Shale gas is natural gas produced from shale rock which is rich in organic carbon. Shale is the earth's most common sedimentary rock and is as impermeable as concrete. Resembling a chalkboard slate, the clay-sized particles contain oil and natural gas that have been created over millions of years through the breakdown of organic matter left in the rock. 

Due to its impermeability, the challenge is to move the enormous amount of fluids and gases through the rock. Some shales can hold such an enormous amount of natural gas that their wells could produce gas at a slow, steady rate for decades.  Shale gas has been produced for more than 100 years but the wells were always marginally economical. 

Due to demand and high gas prices, North America has been driven to make monumental advancements in technology. As such, in recent years, shale gas production has become viable and economical, creating a boom in recovery efforts. The success of this state of the art technology, which includes horizontal drilling, multi stage fracturing and micro seismic monitoring, has made shale gas an increasingly important source of natural gas, altering global gas markets. 

The magnitude of this success is fueling a migration of interest and enthusiasm in Europe and emerging countries, potentially allowing many nations to increase their level of energy dependence . Presently, many European countries are heavily dependant on Russia for critical natural gas supplies. Shale gas development in Europe and emerging countries is currently embryonic, compared to the USA. It is anticipated that within the next five years many new shale plays will develop worldwide.