Work will begin Thursday on an emergency pipeline to pipe gas from a leaking well in Xuanhan County, in southwest China's Sichuan Province, said sources with Sinopec, one of China's leading oil/gas and petrochemicals producers.

It was officially announced on Thursday morning that the second capping operation, which lasted for more than four hours on Wednesday, had failed.

"We need to pipe the high-quality natural gas out of the well. It would be a pity to seal the well," said Lei Ming, deputy head of Sinopec's north Sichuan prospecting headquarters.

It will take about 20 days to complete the pipeline laying operation.

Earlier reports said the gas well began leaking again after the capping attempts failed and the leak was re-ignited on Wednesday.

The gas well began to leak last Thursday during drilling. More than 12,000 nearby residents were evacuated. The first attempt to cap the well was carried out on Monday but to no avail.

Most of the 12,000 residents returned home after local environmental protection authorities said no toxic chemicals were detected in the air.

But 803 people are yet to return because their houses are within 500 meters of the well.

They will not be able to go home until the pipeline laying operation is completed and the quality of water and air in the area has returned to normal, Wang Nengqiu, the county head of Xuanhan, told Xinhua.

No casualties have been reported in the gas leak, according to local officials.

(Xinhua News Agency December 28, 2006)