Tight Gas : Natural gas held in reservoirs of low permeability that cannot be accessed in an economically reasonable time by natural flow methods. Hydraulic fracturing is required to create formation exposure sufficient to produce the gas
George E. King Engineering, 5000 Oilfield Terms: A Glossary of Petroleum Engineering Terms, Abbreviations and Acronyms, US 2010. http://gekengineering.com/Downloads/Free_Downloads /Glossary_of_Petroleum_Engineering_Terms_25_August _2010.pdf, (Oil - Amer) {593}