Back to frac...
So far, we've looked at pretty conventional sources of oil and gas. We looked at formations that are porous and permeable that have a non-permeable "cap" preventing the oil and gas from naturally migrating to surface. We have drilled vertically through the cap, cemented casing into the well, then opened up the casing to produce the resource. We have looked at fracing to increase the permeability of a producing zone, allowing a greater amount of the oil and gas to get into the well bore.
Because we have a well that is vertical, when we frac the producing zone, the fractures radiate out horizontally outwards from the casing (mostly). This is important, because the non-permeable cap has remained whole preventing any oil and gas from seeping towards the surface. The only path it can go is into the casing where we can control it. (Remember this.)
Shale gas and shale oil.
Shale gas and oil is different from the resources we have talked about so far in a couple of important ways. First of all, many of the shale zones ARE the cap from more conventional zones. Shale is porous, so it HOLDS the oil and gas, but because it is non-permeable, it does not allow the oil and gas to migrate through it. Other than the shale itself, there does not need to be a non-porous cap above it to keep the oil and gas in place. Shale is so effective at holding the oil and gas, that it is very difficult to produce at all. Fracing the shale in a vertical well does not open up enough of the resource to be economical. So, the wells must be drilled horizontally.
Wells are drilled vertically to the shale, and then are turned horizontal for many thousands of feet. The well follows allong inside the shale, and casing is again cemented into place along the entire well. Many wells are drilled and radiate out from a large pad.
The casing is then perforated in stages all along the horizontal section, and the well is frac'd in many stages along this section as well. Remember that the frac's are measured in tons of sand? Well in the conventional wells, I remember being at location when there was a 5-10 ton frac going on. In a horizontal shale well, the frac's in a single well can measure in the multiple hundreds of tons. (More trucks, more pumps, more fluid, more sand, etc..)
All of the multiple wells on the pad are produced in the same way, and hopefully (to the oil company anyway) all of the space in between the different wells becomes fractured. This means that there are now pathways not just leading outward from one well as before, but now there are multiple pathways spread out between all the wells. In this manner, enough of the shale resource becomes available to make things economical.
So now, we are back to the original question. Have I seen frac fluids coming back to surface through the well and spilled all over the place? The answer is no. For this to happen, something on the surface would have to break to allow the frac fluid out. Technically it could occur, but it would be very rare. The oil companies do however use waste water ponds that could potentially leach into rivers or streams. Another more sinister form of pollution would be the deliberate dumping of the used frac fluid into waterways. And the third potential for pollution is the migration upwards from the shale itself.
Remember that I said that the shale doesn't necessarily have a cap? A shale zone not only does not need a cap, but we are now fracturing it vertically. Remember that the pipe is horizontal - so our fractures are now radiating out in directions that include UP. This is important because it is technically possible to fracture all the way through the shale zone, and into the zone above it. If this happens, and the upper zone is permeable, there is now a path for the oil and gas to migrate upwards. It will migrate upwards until it reaches a new layer of non-permeable rock. In this manner, underground aquifers could be potentially contaminated.
What about contamination of underground aquifers? In CO, there are places where people's water now has flammable gasses in it and you can literally light the water coming from the tap.
[QUOTE=Mud Flinger;1089987]What about contamination of underground aquifers? In CO, there are places where people's water now has flammable gasses in it and you can literally light the water coming from the tap.[/QUOTE]
You didn't read the last paragraph of my last post.
[QUOTE=itchy166;1089994]You didn't read the last paragraph of my last post.[/QUOTE]
You are too right sir! Thought I'd read the whole post but obviously not. So what is the best protection for people in these areas that use well water?
[QUOTE=Mud Flinger;1090211] So what is the best protection for people in these areas that use well water?[/QUOTE]
Hi Mud Flinger! We have a well. We live in tight, rolling hills, and our house is sited on top of one of those hills. Our well is about 265 feet deep. Aside from some small lakes (and not many of those), there is little natural running/standing water in this corner (year-round - I am not counting snow melt or spring rains) and it is rural enough that simply most of the county is on well water, that if your house catches on fire, you had better have a full swimming pool or a farm pond to help out - otherwise your house is ash.
Anyway, the answer, I fear, will be this: simply no fracking. Just to protect the water - take zero chances with it. I am beginning to get the nightmarish vision that it won't be long before we end up with contaminated water in the county, and then all those family farms around here won't be worth shit. At that point, I hope everybody got their jollies out of their new cars and whatever nonsense they used their signing bonuses for, because nobody will be able to live here after the water goes.
The other day I saw a photo, it was on the front page of the (weekly) local town newspaper, of the county engineer and some other county officer, and there were pins stuck in the map which represented all the new wells/pad sites in the county... there were multiple pins in each and every township in this county. Remembering what itchy said about horizontal drilling (I knew about that, itchy just gives me tons of detail and puts it all together so well), that pretty much means that very soon nearly every square inch of the deep geology under this county will be pumped full of pretty much poisonous crap. And less or more poisonous is wurst to me - contaminated water is contaminated water, the degree matters not once that happens - neither you nor your animals can drink it either way.
I know I feel like Chicken Little right now. But the more I learn, the more I feel justified.
We love it out here, but I seriously am contemplating moving before the shit hits the fan, i.e. my property is still worth something in this oil boom. Because of the oil, land prices have gone UP for the first time since the first English crossed the Appalachians into the Ohio Country.
Itchy is probably getting tired of my ranting, but I have a kid who cries every time she leaves the house - the pipeline people are digging up our road as we speak, because my neighbor two plots of land down signed when we wouldn't, taking truckloads of her beloved trees with them (even if they were on the neighbor's land and not ours). Which, btw, can never be allowed to grow there again (at least while the pipeline is there) - roots and all, you know.
Crab cakes- I grew up inOhio and know almost exactly where you live and about the need for well water, which is why I asked the question. Sad to say it but moving now may be your best bet.
I wish I had an answer for you both. I don't. The shale zone that I have worked on northern B.C. is "crown land". Crown land isn't occupied, we are talking vast wilderness. If it wasn't for us and the loggers, there wouldn't be anyone there.
The conventional wells are all over the province, but they are much less disruptive, and there is much less potential for ground water contamination. (The fractures are very unlikely to puncture the cap, so the oil and gas stays put). This will eventually change though, and the large scale shale extraction will move into more populated areas here too.
Crabbcakes, I would never advise that someone move, but I would not want them going after shale oil/gas on my land or in my neighborhood.
With good engineering, good regulatory oversight, and responsible oil companies and services, the environmental effects of shale oil/gas should be minimal. Unfortunately, the booming states such as yours are lacking in of these things. Unfortunately the Oil lobby is extremely powerful there and I don't see the possibility of better oversight in your future.
The biggest problem is that the world is running out of ways to increase production (we can just barely maintain it), and worldwide demand is still increasing. As production decreases, the world is only going to get more desperate and go after harder and harder deposits. The environmental damage they do will increase in step with the difficulty of extraction.
Also Crabbcakes, I am not at all sick of your rant. In no way do I represent the oil companies or condone their indiscretions when they occur. I worry about these things probably much more than the average person in fact. I merely make a living much closer to the source than most. (everything in the modern world depends on cheap oil, and our entire economies are merely reflections of how well we use that energy).
I believe that our dependance on oil is the biggest challenge facing us by far.
I will be 6 weeks tomorrow following a strict Paleo diet.
I woke up this morning with my first headache since changing my lifestyle. Before going Paleo I was having frequent and severe headaches. I've had x-rays, cat scans, and cameras put up my nose. No explanation was found.
Last night for supper, I had a meal that had a small amount of (non-primal) mayo in it. I wonder if the veg oil is the culprit?
Anyway, on the positive side I am down 13lbs since Jan 1. From my measurements, I am estimating that I am about 15% bf. I am wondering if my body will find a "set-point", or if I will have to begin adding calories at a certain point. I consistently eat around 3000 calories/day, and am never hungry. My macros are probably putting me in and out of ketosis however, so it may just be a matter of a few more veggies..
Not feeling too caveman this evening, I aggravated a lower back injury today while deadlifting. Stupid mistake, I knew I was too heavy after my first set, but tried to push the second one anyway...
Primal Blueprint Law #9: Avoid stupid mistakes.
Anyway back to work tomorrow, a pretty full day (at least its day shift) and about 800kms driving. I hope the drive doesn't wreak havoc with my now re-injured back. :mad:
If you ever learn to avoid stupid mistakes, please let me in on the secret! Although I think I am doing less stupid things since going primal.
Maybe the mayo had sugar in it? You could be really sensitive to sugar if you never eat it. It's amazing how much sugar the manufacturers can pack into processed food.
I really enjoy reading your posts, although I don't have anything intelligent to add. Thanks for taking the time to explain this stuff so thoroughly and clearly.