But since the break-up of the Soviet Union, it's been eyeing a potential new source of oil and gas -- the Caspian Sea.

BBC: Oil flows from the Caspian Sea

Fuels would be taxed according to their CO2-generating potential (ie, coal more than oil, and oil more than gas) rather than the miscellaneous system of duties to which they are now subjected.

ECONOMIST: A cooling off period

While Australia is the best part of 10-years behind the U.S. in terms of exploring for and developing its unconventional oil and gas potential it is a country which featured prominently in a 2011 analysis of world shale gas potential by the U.S. Energy Information Agency.

FORBES: Chevron Gets A Sniff Of Australian Shale Gas

The application to test drill near the village of Llandow in the Vale of Glamorgan may still happen, and there are six other potential drilling sites in south Wales accordiing to Gerwyn Williams, of Bridgend-based Coastal Oil and Gas Limited.

BBC: Autumn statement: A future for shale gas in Wales?