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Study Says Fracking is Safe In Theory But Often Not In Practice
First time accepted submitter chadenright writes "A university study asserts that the problems caused by the gas extraction process known as hydraulic fracturing, or 'fracking,' arise because drilling operations aren't doing it right. The process itself isn't to blame, according to the study, released today by the Energy Institute at the University of Texas at Austin."
The article stated that one of the main problems was bad cementing jobs, but from what I've gathered from reading and talking is that it is really hard to get a good cement job. There are things you can do to screw it up, but even if you do everything by the book, you can still end up with an imperfect seal. According to the US U.S. Minerals Management Service, cementing problems were associated with 18 of 39 blowouts between 1992 and 2006.
So, if doing fraking "right" requires you to have perfect cement jobs everytime, then it isn't possible to do fraking right.
That sound great, until you realise that by frac'ing and drilling into the rock, they've changed the permeability of the rock (ie: the point of frac'ing).
Drilling does not change the permeability of the surrounding rock. Keep in mind there is something called well casing which essentially protects the hole all the way to the surface.
If you drill a hole in concrete and fill it with water, did it make all of the concrete more permeable? Nope.
Many of the chemicals are water soluble and/or are lighter than the ground water, why wouldn't the ground water seep down in the now permeable rock and mix with the chemicals?
The ground water would not seep down because all of the rock formation did not have a uniform increase in permeability. It was like a bunch of cracks in a concrete wall that was further separated from the water table (we will just say a layer of dirt) by another layer of concrete that was unaffected by the frac.
Imagine this.
You have a mix of concrete in which you suspended bubbles of Coke. It is 100 feet thick. You then have a layer of normal concrete that is 1000 feet thick. On top of that you have a 100 foot layer of dirt that has a bunch of water in it.
The water table is only going to extend to the concrete itself, and not all the way to the bottom. That's the way they work, otherwise water could just fall all the way to the core of the Earth.
You then drill a hole through the whole thing. Before you frac, or do anything else after drilling the hole, you make a nice reinforced straw. That is called casing. All of the dirt does not directly interact with any fluid in the hole. It can't. The casing is there.
The water table is protected by the casing.
Now you perforate the casing all the way at the bottom with shaped explosives. This allows the Coke to flow into the hole under pressure and go to the surface. However, since the permeability is so low... you are not getting a lot. The Coke does not interact with the water table due to the casing.
That's where fraccing comes in. You create thousands of small fractures (hence the name) in the bottom layer with that nasty fluid everyone hates. Pump in proppant (which is like sand) and remove the fluid.
Now what you have is a bunch of fractures that allow the trapped Coke to travel to the hole faster. That's why it is done.
The fractures themselves extend out horizontally some distance, and vertically, but they they simply don't make it all the way through that 1000 foot thick layer of concrete to get to the water table above it.
That is why ground water does not seep into fractured formations thousands of feet below it. A path does not exist.
So now that you understand that, the only way the water table can be affected is with damaged casing (has nothing to do with fraccing) or a fraccing process that put the water table at risk because it was too close.
That's why the technology is perfectly fine in theory. Any dickhead that decides to do something like that too close to water table is the real problem.
If the area they are frakking is 10,000 feet "Below" the water table, then they probably have to go through the water table in order to reach it.
So there is at least one path for contamination.
No. There is no path with proper well casing.
Additionally, frakking is the process of breaking geological formations in order to allow for the collection and extraction of liquid petroleum and gasses, AND a direct correlation has been show between frakking and increased geological activity.
So, they are intentionally breaking the layers of rock separating pockets of gas and oil, and causing small earthquakes.
Extremely small earth quakes. It is misleading to give it that term because it implies to most lay people that you could feel it long distances away. You can't. Unlike the vast majority of posters I have been less than 100 feet away from the well bore in a trailer when a large frac was performed. I did not fall down, and other than a light amount of vibration, it was just a big bang. Also keep in mind, that any release of energy that high would require some impressive engineering on the well bore and drilling rig.
I would like to see studies that show a direct correlation between fraccing and increased geological activity. "Correlation does not imply causation". While I don't wish to seem like I am resistant to the truth, the science behind fraccing does not, at a glance, support sustained increases in geological activity.
Citation please.
Meanwhile you are arguing that "it is impossible for the technology to cause the problems", and that there is no way that during all of the intentional layer breaking they might cause something to change in the layers that are sitting on top of the work area
They can't cause any large scale or meaningful changes in layers sitting on top of the work area. I am assuming that you mean that a frac conducted at 15k feet deep can change layers between a thousand feet and the surface. That would not happen.
In order for it to be true, the energies required would be impressive to say the least. The frac would not be limited to the production zone, but would result in fractures at the surface. Such energies would result in an earth quake comparable to a nuclear blast. You would feel that in major cities hundreds of miles away.
You simply cannot affect changes through that many thousands of feet of rock without the requisite increase in energy levels. It's not like they are bringing out portable nuclear power on site. It's diesel man.
Additionally, and so many people here overlook this, for every fracture that is created you need to pump proppant into it. This means you can tell how well your frac performed, in part, by looking at how much proppant was pumped into it. To have large scale effects at the water table, thousands of feet above your target, would require many many times the amount of proppant you estimated was required. You would know.
I'm not sure that "impossible" is the right term to use. I'd have chosen "marginally unlikely", but that's just me.
Impossible might have been over doing it. However "marginal" is over doing it as well. Highly unlikely would be a better way to say it. You have better chances of winning the lottery.