This post represents two milestones for WUWT.
1. It is the first post where a detailed examination of fracking has been offered to the readers.
2. It is the first post I’ve authored from an airplane cruising about 35,000 feet enroute from Atlanta to Phoenix. I’m connected to Southwest’s new inflight WiFI service. Mr. McClenney sent me this post just as I was about to board and I emailed back that I wouldn’t be able to get to it for hours. And then I discovered this new miracle of technology. Here’s my view just before posting:
Guest post by William F. McClenney
I had occasion recently to watch several presentations on environmental aspects of hydraulic fracturing at the world’s largest oil and gas industry conference. To this day I remain dumbfounded as to why the argument I am about to present here has never been mentioned before (at least to my knowledge).
It is fundamental to all arguments which attempt to deal with the effects of oil and gas development to consider the initial discoveries of petroleum: seeps. Seeps are natural leaks from traps where migration of hydrocarbons have accumulated predominantly in reservoir rocks in the subsurface. These seeps represent leakage of these trapped hydrocarbons along predominantly fractures and faults, and to a lesser extent other pathways (such as unconformities etc.). (For a basic video see: http://wn.com/oil_trap)
Until the past decade or so, the search for these traps has been the focus of the O&G industry since its inception. Reservoir rocks are those rocks which have facilitated this migration through the provision of porosity and permeability necessary to allow the movement of fluids and gases derived primarily from the maturation of hydrocarbons most commonly derived from source rocks such as shales and mudstones which lie beneath them stratigraphically. Perhaps the most common reservoirs are sandstones.
Let me repeat that, the source rocks almost always lie beneath the reservoir rocks.
The other necessity for a reservoir rock to be a reservoir rock is a top seal or rock of low to minimal porosity and permeability (often also shales), sometimes in association with a structural discontinuity, such as a fault or anticline, which prevent the majority of the migrated hydrocarbons to keep migrating towards the surface. Stratigraphic traps, which also require a top seal rock, are also targets, such as conversion of limestone to dolomite through the addition of magnesium rich fluids which ideally can result in creation of up to 11% porosity in the dolostone. Where the updip limit of this conversion occurs defines the limits of the stratigraphic traps.
http://www.geo.wvu.edu/~jtoro/petroleum/Review%202.html
So traps, however they were formed, are the key to comprehending not only how economic accumulations of hydrocarbons occur, but also the how and why you literally cannot get here from there with hydraulic fracturing.
http://www.geo.wvu.edu/~jtoro/petroleum/Review%202.html
http://www.geo.wvu.edu/~jtoro/petroleum/Review%202.html
Let’s start with hydraulic fracturing itself. This only recently impinged on the popular consciousness and is therefore “new”. To the petroleum or gas geologist, these arewere new techniques to increase porosity and permeability beginning in the 1960s, with their initial use in the reservoir rocks in mostly vertical wells. Read reservoir rocks, not top seal or much lower source rocks. “New” must therefore encompass the massive use of this technique for over half a century in strata which overlie the source rocks, and in just about every known oil or gas field in the world.
Combine source, reservoir and top seal and you have what we call a “petroleum system”.
http://www.geo.wvu.edu/~jtoro/petroleum/Review%202.html7
Oddly, use of hydraulic fracturing for the last half-century in the reservoir rocks has not caused a groundwater problem anywhere I am aware of. Those of you that can provide examples of where this half-century of intense reservoir hydraulic fracturing has caused drinking water aquifer impacts please chime in.
But the game changed ever so slowly with the development and evolution of directional drilling into steerable horizontal drilling now all the rage. The horizontal evolution spanning mostly just the last decade or so.
What this means is that for the most part, we are now targeting for the first time the source rocks themselves. What that means is we are now going after the much lower, stratigraphically, tight organic source shales etc. This could be the end game for petroleum and gas exploration, for once we have exhausted the source rocks……………..
So here is what has been missing entirely (from what I can tell) from the present “hot” discussion on fracking. So think “source rock”. Lying beneath the reservoir rocks, where fracking has been going on extensively for decades. Now add in horizontal drilling, sometimes for miles away from the drillpad in several directions. As they are “fracked”, enormous lift, on the order of maybe millimeters to maybe inches or possibly a few feet occurs to open up pathways for migration of the hydrocarbon load towards the horizontal well(s).
Do you realize what this means? It means that there is a definite possibility that such radical lifting and fracturing of the source rocks has a very slight possibility of increasing what for tens to hundreds of millions of years was already the natural seeping of hydrocarbons from the source rocks into the reservoir rocks!
Do you realize what that means? That means that meager induced releases of new hydrocarbons from the surfaces of the source rocks could actually “get on the freeway” of the reservoir rocks where they could mischievously, eventually, make their way into the structural and stratigraphic traps where they could literally be “stuck” under the top seals or structural seals, at least until removed by say existing oil field wells in the reservoir rocks, or egregiously eke their way through the labyrinthine natural plumbing of the natural seeps to say drinking water aquifers.
Imagine even a few feet lifting from hydraulic fracturing in the source rocks propagating all the way through the reservoir rocks, literally blasting past all the hydraulic fracturing maybe occurring there for decades before, and even more powerfully fracturing not only the top seal rocks but the miles of sediments and beds above. Very, very impressive, if we could only do it…….. A nuclear test might, repeat might, crack the entire stratigraphic section to1 the surface a mile or two above it, but not much else is likely to.
http://maps.unomaha.edu/maher/GEOL1010/lecture18/lecture18.html
For oil and gas, the migration process could be considered “fast” geologically, perhaps taking from tens of thousands to tens of millions of years to occur due to the density drive which allows crude and gas to “rapidly” migrate into the reservoirs above the formation water. You know, oil floats on water, and so on.
Seismic section image off the coast of California showing sedimentary layering, faults, and other geologic features. Some of the features, especially in the deeper and lower parts, are artifacts of the imaging technique, and it is helpful to be trained in the interpretation of seismic sections. This type of data is crucial and common in oil exploration. Note the vertical scale of depth. Image source: http://walrus.wr.usgs.gov/mapping/csmp/data_collection.html
But the fate of the myriad chemicals being employed in today’s hydro-fracturing
regimes is not so sublime. What would drive these chemicals even into the culminations of the structural or stratigraphic traps? Most are water based solutions, with water starting out with a slight density advantage to say salt water (most connate waters are salty, surface seawater today ~1.025 specific gravity), that is until you dissolve said myriad chemicals into them, when the density drive case gets rather murky at best for water-based chemical fracking fluids, if not strongly negative (specific gravities being greater than 1.0).
Shoot these out into the connate water parts of the oil/column/reservoir rocks and voila, there you have it! They might be denser than even the connate waters, but unlike oil, they will dissolve and disperse. Whereas we have natural oil seeps above many known oil finds, we don’t often find brine springs. Why? Well oil is generally lighter than water (gas dramatically lighter) so it floats. If fresh water can “float” atop the denser warm Gulf Stream waters of the Atlantic, and shut down its circulation (according to many), how is this denser, salty or chemically laden, probably denser formation and frack water supposed to rise up, undispersed, through the top seal and structural traps, cascading and being refracted along countless bedding planes and unconformities to arrive, and still be detectable in near-surface (say less than 1,000 foot deep, and that’s being generous) aquifers thousands of feet to miles higher in a geologic instant?
Such that the USEPA can claim that they have found its signature in 3 places, only to later recant that they bungled that badly in each case.
With one exception, the ONLY way to get these “dangerous chemicals” into an aquifer quicksmart is if they
-
Possess a density less than crude oils yet greater than methane (assuming they remain water-based solutions and do not spontaneously become a gas at deep formation pressures (ludicrous just to cogitate)
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Have an yet unreported ability to jet through the labyrinth of bedding planes, other shales etc. in order to reach the surface often miles above in no time flat, where we can sample them.
The exception being transmission up the annulus of the exploratory boring/well itself. Now this can be a rather egregious problem as Macondo informs us. Are we not yet to learn the dirty details of Halliburton’s slipshod cementing of Macondo’s annulus? And this is an all too common problem for the O&G industry, driven as it is by economics, often offering bonuses to drilling contractors for completing the well ahead of schedule. Newly drilled wells are all too frequently subjected to anthropogenic pressures “before their time”, i.e. before the cement has been allowed to properly setup. Assuming it is proper cement in the first place.
This egregious problem can readily be addressed with some skillful regulations on concrete formulations (with allowances for evolution of these formulations by rigorous engineering standards which they must achieve), and a permit-specified curing time etc.? At least at the minimum.
That is literally about all it would take. This would not be egregiously expensive to the O&G industry, at least not when compared to blow-outs, extensive baseline groundwater monitoring ahead of and during drilling/production, cleanup costs etc. Environmental considerations, frankly, should be everyone’s first move these days. Would better up-front due diligence have prevented Macondo, Elgin or Frade? It’s just risk management, which Macondo informs us, can be a pretty big part of exploration management, and cost.
Just as “A stern chase after a lie is a long one” so is the trip for natural oil and gas seeps, which have had tens to hundreds of millions of years to do it, and a much more robust density drive than water based, and therefore easily further dissolved/dispersed chemical fracking solutions are likely to ever have. The “hole” in this theory is the exploration/production borehole itself, a relatively trivial and inexpensive problem to solve.
William F. McClenney
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An excellent analysis of the physics of rocks and reservoirs.
The only exception I might take is to point out that Halliburton’s models of Macondo indicated that cementing the well in one pass (rather than cementing the bottom third and letting it set before doing the rest in a second pass) risked having the weight of the cement exceed the fracture strength of the reservoir rock, resulting in the loss of unpredictable amounts of cement into the reservoir and possible gaps in unpredictable locations along the length of the borehole. It was a decision of the BP rep on site to proceed with a single pass cementing anyway (and with fewer centralizers than recommended) despite Halliburton’s concerns.
It was also the BP rep who told the Schlumberger crew to demobilize and not do the standard verification of the cementing job with a wellbore log.
The rig toolpush who argued with the BP rep died on the platform, but was after their earlier discussion heard swearing “I guess that’s what we’ve got those f***ing shears for”, implying he thought the well was going to try to back up and they would need to use the blow out preventer shears.
On the bright side, any toolpush today who feels the need to argue with a client rep can point out how much it cost BP to cut those important corners. It’s an argument that now carries considerable weight.
Personally, I have ignored the fracking discussion for exactly those reasons – as an ex-oilfield geologist, it was obvious there was not a serious issue. By contrast, for example, there are places which are grossly affectd by geothermal ‘extraction’ works – IIRC, there’s a place in Germany (?) settling due to warm water extraction! But, funnily enough, I don’t see the greenies up in arms over this kind of problem…..
GlynnMhor says:
April 29, 2012 at 3:25 pm
Thanks GlynnMhor. A good recollection of what is likely to be a lively litigation someday…..
I read that Cheney got this exempted from groundwater regulations, which is why they haven’t been testing systematically for contamination. There is an effort to get a regulation passed that would result in more testing.
It’s amazing what is ignored by the public. Insitu leaching of uranium deposits (ISL) has been going on for about 40 years, and now accounts for about 35% of total world production. Production is by injecting acid into the deposit from injection wells and sucking out the solutions from production wells. Acid and uranium versus water and gas?? Which method would you be worried about contaminating your water. And the uranium deposits are sometimes proximal to the aquifers – i.e. not deep. And to date no significant problems have developed. Trust me, you would have heard about it.
I read that methane hydrates were probably flowing into the Macondo well in a semi-solid state and the methane hydrates sent confusing signals to the drillers – who normally have clear indications what exactly was going on during the cementing process. Methane hydrates are supposedly abundant deep within the earth’s crust. But I can’t imagine how to extract them.
Kev-in-UK says:
April 29, 2012 at 3:32 pm
Personally, I have ignored the fracking discussion for exactly those reasons – as an ex-oilfield geologist, it was obvious there was not a serious issue. By contrast, for example, there are places which are grossly affectd by geothermal ‘extraction’ works – IIRC, there’s a place in Germany (?) settling due to warm water extraction! But, funnily enough, I don’t see the greenies up in arms over this kind of problem…..
It sure depends on the fluid. I’m STILL an oilfield geologist, and generally avoid discussing fracking to laypeople, because of all the AdHom about being a shill and the like. Yes, I make my living finding the stuff, but nope, I’ll tell ’em what they NEED to hear, not what they want me to say. And bad cement jobs are not uncommon, with the blessing that subsequent squeeze jobs can remedy the situation. Pretty well all of my clients in the last 15 years have made sure their casing sealed off the access point to the reservoir.
But, on the hype about fracking, I sometimes find myself having to cut a discussion short when people repeat stories about fracking water contaminating some slew water somewhere. In Alberta, we recently saw the death of on Wiebo Ludwig, a fanatical commune ‘pastor’ who was responsible for bombing a number of oilfield installations because, he said, their effluent was causing miscarriage in some of his livestock. No evidence, just bombs.
The above analysis is spot on, although I would add a fourth category to the petroleum system mentioned: “maturation”, that is, the thermobaric conditions which must take place to actually generate the hydrocarbon in the source rock, prior to its migration. Also, some frac jobs are relatively shallow, like some jobs I recently supervised in Alberta, at 700 meters below surface. But even then, there is a thick roof of several hundred meters of ductile marine shale above the reservoir…which resists fracturing.
Unfortunately, you will never see such a concise analysis in the mainstream, who prefer to demonize anything petroleum in lieu of investigative facts.
Relieve the pressure around them and they “extract” themselves. Albeit sometimes explosively so.
While most of your essay is pretty spot on, you missed probably the most important and most likely way to get the frakking chemicals into surface waters and aquifers – surface discharges of untreated or poorly treated drilling fluids and frakking water. This is the real threat from frakking.
Willam Abbott says:
April 29, 2012 at 3:58 pm
I read that methane hydrates were probably flowing into the Macondo well in a semi-solid state and the methane hydrates sent confusing signals to the drillers – who normally have clear indications what exactly was going on during the cementing process. Methane hydrates are supposedly abundant deep within the earth’s crust. But I can’t imagine how to extract them.
Uh, no. And drillers don’t do cementing, either.
JC, I’m guessing, that you speak in part about the vast Uraninite/Tyuyamunite/Carnotite deposits of the Morrison Formation of the Colorado Plateau, an area crosscut by vast canyons whose talus slopes are literally riddled with those three minerals. The Natives used the yellowcake ochre as paint. The uranium for Fat Man and Little Boy was mined in Uravan, CO, whose vast tailings ponds were set along the San Miguel River, and eventually into the Colorado via the Dolores river. The tailings ponds were remediated somewhere around 1990 while I was working on my thesis project in the area. The tonnage of uranium carried away by the Colorado River over time is simply immense.
William, thanks for that informative recital on fracking. Keep on it. As boring as it can be, the truth needs repeated over and over again.
The problem isn’t that people are concerned with it getting into our water system. A five minute excursion on the nets to the right places will inform us that it isn’t a danger. And, no one with an ounce of sense seriously believes the briny solutions are going to come get us.
The problem is, there are people in this country who are hell bent on depriving this nation of cheap reliable fuel and energy. Any successful fuel of energy industry will be despised by the radical left. Always.
Thanks again for the post!
Kev-in-UK says:
April 29, 2012 at 3:32 pm
“By contrast, for example, there are places which are grossly affectd by geothermal ‘extraction’ works – IIRC, there’s a place in Germany (?) settling due to warm water extraction! But, funnily enough, I don’t see the greenies up in arms over this kind of problem…..”
That would be the town of Staufen. Report from 2008, they drilled through keuper and then into a ground water layer and the water came into contact with the keuper, forming gypsum, leading to expansion. As a result at least a hundred houses developed large cracks. German houses are generally made from stone or concrete.
http://backreaction.blogspot.de/2008/11/town-rips-up.html
Since then, the process has continued and some places have risen by 30cm (1 foot).
http://en.wikipedia.org/wiki/Staufen_im_Breisgau#Geothermal_drilling_controversy
All of this just because they wanted to heat the city hall in a “climate-friendly” way (given the low energy density of geothermal, I wonder if the entire operation would even have had a positive EROEI if everything had gone smoothly).
crosspatch says:
Maybe one could collect them with robot submarines.
from central South America now 12 C probably because of this.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.recent.antarctic.png
we are getting colder and colder every year as the sun is going into a dormsnt state and Antarctica is growing every year. The AGWers are MAD
Sorry about my rapid-fire postings here, but:
BobN says:
April 29, 2012 at 4:16 pm
While most of your essay is pretty spot on, you missed probably the most important and most likely way to get the frakking chemicals into surface waters and aquifers – surface discharges of untreated or poorly treated drilling fluids and frakking water. This is the real threat from frakking.
The whole point of fracking is to pump those ‘drilling fluids’ into the rocks below the surface. And pump them until the tanks are dry. There is no ‘release’ of fluids at surface unless it is unintended, and believe you me, with the pressures involved on a frac unit, they make sure there won’t be such a release…because it would be deadly. I’m sorry, but the “Drilling Fluids” are long gone from the site by the time fracking begins. Gone with the rig that drilled the well. And just to be sure, most fracking fluid consists of….water. Water with some sifted sand added to act as a ‘proppant’, to keep the fractures from collapsing. Both, I might add, highly toxic substances. I think, BobN, that this is YOUR real threat from fracking. You haven’t done much research to support your assertion, I can tell. I’ll leave it at that.
Try this website for a review of oil seeps and oil spills – and why they are GOOD for the environment!
http://carbon-sense.com/2010/08/23/oil-spills/
Since 17-days after the Macondo well was capped in August 2010 has anyone heard anything about “The worst environmental disaster tin America’s history” (Obama in May 2010)?
Neither have I!
TheOilDrum.com has more posts on fracking.
See also The EPA’s Unconscionable War on Fracking
I believe I have read that it is estimated that globally, wind turbines kill more birds in a day than the Deepwater Horizon blowout killed.
I doubt that fracking will “lift” rock unless the work is extremely close to the surface. Otherwise fracking just produces connections among pre-existing fractures that are oriented perpendicular to the direction of least principal stress (favorably oriented). But, at any rate, there are probably a million wells in the U.S. that have had some method of enhancing permeability — fracking or acidization–with little to talk about until now.
My understanding was that the hydrates formed when gas, under high pressure, encountered cold bottom water in the Gulf. To extract hydrates you either warm them, or reduce pressure on them, and take them out of their field of stability. The hydrates then break down and release gas. At the depth of the Macondo well this would be 20C or so. So the Gulf bottom water would have induced hydrate formation.
BobN says:
April 29, 2012 at 4:16 pm
Well, I might have missed some. But flowback is a market for my firm. Municipalities, large and small, are coming to grips with the exigencies represented by return frack water, flowboack. Only those ventures that believe they can get away with direct surface discharge even flirt with such. Any size municipal water treatment system these days is becoming aware of the issues such a large discharger modern-day O&G operations can generate. And it isn’t pretty. Even for a boutique wastewater treatment enterprise, such large volume, near instantaneous discharges pose an engineering challenge. If surface discharges of flowback water are still occurring, my presumption would be that such a practice is destined for extinction.
We must continue to remove these poisonous hydrocarbons from the environment. I recommend that we either burn them or convert them to inert plastic products so they can do no more harm.
I’m torn on the subject: Oil or water?
In all seriousness, lately it seems that clean water is more rare than hydrocarbon deposits (here in the US) and something that we ought to be spending more time and effort in securing.
Jus’ sayin’
http://chiefio.wordpress.com/2012/04/27/caliche-co2-feldspar-and-climate-dust/
The ONLY reason fracking has been in the news is environmentalists’ campaign against abundant cheap energy afforded by shale gas. period.
I also work in the oil industry, 20 years, manager with major international, based in SE Asia, earth scientist by background.
This article has the correct conclusions (frakking is not an issue as its been going on for decades) but unfortunately is not well written, misses some key points and pieces of information and makes some erroneous statements. Not least of these is that source rocks occur below reservoir rocks. Generally true for [the] traditional petroleum system but this has nothing to do with what is being targeted under current frack type development proposals. Source rocks occur everywhere and the areas where they are currently being don’t necessarily have to be deep or associated with reservoir rock at all.