SHANGHAI - PetroChina Co, the country's biggest energy producer, is planning to build underground natural-gas storage tanks in Hutubi county in western Xinjiang Uygur autonomous region to guard against supply disruptions.

Construction of the 4-billion-cubic-meter (cu m) Hutubi storage base will begin "soon", China National Petroleum Corp (CNPC), the parent company of PetroChina Co, said in its online newsletter on Wednesday.

PetroChina will start filling the tanks in June next year, CNPC said. Hutubi will be the first storage complex on the nation's second West-East pipeline that's linked to Central Asia, CNPC said.

China is building oil and gas stockpiles as demand surges in the world's fastest-growing major economy. The nation aims to double the use of gas to about 8 percent of energy consumption by 2015 to help cut reliance on more polluting oil and coal.

The Hutubi base will be completed in four years in two phases, CNPC said.

The company plans to build 10 gas storage tanks by 2015, Caijing magazine said on Feb 25. The tanks will be able to hold 22.4 billion cu m of gas, as much as 10 percent of the company's total sales, Caijing cited CNPC Vice-President Liao Yongyuan as saying.

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PetroChina aims to spend an estimated 77.3 billion yuan ($11.8 billion) on natural-gas and pipeline development this year, compared with 53.6 billion yuan in 2010, according to its annual report.

The second West-East pipeline connecting Xinjiang with Hong Kong can transport as much as 30 billion cu m of gas a year from Turkmenistan.

PetroChina started building the 9,102-kilometer link in February 2008. The pipeline may be completed by this year. CNPC may double gas imports from Central Asia to between 55 billion and 60 billion cu m a year with an additional pipeline, the company said in January last year.

China's gas demand may rise to 230 billion cu m in 2015 from 130 billion cu m this year, CNPC said on Jan 20.

Domestic production may climb 11 percent to 105 billion cu m this year, while imports may exceed 30 billion cu m, the Beijing-based company said.

Bloomberg News