Fracking for Dummies
Natural gas hydraulic fracturing (it’s a mouthful I know) is a technique used to extract natural gas from shale rock. Water is pumped into a well at a high pressure creating fractures in rock formation. With the water are other materials like sand which are added to keep the fractures open during the process so more oil or gas can be extracted.
The Good
It has been projected that 42 trillion cubic meters of recoverable gas is sourced from hydrofracking. This number is almost equivalent to the amount of conventional gas found in the United States in the past one-and-a-half centuries. It’s also approximately 65 times the US consumption rate which is what makes it seem the ideal source of energy until we are able to find renewable energy resources. The 50 billion barrels which have been discovered through this method has the potential to produce 3 million barrels of oil a day by the year 2020. With it our dependency on foreign oil imports would significantly decrease in the coming years.
Precautions have been put in place in the event of blowout or methane gas leaks. Old pipelines have been updated and alarms which warm of these leaks have been installed.
The Bad (supposedly)
Despite the benefits of natural gas hydraulic fracturing, many remain opposed to it. This is because of the environmental risks that fracking poses. The first of these is water use and wastage. Water is the planet’s most valuable resource and it supplies of it are decreasing all over the world. With fracking, about 20 million liters of water is pressurized into each well along with sand and more that help keep it open. But worst of all is the amount of chemicals used in the process. There are about “200,000 liters of acids, biocides, scale inhibitors, friction reducers and surfactants” combined in with the water. In fact, of the 2 million liters used, only 1 – 2% is used to extract shale gas. That means that millions of liters of water are being wasted; this does not make for a sustainable replacement of conventional oil.
Furthermore, of the natural gases contained in shale rock, methane gas is number one. As you may or may not know, methane is the second most important greenhouse gas. Some researchers have found that in twenty years shale gas has contributed to the greenhouse effect more than both coal and oil. Blowouts, spills, and improper disposal can lead to contamination of drinking water as has happened in Pennsylvania. Pennsylvania citizens complained of contaminated water from municipal supply and it was confirmed that toxic methane was found in the fresh water supply from the wells near drilling sites.
BUT supporters of the method argue that their opponents base much of their hesitations on fear not science. Their arguments are based on “what-ifs” not on evidence or instances of bad things happening as a result of fracking. In the Pennsylvania case above, data about the contamination has not been made available for outside evaluation. This casts shade on the truth about the situation.
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Bibliography
Howarth, Robert W., Anthony Ingraffea, and Terry Engelder. “Natural gas: Should fracking stop?.” Nature 477, no. 7364 (September 15, 2011): 271-275. Academic Search Complete, EBSCOhost (accessed October 7, 2012).
Hutchinson, Cliff. “Hydraulic fracturing: An environmentally safe method.” Fort Worth Business Press 21, no. 4 (February 2, 2009): 13. MasterFILE Premier, EBSCOhost (accessed October 7, 2012).
“Hydraulic Fracturing Overview: Growth of the Process and Safe Drinking Water Concerns.” Congressional Digest 91, no. 3 (March 2012): 71. MasterFILE Premier, EBSCOhost (accessed October 7, 2012).
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Howarth, Robert W., Anthony Ingraffea, and Terry Engelder.. “Fracking for Fuel.” Diagram. Nature 477, no. 7364 (2011): 272. Academic Search Complete (accessed October 7, 2012)
Today was Lego Mindstorm Experiment numero dos (that’s #2 for all you non-Spanish speakers). We were to use the Lego Mindstorm motor to control a pulley to lift weights. Doing so we would explore:
- Force and energy: Newton’s 2nd Law of Motion
- The law of conservation of energy – energy can’t be
created or destroyed only transferred or transformed.
- Velocity and Acceleration
- Power – measures the time rate at which work is done
However do to some technical difficulties with the Labview program, our experiment was limited to testing force, mass, and acceleration. Here is the main equation used in the experiment:
Force = mass x acceleration
F=ma
A few of things to know before getting into the nitty gritty of the experiment:
- Force (F) is measured in Newtons (N)
- Mass was converted from grams (g) to kilograms (kg)
- Meters (m) was converted from inches (in)
We ended up conducting twoexperiments – one in which we made force constant and the other in which we made mass constant.
Experiment 1
As previously stated, force remained constant at 10 N for all trials.
The Labview program runs the motor works the pulley to lift the weight. We plugged the number 10 (constant force) into the program so the motor would “know” to lift the weight with that amount of force for each trial.
Because acceleration is dependent on the change in velocity or the change in distance over time, we wanted to see how acceleration changes at different levels of mass. So we altered the weight five times to calculate those differences. This is what our numbers looked like in the end:
Force (N) Mass (kg) A (m/s^2)
10 0.05 200
10 0.1 100
10 0.15 66.66
10 0.2 50
10 0.25 40
I know, you’re looking at this, scratching your head without a clue as to what any of this means. But don’t worry, I’m here to explain it to you.
As I already told you, acceleration is a change in velocity over time. This is to say that acceleration is calculated by diving velocity by time or better yet, diving meters per second by second which is the same as dividing distance (meters) by time twice (seconds squared). The end equation is this:
Acceleration = meters / seconds squared
A=m/s²
In the above chart you can see that acceleration is greater when mass is lesser. This is due to a simple fact – the lesser the mass, the greater an object can travel in a shorter amount of time and vice versa.
Still don’t get it? I’ll use a real world example for you.
You have a golf ball, a baseball, and a bowling ball. If you are a pitcher throwing at a constant force for each throw, what do you think will happen when you try to throw each ball? The golf ball will have the greatest acceleration because you will throw in the farthest in the shortest amount of time since it has the least amount of mass. The bowling ball will have the least acceleration because its great mass will cause you to throw it the shortest distance in the longest amount of time. And finally the baseball will have the middle acceleration. Its mass is greater than the golf ball but less than the bowling ball so you will throw it somewhere between each; it will go the median distance in the median amount of time.
So going back to Lego Mindstorm and the chart, when mass of the weight was smallest at 0.05 kg, acceleration was greatest at 200 N. And as mass increased, acceleration decreased.
Experiment 2
In our second experiment mass was kept constant at 0.25 kg at five different levels of force. The same concept introduced in Experiment 1 applies to this one. again acceleration is the change in velocity over time so our goal was to see how different levels of force, intead of mass, affected acceleration. Here’s a chart of our results:
Force (N) Mass (kg) A (m/s^2)
10 0.25 40
20 0.25 80
40 0.25 160
80 0.25 320
120 0.25 480
Alright, either your scalp is really itchy or you’re once again confused. I’ll use the baseball example from earlier to break it down for you.
Now you have a single baseball that has a mass that doesn’t change. You’re a pitcher warming up for a game. You’re a little rusty so the first time you throw it you do so with a small amount of force and the ball takes a while to go practically nowhere. You build your confidence with each throw. Now when you throw it you use more force and the baseball goes much farther much quicker. You’re excited but the game’s about to start and you only have time for one last pitch. You give it your all, using all the force you have. In what seems like a split second the ball goes flying – it’s going, going, gone. You’re ready to win.
This example shows how added force on a given object increases its acceleration. Take another look at the chart. You can see that at the constant mass the greater the force, the greater the force the grater the acceleration. At a force of 10, acceleration is a measly 40 but at a force of 120, acceleration is a whopping 480.
Hopefully you all learned a lot about force, mass, and acceleration through this experiment and how each can be found in everyday life. Maybe now you’ll recognize it and the next time your favorite pitcher is throwing with an injured rotator cuff, you’ll know what might be in store for your team.
Thanks for reading!