Northwest China's Xinjiang region increased its proven natural gas reserve to 1.29 trillion cubic meters in 2006, ranking first in the country.
Xinjiang has an estimated natural gas reserve of 10 trillion cubic meters, accounting for a quarter of China's continental total.
Last year, Xinjiang added 140 billion cubic meters proven gas reserve, with 110 billion found in Tarim oilfield, the largest in the region.
The autonomous region saw a gas output of 16.1 billion cubic meters in 2006, overtaking southwestern Sichuan Province to become the country's top gas producer.
The output, an increase of 5.5 billion cubic meters over 2005, compared with an estimated 12 billion cubic meters produced in Sichuan, authority sources said.
The Tarim, Karamay and Tuha oilfields, the three major fields in the region, produced 11 billion, 2.88 billion and 1.65 billion cubic meters of gas respectively last year.
The Tarim oilfield is a source for the 4,000-km pipeline project to bring natural gas from western China -- primarily Xinjiang Uygur Autonomous Region and Shaanxi Province -- to 34 cities in the economically developed eastern regions.
Last year, the region channeled 9.8 billion cubic meters of gas to eastern regions.