Commercial viability of coal seam gas

Australian coal seam gas is expensive to extract: about $4 to $5 a gigajoule. 

Rising cost of extracting coal seam gas

 The U.S. wholesale gas price is only $3 a gigajoule.

U.S. natural gas price

One option for increasing the natural gas supply in Australia, though it isn't the preferred option, is to import LNG from the U.S. 
The point to take away from this is that coal seam gas in Australia, facing competition from the U.S. that is rapidly expanding its LNG export capacity, is unlikely to be commercially viable within a few years. 

Expanding the unconventional gas industry that  has little prospect of long-term commercial viability isn't a good investment.

Another option for increasing the supply of natural gas is to make it from coal. Black coal in Australia is being sold into an over-supplied export market where the price is falling to around $2 a gigajoule.

Brown coal costs only about 50 cents a gigajoule.

 
New processes are available that can make methane from coal relatively cleanly. 

Supercritical Water (SCW) gasification of coal and wet biomass

 Coal mixed with water and heated to 400 centigrade with solar thermal energy reacts to form approximately equal quantities of carbon dioxide and natural gas. 
Another way to heat the mixture is to add hydrogen produced by wind turbines or solar PV systems. With sufficient hydrogen, all of the carbon in the mixture reacts with the hydrogen to form natural gas and no carbon dioxide is created.