What is Hydraulic Fracturing?
Hydraulic fracturing (also called hydrofracking or just fracking) is a process of deriving energy from the Earth that has been around for about the last 50 years, but is equally as controversial as it is useful. Developed in 1947 in the United States, hydraulic fracturing was a way of using the earth’s natural resources to obtain energy. In other words, hydraulic fracturing or fracking is the process of pumping millions of gallons of water, sand and chemicals underground to create enough pressure to crack or break apart the rock and release the gas. These wells containing natural gas start by drilling vertically (straight down) hundreds of thousands of feet below the land surface and then turning the drill so that it drills horizontally extending thousands of feet.
Heard the term “natural gas”?
This is basically what hydraulic fracturing makes happen; it is a process designed to release and capture natural gases that can then be refined and distributed as an energy source.
The appeal of hydraulic fracturing is that it makes countries less dependent on Middle East and Asian countries that control some areas of oil production. As the last few decades have shown, rising oil prices can cause turmoil in an economy, so more and more countries look to domestic ways of producing energy.
According to the United States Environmental Protection Agency (EPA),
Hydraulic fracturing is a process to stimulate a natural gas, oil, or geothermal well to maximize extraction. The EPA defines the broader process to include acquisition of source water, well construction, well stimulation, and waste disposal.
Fracking is doable if there’s full disclosure of all chemicals used. Secondly, science dictates the policy rather than politics. Third, there’s collaboration between environmental groups and the natural gas industry.
– Bill Richardson
However, fracturing can also be used to:
- Make rocks cave in for mining
- Make groundwater wells more productive
- Dispose of waste
- Measure how the Earth is able to tolerate stresses of similar processes
Read here more about fracking:
Gases Recovered in Hydraulic Fracturing
Depending on the type of natural energy desired and the natural landscape where the operation occurs there are several types of gases that are mainly focuses of hydraulic fracturing:
- Tight gas is when tiny pockets of gas get trapped in dense rocks under the Earth, most commonly in either sandstone or limestone. The fracturing procedure is necessary to remove the gas in these cases, but tight gas hasn’t proven to be that reliable or consistent of an energy source.
- Tight oil is a crude oil trapped in rock formations underground, and can be removed via hydraulic fracturing. This is becoming more popular as a source of energy, but areas can give varying amounts of oil and it can be incredibly dangerous to move and transport.
- Coalbed methane is as its name suggests: methane gas that is produced in areas of coal. This used to be one of the greatest toxic concerns to coal miners who worked underground, but now more and more areas are using it as an energy source.
- Shale gas has become the most popular method of natural gas extraction in the last couple of decades, and has become the focus of most hydraulic fracturing that happens in the United States.
What is shale?
Shale is a rock formation similar to slate, that is comprised of a variety of minerals, rocks, and mud or clay that occurs below the ground. Shale is most typically found near bodies of water, which is why offshore drilling is often the same or a similar process to hydraulic fracturing.
In order to form, the composites that make up shale are pressurized enough to bond together, making a solid piece of rock over time.
Since this occurs under the ground or in water, certain natural gases get caught in between the shale formations; the process of hydraulic fracturing was developed to remove this gas.
The Hydraulic Fracturing Process
At its most basic, the process of hydraulic fracturing goes like this:
- An above ground station sends millions of gallons of a mix of water, chemicals, and abrasive materials at an incredibly fast rate down into the ground;
- The force and mix of this solution breaks apart the Earth’s underground rock layer, which releases a gas that is then used as an energy source.
Hydraulic fracturing technique is used in “unconventional” gas production. A special stimulation technique or other special recovery process and technology is used to extract the gas that is highly dispersed in the rock rather than concentrated at a single place. It involves injection of large quantities of water, sand and chemicals at high pressure down a wellbore and into the target rock formation that helps keep the fractures open to allow oil and gas to be produced to the well.
Once the injection is completed, the pressurized mixture enlarge fractures within rock formation and can extend several hundred feet away from the wellbore. These fissures are held open by the sand particles so that natural gas can flow up the well. The internal pressure causes the fluid to return to the surface through the wellbore. The recovered water is stored in tanks or pits, then taken to treatment plant where it is treated and then disposed to surface waters.
Just as pressure is responsible for combining elements to form a rock, equal amounts of pressure can also be exerted to break that rock apart, releasing the gas that was trapped in between.
What Types of Solutions are Used in Hydraulic Fracturing?
Chemicals added to water for fracturing purposes include:
- Hydrochloric and acetic acid
- Sodium chloride
- Borate salts
- Sodium and potassium
- Ethylene glycol
- Guar gum
- Citric acid
When added to water, these solutions take a number of final forms:
- Linear gels: usually derived from cellulose
- Borate-crosslinked fluids: using a guar based mixed with boric acid, these are more viscous fluids
- Organometallic-crosslinked fluids: these combine chromium, zirconium, and titanium salts to crosslink with a guar gel
- Aluminum phosphate-ester oil: a combination of aluminum phosphate and ester oils used to make a gel
Most of these fluid types are designed to be flushed out once the actual process of breaking down the rocks is completed.
What Areas of the World use Hydraulic Fracturing?
As concerns about energy rise with growing populations and technological advances, more and more areas around the world are looking to hydraulic fracturing to supplement traditional energy sources.
Of course, since this process is tied to the formation of natural rock, it is only possible to do so in areas of the world where these rock formations exist. However, natural shale formations can be found on just about every continent.
- It is currently believed that China has the most natural shale gas reserves, but they currently do not use enough to be significant in their energy use.
- The United States both produces a significant amount of shale gas, and uses it as a percentage of their total natural gas energy use.
- Canada also produces shale gas, and it is also used for energy purposes domestically.
Coalbed methane has become popular in a number of regions as well:
- Australia has put a lot of resources into extracting coalbed methane from areas like Bowen Basin and Sydney Basin
- In traditional coal mining areas around the United States, such as Colorado, New Mexico, Wyoming and other states around the Rocky Mountain region
- Kazakhstan has looked to coal methane has both a source for economic growth and energy production
- Canada, particularly in British Columbia, is an area of focus for coalbed methane, but environmentalists and energy companies are currently locked in a debate about the benefits and harms of this as a source of energy
- India has recently begun significant drilling into coalbed gas, as a way to become more self-reliant, particularly with growing populations and energy shortages
There are a number of locations around the world that have tight oil resources that haven’t been developed, and many countries are looking to this as a global solution for energy dependence.
- United States: Bakken Shale (North Dakota), Barnett Shale, Niobrara Formation, Eagle Ford Shale
- Persian Gulf: Sargelu Formation
- Syria: R’Mah Formation
- Russia: Bazhenov Formation, Achimov Formation
- Australia: Coober Pedy
- Mexico: Chicontepec Formation
- Argentina: Vaca Muerta oil field
The Controversy Behind Hydraulic Fracturing
While this form of energy production is gaining in popularity around the world to reduce global dependence on oil producing regions, there are many who cite a number of reasons for concern about hydraulic fracturing.
- Many areas touted fracturing processes as ways to grow local economies, but recent reports have shown that most have very little impact on surrounding areas. This has made many area residents weary of oil companies that promise local growth.
- Most research related to hydraulic fracturing has been released by energy companies involved with the process, causing many to call into question the legitimacy of such reports
Additionally, many environmental groups cite a number of concerns about the effects hydraulic fracturing can have on the environment, including:
- A major concern is that the process of hydraulic fracturing can cause the presence of toxic gases in local water sources, leading to illnesses and other consequences.
- Another concern is that the process releases harmful methane into the Earth’s atmosphere, which can have long-term effects on climate and the environment.
- Furthermore, those areas that are immediately located near a hydraulic fracturing well are prone to more harmful chemical exposures related to leaking wells.
- Because the process requires breaking up rocks under the earth’s surface, there have also been links made to seismic earthquake activity. This has led to concerns not only about property damage, but also personal wellness.
Image credit: Stephen , eranderson428
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