>Many of Exxon's new fields are shales, similar to the Barnett Shale in North Texas, where Exxon had a joint venture but sold out. The Piceance Basin isn't shale but sand. The company hasn't tried the new technology on shale reserves, and officials won't say where, exactly, they will try the process next.

Looks like someone has since let the cat out of the bag :)

"ExxonMobil is undeterred by the current lull in natural gas prices, and in fact now plans to export this process to other unconventional gas reserves it has accumulated elsewhere in the world, including in Germany, Eastern Europe, Canada, and the Marcellus Shale in the northeastern US."

http://www.spe.org/jpt/2009/08/innovative-fracturing-process-proving-itself-in-tight-gas-production/