The Importance Of Natural Gas From Shale

Shale gas, or natural gas that comes from shale rock, is our most important new source of fossil fuel energy.

Shale is a type of rock that is dense and not generally porous or permeable. I can, however hold hydrocarbons such as oil and natural gas within it. This gas can now be released using horizontal well drilling techniques that were unavailable only a couple decades ago.

Geologists have identified a number of the shale reservoirs.

The Marcellus Shale

In the Northeast, under much of Pennsylvania, West Virginia, New York and other states, lies the Marcellus shale. This vast underground rock formation holds incredible quantities of natural gas. Geologists estimate that the Marcellus shale holds over 500 trillion cubic feet of natural gas.

The Barnett Shale

In Northeast Texas the Barnett shale has been developed over the past ten years. Much of the activity is in the Fort Worth Basin however the shale reaches underground as far as New Mexico where new wells are being drilled. There is still much area to be drilled in the Barnett shale and trillions of cubic feet of natural gas to be produced. The Barnett shale also produces oil and condensate in some areas.  You can learn more about the Barnett Shale here: Barnett Shale Info

The Haynesville Shale

In Arkansas the Haynesville shale is gaining recognition as a shale gas reserve greater in size than the Barnett shale. Gas quality from the Haynesville shale is very high, containing more BTU’s per cubic foot than even Barnett shale gas. Chesapeake, Petrohawk and other companies are actively drilling in the Haynesville shale in Arkansas.

The Eagle Ford Shale

In South Texas a new shale play has been identified. It is called the Eagle Ford shale and it lies south of San Antonio in an arc that reaches from southeast Texas to the Mexican border near Del Rio. The Eagle Ford shale contains vast quantities of oil and gas and is only now being developed. Geologists are using 3D seismic surveying to determine which areas of the Eagle Ford shale have the highest gas and oil content and are concentrating drilling efforts there. Those areas include McMullen, LaSalle, Dimmitt, Zavala, and Maverick counties. More wells are being drilled outside of those counties and continuing to expand the area of interest.

There are a number of other shale formations where oil and gas wells are being drilled. These include the Mancos shale, Antrim shale, Devonian shale, Fayettville shale and several others. For a map of these shale formations you can go here: Shale Gas Area Maps

Shale gas has increased US reserves of natural gas to over a century’s worth. The price of natural gas has fallen significantly in the past decades due to these important discoveries.

If you are looking for a good book that explains how oil and gas wells are drilled see The Nontechnical Guide To Oil and Gas Drilling
Nontechnical Guide to Petroleum Geology, Exploration, Drilling and Production (2nd Edition)