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ChrisFromIT t1_jdim6j1 wrote

Reply to comment by garlicroastedpotato in The largest recorded earthquake in Alberta's history was not a natural event, but most likely caused by disposal of oilsands wastewater, new research has concluded. by GeoGeoGeoGeo

With the oilsands, they aren't injecting fluid into the ground.

The sand/dirt containing the oil is dug out, then goes through a process of extracting the oil from the sand/dirt that involves the usage of water.

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garlicroastedpotato t1_jdio1xp wrote

You're wrong. I can see what you're saying, but you're wrong on this. They mine the bitumen in a mine then bring it to a facility where it's processed and one of the end products is slurry wastewater. Since the waste water is a byproduct of bitumen it's technically not pollution to put it from where you got it. This stuff is more toxic than the slurry ponds and more toxic than the tailings ponds.

It's called deepwell disposal and its a cost effective means of getting rid of waste water (that otherwise has no way of getting rid of it). It's not fracking (fracking loosens up material making them easier to extract), it's probably worse.

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Tirannie t1_jdj0is0 wrote

That kind of strip mining is only done on shallow sites. Since most of Alberta’s deposits are deep well, they use thermal in-situ extraction methods (usually either SAG-D or CSS).

Most oil sands sites in Alberta use SAG-D (steam-assisted gravity drainage). They drill two wells on the site, one slightly higher than the other, then inject high-pressure steam into the site to decrease the viscosity of the bitumen, which then gets pushed up the higher well. The bitumen gets processed after that (because we can’t use oil with sand in it), which creates a lot of waste water.

What this article is talking about it the disposal of the waste water after, which is injected into deep well sites. Though I’d be interested to see if there’s more research into “induced seismicity” from the extraction process as well.

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ChrisFromIT t1_jdipk43 wrote

>You're wrong.

Nope. While you are right that there is a thing called deepwell disposal, it happens in other parts of the oil and gas industry. The byproduct of the oil sands isn't disposed of in deepwell disposals. At least when it comes to the surface mines.

When it comes to them having to extract the oil from the ground, yes, deepwell disposal is done. Because the well is already there for them to use.

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Un0Du0 t1_jdjwxny wrote

In this case the article actually says:

> "This event was caused by wastewater disposal,"

So yes, this was a result from deepwell disposal in the oilsands.

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ChrisFromIT t1_jdk0dnb wrote

The issue is that there is an misunderstanding of what is happening and location.

Based on u/garlicroastedpotato first comment of this

>This isn't fracking. This is the Canadian oilsands.

He is very likely referring to the open pit mining/surface mines of the oilsands. It is pretty much what everyone refers to when they say the oil sands.

The article is talking about the oil sands formation. It is actually fairly large, it goes so far south that the oil fields in Montana and North Dakota are part of that oil sands formation. To get access to the oil in that formation, if you are not doing open pit mining you are pretty much doing drilling which is part of the process of fracking. On top of that Fracking and Steam-assisted gravity drainage is very similar in nature.

And considering u/garlicroastedpotato said it isn't fracking in his comments, he has to be referring to the open pit mining commonly referred to as the Canadian oilsands.

And if you look at the article, the earthquake is around the the Peace River oil sands deposit. Very far away from the open pit mines.

Ergo, u/garlicroastedpotato is both right and wrong. He is right in what is happening, but wrong terms and locations. And because he used the wrong terms and location, he is overall wrong.

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