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Jonothan Tucker
ENGL 1010
Dr. Greenwell
April 23 2013
Is Hydraulic Fracturing good for the environment?
Slick water hydraulic fracturing or “fracking” is a technology used to extract natural gas and oil
that lies within a shale rock formation thousands of feet beneath the earth’s surface. Combined
with another technique called “horizontal drilling,” natural gas companies are able to drill
previously untapped reserves. The combination of the two has resulted in a boom in domestic oil
and gas production over the past five years. Horizontal drilling allows one surface well to tap gas
trapped over hundreds of acres. Once the conventional vertical drill hits the shale-formation, it
turns horizontally. Drilling can then occur in several directions, much like the spokes of a wheel.
The well is cased with steel and cement, which is meant to protect gas and frack water from
leaking out. Explosives are placed at intervals along the horizontal section of the well to
perforate the steel casing. These holes allow the gas, which is trapped in tight formations, to flow
up the vertical section of the well. Under very high pressure, a combination of water, sand and
chemicals are sent deep into the earth to create cracks and fissures in the shale rock. Those
fissures are held open by the sand, allowing the natural gas to flow through those cracks, into the
well bore and up to the surface.
Non-hydraulic Fracturing as a method to stimulate shallow, hard rock oil wells dates back
to the 1860s. It was applied by oil producers in Pennsylvania, New York, Kentucky, and West
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Virginia by using liquid and later also solidified nitroglycerin. The same method was applied to
water and gas wells. The idea to use acid as a non-explosive fluid for well stimulation was
introduced in the 1930s. Due to acid etching, fractures would not close completely and therefore
productivity was enhanced.
A hydraulic fracture is formed by pumping the fracturing fluid into the wellbore at a rate
powerful enough to increase pressure down hole to exceed that of the fracture gradient of the
rock. The rock cracks and the fracture fluid continue further into the rock, extending the crack
even further, and so on. Operators usually try to maintain "fracture width", or slow its decline,
following treatment by putting a prop pant in to the fluid – a material such as grains of sand,
ceramic, or other particulates that prevent the fractures from closing when the injection is
stopped and the pressure of the fluid is reduced. Consideration of prop pant strengths and
prevention of prop pant failure becomes more important at greater depths where pressure and
stresses on fractures are higher. The propped fracture is enough to allow the flow of formation
fluids to the well. The fluid being gas, oil, salt water, fresh water and fluids introduced to the
formation during completion of the well during fracturing.
During the process, some of the fracking fluid may be lost into the surrounding rock. The
location of one or more fractures along the length of the borehole is strictly controlled by
different methods that create or seal off holes in the side of the wellbore. Hydraulic fracturing is
performed in cased wellbores and the zones to be fractured are accessed by perforating the
casing at those locations.
Hydraulic-fracturing equipment used in oil and natural gas fields usually consists of a slurry
blender, one or more high-pressure, high-volume fracturing pumps and a monitoring unit.
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Associated equipment includes fracturing tanks, one or more units for storage and
handling of prop pant, high-pressure treating iron, a chemical additive unit (used to accurately
monitor chemical addition), low-pressure flexible hoses, and many gauges and meters for flow
rate, fluid density, and treating pressure. Fracturing equipment operates over a range of pressures
and injection rates, and can reach up to 15,000 psi and 100 barrels per minute of water. Hydraulic
fracturing is used to increase or restore the rate at which fluids, such as petroleum, water, or
natural gas can be recovered from subterranean natural reservoirs. Reservoirs are typically
porous sandstone, limestone or dolomite rocks, but also include "unconventional reservoirs" such
as shale rock or coal beds. Hydraulic fracturing enables the production of natural gas and oil
from rock formations deep below the earth's surface generally 5,000–20,000 feet. At this depth,
there may not be enough pressure to allow natural gas and oil to flow from the rock into the
wellbore at high rates. So creating conductive fractures in the rock is important to extract gas
from shale reservoirs because of the extremely low natural permeability of shale. Fractures
provide a path connecting a larger volume of the reservoir to the well. So-called "super
fracking", which creates cracks deeper in the rock formation to release more oil and gas, will
increase efficiency of hydraulic fracturing. The yield for a typical shale gas well generally falls
off sharply after the first year or two, although the full producing life of a well can last several
years.
For many decades the only way we could extract natural gas was to drill a well straight
down into the ground. However, in many cases, this is not possible, not economically feasible, or
simply not efficient. Technological advances now allow us to move from 'straight line' drilling,
and steer the drilling equipment to reach a point that is not directly underneath the point of entry.
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while what is known as 'slant drilling', where the well is drilled at an angle instead of directly
vertical, has been around for years, new technology is allowing for the drilling of tightly curved
well holes, and even wells that can take a 90 degree turn underground in just a few feet!
Directional drilling is the process of drilling a curved well, in order to reach a target that
is not directly beneath the drill site. This is useful in many circumstances where the area above
the targeted deposit is inaccessible. For example, to reach reservoirs that exist under shallow
lakes, protected areas, railroads, or any other area on which the rig cannot be set up, directional
drilling is employed. It is also useful for long, thin reservoirs. These types of reservoirs are not
efficiently mined with a vertical completion. However, horizontal entry into the reservoir allows
it to be drained more efficiently. Directional drilling is especially useful for offshore locations.
The cost of offshore drilling rigs can make it uneconomical to drill a single well. With
directional drilling, the offshore rig can gain access to deposits that are not directly beneath the
rig, meaning that 20 or more wells can be drilled from a single rig, making it much more cost
effective to drill offshore.
There are many proponents against fracking, all having their own various reasons that
fracking is dangerous. The fluid used in fracking is made up of 15% of recycled fluid (flow back
and recycled fluid from other wells), 20% public water (water purchased from public utilities),
63% surface water (water taken from rivers and streams requiring permission from the
Susquehanna river basin commission), and 2% proppants and chemicals (proppants are sand
material that are used to keep bedrock fractures open to allow gas to flow out, and the chemicals
are used to dissolve minerals, kill bacteria, thicken fluid, prevent the corrosion of pipe and
otherwise aid in the fracking process Mooney, Chris. 83. One of these reasons they dislike fracking
is that they say the wells that are drilled for fracking are not safe enough or controlled enough.
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They say that the wells are easily cracked and the fluid used in the fracking process seeps in to
ground water or in to the well water used in their own house, and water for their livestock and
crops. They say that the water makes their livestock sterile among other things and poisons their
crops. After looking into this issue, I found that in the process of drilling these wells, they have a
thick 6” metal pipe with a 1/2 inch thick metal walls; they put it in the center of a 10” metal pipe
than place that in a 15” metal pipe than place that in a 20” metal pipe. Next they fill all of the
space between each pipe with concrete, than they surround that whole thing with 5” of solid
concrete eventually creating a 30” concrete/metal pipe that has only a 6” opening. Grealy, Nick 24.
So there is no way that any fluid or chemicals can escape.
Fracking is often criticized for the amount of water it consumes as well. A common
figure given of water usage is 2-3 million gallons per well. One way to look at this is to ask what
amount of rainfall would be needed to replace this. Let's take an actual example. A drilling unit
in Pittsburg covers 351 acres, with two drilling pads. One pad has 1 horizontal bore, the other has
3. Let's assume that the greatest amount of water will be used--3 million gallons for each of the
4 legs. To produce the required 12 million gallons would require rainfall of 1.26 inches on 351
acres. Even in the driest month, October, with an average monthly rainfall in Pittsburgh of 2.25
inches, this means that the water required for fracking all legs would be replaced in just 17 days
of rain on just this unit. CHIARELLA, TOM, 111. Also water is required only one time in the
process, so 3 million gallons of water total throughout the entire operation cycle of this well,
which can be decades long. So if a well lasted 20 years, (most last much longer) having its water
usage spread out over its life, would use just over100 gallons a day and that is less than the
average American household uses in one day.
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Truck traffic and the natural gas well, being an eye sore is another controversial issue.
Hydraulic fracturing operations generate a large amount of truck traffic. All of the materials and
equipment needed for activities associated with hydraulic fracturing, including water and
chemicals, are typically transported to the site by trucks. Additionally, wastewater from natural
gas operations is usually removed by tanker truck to the disposal site or to another well for reuse.
Using information from the natural gas industry, the New York State Department of
Environmental Conservation estimates that high-pressure hydraulic fracturing in a horizontal
well would require 3,950 truck trips per well during early development of the well field, two-tothree-times greater than is required for conventional vertical wells. Weinhold, Bob 120.7. Much of
the truck traffic is concentrated over the first 50 days following well development. Truck traffic
could be reduced by nearly 30% if pipelines were used to move water between sites, although
pipelines can create other concerns, e.g., leaks, spills, and right-of-way controversies. Truck
traffic raises a variety of social and environmental concerns. Trucks increase traffic in the region
and create noise and air pollution. Trucks also increase wear and erosions on local roads and the
risk of spills, both of which can pollute local surface and groundwater. In addition, because so
much of new drilling is occurring in rural locations, new roads must be built to accommodate the
truck traffic, increasing habitat fragmentation and ecological disturbances. However, all of these
disturbances only affect the area for the first few weeks while the well is being drilled, but for
the many years after that there will only be the occasional truck sent to pick up product or to do
preventive maintenance on the well. And the well sight is hard to recognize in the middle of a
field after the well has been drilled. It is like building a house, during the building of a house
there is a lot of traffic that can be annoying but once the house is built, it fits in with minimal
disturbances.
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There are many reasons that people find to discourage fracking, and one of the last main points
that people bring up is air pollution. Fracking activities can lead to emissions into the air of
methane, volatile organic compounds, hazardous air pollutants, and greenhouse gases. The EPA,
the Department of the Interior, and other federal agencies and states are currently working to
better characterize and reduce the air emissions from fracking and their associated impacts. For
example, through the Clean Construction USA program, the EPA is promoting newer, more
efficient technology and cleaner fuels to increase the ways in which hydraulic fracturing
equipment and vehicles reduce emissions. Emissions from fracking may also contribute to
global climate change, according to a study performed by a group of researchers at Cornell
University. However, another group of Cornell researchers recently released a competing report
claiming the previous research overestimated leaks from fracked wells. Although natural gas is a
lot more toxic than the fuels we use now when its natural form is let directly in to the
environment, when burned and used it is much better for the environment than other fossil fuels.
After going over this, I have found that the pros of fracking for natural gas by far
outweigh the cons. Natural gas is the fuel of the future, it is safer greener, and much more
abundant so it is cheaper. If fracking for the natural gas is the only way to get it than I say go for
it because all the harm that could come from it is well worth it for the benefits you get.
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Sources

Ratcliffe, Ian. “Fracking is dangerous to Environment and throws good energy after bad”
Engineering & Technology 8.1 (2013):25-25. Print.

Grealy, Nick. “Fracking is one of the best things to happen to onshore gas exploration for
a century” Engineering & Technology 8.1 (2013): 24-24. Print.

CHIARELLA, TOM. “thank you for fracking” Esquire 159.1 (2013): 110-120. Print

Heywood, Peter. “fracking safer and greener” TCE: The Chemical Engineer 850.
(2012):42-45. Print.

Mooney, Chris. “the truth about fracking” Scientific American 305.5 (2011): 80-85.
Print.

Weinhold, Bob, “the future of fracking” Environmental Health Perspectives 120.7
(2012):8. Print.