Natural gas and crude oil production from hydrocarbon rich deep shale formations, known (incorrectly) as shale oil and shale gas, is one of the most quickly expanding trends in onshore domestic oil and gas exploration. Vast new natural gas and oil resources are being discovered every year across North America—drilling activity is at a 25-year high and supplies are rapidly growing. One major source of these “new resources” comes from the development of deep shale formations, typically located many thousands of feet below the surface of the Earth in tight, low-permeability formations. Recent technological advancements in horizontal drilling and hydraulic fracturing are unlocking an abundance of deep shale natural gas and oil in the United States. However, the issues of oil and gas recovery relate to the differences in shale plays.