I wouldn't mind trying my hand at a bit of freelance journalism, actually...
So anyway.
CSG is natural gas trapped in coal seams. Fairly straight forward. It is comprised mostly of methane and burns quite cleanly. To extract it, a well is drilled, water/fracking fluid is pumped in (or water is removed) to change the pressures underground and encourage the gas out :)
It is a pretty clean energy source, in terms of its emissions. The problem is the fracking fluid.
The idea of fracking fluid is that it fractures the rock it travels through, creating escape paths for the gas. To do this, they must be viscous and able to transport proppants (a solid to keep the fractures open after the pumping stops).
There are many flavours of fracking fluid. Some sources indicate that fracking fluid is 99% water and sand (with sand being the proppant), with the remainder being, for example, surfacants (which can be found in toothpaste), guar gum (found in icecream) and acetic acid (think vinegar). However, water as the main fluid is sometimes not viscous enough to fracture the rock. In this case, other fluids are used, including:
- Gelled fluids: high viscosity, man-made fluids. Includes guar gum and other products from the guar plant, which is biodegradable. So far, so good, but diesel fuel has been reported as the substance used to dissolve the guar powder. Ack. Diesel fuel is known to carry carcinogens. The thickener for the fracking fluid may contain anything from 30-almost 100% diesel fuel. Other gelled fluids contain boric acid (I remember, as a child, my parents using borax, the salt of boric acid, to kill ants ~they do not do this now~) and ethylene glycol (antifreeze). I am not entirely certain of the concentrations of these materials. I only hope that, as advocates of CSG say, it is a
nominal quantity, because I sure as hell don't want any of it in my groundwater.- Acids: used particularly in limestone regions to dissolve the rock. This is generally hydrochloric acid, or a mixture with acetic or formic acid (ants also produce this, btw). This type of fracking requires huge amounts of acid. However, it has been noted that the concentrations of acids are 1000x weaker than the levels presented in standard MSDSs.
- Others include: biocides (kill bacteria), breakers (break down fracking fluid viscosity), and acid inhibitors (to stop acid from eating well casings).
The affects of these chemicals are not fully understood. As such, the precautionary principle should be applied, but who does that?
I would be rather concerned about some of these materials. Water is a precious commodity, and any further pressure could be very dangerous for the water-sucking vampires that the human race is. O.O
Anyway, I'm reserving judgment (do I sound impartial? :P). I don't like the fact that these chemicals are being used, but if they are employed safely (or replaced, preferably) I really don't have a problem with CSG.
I'll probably ramble about this again in the future after the protest. It seems a little small atm :( but we'll see what happens.
The link is here: https://www.facebook.com/event.php?eid=277937405556316 if anyone is interested in wandering over. I believe that they will be joining up with others from Parramatta, before heading to Hyde Park, Sydney, to create a giant bike. Rawk.
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Most of my info came from here: Environmental Protection Agency (2004) Evaluation of impacts to underground sources of drinking water by hydraulic fracturing of coalbed methane reservoirs, Chapter 4: Hydraulic fracturing fluids. Just FYI.
And a little from Australian Petroleum Production and Exploration Association, Fraccing Facts. Anyone know when this was published?
Heh, I researched his topic last semester. Fun stuff. I still have a copy of 'Gasland' on my hard drive somewhere...
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