Study: Methane Migration Not Connected to Fracking

Methane Migration - Jim Willis reportsJim Willis
Editor & Publisher, Marcellus Drilling News (MDN)

   

Methane migration, when man-caused, is not the fault of either horizontal drilling or hydraulic fracturing, says a new study, but correctable casing issues.

Another new “study” and already the headlines have been blaring. A research team led by Ohio State University and composed of researchers at Duke, Stanford, Dartmouth, and the University of Rochester have just published their findings that methane migrates from some shale wells into local water wells.

It certainly doesn’t sound like earth-shattering news, but the headlines across the country range from “Bad fracking wells taint water, scientists find” (Sacramento Bee) to “Weak wells not fracking caused US gas leaks into water” (BBC). The media has picked up on this latest study and, depending on the view of the reporter, has spun it to either say fracking is the culprit, or fracking isn’t the culprit – and just about everything else imaginable in between. Here’s how we see it at MDN.

New Methodology Used to Analyze Methane Migration

The “big deal” and “new news” to come from this study is the methodology used by the researchers. They attempted to answer two questions: (i) Are elevated levels of hydrocarbon gases in drinking-water aquifers near gas wells natural or anthropogenic? (ii) If fugitive gas contamination exists, what mechanisms cause it?

And, how did the researchers answer those questions? By measuring the presence of noble gases and their isotopes: helium, neon and argon. It is the innovation of using the presence of noble gases that has, according to the researchers, given them ironclad assurance as to whether the methane in someone’s well is naturally occurring, or from shale drilling.

Methane Migration - Shale Plays

Perhaps the best starting point for understanding the research and its results is the press release issued by Ohio State University – the lead researchers who published the study (emphasis added):

A study has pinpointed the likely source of most natural gas contamination in drinking-water wells associated with hydraulic fracturing, and it’s not the source many people may have feared.

What’s more, the problem may be fixable: improved construction standards for cement well linings and casings at hydraulic fracturing sites.

A team led by a researcher at The Ohio State University and composed of researchers at Duke, Stanford, Dartmouth, and the University of Rochester devised a new method of geochemical forensics to trace how methane migrates under the earth. The study identified eight clusters of contaminated drinking-water wells in Pennsylvania and Texas.

Most important among their findings, published this week in the Proceedings of the National Academy of Sciences, is that neither horizontal drilling nor hydraulic fracturing of shale deposits seems to have caused any of the natural gas contamination.

“There is no question that in many instances elevated levels of natural gas are naturally occurring, but in a subset of cases, there is also clear evidence that there were human causes for the contamination,” said study leader Thomas Darrah, assistant professor of earth sciences at Ohio State. “However our data suggests that where contamination occurs, it was caused by poor casing and cementing in the wells,” Darrah said.

In hydraulic fracturing, water is pumped underground to break up shale at a depth far below the water table, he explained. The long vertical pipes that carry the resulting gas upward are encircled in cement to keep the natural gas from leaking out along the well. The study suggests that natural gas that has leaked into aquifers is the result of failures in the cement used in the well.

“Many of the leaks probably occur when natural gas travels up the outside of the borehole, potentially even thousands of feet, and is released directly into drinking-water aquifers” said Robert Poreda, professor of geochemistry at the University of Rochester.

These results appear to rule out the migration of methane up into drinking water aquifers from depth because of horizontal drilling or hydraulic fracturing, as some people feared,” said Avner Vengosh, professor of geochemistry and water quality at Duke.

“This is relatively good news because it means that most of the issues we have identified can potentially be avoided by future improvements in well integrity,” Darrah said.

“In some cases homeowner’s water has been harmed by drilling,” said Robert B. Jackson, professor of environmental and earth sciences at Stanford and Duke. “In Texas, we even saw two homes go from clean to contaminated after our sampling began.”

The method that the researchers used to track the source of methane contamination relies on the basic physics of the noble gases (which happen to leak out along with the methane). Noble gases such as helium and neon are so called because they don’t react much with other chemicals, although they mix with natural gas and can be transported with it.

That means that when they are released underground, they can flow long distances without getting waylaid by microbial activity or chemical reactions along the way. The only important variable is the atomic mass, which determines how the ratios of noble gases change as they tag along with migrating natural gas. These properties allow the researchers to determine the source of fugitive methane and the mechanism by which it was transported into drinking water aquifers.

The researchers were able to distinguish between the signatures of naturally occurring methane and stray gas contamination from shale gas drill sites overlying the Marcellus shale in Pennsylvania and the Barnett shale in Texas.

The researchers sampled water from the sites in 2012 and 2013. Sampling sites included wells where contamination had been debated previously; wells known to have naturally high level of methane and salts, which tend to co-occur in areas overlying shale gas deposits; and wells located both within and beyond a one-kilometer distance from drill sites.

As hydraulic fracturing starts to develop around the globe, including countries South Africa, Argentina, China, Poland, Scotland, and Ireland, Darrah and his colleagues are continuing their work in the United States and internationally. And, since the method that the researchers employed relies on the basic physics of the noble gases, it can be employed anywhere. Their hope is that their findings can help highlight the necessity to improve well integrity.

This research was funded by the National Science Foundation, Duke University, and a gift from Duke alumni Fred and Alice Stanback to the Nicholas School of the Environment.*

MDN’s Takeaways from this Study on Methane Migration

1. This appears to be serious research that tackles an important issue. The researchers are not (from all appearances) agenda-driven. They let the science do the talking.

2. The researchers used a new innovation to help identify the “fingerprint” of methane: noble gases (helium, neon and argon). This is the crux of what’s new and different about this research versus other studies done in the past.

methane migration - PA

Marcellus Shale Areas Studied

3. The media is sensationalizing this research by blaming fracking. However, the researchers clearly state fracking itself does not cause methane to migrate! What causes the migration, when it happens, is faulty construction of the vertical well. It has zero to do with fracking itself. The media either ignorantly or intentionally confuses “fracking” with the larger topic of “shale drilling”.

4. The media misuses the term “contamination” of water supplies. While you can argue that methane traveling into a water well is “contamination”–it’s not like chemical contamination. As the authors of the research point out–methane migration (or “fugitive” methane) is a fixable problem. Eminently fixable. Even after a well casing has failed methane leaks can be fixed and the methane will stop. You don’t die from drinking water with methane in it (i.e. “contaminated” water). You can die if the methane collects in an enclosed space and explodes when a spark or fire source occurs nearby. To say methane “contaminates” water, knowing that most people think of that word in the chemical sense, is misleading at best.

Methane Migration - Barnett Shale Area

Barnett Shale Areas Studied

5. The study looked at two specific areas where they either knew–or suspected–methane had leaked or migrated from shale wells into local water supplies. Hey, it happens. It gets fixed. The shortcoming of this study, if we can be sold bold as to point it out, is in characterizing how often it happens. It’s easy to look for the precise area where a problem occurs and measure it–but what if there are only a very few places where it actually happens? What if, in the vast majority of cases, methane migration from faulty wells doesn’t happen? The study doesn’t answer how often well casings fail and leak methane–it only focuses on a few cases where it did happen.

6. We welcome this kind of intelligent, thoughtful, in-the-field research and applaud this group for the work they have done and continue to do. We (those of us who support shale drilling) will learn and grow and fix problems because of this kind of research. No one on “our side” of the drilling debate has ever pretended there are no problems. This industry is so fantastic precisely because year after year it gets better. We learn, we fix things, we improve the way we do things. And this type of study will further that effort. As will this one demonstrating much the same thing.

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19 thoughts on “Study: Methane Migration Not Connected to Fracking

  1. Drilling disturbs natural shallow deposits that have been stable for ever .This is where most problems are caused .In the drilling when No casing is in place .Actual pre drilling and during drilling testing has shown this .I have the tests .

    • So you are saying that we should ban water well drilling as well??? Or geothermal? ? Tell ya what Bill F. Why aren’t we pushing for better water well integrity.

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  3. So Bill your tests prove un cased wells all disturb shallow deposits ? That sounds interesting. What about water wells ? And geothermic wells for home energy ? Is it possible they might be part of the trouble? A lot of them are quite deep. Any ideas?

    • @ Freegas …..yes water wells etc can cause issues too ! Water wells go to aquifers sources …….NG (HVHF ) wells go beyond water sources and can hit deposits below water supplies causing substances to rise up into aquifers ( initial drilling without casings 0 .Not all drilling disturbs deposits or causes issues ,but cases do exist .When this happens the people involved have very little help or recourse .Possibly years before settlement if ever .The important thing is this has happened and will happen every time NG wells are drilled in certain locations .Denying it is just plain ignorant .

        • I seem to have said “.Not all drilling disturbs deposits or causes issues ,but cases do exist “…..and those affected ( and they can be anyone anywhere ) have a real fight to get compensation ( if ever )….been through this with people .

    • Sorry free gas didn’t see your post before I wrote mine. What Bill F seems to leave out is that even in the rare cases that we see higher methane levels, the situation is almost always temporary.

  4. How hard would it be for NG industry and for that matter any driller going down say 500 foot submit core samples to guard against this type of issue? And I hate to dog the heating and cooling guys but in light of the fact that they use hundreds of gallons of anti freeze in plastic pipe for heat transfer it seems real risky too ? Has there been any great minds checking this out ? The same for wells drilled within a few miles of coal ash storage for instance? Gentlemen i think we just stumbled onto some serious issues? Just think ,some well meaning slob drills down a few hundred feet in the wrong place and poisons billions of gallons of water ! I realize i am turning this whole issue upside down but like the old saying goes, what goes up must come down ,right? Bill how deep would you say those deposits you mentioned are ? Couldnt they be migrating for many miles looking for a way to be forced to the surface? It would seem that by simply checking for these issues prior to deciding how deep to cement the casing all those problems would be avoided ? But then again isnt that what the studies have been saying all along ? And Bill i really do feel bad for those folks caught up in the nasty web of trying to prove liability ! It sucks, i think i can safely say for all reading this post we hope all that ends well ! But if we all work together it just seems all these problems can be solved easily. Too bad the political issues are not so easy to fix! Maybe if we could find a way to cement them in too all would be just fine? Sadly they migrate around a lot too ! Any ideas ?

  5. Right, Jim. Similarly, the Gulf oil spill was not caused by deep-water drilling, it was simply a poor cement job.

    You can’t duck the responsibility? The only reason the cement was there to fail was because of the drilling and fracking activity. If you weren’t doing it no one would be there doing half-assed cement jobs.

  6. I see , they should of been building wave machines and all would be just fine now ? Hmm maybe the park ave gang will send a research grant to save the -their world? Until then we ,us consumers in the US need affordable energy to keep our homes warm and our lights on. As for that Gulf mess, was it ever decided whether it was cementing or a bad valve ? Also all the delay with NG here in NY and Pa. will ensure there is lots of off shore drilling in the future. It sure would be nice to keep all that half assed energy development out of the Gulf. What do you think Cliff ? Bill ?

  7. Most important among their findings, published this week in the Proceedings of the National Academy of Sciences, is that neither horizontal drilling nor hydraulic fracturing of shale deposits seems to have caused any of the natural gas contamination.

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