http://www.guardian.co.uk/environment/2 ... king-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...
Methane contamination rises near shale gas sites
Moderator: Peak Moderation
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RGR
Re: Methane contamination rises near shale gas sites
[quote="Kieran"]
Last edited by RGR on 12 Aug 2011, 06:21, edited 1 time in total.
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An Inspector Calls
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?
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?
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RGR
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An Inspector Calls
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!
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!
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RGR
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kenneal - lagger
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An Inspector Calls
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kenneal - lagger
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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.
I'm not sorry about asking someone for the benefit of their expertise. No point in having him here and not using experience.
Action is the antidote to despair - Joan Baez
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An Inspector Calls
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RGR