Oil Recovery May Have Triggered Texas Tremors

ananyo writes "First came reports of earthquakes caused by hydraulic fracturing and the reinjection of water during oil and gas operations. Now U.S. scientists are reporting tremors may have been caused by the injection of carbon dioxide during oil production. The evidence centers on a sudden burst of seismic activity around an old oil field in the Permian Basin in northwest Texas. From 2006 to 2011, after more than two decades without any earthquakes, seismometers in the region registered 38 tremors, including 18 larger quakes ranging from magnitude 3 to 4.4, scientists report in the Proceedings of the National Academy of Sciences. The tremors began just two years after injections of significant volumes of CO2 began at the site, in an effort to boost oil production. 'Although you can never prove that correlation is equal to causation, certainly the most plausible explanation is that [the tremors] are related to the gas injection,' says Cliff Frohlich, a seismologist at the University of Texas Institute for Geophysics in Austin, who co-authored the study."

Comments

Plausible Explanation?

[Anonymous Coward]

Graboids!

captcha: "bedrock".. Lol.

"Can never prove correlation is causation"

[i kan reed]

I know it's a philosophy of science tangent, but this quote caught my attention. I mean in a strict sense, nothing is "proven" in science, so it's technically true. However, to the extent to which concepts can be "scientifically proven", the difference between correlation and causation comes down to one factor: controls. In experimental science, we control for variables by limiting the systems in play directly. In observational science, that's done with statistical controls on other known (and possible) factors. With enough data, that can be done in a manner that is robust enough to be called science.

I don't think it's fair to take a benign assertion like "correlation is not causation" and extend it to an absolutist position.

But is this....bad?

[TheCarp]

One thing I wonder as people talk about this. Now, I am no geologist but, my understanding of fault lines is that there are areas where tectonic plates cross, with one moving over the top of the other, pushing one down and one up. So far so good right?

So the model I have understood is, the fault compresses over time as the plates move, and then an earth quake happens when the stress is suddenly released, allowing the plates to slip some amount, relieving the stress and starting the process over again from its new position.

So now if this is an accurate enough description of the process, it seems to me like more frequent, smaller quakes are likely preferable to less frequent larger ones. So could this triggering of earth quakes actually be a....good thing? Is that question even being asked?

Re:From TFA

[gstoddart]

Until you figure out why CO2 injection causes problems at one oilfield, and not its neighbors, even though all of them have had similar amounts of CO2 injected, it seems rather more likely than not that the CO2 injection had nothing to do with the tremors.

Or that rocks will break and fracture in ways that aren't necessarily predictable.

It can be the cause in one well, and still not have caused the same problem in another well just simply by the local rocks and what's already happened to them.

I don't think anybody is suggesting "inject CO2, cause earthquake" ... but that the rocks might fracture (or whatever) in ways you don't really have a way to predict very well.

If it was pumping in the high pressure stuff that lead to unexpected mechanical failure of rock structures, you're never going to get a 100% result on something like that.

But I do think it highly likely there's more complexity going on than they're capable of knowing or controlling.

seems like we have an identifiable pattern.

[nimbius]

megacorps never listen.everything from cigarettes to global warming and fracking have all seemed to have this pattern:
1. new technology or idea proposed with limited research. it gets pushed hard by megacorps who want cash.
2. problems arise such as seismic disturbance, gas in the water supply, etc.
3. industry reacts immediately and violently to the concerns of regular citizens. everything classified as an 'isolated event' and media is threatened with advertising boycott if they report too much about it.
4. mounting evidence suggests new technology is dangerous and has negative consequences.
5. industry responds insisting everything is OK.
6. more evidence mounts, legislation gets proposed to curtail the technology and enact regulation
7. industry pushes back with FUD and insists the effects are 'controversial' and 'unknown' with relation to the technology but that regulation is not the answer because jobs..
8. deaths, major accidents, and environmental impacts are being seen.
9. Industry starts gladhanding senators and congressmen to ensure interests are seen to. senators, as usual, are familiar with ignoring constituents with less than a million dollars.
10. industry no longer formally responds to complaints. evidence consists solely of legislation they crafted and enacted to support their industry.
11. industry pulls out after investment potential is exhausted or litigation expenses become annoying. pack up, move out, and assign a 'vacant trust' to the property to ensure superfund only kicks taxpayers in the beanbag.

Re:seems like we have an identifiable pattern.

[BStroms]

Don't forget, there are just as many chicken littles as there are big business coverups. For every "smoking isn't bad for your health" there's a "vaccines cause autism." Both scenarios can lead to terrible things. In the particular case of fracking, the studies I've seen tend to lean my opinion toward the chicken little side of things. Even assuming all those studies are nothing but frauds paid for by corporate interests, fracking is already in widespread use.

If it's really half as terrible a danger to the drinking supplies as it's made out to be, where are all the cases of environmental catastrophe and illness that should be endemic by this point? Putting out fake studies are one thing, but it'd be hard to suppress that kind of event for such a hot button issue in this day and age.

And forgive me if I'm not overly worried about potentially causing earthquakes up to a 4.4 magnitude.

Re:Doesn't matter anyway.

[dex22]

Given that fracking is a permanent change to the environment that can't be undone, EVER, I'd want to see some pretty compelling evidence that it absolutely can't cause harm, EVER, before being used widely across a bunch of different geologies.

Re:From TFA

[houstonbofh]

Nor is it clear why nearby oil fields that have also been injected with CO2 have not experienced similar seismic activity.

Until you figure out why CO2 injection causes problems at one oilfield, and not its neighbors, even though all of them have had similar amounts of CO2 injected, it seems rather more likely than not that the CO2 injection had nothing to do with the tremors.

And it couldn't be the Texas drought for the past three years... I mean what would drought have to do with land settling?