Unconventional hydrocarbons are resources found in reservoirs with geological characteristics and locations different from those where oil and gas are usually produced. They include:
- natural gas from shale formations (shale gas)
- natural gas from coal seams (coalbed methane)
- crude oil from shale formations or other formations with low permeability (tight or shale oil)
Extracting these fossil fuels is generally more difficult than extracting from conventional sources. For example, the extraction of shale gas requires the drilling of additional wells and techniques such as hydraulic fracturing – breaking rock by using large quantities of water under high pressure mixed with sand and other additives in order to release the gas.
Shale gas is widely considered to be the unconventional fossil fuel with the greatest potential for development in Europe. A preliminary assessment by the European Commission's Joint Research Centre estimates that the technically recoverable potential of shale gas in the EU is around 16 trillion cubic meters.
To date, EU countries have adapted different policies towards shale gas. For example, France and Bulgaria have banned hydraulic fracturing. On the other hand, Poland and the United Kingdom have an ongoing programme of exploratory drillings and hydraulic fracturing tests.
Environment and climate concerns
The extraction of shale gas raises public concerns such as the risk of water contamination.
To help ensure that shale gas is extracted in a safe, responsible, and environmentally friendly way, the European Commission has issued a Recommendation for EU countries when creating or adapting legislation related to hydraulic fracturing.
- The European Science and Technology Network on Unconventional Hydrocarbon Extraction will collect, analyse and review results from shale gas exploration projects in the EU. It will also assess the development of technologies used in unconventional oil and gas projects.
- The European Commission intends to assess and map Europe's unconventional gas and oil resources using current assessments conducted by EU countries as a basis. It will also prepare a report on the potential impact to energy markets from unconventional oil.