The Marcellus Shale is a type of geological formation containing extractable Natural gas. This shale is unique in that the only geographical region where it exists runs from West Virginia through Western Pennsylvania up to upstate New York. Marcellus Shale has always been known to have obtainable natural gas, but, years ago, oil companies thought it unproductive to drill. However, high oil prices, newer drilling technology, and encouraging results from similar shale formations in Texas and elsewhere have changed this opinion.
Now, companies in the natural gas industry are betting big money that this shale can be tapped for huge profits. Estimates by Terry Englander, a geoscience professor at Pennsylvania State University, and Gary Lash, a geology professor at the State University of New York at Fredonia indicate that the West Virginia to New York Marcellus Shale formation has around 500 trillion cubic feet of natural gas. Of that volume, they think that around 10% of the gas is recoverable, providing 50 trillion cubic feet of gas, which would be enough to supply US demands for two full years and have a wellhead value of about one trillion dollars. For this reason, Oil Companies, such as Chesapeake Energy (CHK) and Cabot Oil & Gas (COG) are leasing large amounts of land for prospective drilling.