Fred Baldassare who is a nationally recognized expert on gas migration and formerly employed by the Pennsylvania Department of Environmental Protection has published here a must read comment concerning the source of the gas that migrated due to drilling problems in the Dimock area of Susquehanna county.
See Fred's comment to the monday, May 9th posting about the Duke University gas migration study.
Fred did the testing of the gas in the 19 water wells around Dimock that DEP found had been contaminated with methane as a result of gas drilling. But what was the source of the gas? Was it Marcellus gas that was the target of the drilling that migrated?
Fred confirms that the gas in the 19 water wells around Dimock was not naturally occurring (biogenic gas) and that it was not Marcellus gas. Instead the gas was shallower gas that was encountered in the drilling operation as drilled to get to the Marcellus gas. To be clear the gas did migrate due to drilling.
The Duke study, however, was not clear about the precise source of the gas that did migrate. Again please read Fred's comment.
This is a key part of the story that many who are under-informed may not understand. If there is gas in people's water it is not necessarily from the formation that has been hydraulically fractured. In fact it is far, far more likely to have come from either the aquifer itself or from a shallow formation as it did here. The Duke paper showed that thermogenic gas was in a lot of the wells that were not near drilling. Of course this has been understood for many decades by drillers and regulators. It found its way there over millions of years by very slow upward migration.
ReplyDeleteAlthough this may be too subtle a point for some, the gas that got into the water in Dimock may have originally come from the Marcellus, which is a "source rock" for gas and migrated upward into the shallower formations over millions of years. Some of it gets trapped in shallow formations, some makes it to the aquifer and some just leaks out onto the surface over time. That is why it may resemble Marcellus gas isotopically. This is not uncommon, in fact almost all gas we produce that is not shale gas migrated out of a source rock like the Marcellus Shale over millions of years until it was trapped in its present location.
Many people commenting on this issue immediately jump to the conclusion that if gas gets in people's water then it must be from the formation that was hydraulically fractured. they need to take a deep breath and investigate all the possibilities before reaching that conclusion. From what I understand none of the gas that has ended up in drinking water as a result of drilling in the Marcellus actually came directly from the Marcellus - it all seems to have come from these shallower formations and has nothing to do with hydraulic fracturing.
I heard Robert Jackson, the Duke Environmental Scientist, on PRI's "Living on Earth" this morning. The story I came away with leaves the origin of the stray gas up for debate, I believe. Whereas, they found elevated methane levels within the private water wells within proximity of an extremely deep natural gas well, but they cannot precisely determine the origin or the time when the stray gas migrated.
ReplyDeleteTo me, the time at which the methane had strayed is important, yet possibly the most difficult information to obtain. Most likely the stray gas migrated through the annular space between the vertical outer casing and surrounding overburden, but when? Local knowledge allows geophysical professionals to infer that the borehole is the most likely mechanism, by way of poorly regulated downhole pressures advancing the bore or a poor cement bond in the high temperature and high pressure environment. Though, within the regulatory environment I still believe there are too few instances for the public and government enforcement to ensure adequate countermeasures are employed during exploration, completion, production and decommissioning of wells - coalbed methane, shale gas, et al.
It's encouraging that we live in a litigious, market driven society where public perception hurts the bottom line of oil and gas producers to the extent that private industry is now - after a few years of acrimony - changing their exploratory and production methods. Though uncertainty remains in many Pennsylvanians, as they view this "new" industry over the leaching gob piles, acid mine drainage, mercurial fish and hazy air, and wonder.
If time and funding were no limit, a full and fair analysis would test the surrounding private water wells during geophysical exploration, during and after completion of the vertical bore, during and after horizontal bore and fracture, during well production, and then after decommissioning. Comparison of laboratory test results between the water well and production well specimens would be helpful, but good luck getting a producer to hand over their data.
"Fred confirms that the gas in the 19 water wells around Dimock was not naturally occurring (biogenic gas) and that it was not Marcellus gas. Instead the gas was shallower gas that was encountered in the drilling operation as drilled to get to the Marcellus gas. To be clear the gas did migrate due to drilling. "
ReplyDeleteFirst of all, thank you for bringing this to light. It seems as though people are unwilling to listen to the scientific facts of the case. This was not gas sourced from the Marcellus, and it is in no way related to the hydraulic fracturing process. Why doesn't the DEP stand up and say this?
Second, you say the gas migrated due to drilling. Is this data-driven? Or is this just theory? If it's data driven, that should be made public so people are actually talking about how to solve the appropriate problems. I think a lot of people would be interested to hear why this is the case. Simply saying "due to drilling" could mean a lot of different things to different people. Some may immediately associate "drilling" with hydraulic fracturing. Some may associate "drilling" with casing and cement procedures. Either way, you have the federal government stepping in because the DEP has been incapable of making it clear of the facts they have found. The fact this was NOT Marcellus gas is a huge deal. It completely rules out hydraulic fracturing for the blame in the most famous case of gas migration blamed on hydraulic fracturing. Why isn't this in the news??? Doesn't the DEP have an obligation to repeatedly report this finding? I understand the media does not like stories like this, which is why I emphasize the point of repeated press releases.
If the DEP could publicly say "the gas contamination was NOT due to hydraulic fracturing" that would be a game changing statement that would reverberate across the country and into Washington.
The Pennsylvania Department of Environmental Protection has the ability, today, to make a statement that would change this country. The most famous case of gas migration is NOT due to hydraulic fracturing. The flaming faucets are NOT due to hydraulic fracturing. The DEP has done a good job of regulating this industry on their own and the claims of the dangers with hydraulic fracturing are way overblown. Dimock is a PERFECT example for you to present DEP's case that they ARE capable of handling this industry.
DEP confirmed that 19 families had their water wells contaminated by gas that migrated as a result of gas drilling. The gas found in the wells was NOT biogenic gas or natural or preexisting gas. The gas was identified through comprehensive testing that Fred oversaw as thermogenic gas and more specifically gas that the driller in the area encountered at shallow depths on the way toward the Marcellus target gas. Some of the gas wells also had clear indications of problems like high pressure readings and gas bubbling in their cellars. Moreover repairs of the gas wells and other actions lowered to safe levels gas in 14 of the 19 water wells by December 2010. Gas drilling has caused gas to migrate and contaminate water wells. The problems seem to be in cementing and casing. Fracking itself does not seem to be the cause of gas migrating. Fracking has not caused one case of frack fluids returning from depth to contaminate water wells.
ReplyDeleteTo the person who wanted to hear a DEP official say that the gas migration at Dimock had nothing to do with hydraulic fracturing go this site and check it out and then go to the video of Scott Perry saying it at a Q and A session.
ReplyDeletehttp://marcelluscoalition.org/2010/05/in-his-own-words-pa-dep-regulator-separates-fact-from-fiction-on-the-marcellus/
Or if you just want to go straight to the video:
http://www.youtube.com/watch?v=Iheb5QS8rbM&feature=player_embedded
He talks about Dimock starting at 4:50
Thank you for the response. Let me take this one step further, if I may. The largest argument against Marcellus drilling is deeply rooted in hydrualic fracturing and horizontal drilling. You, unfortunately, were portrayed in the negative light alongside these two technologies. Dimock is where this whole outrage started, and where people got their beliefs on the matter at hand. Hydraulic fracturing was blamed, and now people are trying to regulate THAT instead of the real issues.
ReplyDeleteIn my opinion, if the DEP ever wants to seriously protect the people, they first need to steer people in the right direction. All of the resources are being focused on regulating hydraulic fracturing, when in fact the risks involved are no different than historical shallow well drilling. Proper casing and cement to 3000' is critical in both shallow and deep well drilling. It's not horizontal drilling. It's not hydraulic fracturing. People are pushing to regulate the WRONG threats, if that's what we would call those two. The DEP needs to get people on the right track.
In the beast this movement has grown to, Dimock would be the head. People use Dimock as the poster child for why hydraulic fracturing is evil. Chemicals in the water? Fractures 6000' to surface? Marcellus gas in the water table? None of this is true. If the DEP ever wants to steer people to support the right kind of regulation, they need to make the public aware of the actual threats. Use Dimock as an example of what the actual threats are so the citizens of this state and this country support regulation of the appropriate procedures. Publicly state that "Yes, we see that Dimock is the hollywood poster child of how hydraulic fracturing went wrong. But in reality, the problems that caused the gas in their wells were no different than the risks involved in the 100,000 wells across the state. Here was the actual problem, and here is where everybodys focus should be".
I'm not saying gas migration due to poorly cemented/cased wells is acceptable. What I am saying however is that we need to bring this to light, and put contamination from hydraulic fracturing in the background. If the DEP ever wants to protect the people, they should get the people on the right track so they support the right kind of regulation.
The industry is trying to educate the public, but you know as well as I do that anything that comes out of their mouths is interpreted to be a lie, or propoganda. The DEP is the only unbiased organization that has the power, and the voice to get people to understand what has happened, and where we need to go.
I strongly believe that if this country is ever going to get our energy security in line, the only organization to get it on the right track is the PA DEP and nobody else. They have a chance that no other organization has, and I hope they make good use of that chance.
holy cow where have I been. I've been commenting on Linkedin energy group post for months now and no one gets it. Fraccing is not an issue downhole but sure surface management is required for all fluids. Poor casing jobs have caused problems for 100 years and caused the BP blowout among other screwups. Yes the big issue is community planning, surface management and proper disposal and of course properly constructed wells. PA has been managing oil and gas for 100 years and has their acttogether it seems. carry on. John how about a road show say on Oprah.
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