Natural gas output is set to almost triple by 2020 as the country's top producer steps up exploration and exploitation, a top expert told an energy forum in Beijing Monday.

"Gas production will increase fast with the estimated 2020 production hitting 150 billion cubic meters (bcm)," Qiu Zhongjian, an academician at the Chinese Academy of Engineering, told the forum hosted by the China National Committee of World Petroleum Council.

Of the 58.6 bcm of natural gas extracted last year, PetroChina contributed 70 to 80 percent, said Jia Chengzao, vice president of PetroChina and academician at the Chinese Academy of Sciences.

This year, PetroChina plans to prove 100 bcm of natural gas at Songliao Basin, where Daqing and Jilin oilfields are located.

PetroChina is confident of the appraisal results of its Sichuan Longgang Gasfield - whose reserves are believed to be the highest in the country - but Jia would not put a figure to it.

Also in Sichuan Province, the Guang'an region is believed to hold 1 trillion cubic meters of natural gas, Jia revealed yesterday.

"The potential is huge in Guang'an, with reserves in place reaching 145 bcm in 2006," he said.

In the Junger Basin, PetroChina has made its largest gas discovery in the Xinjiang Uygur Autonomous Region, with reserves in place of 170 bcm. The newly confirmed long-term resource volume of Junger is up to 500 bcm, Jia said.

For oil, Jia estimated reserves in place at Nanpu Oilfield in the eastern part of Hebei Province to be 2 billion tons oil equivalent in about five years.

The company's latest discovery in the Bohai Bay has combined proven, probable and possible reserves of as much as 1.18 billion tons of oil equivalent, the Ministry of Land and Resources certified last week.

PetroChina expects its oil output to stabilize at 107 million tons for this year, around the same as last year as new fields make up for depletion in older fields.

The country boasts extractable oil and gas reserves of 21.2 billion tons and 22 trillion cubic meters, Qiu said.