A major refined oil pipeline in western China that had to shut down after Monday's massive earthquake is back in service, the China National Petroleum Corp (CNPC) announced on Wednesday.

The Lanzhou-Chengdu-Chongqing line was able to carry 600 cubic meters of refined oil per hour after a 22-hour suspension following the Sichuan quake, said CNPC, the country's largest oil producer, in a statement.

"It is important for ensuring oil supplies in the rescue and disaster relief work," the company said.

A key project listed in the national plan to develop the west, the 1,250-kilometer pipeline accounts for nearly half of the total length of CNPC's refined oil lines. It starts in the oil-rich northwest and ends at the Municipality of Chongqing, going by way of Gansu, Shaanxi and Sichuan.

Tremors were reported along the whole line when a 7.8-magnitude quake hit Wenchuan County, the epicenter in north Sichuan, on Monday afternoon.

The quake caused leaking at the infiltrator at the Chengdu oil pump station, but no oil leaked outside, and there were no casualties. The line was immediately shut.

The CNPC announced an emergency move to allocate 100,000 tons of refined oil to ensure supplies to disaster-hit regions.

After repairs and a thorough check, the line was put back into use on Tuesday afternoon and remains under close monitoring, said the company.

It said on Tuesday that production of a refinery in Sichuan was also affected, and it vowed to bring it back to normal as soon as possible. However, there's no word on progress yet.

The country's biggest oil refiner, the China Petrochemical Corp, said on Tuesday that most natural gas wells of its southwestern branch were closed after the quake, but the influence was slight on wells in northeast Sichuan and oil refining plants.

Sichuan is abundant in natural gas with one of the country's largest gas fields, the Puguang field, whose proven reserves have been estimated at 356 billion cubic meters.

Guotai Jun'an Securities said on Wednesday it was not worried about the gas pipelines in Sichuan as they were all made of highly quake-resistant steel and major gas fields in Sichuan were outside the worst-hit areas.

"The province's output of crude, diesel and gasoline took only a small share of the country's total. National supplies are hardly affected," it said in a report.

(Xinhua News Agency May 15, 2008)