I read an article today that suggested shale gas extraction will add to our gas supply rather than replace it. To rely just on shale gas would mean drilling rigs all over the place and the countryside lobby would never allow that.

The BGS seems happy enough with it as does the USGS.  I don't think I am up to arguing with them!

What runs through my head is the possibility that with fracturing all the rocks will it lead to solifluction?

Look what happened to Mexico City.  Not due to fracking, but because it had been build on an old lake bed and there was still a great deal of water deep down.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

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I'm a new member looking forward to learning about Geology; sorry John but what is solifluction?

Solifluction technically is a permafrost condition where soils can creep long distances due to repeated freezing and thawing.  One effect of earthquakes, such as the one in Mexico City and several in Japan, is liquefaction, where the repeated shaking of rocks allows water to be squeezed out of them which then floods the surrounding area.  In the case of fracking the release of water from surrounding rocks might be regarded as a good thing as it may create additional pressure to force the gas or oil to the surface.

Thanks Gus, I suppose that I could have tried to find an explanation on Google but you have answered my query very well. Cheers.

Ooops. Sorry it was liquifraction I was thinking about.  Stupid error.

For some reason I wanted to put the American term - conjellification. 

 They really would have been better off staying as one of our colonies, you know.  We wouldn't have these differences, and by now Microsoft would be able to write things in Real English.

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

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These terms just show how much there is to learn; where do you start? Anyway, the article in The Times today about American oil and gas reserves in shale just show how the economic Middle East boom may be coming to an end. One Saudi Prince said many years ago that they would have to prepare for a change as the Stone age didn't end because they ran out of stones!

There was a good program on it on TV a couple of weeks ago. Iain Stewart was in it and it was well put together. I actually watched it on BBC iplayer. He visited the USA and investigated aspects of it over there. 

 The big problem is in the securing of the annulus between the drilled rock and the metal casing. IE the concrete that is used to fill the void and make the seal. Cementing is tricky to get right all the time.

 

 Following on from this - I came across this report. Certainly this makes sense to me.

The images won't come up here, but I've left the link at the bottom so you can look if you wish.

 

Fracking could lead to an 'earthquake domino effect' as it weakens fault lines deep in the earth's crust, scientists claim

• Scientists from Columbia University have claimed that earthquakes could be caused by pressure on fault lines created by hydraulic fracturing




• Danger occurs when the activity is agitated by distant earthquakes that can trigger tremors near waste water injection wells, they said




• Seismologists from the university have identified three quakes that were triggered at injection well sites by a major earthquake a long distance away

By Sarah Griffiths

PUBLISHED: 15:22, 12 July 2013 | UPDATED: 10:57, 13 July 2013

 Fracking could cause powerful earthquakes capable of destroying buildings as the process of extracting gas weakens fault lines deep under ground, scientists have claimed.

American geologists said that a domino effect of quakes could be caused by intense pressure on fault lines created by hydraulic fracturing, combined with seismic activity thousands of miles away.

Columbia University scientists maintain that powerful earthquakes thousands of miles away can trigger swarms of minor quakes near waste water injection wells like those used for in oil and gas recovery.

Geologists from Columbia University have claimed that a chain of earthquakes could be caused by pressure on fault lines from fracking, combined with seismic activity thousands of miles away. A shale fracking facility is pictured

They say a recent surge in U.S. oil and gas production using vast amounts of water to crack open rocks and release natural shale gas has been linked to an increase in small to moderate induced earthquakes in five states.

Seismologists from the university have identified three quakes - in Oklahoma, Colorado and Texas that they believe were triggered at injection well sites by a major earthquake a long distance away.

The discovery, published in the journal Science by one of the world's leading seismology labs, threatens to make fracking even more controversial, Reuters reported.

Geologists have known for 50 years that injecting fluid underground can increase pressure on seismic faults and make them more likely to slip. The result is called an 'induced' quake.

Nicholas van der Elst of Columbia's Lamont-Doherty Earth Observatory in New York, who led the study, said: 'The fluids (in waste water injection wells) are driving the faults to their tipping point'.

He believes that as pressure from waste water wells stresses nearby faults, if seismic waves speeding across Earth's surface hit the fault it can rupture and months later, produce an earthquake stronger than magnitude 5.

The seismologist thinks that waste water injection leaves local faults 'critically loaded,' or on the verge of rupture.

Shale gas has been hailed a possible ingredient in the UK's future energy mix (a map of reserves is pictured), but now American seismologists have claimed that waste water injection leaves local faults 'critically loaded,' or on the verge of rupture

Even weak seismic waves arriving from faraway quakes are therefore enough to set off a swarm of small quakes in a process called 'dynamic triggering.'

And once the tremors stop the danger is not necessarily over.

Heather Savage, co-author of the study warned that the swarm of quakes 'could indicate that faults are becoming critically stressed and might soon host a larger earthquake'.

The seismologists believe that long distance triggering is most likely where waste water wells have been operating for decades and where there is little history of earthquake activity.

Opponents of fracking fear that the process will release toxic chemicals into water supplies.

John Armstrong, a spokesman for advocacy group New Yorkers Against Fracking, said that the new study should be 'a stark warning'.

The study was funded by National Science Foundation and the US Geological Survey.

However, many scientists have previously suggested that fracking will not lead to major earthquakes.

Opponents of fracking (pictured) fear that the process will release toxic chemicals into water supplies. John Armstrong, a spokesman for advocacy group New Yorkers Against Fracking, said that the new study should be 'a stark warning'

Geologist William Ellsworth of the US Geological Study, who was not involved in the study but is an expert on human-induced earthquakes, said that tremors that cannot be felt are routinely produced by fracking.

The largest fracking-induced earthquake 'was magnitude 3.6, which is too small to pose a serious risk,' he write in Science.

A previous study into fracking led by Professor Richard Davies from Durham University’s Energy Institute, said the risk of fracking resulting in seismic activity that could be felt on the surface is ‘not significant’.

Talking about whether the process of extracting shale gas causes seismic actiivity itself, he said: ‘In almost all cases, the seismic events caused by hydraulic fracturing have been undetectable other than by geoscientists.’

‘Most fracking-related events release a negligible amount of energy roughly equivalent to or even less than someone jumping off a ladder onto the floor.’

A joint UK study of hydraulic fracturing by The Royal Society and the Royal Academy of Engineering said that fracking can be managed effectively in the UK as long as operational best practices are implemented and robustly enforced through regulation.

The experts also said that earth tremors induced by hydraulic fracturing are likely to be of a smaller magnitude than the UK naturally experiences or than is related to coal mining activities.

Read more: http://www.dailymail.co.uk/sciencetech/article-2361876/Fracking-lead-earthquake-domino-effect-weakens-fault-lines-deep-earths-crust-scientists-claim.html#ixzz2Z6sH7vjE
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John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

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Yes. I saw this. Did you see the news on the BBC today that said that the Americans were going to export shale gas to the UK?

 http://www.bbc.co.uk/news/science-environment-23317370

 

There is some school of thought that the act of fracking, though leading to small seismic events, might be the catalyst for larger seismic events where two sides of a fault line are building up tension but arent moving as the friction between the two have not been overcome, that is until fracking initiates the act of actual movement. 

I seem to recall long ago that there was a suggestion to pump water into the San Andreas Fault to 'lubricate' it, since most damage comes from the sudden shock and rebound.

Didn't hear any more about that idea. 

John

“Civilisation exists by geological consent, subject to change without notice.” -  Will Durant

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I think the idea was abandoned due to public opinion about the possible side effects.  Incidentally there were coal miners underground during the San Francisco quake who didn't suspect anything was happening until they got to the surface.

Well, today the UK government declared some tasty tax breaks for those that might be considering extract shale gas in the UK.