Source: U.S. Energy Information Administration and Advanced Resources International, Inc., World Shale Gas and Shale Oil Resource Assessment 

As recently as last year, only four countries in the world were producing commercial volumes of either natural gas from shale formations (shale gas) or crude oil from tight formations (tight oil): the United States and Canada, and more recently, Argentina and China. Beyond these four countries, other countries have started exploring hydrocarbons from shale and other tight resources, but they are still short of reaching commercial production.