Shale

What is shale?
Shale is pourous rock that contains natural gas in its layers.  Natural gas supplies from shale rock are one type of "unconventional" natural gas source. While there was a previous awareness of natural gas stores in shale, a lack of cost-effective drilling technology and lower natural gas prices made it impractical to aggressively tap this source.  In the last decade, as natural gas prices increased and the marginal cost of the drilling technology decreased, it became economically viable to drill for natural gas reserves in shale.

Where is it found?
The largest areas are known as "plays" and are located primarily in Alberta, Louisiana, Pennsylvania, New York, and Texas.

How are the wells drilled?
In a process known as fracturing or "fracking," in which water and sand are injected into wells, the shale rock is broken down, allowing the gas to flow out.

What are the benefits of shale?
Shale is an additional source of natural gas, which is a cleaner-burning alternative to oil and coal. Increased production of natural gas from shale, which is forecasted to grow, lowers the energy import requirements for the United States.

Additional info on shale:
Many domestic and international participants have entered the shale production market. In addition, shale has also evolved into a hot commodity, with transactions ranging from $280 million to $3.4 billion (USD).

As of November 2008, FERC estimated that there are 742 Tcf of technically recoverable shale gas in the United States, representing a large and growing share of total recoverable resources. This would represent more than 30 years of natural gas supply based on current consumption levels.