Gas shales are currently amongst the hottest plays in the United States, thanks to the industry's technological successes exploiting the Barnett shale of the Fort Worth Basin and the Fayetteville and Woodford shales in the Arkoma Basin. The Barnett shale alone has already produced 5.6 trillion cubic feet of gas. Currently, between 11% and 13% of total U.S. and Canadian gas production flows from shale reservoirs.

Prospective gas shales occur in many basins around the world, and interest is rising in these untapped resources. The world shale-gas resource is estimated at as much as 32,560 Tcf of gas. No commercial shale gas is currently produced outside of North America, but basins throughout Europe, Asia, Africa, South America and Australia are being evaluated for shale-gas prospects.