China CNOOC Starts Construction of First Offshore Carbon Injection Project for Gas Enhancement

Recently, China National Offshore Oil Corporation (CNOOC) announced that the carbon capture, utilization and storage (CCUS) project at the Dongfang 1-1 gas field has officially started construction. As China’s first demonstration project applying offshore carbon injection technology to enhance natural gas production, it is expected to permanently store more than 1 million tonnes of carbon dioxide underground each year once fully operational. 

Xinhua News Agency reports that the carbon injection technology for gas enhancement, formally known as carbon dioxide-enhanced natural gas recovery technology, is a branch of CCUS technology and is regarded as one of the key technologies to achieve carbon neutrality goals. Currently, this technology is gradually moving from the pilot test phase to commercial application. 

The core of this technology lies in turning carbon dioxide produced during natural gas extraction into a valuable resource. After being captured and purified, the carbon dioxide is pressurized and injected back into gas-bearing formations, where it serves as a driving force to extract hard-to-recover natural gas. This approach not only reduces carbon emissions but also improves the recovery rate of natural gas, realizing the dual benefits of environmental protection and resource utilization. 

Yu Fasong, head of the Dongfang 1-1 CCUS project at CNOOC Hainan, explained the project’s innovative significance. “Relying on this new project, we will move the decarbonization process originally deployed at onshore processing plants to offshore platforms, achieving carbon reduction at the source for offshore natural gas extraction,” he said. 

Yu added that the natural gas decarbonization technology adopted in the project is a global first, featuring high equipment integration, low energy consumption and high recovery of hydrocarbon components. The carbon dioxide captured by this process is of high purity; when pressurized into a supercritical state and reinjected into the formation, it can effectively supplement formation energy and boost gas field output. 

China Economic Net notes that the Dongfang 1-1 gas field is China’s first self-operated offshore gas field and the country’s first offshore carbon-rich gas field. Since its commissioning in 2003, it has produced more than 50 billion cubic meters of natural gas. Currently in the mid-to-late development stage, the gas field faces challenges such as unbalanced block development and rising carbon dioxide content, making it an ideal “test field” for offshore carbon injection technology.

Upon completion, the project will be fully connected to the existing production facilities of the Dongfang 1-1 gas field. It will enhance the transportation capacity of the existing subsea pipeline network in the Yinggehai Sea, create favorable conditions for the economical development of more carbon-rich natural gas resources in the region, and help sustain long-term stable production of the Dongfang gas field cluster. 

As a key enterprise in China’s offshore energy sector, CNOOC has long been committed to promoting green and low-carbon development. This CCUS project not only marks a major breakthrough in China’s offshore carbon capture and utilization technology but also provides a valuable demonstration for the large-scale application of CCUS technology in offshore oil and gas fields.