“Conventional gas” is that gas found in porous layers of the subsurface, with interconnected spaces, which flows easily through rock formations and into bore holes installed to extract the gas. In contrast, “unconventional gas” is that gas found in low permeability rock or sand formations that do not allow for free movement of the gas. Drilling and extracting unconventional gas requires more difficult and more expensive methods. One common method, hydraulic fracturing, or fracking, is used to open the rock formation to allow the gas to move more easily into boreholes and up to the surface for collecting.
There are three kinds of unconventional gas: tight gas (found in tight sands); coal bed methane (founding coal seams); and, shale gas (found in shale deposits). All are low permeability formations. Half of all unconventional gas is found in shale deposits, and the United States and China hold about 45% of all shale gas.
Some further ideas to explore on Unconventional Gas:
Calculate the amount of greenhouse gases emitted for each unit of heating by unconventional gas, conventional gas, coal, and wind – the GHG footprint for each source of heating.
In your calculation, be sure to include the GHG emissions from extracting, producing and using, or consuming, each fuel source for heating.
Also be sure to consider your specific location to include transportation emissions for each fuel source.
Centre for Global Energy Studies, “What is unconventional gas?” www.cges.co.uk/resources/articles/2010/07/21/what-is-unconventional-gas
“Unconventional Natural Gas Resources” www.naturalgas.org/overview/unconvent_ng_resource.asp