Not all experts are taking the same view of the significance of the new find. Wang Ruiqi, an analyst with energy information consultancy ICIS C1 Energy, said gas supply shortages will persist for several years in China.

"CNPC's new discovery will help to ease the situation", she said. "However, the impact will not be huge, and it won't affect the trend of increasing dependency on imported natural gas."

The consultancy estimated that up to half of China's natural gas consumption will come from imports by 2018.

China is devoting more effort to exploring more energy resources and raising domestic output.

PetroChina Co Ltd, the listed arm of CNPC, produced 58 billion cu m of natural gas during the first three quarters in 2013, according to the company.

According to the Ministry of Land and Resources, China's crude oil and natural gas output in 2030 will be more than double the figure for 2013.

China's western region, which includes such reserves as the Tarim Basin in the Xinjiang Uygur autonomous region in the northwest and the Sichuan Basin in the southwest, has huge potential as a source of oil and natural gas, Peng Qiming, director of the ministry's geological exploration department, told a news conference early this year.

"Those areas will become major contributors to the country's energy output, producing 60 percent of the total in 2030 compared with 45 percent in 2012," he said.

The new find in Sichuan gave credence to his comment.

CNPC said on Tuesday that its Changqing oil and gas field in western China had yielded new proven oil reserves of 300 million tons, and total natural gas reserves in the field reached more than 600 billion cu m in 2013.

"The Qinghai oil and gas field, which is owned by CNPC, will see efforts made in the exploration sector this year. The goal is to add 200 million tons of oil equivalent" to reserves, said CNPC.