A new technique using horizontal drilling and high pressure fluids to fracture shale has created a surfeit of natural gas and a revolution in America’s energy equation.
Natural gas is now less expensive, which will help keep home heating costs low and increase natural gas usage for generating electricity.
Fracturing, known as fracking, is accomplished by injecting fluids under high pressure into shale to fracture the shale formation so that oil and gas can flow to a well where it can be brought to the surface. Until the advent of fracking, natural gas supplies were too tightly locked in shale to be extracted.
Some have expressed fear that fracking will endanger drinking water supplies. New York State has enacted rules that virtually prohibit fracking.
In 2004 the EPA published a report on fracking as it is used for extracting methane from coal beds. The report found that fracking did not endanger drinking water supplies and that there was no credible evidence that fracking caused contamination of wells with natural gas or chemicals.
Fracking in shale formations is even less likely to contaminate drinking water supplies when compared with coal bed methane extraction, which occurs closer to the surface. An MIT study said, “Over 20,000 wells have been drilled in the past 10 years and, for the most part, the environmental record has been good.”
Fracking uses freshwater, sand and chemicals. Over 99% of the fluid used in fracking is freshwater. The sand is used to prop open fractures created by the high pressure fluid. The chemicals are used for such tasks as cutting friction, thickening water to suspend sand, and prevent corrosion of the well casing.
In most instances, shale containing natural gas is locked in geologic formations thousands of feet below freshwater aquifers. Fracking will typically take place at least 3,000 feet below freshwater aquifers except in some areas of the Fayetteville formation in Arkansas.
For example, according to the MIT study, the depth to the water aquifer in New York State is 850 feet while the depth to the Marcellus shale formation varies between 4,000 and 8,000 feet. The distances between the aquifers and the shale in the other formations are even greater, with the exception of the Fayetteville formation where the depth to the aquifer is 500 feet and between 1,000 and 7,000 feet to the shale.
In most cases, therefore, at least 3,000 feet of rock will separate fresh water aquifers from fracking fluids.
While the chemicals have weird sounding names, many are found in common everyday products. For example, Muriatic acid is used in swimming pools, Ammonium Persulfate is used in hair coloring, hydroxyethyl is used in toothpaste.
To help prevent extremists from using these weird sounding names to scare people, the fracking companies have begun to release the names of the chemicals used in fracking. Chesapeake Energy has listed those used in the Marcellus formation on its web site, while Range Resources Corp. has said they will also release the names.
More importantly, according to the EPA 2004 study, the chemicals are significantly diluted prior to injection by a ratio of 1 to 3 gallons of chemical per 1,000 gallons of water (some are even more diluted).
In addition, around 40% of the fluids are removed from the well.
Disposal of the used fluids can represent a risk. The risk has been manageable thus far, with only a few instances of improper disposal.
The EPA has announced a new study of fracking to be completed by 2012. In reality, conclusions from the new study should not be very different than from the 2004 study.
There is a genuine concern, however, that the EPA will conduct a witch-hunt that will prevent or severely limit the use of fracking. Limiting the use of fracking will result in less natural gas and higher prices for heating and electricity.
It will also shift the economics between natural gas and coal. Right now, with low prices for natural gas, natural gas combined cycle power (NGCC) plants can generate electricity at a lower cost than coal fired power plants.
Coal is under attack, and coal power plants are being decommissioned.
It has been thought that NGCC plants could replace the electricity lost as the result of having fewer coal power plants, but if fracking is restricted, the cost of electricity from these NGCC plants will be much more expensive than from coal fired power plants.
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