By Tsuey Cham
A few weeks ago we took a look at coal seam gas (CSG) and the hydraulic fracturing (‘fraccing’) process used in its extraction. You may have also heard of shale gas, another type of natural gas found deep underground.
So what exactly makes them different?
In terms of their gas content they’re really quite similar, with both made up predominantly of methane – the type of gas used in homes for cooking and heating.
However, when it comes to extraction and production CSG and shale gas can be quite different. For example, CSG can be found up to about 1000 meters underground, whereas shale gas is found much deeper, usually 1500 to 4000 meters below the surface.
In Australia, hydraulic fracturing – a technique that increases the rate of gas flow for extraction – is used in CSG production 20-40% of the time, whereas in shale gas production it’s used every time.
Another interesting difference is that the process used to extract CSG produces more water than it uses – so there are large quantities of water produced as a by-product. Conversely, for shale gas, the extraction process uses more water than it produces.
Watch our latest short animation to find out more about shale gas, how it’s extracted and some of the potential environmental challenges involved in its production:
If you missed the animation on CSG extraction, watch it here.
You can also find out more from our fact sheets on CSG, shale gas and hydraulic fracturing in coal seams.