How Fracking Works
What is Fracking?
In todays world, oil and gas rule everything. New ways to obtain these commodities are
being developed everyday, and one of the fairly new techniques to extract oil and gas is
fracking. Fracking or hydraulic fracturing is the process of fracturing various rocks,
usually shale, by a pressurized liquid. By doing so, natural gases in the form of methane
and oil can be extracted and refined to be sold on the global energy market. The
process was originally developed in 1947, but the first commercial applications came in
1949 and new wells are still being drilled to this day. It is thought that about 60% of all
gas and oil reserves that could potentially be hydraulically fractured have been
accessed as of 2010, and the percentage is increasing with the recent discovery of
massive shale deposits in northern Appalachia and southern New England. Although
hydraulic fracturing holds the possibility of supplying ample amounts of oil and natural
gas to those who need it, there is a massive controversy around implementing the
process around neighborhoods and farms as the environmental side effects of fracking
are immense if government codes and drilling and waste removal standards are not
met.
How Does Fracking Work?
Finding where to drill
Fracking begins with first locating potential wells to be drilled. Recently, new oil and gas
shale deposits have been found along the east coast of the U.S. and many new wells
have begun to spring up all over West Virginia, Pennsylvania, New York, and Virginia.
(The figure above displays the positions of potentially gas and oil reserves.)
Once a potential drill site is located, the drilling company must receive permission from
the land owner to use and drill on their land. Fracking has been known to cause harmful
environmental side effects and some land owners will refuse their land to be fracked on
in worry that their land and water reserves might be compromised with radio active and
poisonous waste that is produced by the process. Many land owners succumb to the
constant bothering to drill their land and the possibility of having a share of the profits
that will come from drilling their land. If the drilling company receives permission from
the land owner then a drill is set up and the process of fracking begins.
Setting Up the Drill Site
The drill site is set up into two components: the drill and the holding chambers for the
water cocktail run off. The exact location of the drill spot is finely tuned and once found
a well is drilled. The shale, which potentially holds the precious oil and gas is located
about 6,000 to 8,000 ft under the ground and is usually deep enough were the well has
to be drilled through water aquifers that supply water to local communities. Once the
shale is hit, horizontal drilling takes place for about 4,000 ft within the shale deposit.
This makes it possible for the well to potentially be able to fracture more rock per drill
site and creates what is known as a hydrofracking zone (see fig. below.)
When
drilling
of the
well is
complete, a perforation gun is inserted into the well and fed all the way till the end. This
gun, which is fitted with multiple explosive charges that initially break the surrounding
rock, is fired and small amounts of methane are released. The perforation gun is
immediately withdrawn and the well is fitted with cement and steel casings to keep the
soon to be injected water cocktail mixture from spilling out into the rock and soil that
surounds the drilled well. It is very important that this concrete and steel protective lining
is thick enough to protect the surrounding environment and is strong enough to
withstand the constant flow of liquid. It is common for these wells to be injected with
more than 8 million gallons of fracking liquid through out its lifetime, and a breakage in
the well lining will cause leakage, which in return, compromise the whole operation and
shuts down the production of gas and oil.
(The perforation gun in action. The green spots are pockets
of gas and oil)
(Diagram of the protective layers of the well lining)
Once the wells are properly set up, a holding chamber for the used fracking liquid must
be assembled. Gas is extracted from the rock by injecting a cocktail of chemicals and
water into the well which fracture the surrounding rock and release pockets of gas and
oil trapped within the ancient rock formations. When the cocktail comes back out of the
well, it needs to be stored somewhere. It is a very hazardous liquid and can cause
serious environmental problems
by seeping into local water
supplies and surrounding
ecosystems, so having a proper
storage facility is vital in keeping
the integrity of the health of the
environment intact.
(The holding chamber of a fracking site)
As seen in the picture, there are
very loose guidelines in setting up
a holding chamber and they
usually only consist of a pit dug out of the ground and then lined with some type of
plastic sheet. The improper storage of waste material is one of the biggest set backs to
fracking and is responsible for most of the environmental problems that people
associate with fracking.
The Fracking Cocktail
The liquid that is injected into the well is composed of water and a variety of chemicals.
Every company has its own different formula, but it is common to see a combination of
heavy metals such as barium and arsenic, V.O.C’s like kerosene, benzene, and
acrylonitrile, plasticizers, surfactants, and sand. These chemicals when mixed create a
cocktail that is specifically designed to be able to sufficiently fracture rock and extract
the gas and liquid that is trapped within the pockets of the shale formation. Also, it is
worthy to note that this mixture is very dangerous as it has the potentially to be
carcinogenic and can contain radio active properties.
The Process of Fracking
Once the drill and holding chambers are set up, the well is drilled and the fracking
cocktail is injected into the well. The cocktail is delivered to the site in hundreds of
trucks that come from the companies chemical manufacturing plant. When the cocktail
hits the end of the well, the liquid travels through the initial breaks from the perforating
gun and starts to travels through new “fractures” that the liquid itself creates. The
cocktail is shot into the well at extreme pressures which is the driving forces that
contiguously fractures the rock deposits. Sand and chemicals within the cocktail help
keep the fractures open and the process lubricated to make sure noting clogs or blocks
the path of the well. The oil and gas is stored in pockets within the shale deposits and
when the surrounding rock around these pockets is fractured the oil and gas is released
into the well. The oil and gas is then captured at the top of the
(The fractures that the cocktail creates are very small, well. It is thought that about 50% of the
and are held open by pieces of sand)
cocktail that is injected into the well is
returned to the company and that a majority
of the cocktail either stays in the well or
leaks through fractures in the ground and
contaminates the surrounding area.
The Problems Associated With Fracking
Although fracking can produce a vast amount of oil and natural gas for consumers there
are plenty of draw backs to the process. The fracking cocktail that is used is notoriously
known to have radio active and carcinogenic effects to organic matter. Because of this,
if there are any breaks or cracks within the well that delivers the cocktail deep within the
ground, the aftermath could be devastating. Wells are usually drilled deep enough
where they pass through aqueducts where people draw their water from. If there are
leaks in the wells the cocktail could potential move into the aqueduct and contaminate
the water supply. Poorly lined holding chambers are a huge problem as well. The failure
to properly line the holding chambers can lead to additional leakage and contamination.
Also, poorly lined wells can also leak the extracted gas and oil which can lead to
additional consequences. With the majority of the oil that is extracted being sold to
overseas markets, one wonders if the potentially devastating consequences of poor
fracking techniques on local communities is worth the reward of a non renewable
energy resource.
Picuture References
(http://protectingourwaters.files.wordpress.com/2011/03/well_casing_graphic.jpg)
http:smlperspectives.com/wp-content/uploads/2011/11/fracking3_web.jpg
https://www.youtube.com/watch?v=fFUxq9UolN4