I know that industry very much wants to have their frack and eat it too. And I know that they have gotten away with that for a very long time now, but I think they are facing a reckoning here.
In response to my post, Absolution in Marcellus Shale Water Contamination Premature, I got the following comment:
Hydraulic fractures extend approximately 200 to 250 feet from the wellbore. The aquifer in this area is at least 5,000 feet above any hydraulic fracture. If Marcellus gas is contaminating the water wells, it is leaking from a poor cement job in the casing, not from the hydraulic fractures.
We really don’t know where the gas is coming from. We do know it wasn’t there before the hydraulic fracture occurred.
From Halliburton’s Manual for the Independent Operator:
“An improperly designed or poorly performed stimulation treatment can allow a hydraulic fracture to enter a water zone.”
From a recent court case:
Dispute has industry, mineral owners nervous
The problem is, however, that fracture stimulation isn’t a precise science, and doesn’t always crack the shale in equal portions. In some ways, cracking the shale evenly could be thought of as trying to hammer a dinner plate into equal pieces – it’s not easy.
“You may plan a fracture that will go 1,000 feet, and it might go 2,000 feet or 400 feet,” said John S. Lowe, a professor of energy law at Southern Methodist University’s Dedman School of Law.
But knowing what has happened thousands of feet below isn’t easy.
“How do you prove any fracing was correct or incorrect in an area that is not precise to begin with?” asked Holden, who has practiced natural resources and energy law for more than 30 years. “Either side has to prove what’s going down below, and that’s hard for both sides.”
When faced with charges of water contamination, industry claims hydraulic fracture is precise.
When faced with paying royalties because fractures went astray, industry claims hydraulic fracture is imprecise.
Which is it?
Updated to include more industry double speak:
“These are surgical operations utilizing the most advanced drilling technology known to man,” Tom Price Jr., senior vice president of Chesapeake Energy, told state lawmakers in Albany at a recent hearing.
Thanks to Abrahm Lustgarten & Propublica
Surgical operations should be fairly precise. But wait! Maybe not…
And, from a presentation given by James Herman:
FRACS TRACKED USING MICROSEISMIC IMAGES
S.C. Maxwell and T.I. Urbancic, ESG International, Kingston, Ontario, Canada.
N. Steinsberger, Devon Energy, Fort Worth, Texas and
R. Zinno, Schlumberger, Houston, Texas.
Hydraulic fracture geometries are difficult to predict. Even in environments with relatively simple fracture geometries, hydraulic fractures can grow asymmetrically, have variable confinement across geologic horizons, and change orientation. In naturally fractured reservoirs, such as the Barnett Shale, hydraulically created fracture patterns become amazingly complex as the injected slurry preferentially opens the pre-existing fracture network.
This excerpt is from Schlumberger’s publication Oilfield Review Winter 2005/2006.
Article title: THE SOURCE FOR HYDRAULIC FRACTURE CHARACTERIZATION; p.46.
“While it is possible to have a good understanding of existing natural fracture systems, our ability to determine hydraulic fracture geometry and characteristics has been limited. Geologic discontinuities such as fractures and faults can dominate fracture geometry in a way that makes predicting hydraulic fracture behavior difficult. Clearly, the exploration and production (E&P) industry still has much to learn about hydraulic fractures.”
Hat tip to un-naturalgas.org for the assist.
UPDATE: Another example of industry accidentally telling the truth:
Four wells have been fraced and are producing gas, but
Bill Barrett has had troubles with its frac jobs diverting into salt formations. When that happens, saltwater flows up along with the gas.
About Sharon Wilson
Sharon Wilson is considered a leading citizen expert on the impacts of shale oil and gas extraction. She is the go-to person whether it’s top EPA officials from D.C., national and international news networks, or residents facing the shock of eminent domain and the devastating environmental effects of natural gas development in their backyards.
- Web |
- More Posts(5116)
Superb piece on this matter! Thank you! It reminds me of O. J. Simpson claiming that he would not rest until the killer of Nicole and Ron was found. I think one of the late-night comics said, “Well, he hasn’t looked on all the planets yet.” Placing blame for the contaminated wells in Dimock seems to be a choice between the most obvious and other less likely causes. I would give more credence to Professor Lowe and Mr. Holden than to the explanations of Cabot or even the PA DEP.
to the extent that we have any hope of saving our environment from the ravages of horizontal drilling, we need some incontrovertible proof of the irrevocable damage we understand is being done. this post seems to me to support, beyond any controversy, that it is impossible to prove scientifically (in a court of law?) that fracking is sound.
bravo sharon! i think this may be your best post ever!!! 😉
here’s a comment that was posted in the daily review up in bradford county, pa that may shed light on the imprecision… “You don’t have to be a genius to understand it. I think even the average person can get this. First, water is incompressible. That’s how they can frac in the first place. The frac fluid does not compress. So a pressure pulse applied up at the top of the well is transmitted all the way to the end of the line, a mile below ground.
But this means that during fracing the entire well is under pressure, very high pressure. A mile below ground that pressure fractures the shale, sure enough, as intended. But further up the well shaft much closer to the surface, that same pressure can force frac fluid, including the chemicals everybody is concerned about, into the water table through natural fractures in the rock.
This is not all that tough to envision. The pressures used to fracture the shale are very, very high. Of course, once the poison frac fluid gets into the water table, heck, that’s the end or our drinking water right there. You and me and the farm animals, whatever, we’re all drinking the stuff. And the gas companies won’t even disclose what chemicals they are using. This makes testing our water nearly impossible, because nobody knows for sure what to test for.”
This fracking procedure generally results in a “vertical fracture”. This means that (especially for vertical wells) the facture can damage the cement, collapse the casing, and cause other problems which allow easy upward migration of the fracking fluid to eventually damage water aquifers. Also during fracking, if the casing or a coupling leaks high up in the well, the fracking fluid goes to the water aquifer. None of this is predicted by the computer models!
The chance of a fracture propagating up the cemented wellbore is unlikely, but is guaranteed to happen eventually given the number of opportunities.
Where people got that poison is being injected into the earth is somewhat beyond me, except for the potential of certain corrosion inhibitors (chromium salts), which break down quickly and are used in very small amounts. I would gladly drink frac water that was flowed back. It would be gross, but not even close to lethal.
To correct anothers comment… Water is compressible. Rock is also compressible. The average pressure of fluids and gases in the earth at any given point is 14.7 + depth (ft) * .433. The average frac pressure ranges, but will not exceed 5000 psi (the strength of casing with a safety factor of 2). Gas present is also extremely compressible… Voids in the earth filled with gas and liquid close or open with the frac.
Also, for the record, the oil and gas companies do not know the make up of frac fluids. It is the service companies who are completely different (Schlumberger, Halliburton, etc.) but these fluids are generally special polymers (plastics).
I guess it's just some kind of statistical anomaly that all these cattle suddenly died a gruesome death after chemicals sprayed into their pasture during hydraulic fracture.
Here is a list of Frack Chemicals.
You can find a list of drilling chemicals specific to Texas at The Endocrine Disruption Exchange.
If the chemicals are harmless and the process is harmless as you say, then you and EOG should have no problem with federal regulation.