China is a quarter way through filling four strategic oil reserves designed to secure its economy against any obstacles of energy supply.
The first of four facilities in Zhenhai, in the Zhejiang province south of Shanghai, has a storage capacity of 5.2 million cm or 32 million barrels a day.
Construction of the reserves began in 2004 as an effort to reduce growing reliance on imported oil and gas.
'The establishment of these oil reserves is a measure to prevent supply disruption hazards, protect the nation's resource security and to respond to sudden incidents,' the National Development and Reform Commission comments.
The reserves are supposed to store the equivalent of 30 days of imports, or about 70 million barrels of oil.
China's economic boom has made it the world's second largest oil consumer after the US. The country supplied its own needs for decades from domestic oil fields but became a net importer in the 1990s. It now relies on imports for nearly half its energy needs.
The other bases are under construction in Zhoushan, also in Zhejiang province; in Huangdao in the eastern province of Shandong and in the port of Dalian in the northeast.