Gas Instead of Oil: Is Natural Gas the Future of Energy?

What is shale gas and where does it come from? Shale is a kind of rock that was formed millions of years ago in ancient bays and oceans and it is rich in organic matter called kerogen. That kerogen, under the right circumstances is either cooked (thermogenic) or eaten by bacteria (biogenic) and natural gas and crude oil is produced.

For years geologists have known that shale formations deep underground  are the “source rock” for conventional reservoirs of oil and  gas.  Normally the oil  and gas are “cooked” out of these  shale formations and travel upward into  stratigraphic traps like sandstone or porous limestone where they accumulate.

Horizontal Drilling And Unconventional Reservoirs

In the case of shale gas reservoirs much of the oil or gas is still contained in them. Only recently was the technology available to extract oil and gas from unconventional reservoirs such as shale through horizontal drilling. Horizontal drilling allows for much more surface area of the rock to be exposed inside the well and therefore for more natural gas and oil to be recovered.

Imagine a hard layer of shale rock deep underground, perhaps twenty feet thick, being pierced by a vertical well. The vertical gas well has small holes or perforations in the steel lining or casing that are punctured at the depth of the gas bearing rock.

Since the well only goes trough twenty feet of the dense rock, only a small amount of gas can flow into the well.

Now imagine if the well bore went through three thousand feet of the shale rock instead of twenty. Now the oil and gas company can perforate the casing with thousands of holes over hundreds of feet instead of just twenty or so feet as in a vertical gas well.

Because of this engineering revolution shale formations around the United States are now being “re-discovered”.

Formations like the Marcellus Shale, which covers a wide swath of territory extending from Appalachia to New York and across into Ontario, and ones like the Barnett Shale near Fort Worth, Texas, are already producing millions of cubic feet of natural gas.

The Marcellus shale alone could possibly contain up to 500 trillion cubic feet of clean natural gas according to some geologists.

New Shale Gas Discoveries

Oil and gas companies have only touched the surface when it comes to exploring shale formations in the United States. New discoveries are being made every few months. Most recently the Eagle Ford shale in McMullen, Maverick, and LaSalle counties of South Texas was discovered by Petrohawk Resources.

The Haynesville shale, in northwestern Louisiana, parts of Texas and Arkansas was “discovered” by the same company a couple of years ago.

While these shale formations have been known about by geologists for years, the fact that so much natural gas could be extracted from them is a new realization.

Energy Independence?

It is highly possible that the United States could one day achieve energy independence by exploiting the massive shale gas reservoirs located across the country.  Oil baron T. Boone Pickens has lobbied heavily for his “Pickens Plan” to use domestic wind energy and natural gas to power the nation.

Of course Mr. Picken’s motives are partly self serving, (he owns a huge stake in natural gas and wind energy companies), but his plan does make sense.  Using wind energy from the “wind corridor” which is an area that runs roughly from Sweetwater, Texas to Canada, his plan aims to reduce the amount of natural gas burned by power plants by twenty percent and divert that natural gas to use as a vehicle fuel.

The technology exists to use natural gas as a motor fuel. In fact many vehicles such as city buses already run on natural  gas and there are CNG or compressed natural gas stations in many cities. In addition a technology called “gas to liquids” or GTL, can make regular gasoline and even diesel from natural gas instead of crude oil.

It may be that America’s energy future may not lie in the desert sands of the Middle East but instead is beneath our feet in hard black shale.