Unconventional resources are resources, generally oil or natural gas resources, that do not appear in traditional formations and must use specialized extraction or production techniques to obtain fuel from the deposit. For oil and gas, conventional deposits are porous and permeable rocks below ground that contain tiny connected pore spaces that contain oil or natural gas. Generally, these resources are locked in geological structures where extraction is not economically or technologically feasible, however with technological advancements these can turn into viable fossil fuel reserves.
Unconventional resources are being utilized more and more as decades of oil and natural gas production have resulted in extensive use of conventional resources. Because of this, new technologies are constantly being introduced that allows for the more economic extraction of non-traditional oil and gas that may have been previously impossible to obtain. Development of these unconventional resources has significant economic potential as a large portion of oil and gas resources is estimated to exist in unconventional deposits.
Unconventional oil is a very specific type of petroleum obtained by methods that are different from the extraction technique of using a traditional well. This type of oil is seen as being more costly and difficult to extract and refine, as well as being more environmentally harmful. In general, unconventional oil is heavier and requires more processing and upgrading. Unconventional oil includes shale oil, oil sands and extra-heavy oil (natural bitumen deposits). In total, only about 3% of 2009's oil production came from unconventional oil sources. Although it is more difficult and costly to extract unconventional oil, it is becoming more common as the demand for oil is increasing and more research is being done to see how unconventional oil can be made more simple and cost-effective to produce.
Unconventional natural gas is simply natural gas obtained by methods that are different from traditional extraction. Unconventional natural gas can refer to tight gas - natural gas locked in low-permeability rocks, shale gas - natural gas locked in shale, or coal bed methane - natural gas contained in coal. The extraction of natural gas from these deposits can be an issue, as arguments about the environmental impact of hydraulic fracturing can be brought up. Additionally, the water use in the extraction of coal bed methane can be an environmental concern.