U.S. Shale Gas By Vorys on November 22, 2008 Email this postTweet this postLike this postShare this post on LinkedIn The Natural Gas Supply Association has calculated that 25 percent of U.S. natural gas demand could be met by shales located in Appalachia, the Barnett Permian Basin of Texas and elsewhere in the U.S. A copy of the statement can be found here.