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Kieran · Joined: 25 Jul 2006 Posts: 1091 Location: West Yorkshire

http://www.guardian.co.uk/environment/2011/may/09/shale-gas-methane-drinking-water

"Methane levels in water supplies close to shale gas extraction sites in Pennsylvania and upstate New York are up to 17 times higher than normal, according to research.

A study on the impact of drilling in the region found that about 85% of drinking water wells within 1km of a natural gas well were contaminated.

The study is the latest to challenge efforts to sell natural gas as a cleaner, safer source of energy, and could build momentum for greater federal governance of the industry."

Article continues...

RGR · Last edited by RGR on Fri Aug 12, 2011 6:21 am; edited 1 time in total

[quote="Kieran"]

An Inspector Calls · Banned Joined: 27 Jan 2011 Posts: 958

I don't understand the mechanics of how fracing is supposed to result in water contamination.

As I understand thus far, the water bearing rocks are usually above the shale gas rock and to get to the shale you have to drill through the water levels. Fracing involves water at very high pressure (>100 Bar!) being injected into the shale. It will be necessary to line the drill pipe in order to achieve these high pressure levels. Any leakage in the drill pipe will compromise the ability of getting high pressures at the shale level.

So, if that's the case, the risk of water contamination must be low.

Or am I missing something?

RGR · Posted: Fri Jun 24, 2011 2:34 pm Post subject:

[quote="An Inspector Calls"]

An Inspector Calls · Banned Joined: 27 Jan 2011 Posts: 958

So for supposed well casing failures where water contamination was detected possibly due to negligence at the fracing 'plant', a quick pressure test on the wells concerned would soon indicate if there's a potential leak or not. The nice thing about the fracing process seems to be, then, that it demands technical excellence for it to have any possibility of success.

Just what is the fracing pressure? You talk of well depths of 10,000' (3,000m), so to me that would imply the 'background' hydraulic pressure must be 300 Bar and so you'd need something like that pressure to frac?. Jee wiz, these are high pressures - very dangerous too!

RGR · Posted: Fri Jun 24, 2011 6:49 pm Post subject:

[quote="An Inspector Calls"]

kenneal - lagger · Posted: Sat Jun 25, 2011 4:03 am Post subject:

If the shale strata is under water bearing strata could the fracking pulse not blow gas into the water column from where is would migrate upwards?
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RGR · Posted: Sat Jun 25, 2011 4:39 am Post subject:

[quote="kenneal"]

An Inspector Calls · Banned Joined: 27 Jan 2011 Posts: 958

RGR:
Can you direct me to a web site, (or god-forfend, a book) that gives an introduction to the techniques we're discussing?

kenneal - lagger · Posted: Sun Jun 26, 2011 2:33 am Post subject:

I'm couldn't say for certain but I don't think the shales in the UK are more than 500 to 600 foot thick so water contamination could be a problem.

I'm not sorry about asking someone for the benefit of their expertise. No point in having him here and not using experience.
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Action is the antidote to despair - Joan Baez

An Inspector Calls · Banned Joined: 27 Jan 2011 Posts: 958

Does anyone know much about any of the UK shale deposits?

And even so, the width of the shale strata is immaterial: it's the distance between the shale strata and the water bearing strata that matters.

Bandidoz · Site Admin Joined: 24 Nov 2005 Posts: 2705 Location: Berks

<deleted the sock-puppet accusations>
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RGR · Posted: Mon Jun 27, 2011 9:57 pm Post subject:

[quote="An Inspector

RGR · Posted: Mon Jun 27, 2011 10:02 pm Post subject:

[quote="kenneal"

RGR · Posted: Mon Jun 27, 2011 10:04 pm Post subject:

[quote="An Inspector Calls"]