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What is Hydraulic Fracturing aka Fracking?

Fracking rig

Fracking also known as hydraulic fracturing is an extraction technique that uses a pressurized fluid to harvest shale gas and oil reserves from the underground rock.

Fracking (Hydraulic fracturing) – Definition

Hydraulic fracturing or simply fracking is an extraction process that relies on a fluid which is pumped under high pressure into the wellbore to create small cracks in the underground rock and reach the deep layers of shale gas and oil.

To extract natural gas and oil from the underground rock, the high-pressure fracking fluid (containing water, sand or other proppants and also thickening agents) is injected into the wellbore.

The injected liquid will produce cracks in the underground rock, and the sand will keep the cracks open while the chemicals will kill the bacteria and dissolve minerals to reach the underground layers of shale gas and oil, which will be recovered after pumping out the fracking fluid from the well.

What is Hydraulic Fracturing and How Does it Work?

According to gas companies, fracking is a three-step process.

1. Drilling the Well

The gas company will start by creating a drill pad in the area where the shale gas and oil reserves have been detected in the underground rock.

The drill pad usually covers an area of about 258,000 square feet, which means that all the trees and vegetation will be removed from the area to make room for the drilling equipment.

After cleaning the soil of vegetation and trees, the entire surface of the drill pad will be covered with white, chalky caliche rock.

When the drill pad is ready, the company will bring the drilling equipment consisting of a drill rig (with a height of about 150 feet).

Large underground reservoirs

The underground gas reservoirs can be large, so the company will need to drill several wells in the area to extract as much natural gas as possible.

Drilling the first well will take a couple of months because the depth reached in the underground rock is between 7,000 and 12,000 feet.

After drilling the first well, the company will understand the characteristics of the local rock, which means that they can drill an additional well in just a few weeks.

To use fewer wells and increase the production of natural gas, the company will also use horizontal drilling.

2. Initiating the Fracking Process

When the well is ready for fracking, the area will look pretty busy because besides the large equipment that works day and night, a large number of trucks will bring water and chemicals for fracking, and the company will install large tanks to separate fracking fluids from the extracted gas.

Using pumps to inject the fracking fluid inside the well to reach the gas reserves, creates a loud noise in the area.

Noisy stations

Noisy compressor stations will also be used to squish the extracted gas and send it away through a pipeline.
Besides the continuous noise, the odors in the area could also be changed due to the chemicals used in the fracking process.

If the fracking site is located near a small town, the life of the people living there will be changed.

They will hear a loud noise day and night (which can severely affect the sleep of the people living close to the drilling area), their underground water may be contaminated with dangerous chemicals, and in time they could face small earthquakes produced by the moving rocks which are filling the gaps created in the underground rock by the fracking process performed there.

For each well, the fracking process can take between two to three days.
On a big frack site, up to 4.5 million gallons of water can be used per frack.

When the underground rock is fractured, the company will install equipment (a series of valves and pipes) atop the shale deposit, which will keep the gas contained.

The equipment will allow the gas company to extract the natural gas at a manageable pace.

3. Finishing the Extraction Process and Closing the Well

When the gas reserve is depleted, the extraction process ends, and the final well-pad area containing the closed well will cover an area of about 4,000 square meters, and green plants will be allowed to repopulate the surrounding land.

Chemicals Used in the Fracking Process

A large number of chemicals are used in the fracking process due to the fact that they have a specific role in this extracting technique.

1. Chemicals used to dissolve minerals and initiate cracks in the rock

Hydrochloric Acid (CAS 007647-01-0).

2. Chemicals used to eliminate bacteria in the water that could produce corrosive by-products

Glutaraldehyde (CAS 000111-30-8), Quaternary Ammonium Chloride (CAS 012125-02-9), Quaternary Ammonium Chloride (CAS 061789-71-1) and Tetrakis Hydroxymethyl-Phosphonium Sulfate (CAS 055566-30-8).

3. Chemicals used to allow a delayed break down of the gel

Ammonium Persulfate (CAS 007727-54-0), Magnesium Peroxide (CAS 014452-57-4), Magnesium Oxide (CAS 001309-48-4).

4. Chemicals used as product stabilizer and / or winterizing agent

Sodium Chloride (CAS 007647-14-5), Calcium Chloride (CAS 010043-52-4), Isopropanol (CAS 000067-63-0), Methanol (CAS 000067-56-1), Ethylene Glycol (CAS 000107-21-1), Ethanol (CAS 000064-17-5), Methanol (CAS 000067-56-1), Isopropyl Alcohol (CAS 000067-63-0), 2-Butoxyethanol (CAS 000111-76-2).

5. Chemicals preventing clays from swelling or shifting

Choline Chloride (CAS 00067-48-1), Tetramethyl ammonium chloride (CAS 000075-57-0), Sodium Chloride (CAS 007647-14-5).

6. Chemicals preventing the corrosion of the pipe

Formic Acid (CAS 000064-18-6), Acetaldehyde (CAS 000075-07-0).

7. Chemicals used as carrier fluid for borate or zirconate crosslinker, for guar gum in liquid gels, and as friction reducer for polyacrylamide

Petroleum Distillate (CAS 064741-85-1) and Hydrotreated Light Petroleum Distillate (CAS 064742-47-8), Polyacrylamide (CAS 009003-05-8).

8. Chemicals used as carrier fluid for the active surfactant ingredients

Naphthalene (CAS 000091-20-3).

9. Chemicals used to maintain fluid viscosity as temperature increases

Potassium Metaborate (CAS 013709-94-9), Triethanolamine Zirconate (CAS 101033-44-7), Sodium Tetraborate (CAS 001303-96-4), Boric Acid (CAS 001333-73-9), Zirconium Complex (CAS 113184-20-6), and Borate Salts.

10. Chemicals used to thicken the water in order to suspend the sand

Guar Gum (CAS 009000-30-0), Polysaccharide Blend (CAS 068130-15-4).

11. Chemicals preventing precipitation of metal oxides

Citric Acid (CAS 000077-92-9), Acetic Acid (CAS 000064-19-7), Thioglycolic Acid (CAS 000068-11-1), Sodium Erythorbate (CAS 006381-77-7).

12. Chemicals used to prevent the formation of emulsions in the fracture fluid by increasing its viscosity

Lauryl Sulfate (CAS 000151-21-3).

13. Chemicals used to adjusts the pH of the fracking fluid to maintain the effectiveness of other components (crosslinkers)

Sodium Hydroxide (CAS 001310-73-2), Potassium Hydroxide (CAS 001310-58-3), Acetic Acid (CAS 000064-19-7), Sodium Carbonate (CAS 000497-19-8), Potassium Carbonate (CAS 000584-08-7).

14. Chemicals used to prevent scale deposits in the pipe

Copolymer of Acrylamide and Sodium Acrylate (CAS 025987-30-8), Sodium Polycarboxylate (CAS 59233-52-2), Phosphonic Acid Salt (CAS 13708-85-5).

Benefits of Fracking

Fracking involves the recovery of natural gas from deep layers inside the Earth, and represents an extraction technique that proved to be very useful for many energy companies in America and Europe especially in the period when the natural gas sources have been almost exhausted.

Fracking managed to increase the reserves of natural gas and oil, which decreased the price of oil on the market, and created the possibility to use more natural gas and less coal for energy and heat generation.

Natural gas is considered a cleaner fossil fuel compared to coal because it produces a smaller amount of harmful emissions while burning.

Environmental Concerns Raised by Fracking

The environmental issues created by fracking are way numerous compared to the benefits produced for the economy of a country.

The U.S. is the country where fracking has been used more than a million times by now, and even today, more than 60% of all new oil and gas wells are drilled using hydraulic fracturing.

Fracking turn to be bad for the environment mostly due to the chemicals used in the fracking fluid.

The fracking fluid is not used only one time to create cracks in the underground rock and release the natural gas resource, because once the fossil fuel is recovered, before closing the well, the company will pump back the fracking fluid in the well and will close the well.

Once pumped back into the well, the large volume of fracking fluid, which is still full of dangerous chemicals can contaminate the drinking water sources located underground.

Fresh water consumption is a major issue

Hydraulic fracturing consumes large quantities of fresh water, but at the same time it can contaminate important sources of fresh water for the local communities neighboring the fracking site.

The contamination of the fresh water with dangerous chemicals present in the fracking fluid turns to be so severe that not even a treatment plant can clean it.

Many sources of underground fresh water have been already contaminated in the U.S. by the fracking fluid due to negligence.

No one knows today how the enclosed water sources will behave in the future because nobody was interested to conduct a long-term study on the subject.

Besides water contamination with dangerous chemicals, hydraulic fracturing is also a source of greenhouse gas emissions.

The air pollution created when we burn natural gas is another major issue

Natural gas is cleaner than coal when burning, but the impact of fracking on global warming and climate change is greater than the benefits produced by increasing the use of a cleaner fossil fuel.

Fracking is polluting the air by consuming more energy than regular natural gas wells because a fracking well is exhausted much often (in two or three days), so new wells must be drilled (a larger consumption of energy).

About 3% of the natural gas is lost in the extraction process and escapes into the atmosphere.

Final conclusion

In the short-term, fracking can be considered useful for the economy because produces a cheaper and cleaner source of power compared to coal.

However, on the long-term, the consequences of using fracking as extraction technique are not yet known, but the effects on the underground fresh water sources is more than obvious.

Article written by:

I am a writer and reporter for the clean energy sector, I cover climate change issues, new clean technologies, sustainability and green cars. Danny Ovy

1 Comment

  1. Thomas Jameson

    It’s good to know that fracking is a process by which small cracks are made in the underground rock to reach deep layers of gas and oil. My brother has been wanting to learn more about fracking, and he was totally unsure about what it was. I’ll pass this information along to him for his benefit.

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