Environment officials said no toxic gas had been detected within a one-km radius of the well.

Water quality remained normal in rivers downstream the well.

"Everything in my home remains untouched and I'm going to buy moon cakes to have a good celebration for the Mid-Autumn Festival," said 50-year-old Yan Zhisheng who returned home on Wednesday.

Moon cakes, the traditional dim sum that resembles the full moon in shape and is eaten on traditional Chinese Mid-Autumn Festival when the whole family get together to enjoy the full moon. The festival falls on Oct. 6 this year.

The blowout occurred at 7:25 p.m. Sunday on Huaqiao Farm in Luliang County, about 150 km east of the provincial capital Kunming. The well was managed by Deyang Geological Technology Service Company based in neighboring Sichuan Province.

The blowout reached at height of 15 meters high and the gas was more than 90 percent of methane with mud and water, experts said.

No casualties were reported, according to local government sources.

A capping operation began at 9:00 a.m. Tuesday when the pressure reduced and was completed at 10:10 a.m.

After the evacuation of 770 people, the local government mobilized police and militia to take care of the homes of the evacuees and the government allocated 100,000 yuan (12,500 U.S. dollars) to buy daily necessities for them, such as quilt, towel, basin, toothpaste and toothbrush, said Xu Desheng, deputy county head of Luliang.

An investigation team had been set up to probe the cause of the accident, Xu said.

Farmers whose crops or fishing ponds were damaged or affected by the accident would receive compensation, he said.

Monitoring of the well would continue to ensure safety.