Both exploration proactice and physical modelling indicate that deep basin gas accumulations contain aquifers of various geneses.Aquifers in deep basin gas pool of He-8(the eighth member of Shihezi Formation)in Sulige region

Ordos basin

are of two origins—one is bottom water in common lenticular sandstone gas reservoirs with mixed water and gas layer

and the other is bottom water in "lithologic" gas reservoir within the local sandbody of high-porosity and high-permeability in gas-water transition zone of deep basin gas pools.Experiments indicate that water present almost in all but the high tide stages of the evolution of deep basin gas pools.It could be pore space water existed before the accumulation of deep basin gases or bottom water in lithological gas reservoirs formed during the senescence phase of deep basin gas when formation water entered the high-porosity and high-permeability sandstones.It is suggested that the high-porosity and high-permeability sandstones on the migration paths of deep basin gases contains no or very limited amount of water and serve as the most favorable exploration targets for deep basin gas.