A subsidiary of China National Offshore Oil Corporation (CNOOC) has completed the construction of China's largest LNG storage base, a move that aims to ensure energy security and support green growth in the Yangtze River economic belt.

The base in the city of Yancheng, east China's Jiangsu Province, has a group of gas tanks with a combined LNG storage capacity of 2.5 million cubic meters, the company said.

It has four tanks each with a storage capacity of 220,000 cubic meters and six larger tanks each with a storage capacity of 270,000 cubic meters.

Li Feng, vice president of CNOOC Gas and Power Group, said the base is connected to the country's major gas pipelines and provides supplies to provinces including Jiangsu, Henan, Anhui and Shandong.

Once fully operational, the base will have the capacity to process up to six million tonnes of LNG annually, equivalent to 8.5 billion cubic meters of natural gas.

This volume is enough to sustain residential gas needs in Jiangsu Province, which has a permanent population of about 85 million, for about 28 months.