Q: What is the picture for long-term methane leakage from tapped out fracking operations? Pondering it spooks me. Any science on it?
Social media postscript: asked here, on Twitter, on Google+, and on Quora. Apologies if you see it more than once. (Not bothering with Facebook.)
"Our greatest responsibility is to be good ancestors."
-Jonas Salk
Wednesday, July 13, 2011
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22 comments:
Let us know if someone has a decent answer?
Why wait for pollution, feel the effects now!
Fracking fluids poison a National Forest 7.6.11
http://www.peer.org/news/news_id.php?row_id=1498
To your question, yes -
NG fracking could be 'dirtier' than coal: Cornell profs
http://www.news.cornell.edu/stories/April11/GasDrillingDirtier.html
Finally, who needs Clean Water if fracking's to be done?
http://thinkprogress.org/green/2011/06/30/258676/while-texas-faces-drought-oil-companies-use-millions-of-gallons-of-water-for-fracking/
No, that's the problem. I think those studies may be asking the wrong question.
The question is not how much methane leaks during production. It is how much leaks on human time scales that ought to have leaked on geological time scales, after the operation is shut.
In old fashioned drilling, those two numbers are the same. Are they the same for fracking? My intuition says no.
Which two numbers are the same?
http://www.gao.gov/products/GAO-11-34
Federal Oil and Gas Leases: Opportunities Exist to Capture Vented and Flared Natural Gas, Which Would Increase Royalty Payments and Reduce Greenhouse Gases
GAO-11-34 October 29, 2010
"Estimates of vented and flared natural gas for federal leases vary considerably, and GAO found that data collected by Interior to track venting and flaring on federal leases likely underestimate venting and flaring because they do not account for all sources of lost gas. For onshore federal leases, operators reported to Interior that about 0.13 percent of produced gas was vented or flared. Estimates from EPA and the Western Regional Air Partnership (WRAP) showed volumes as high as 30 times higher. Similarly, for offshore federal leases, operators reported that 0.5 percent of the natural gas produced was vented and flared, while data from an Interior offshore air quality study showed that volume to be about 1.4 percent, and estimates from EPA showed it to be about 2.3 percent...."
and
http://www.google.com/search?q=methane+leakage+decommissioned+wells
and the same search at Scholar turns up more:
http://scholar.google.com/scholar?q=methane+leakage+decommissioned+wells
including:
100,000 Inactive Oil Wells: Half Empty or Half Full?
Lucija Muehlenbachs ∗ February 15, 2009 Work in progress.
Abstract
[PDF] http://www.sgvs.ch/congress09/upload/p_294.pdf
"... Methane indicates that a leak exists, meaning that other contaminants that are in lower concentrations, and slower moving than methane, follow shortly behind. ... The third dataset is of wells that were permanently decommissioned. ..."
"... There are over 100,000 inactive oil and gas wells in Alberta, Canada. According to industry regulators these wells are inactive, and not permanently closed, to allow for the possibility of reactivation. However, for many of these wells, it is not the option value of reactivation that keeps them inactive, but rather the hefty cost of complying with environmental regulations for permanent closure...."
-----
Plenty more turns up; there are different rules in different areas for how a well should properly be decommissioned, but no consistent requirements and very little in the way of inspection or enforcement.
I'd like to know what the geologists think the likelihood of new methane leakage pathways from fracking is. They may not be thinking about it.
This is the point I am making. With conventional wells clearly any leakage will be at the well head. With fracking, additional escape pathways with intermediate time constants (decades, centuries) could maybe (conceivably to me, whether or not I am right) be created. This would show up as a methane pulse on the century scale that we can ill afford, though the ramp-up might be slow.
It's a scary damn scenario. I am not saying it's true. I would like to find someone to convince me it's false, though.
Twitter takes the early lead with this.
MT-
Twitter takes the early lead with this.
yeah, whatever. The very same article I gave you.
Whoop, sorry, Jay. Wires crossed. Thanks.
> With conventional wells clearly any
> leakage will be at the well head.
Why do you believe this? My recollection is that multiple pathways exist -- you get lateral movement all along the drill hole. Steel and concrete filling the hole corrode away allowing gas to move into other strata, and reach undocumented and unfilled old wells and exploratory drillholes as well as natural routes to the surface.
See also http://www.nicholas.duke.edu/hydrofracking/responses-about-gas-shale and many links at
http://www.nicholas.duke.edu/thegreengrok/postvacay-2011
My hunch is that this is not generally going to be a big problem, although there may be specific instances where it could be, so it's definitely worth thinking about.
Any fracking operation risks opening fractures between the impermeable shale reservoir and more permeable adjacent beds, potentially facilitating gas to leak into formations more likely to provide a path to the surface. However, the time frame required for a new migration pathway to the surface to be formed is probably long by any human standard. Also, the very act of production of the shale gas will lower the pore pressure in the shale, meaning any gas leakage into the naturally permeable beds may be short-lived and small.
There is some evidence that oil and gas production may actually reduce the size of natural seeps, as has been suggested in the Santa Barbara Channel.
This is not to argue that shale gas production does not need to be to closely regulated. Another negative associated with some shale gas operations that has not recieved much publicity is the venting of CO2 contained in the shale gas. CO2 can sometimes exceed 10% of the produced gas and it must be separated out and vented (or sequestered) before the gas is transported or marketed. See for example, this report by Mark Jaccard and Brad Griffin.
To be clear, my assumption was that Michael's question was directed to leakage not specifically related to the borehole, ie, failures in the casing or cement. Any unintended emission of methane to the atmosphere on a century scale after abandonment is most likely to go through that route, I think. And that is a matter for concern.
Here's a link to a paper on natural gas and oil seeps that have been reduced as a result of petroleum production offshore S California.
Worth following for the links and xrefs accumulating as they cover the Pennsylvania fracking stories among others:
http://stateimpact.npr.org/pennsylvania/author/sphillips/
Desmogblog has many posts about fracking.
Hank, your link to the Muehlenbachs paper doesn't work, but she seems to have changed the title to "Idle Oil Wells: Half Empty or Half Full?" and that pdf can be googled.
Odd; the direct link doesn't work today, yet going to the individual page file via the index page at
http://www.sgvs.ch/congress09/upload/
then right-click and save-as to get
p_294.pdf
That worked for me just now.
That's:
100,000 Inactive Oil Wells: Half Empty or Half Full?
Lucija Muehlenbachs
That works to find the paper Hank cited. It is dated Feb. 15, 2009; the one entitled "Idle Oil Wells: Half Empty or Half Full?" is dated March 25, 2009, and has a simulation and a conclusion, both of which the first one lacks.
It's not that I understand the technical stuff, but as an Albertan I appreciate having this information, so thinks for the link.
Nicole Foss at The Automatic Earth has great post on this topic:
Fracking Our Future
http://theautomaticearth.blogspot.com/2011/07/july-19-2011-fracking-our-future.html
Alex
Does methane matter that much more than CO2 (per kg) in the long term (50+ years)?
Because of the bathtub with a very small drain accumulation style of the CO2 problem compared to the others which are more kind of just offsets that can be "fixed" later (Soot, N2O, CH4 etc etc).
Maybe in this long term constant leaking from fracking it can end up as a longer term acccumulating problem, not purely in the atmospheric sense like CO2 (that it's hard to get CO2 out from the air) but in a well sense that it's hard to plug the frack wells once they're opened.
Maybe I worded it poorly:
Scenario: climate disruption will get so massive in 2080 that it will cause big areas to dry out or some other massive damage.
If we cut CO2 emissions in 2070 on by 80%, we get a small effect at 2080.
If we cut Methane emissions in 2070 by 80%, we get a small effect at 2080, though big compared to the easier than CO2 reduction effort.
If we cut CO2 emissions in 2020 by 80%, it will have a large effect by 2080.
If we cut the Methane emissions in 2020 by 80%, it will have a roughly similar effect at 2080 as cutting them only in 2070.
Wikipedia: Methane has an atmospheric lifetime of about 10 years
Roughly speaking.
Moot point.
There is far more methane frozen in Siberian and Canadian permafrosts and we know for sure that those permafrosts are melting and releasing that methane in vast quantities.
(see: Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming_K. M. Walter et al)
I would bet the methane leakage from fracking would count as a rounding error in comparison. We put the brakes on yesterday or the clathrate gun goes off.
Maybe. And maybe.
Andy successfully calmed me down, though. I didn't really think this would be ignored if it were a real risk. But it's the sort of thing I encourage others to ask, so I did.
I have not seen anyone pose a question about the voc's and svoc's that were reported in New York State DEC July 2011 SGEIS. The report is inconclusive but it contains quite a bit of information on chemicals present at wells in West Virginia and Pennsylvania. The chemicals they have info on are used in additives and others were found in the flow-back process. I also noted that most of the chemicals that went in did not come back out. In my opinion after reading it fracking sounds worse than a nuclear bomb exploding. If you have not read it you should. Also spread the word about this enlightening report far and wide.
One possible reason no problems are reported: legal settlements forbidding disclosure of problems.
http://www.nytimes.com/2011/08/04/us/04natgas.html
-----excerpt follows-----
“There have been over a million wells hydraulically fractured in the history of the industry, and there is not one, not one, reported case of a freshwater aquifer having ever been contaminated from hydraulic fracturing. Not one,” Rex W. Tillerson, the chief executive of ExxonMobil, said last year at a Congressional hearing on drilling.
It is a refrain that not only drilling proponents, but also state and federal lawmakers, even past and present Environmental Protection Agency directors, have repeated often.
But there is in fact a documented case, and the E.P.A. report that discussed it suggests there may be more. Researchers, however, were unable to investigate many suspected cases because their details were sealed from the public when energy companies settled lawsuits with landowners.
Current and former E.P.A. officials say this practice continues to prevent them from fully assessing the risks of certain types of gas drilling.
“I still don’t understand why industry should be allowed to hide problems when public safety is at stake,” said Carla Greathouse, the author of the E.P.A. report that documents a case of drinking water contamination from fracking. “If it’s so safe, let the public review all the cases.”
Eric Wohlschlegel, a spokesman for the American Petroleum Institute, dismissed the assertion that sealed settlements have hidden problems with gas drilling, and he added that countless academic, federal and state investigators conducted extensive research on groundwater contamination issues, and have found that drinking water contamination from fracking is highly improbable.
“Settlements are sealed for a variety of reasons, are common in litigation, and are done at the request of both landowners and operators,” Mr. Wohlschlegel said.
Still, the documented E.P.A. case, which has gone largely unnoticed for decades, includes evidence that many industry representatives were aware of it and also fought the agency’s attempts to include other cases in the final study.
The report is not recent — it was published in 1987, and the contamination was discovered in 1984. Drilling technology and safeguards in well design have improved significantly since then. Nevertheless, the report does contradict what has emerged as a kind of mantra in the industry and in the government.
--- end excerpt ---
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