC) has begun construction on an offshore carbon capture, utilisation and storage (CCUS) project at the Dongfang 1-1 gas field in south China’s Hainan Province. The project marks the country’s first demonstration initiative applying offshore carbon injection technology to enhance natural gas production.

The principle behind carbon injection for enhanced gas recovery is to use the carbon dioxide emitted during natural gas extraction to enhance extraction efficiency. This is achieved by pressurising the purified carbon dioxide post capture and injecting it back into gas-bearing reservoirs, where it actively unlocks hard-to-recover natural gas reserves.

Yu Fasong, head of the Dongfang 1-1 CCUS project at CNOOC Hainan, says shifting decarbonisation processes from onshore facilities directly to the production source on offshore platforms represents a significant boost both to operational efficiency and to environmental performance.

Upon completion, the project will be fully connected to the existing Dongfang 1-1 gas field production infrastructure, which includes a subsea pipeline network in the Yinggehai Sea.

Once fully operational, the project is expected to permanently store more than 1 million tonnes of carbon dioxide underground each year. In addition, it will support the cost-effective development of more carbon-rich natural gas resources in the region, thus sustaining long-term stable production.