Mag 5.8 (upgraded from 5.6) Earthquake, Pawnee, Oklahoma

[aaCharley]

People with little knowledge of energy production or geology often confuse fracking with disposal wells. This thread is rather full of poor logic as a result of the misinformation.

Oklahoma has some oil producing formation which generate a very large amount of water along with the oil. That is why there are so many disposal wells to take the volumes without long distance transport.

Fracking involves a fairly small volume of water relative to the formation volume capacity. Further, removing the oil and gas after the frack job increases the open pore volume, reducing whatever initial stress was created by the frack fluid injection. Much of the initial injection volume is immediately recovered with initial flow back.

 

[Ophiolite]

People with little knowledge of energy production or geology often confuse fracking with disposal wells. This thread is rather full of poor logic as a result of the misinformation.

Oklahoma has some oil producing formation which generate a very large amount of water along with the oil. That is why there are so many disposal wells to take the volumes without long distance transport.

Fracking involves a fairly small volume of water relative to the formation volume capacity. Further, removing the oil and gas after the frack job increases the open pore volume, reducing whatever initial stress was created by the frack fluid injection. Much of the initial injection volume is immediately recovered with initial flow back.

My understanding is that the significant increase in earthquakes followed the initiation of extensive fracking operations, whereas injection wells have been activley used well before that. This would tend to suggest that

• the occurrence of eathquakes is unrelated to either
• the occurrence of earthquakes is related to fracking
• the occurrence of earthquales is related to water injection, but has taken several years to have any effect

I don't see that your well made points take us any closer to a solution, but by introducing the practice of water injection it does, usefully I think, broaden the scope of the enquiry.

 

[aaCharley]

Your understanding is simply confused.

There were some injection wells there for a long time. However one operator decided on a different method of producing oil from a high water cut formation. Just pump the hell out of it and try to drain the water. That resulted in a massive increase in water production and disposal in the injection wells. Wells in that formation were previously plugged when water cut got too high as the disposal systems were not developed, just some wells that operators hauled the water to. Now there are water disposal pipelines just like the oil gathering lines. The volumes going into the disposal wells are very, very large.

Fracking has nothing to do with causing the earthquakes. And freckling has not caused anyone's water to catch fire either.

 

[Ophiolite]

Your understanding is simply confused.

Technically I am not confused. Rather my information is currently incomplete and so I have offered what I presently see as the possible interpretations of such data as I do have. You can help my data drought by providing specific information.

There were some injection wells there for a long time. However one operator decided on a different method of producing oil from a high water cut formation. Just pump the hell out of it and try to drain the water. That resulted in a massive increase in water production and disposal in the injection wells. Wells in that formation were previously plugged when water cut got too high as the disposal systems were not developed, just some wells that operators hauled the water to. Now there are water disposal pipelines just like the oil gathering lines. The volumes going into the disposal wells are very, very large.

Related questions:

• When did this substantial increase in water injection occur?
• Which part of Oklahoma is this taking place in?
• To what extent do these locations match those of the earthquakes?
• To what extent, if any, was/is water injection conducted in Oklahoma as a Secondary Recovery technique?

Also, I'm not clear; are you arguing that the earthquake increase is a consequence of these injection wells, or...?

Fracking has nothing to do with causing the earthquakes.

This paper contradicts your assertion, though it would support your view that water injection is the problem, if that is, indeed, your position.

And freckling has not caused anyone's water to catch fire either.

Well, we agree on something at least, though I don't think its relevant to the thread.

 

[aaCharley]

This Bloomberg article will give you some idea of what changed in Oklahoma oil production to increase the amount of water for injection. Note that the Bloomberg writer has to inject the term "fracking" into the article for unknown reasons as it is not related to the major source of produced water. The field that Chernicky dewatered was not a singular event. It did cause others to try the same approach in other fields. With oil at over $100, just pump water faster and dispose of it. Even when "dewatered" it was still 7 bbl water to one oil.
https://www.bloomberg.com/news/arti...ilman-s-company-withstand-another-earthquake-

In any case, it is not fracking that is causing the quakes.

The exact cause of a particular quake happening at a particular moment is almost unknowable. Tensions and stresses build up in faults over geologic time. One theory is that the injection water may make it easier to slip and relieve the stress today instead of 10 years from now. However, it does not induce the stress. That results from plate tectonics.

 

[Ophiolite]

Thank you for the Bloomberg article. I shall read it more carefully tomorrow.

In any case, it is not fracking that is causing the quakes.

You have made this assertion three times now, but have not provided evidence to support it. (The Bloomberg article is inconclusive on the point and, more to the point, is newspaper article, not a research paper.) In contrast I have cited a paper that notes the potential of fracking to induce earthquakes. Do you intend to provide any support for your assertion, or may I accept it simply as your opinion?

The exact cause of a particular quake happening at a particular moment is almost unknowable. Tensions and stresses build up in faults over geologic time. One theory is that the injection water may make it easier to slip and relieve the stress today instead of 10 years from now.

However, as I noted in an earlier post, conventional earthquakes are not the only means of relieving stresses. So called slow earthquakes, whose effects are - from an economic and safety standpoint - non-existent may be doing this. Then, in Oklahoma, fracking or water injection may be overcoming that mechanism by sufficiently altering the stress fields, or fracture networks and thereby inducing conventional earthquakes that would not otherwise occur.

However, [injection water] does not induce the stress. That results from plate tectonics.

Just to be pedantic, but more thorough. The stress may arise from isostatic adjustment to post-ice age ice removal, while earthquakes may also be a consequence of volcanic activity and landslides.

 

[1oldman2]

New news on the subject.
https://phys.org/news/2017-12-geologists-discoveries-kansas-oklahoma-earthquakes.html