The Earth contains large amounts of hydrocarbons that are not contained within what might be called conventional reservoirs. These unconventional deposits are often difficult to access, relatively expensive to develop and require advanced technologies to make production possible.
Unconventional hydrocarbons represent the future of fossil fuel supply. Arguably the most exciting unconventional deposits are those provided by shale gas and shale oil, hydrocarbons generated and retained by fine grained sedimentary rocks.
With conventional hydrocarbon reserves being rapidly utilised, a future in which demand for conventional deposits outstrips supply is inevitable. Hence, attention is turning to unconventional resources to satisfy our present and future oil and gas needs.