Additional Types of Unconventional Resources

In the mid-2000s, there was considerable concern that the world was running out of oil and, ultimately, natural gas. And that the oil and gas industry was going to go the way of the dinosaurs and become extinct. Such speculation has largely been quelled by this, hydro carbon rich shale. This particular piece is from the surface outcropping of the Marcellus shale in western Pennsylvania. Marcellus shale is both the source rock and reservoir rock of one of the largest accumulations of natural gas ever to be produced in the US.
Similar shales occur elsewhere throughout the US and are being successfully tapped for not only natural gas, but also oil.
Shale gas and shale oil were once referred to as unconventional resource or resources that required unconventional methods to get any gas or oil out of the reservoir rock.
And being unconventional, these methods were also typically uneconomic. Consequently, unconventional resources remain just that, resources that we knew were there, but that were too costly to extract.
Cost reductions in horizontal drilling and fracking however, have transformed shale oil and shale gas from being unconventional resources, into being conventional resources. This transformation has in fact been so significant that it has turned the U.S. from being a net importer of oil to being a net producer of oil. And it has raised our domestic production of natural gas from being five times what we imported in 2006. To now, in 2015, being 10 times our imports.
Further more, large accumulations of shale gas and shale oil still remain to be produced. Not just here in the US, but also around the world. Estimates for these resources suggest that supplies could last another hundred or more years at current rates of consumption.
On top of this, our massive accumulations of other types of hydrocarbon resources that have also largely remained untapped. One of these, heavy oil, is like shale oil and shale gas in that it was formally an unconventional resource that has since become conventional.
Heavy oil is a viscous oil that is composed mostly of long chained hydrocarbons and can be so dense that it actually sinks in water, rather than floats like conventional oil.
The largest accumulations of heavy oil are found in Canada and Venezuela, with the Venezuelan heavy oil resources being as big as Saudi Arabia's conventional oil resources.
Canada also contains vast accumulations of oil sands. These are sands saturated with bitumen or what is more commonly referred to as asphalt, an even more viscus form of oil that is often semi-solid in appearance.
Technologic advances have reduced the cost of processing heavy oil and oil sands so much that the average break-even price to produce heavy oil has fallen to less than $50 a barrel in 2015. And the average break-even price for oil sands is at $70 a barrel. These prices are comparable to the average break-even price for producing shale oil in North America, which is currently about $65 a barrel. And then there are the unconventional natural gas resources. For example, in addition to shale gas, there is tight gas, which is gas in what would be conventional rock reservoirs except that the rocks have such low porosity, and or permeability. They are referred to as being tight. Like shale gas, tight gas reservoirs have been turned into economic reservoirs by directional drilling and fracking.
Another unconventional form of natural gas is coalbed methane.
This is methane that is formed along with the coal and is absorbed onto the surfaces of the coal.
Coalbed methane is produced by simply drilling a well into the coal.
The well provides a low pressure conduit for the gas to escape from the high pressure confines within the coal.
Possibly the largest source of unconventional gas in the world is methane hydrates. These are located beneath the sea floor in water depths greater than 300 meters, where water temperatures are around two degrees celsius or 36 degrees fahrenheit.

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