The distribution characteristics of China's on-land natural gas resources were analysed based on the distribution locality

stratum

origin

buried depth

geography and unproved resources of natural gas.It is considered that the on-land gas resources are mainly distributed in Central and West China (about 40% and 36% respectively).Natural gas reservoirs are primarily in Carboniferous

Ordovician

Permian

Triassic and Tertiary systems.Within the natural gas resources

oil-gas in up to 70% of the total amount

and coal-gas is 29%.Natural gas is buried mostly deeper than 2 000 m

and 80.98% of it is under thick loess domes

hills and desert areas.The gas resources could be divided into 3 types based on their geological and exploration conditions.Among them

type-Ⅰ is basically distributed in the central depressions of Songliao Basin

Tertiary sediments of hydrocarbon-rich depressions in Bobai Bay Basin

the central and east of Sichuan and Ordos Basins

Ih Ju League

Tarim

Junggar

Turpan-Hami and Qaidam Basins in West China.