A LEAK AT WEYBURN? Scientists say a recent report's conclusion that anthropogenic CO2 is leaking from an underground storage site into the prairie soils near Weyburn, Saskatchewan, is unfounded.
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The recent release of an independent geochemical consulting firm's report concluding that carbon dioxide is leaking from one of the world's largest CO2 geologic storage projects—located at the Weyburn–Midale oil fields in Saskatchewan—has caused a public relations crisis, not only for Cenovus Energy, the oil company that operates the site, but for the CO2-alleviation strategy of carbon capture and storage (CCS). But scientists are pushing back, arguing that the evidence does not justify the report's conclusions.
Cenovus uses CO2, which arrives via pipeline from North Dakota, for enhanced oil recovery—a technique in which the greenhouse gas (GHG) is injected into an oil reservoir to coax out extra oil. Much of the CO2 (around 18 million metric tons as of July 2010) is then stored 1.5 kilometers underground in a depleted reservoir, where it is supposed to stay trapped. The International Energy Agency (IEA) GHG Weyburn–Midale CO2 Monitoring and Storage Project, a research group affiliated with the Paris-based agency has spent the past decade studying CO2 injection and storage at Weyburn, the goal being to "deliver the framework necessary to encourage implementation of CO2 geological storage on a worldwide basis," according to the group's web site.
Many scientists and engineers argue that geologic CO2 storage, which is today underway at only a few sites in the world, is a necessary weapon against planet-warming emissions. But CCS faces an uphill battle in terms of public perception. Chemically capturing CO2 is extremely expensive, the construction of a network of pipelines for its transport would also be costly, and questions remain regarding the safety of burying millions of metric tons of the gas underground. Is it certain to stay there? A confirmed leak at Weyburn, a site seen as a CO2 storage test case, would embolden critics—and initial news of the alleged breach has already inspired alarming headlines.
The report, published by a Saskatchewan firm called Petro-Find Geochem, was commissioned by a local couple alarmed by strange occurrences (ranging from gaseous bubbling in their pond to unexplained animal deaths) on their property, which sits above the Weyburn oil field. This past July the firm analyzed soil samples taken from the property.
On January 19, however, scientists affiliated with the IEA project—which is funded by 15 government and industry sponsors (including the U.S. Department of Energy) but does not receive cash support from Cenovus—released a statement saying there is "no substantiated evidence in the Petro-Find report to support [the authors'] claim that 'the source of the high concentrations of CO2 in soils of the Kerr property is clearly the anthropogenic CO2 injected into the Weyburn reservoir.'"
Data doubts
To justify their assertions, the Petro-Find consultants cite two values—a measured chemical signature for CO2 in the soil that is similar to the signature of the injected CO2, and an anomalously high CO2 soil concentration measured at a single point on the property. But Steve Whittaker, the senior project manager of the IEA project, tells Scientific American the consultants are overinterpreting their results.
Although an analysis of stable carbon isotopes showed that CO2 collected near the soil's surface had a similar chemical signature to that of the injected CO2, this is not enough evidence to claim that it is the injected CO2, and not gas produced naturally by microbes, plants, and other organic matter in the soil, Whittaker says. "We've performed similar measurements for soil gas and the numbers they have are all within our range of sampling," he notes, adding, "Multiple lines of evidence collected in the area have indicated that CO2 having that isotopic composition is of natural origin."
Petro-Find also claims that the results of its isotopic analysis represent a major shift from baseline soil carbon isotopic values for the area. But this claim is unfounded, Whittaker says, because the consultants failed to measure an appropriate baseline value. According to Wednesday's statement: "The Petro-Find report incorrectly uses the carbon isotopic values of naturally occurring CO2 in an oil reservoir at 1.5-kilometer depth to represent initial values of CO2 in soils at surface," meaning, "the argument for a dramatic shift in isotopic composition is technically flawed."
Regarding the report's finding of a "major anomaly" in the tested soil's CO2 concentration—110,607 parts per million, compared with a reported average of 23,000 ppm for 25 additional samples—the project statement holds, "The concentrations of CO2 in soil gases collected by Petro-Find are similar to those found in prairie soils in the vicinity of Weyburn." Further, Whittaker points out that one data point is not a sufficient basis for scientific conclusions, especially given the highly variable nature of soil gas composition. He notes that soil CO2 concentration depends heavily on soil features, and a lower-lying area with more moisture similar to the area from which Petro-Find collected samples would have more vegetation (especially in the summer), which would thereby produce more CO2 through respiration.
There is also the question of how the injected CO2 could have traveled to the studied property, given that the nearest active injection site is nearly two kilometers away. The Petro-Find report blames "deep-seated faults/fractures," which it says could serve as conduits for migration of the GHG. But according to Wednesday's statement from the IEA scientists, "There is no credible evidence that the surface lineaments proposed by Petro-Find indicate a 1.5-kilometer-deep open fault." The reservoir has "contained oil for tens and tens of millions of years," Whittaker notes. "These are natural containers."
Finally, the statement addresses Petro-Find's implication that high CO2 soil content could lead to unhealthy levels in the air, pointing out that "CO2 concentrations that would be of concern in the air aboveground are quite normal in soil gas at a depth of one meter," the depth from which the consultants gathered the samples, and, further, "There are no data in the Petro-Find report demonstrating dangerous levels of CO2 in the atmosphere."
More analysis required
Susan Hovorka, a senior research scientist at the Bureau of Economic Geology at the University of Texas at Austin and an expert in monitoring geologically sequestered CO2, agrees based on her reading of the report that "the conclusions are way ahead of what can be supported by the data." Before immediately drawing connections between the CO2 in the soil and the injected CO2, efforts should have been made to rule out other sources of the greenhouse gas, she says.
Hovorka says the consultants neglected to perform a relatively simple test that could have given a preliminary determination of whether or not the high CO2 concentration was due to natural processes. "We need to see the CO2 concentration versus that of oxygen and nitrogen," she explains. Because soil microbes take in oxygen from the atmosphere and release CO2, "we can deduce that this process is occurring because oxygen is consumed at a molar ratio of twice the CO2 increase." On the other hand, "if CO2 has come in from someplace else, both [the concentrations of] oxygen and nitrogen will be reduced, by dilution," she says.
Whereas this test would not necessarily confirm anything definitively, "it helps you start to pick apart the system with a large number of simple measurements, and gives you a hypothesis as to the major processes," so that scientists can know which more-expensive tests are necessary, Hovorka says. "Absence of this kind of analysis," she adds, "shows that the study presented is preliminary, and that it is premature to discuss evidence that Weyburn is leaking."
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26 Comments
Add CommentCO2 sequestered into the crust of the earth will eventually leak into the troposphere. The crust of the earth is constantly evolving at a relatively rapid rate compared to the crust of our moon and other nearby solid planets. Reason: The available volume of liquid water and the atmospheric storms which dump tons of liquid water on the land masses of this planet. Life too impacts on its rate of change, including activities of burrowing life forms and the large mining mole called Homo sapien.
Reply | Report Abuse | Link to thisOne day, as has happened in the past, the sequestered CO2 will be released. Most probably it wont effect Homo sapiens since the species will be extinct in a few hundred years, another victim of the ubiquitous sixth extinction.
This story illustrates the fact that we have no good diagnostics to measure CO2 leakage from underground storage.
Reply | Report Abuse | Link to thisThe industrie has many methods of tracking CCS underground, They include Chemical tagging, Satellite imagery of elevation and other underground instrumentation coupled with scientific data collection of soil samples. These are just a few. Please.
Reply | Report Abuse | Link to thisI think Whittaker is working too hard in trying to pull the wool over the eyes of the people living in the area. He refused to admit that that site can become a dangerous failure and endanger the lives of everything living in the area. Wait until thousands of birds fall out of the air dead like they are doing in the southern U.S. and other parts of the world and see how he explains that away.
Reply | Report Abuse | Link to thisThe one thing that struck me as funny was the comparison of a viscus oil vs a gas....I think its highly probable that the gas will escape exponentially faster than the oil did.....
Reply | Report Abuse | Link to thisRecently the Canadian Federal Environmental Commissioner participated in a meeting at MUNK in Toronto. The experts stated how initial pre-development data is woefully lacking to the point that damages after development can't reasonably be proven. Industry/developers pay for their own science and they own the that data. Our Canadian Government lacks access to it and industry holds the data like scouting reports for their own advantage.
Reply | Report Abuse | Link to thisI've seen many studies that avoid spring thaw, seasonal water variants, projects that rely on models instead of actual readings and the predictions are many. Poor test times for certain species and questionable methods are frequently seen. We really need to mandate appropriate test times and standardize best practice methodologies.
In my view, since water is a public commodity the data about it should be too. We need more transparency.
We need to set the benchmark on acceptable pre and post development data and hold industry/developers fully accountable for their actions should things not work as planned. Holding a line of credit worth the value of the mitigation systems until they have proven it actually works might help. If it doesn't work, they should pay up and fix it or no new permits.
By developing carbon capturing systems Canada is putting it's own groundwater resources at risk at a time when the world is going to face major water shortages. Is that morally or ethically correct? Furthermore, we are creating innovations that will be used to further promote tarsands extractions in other nations and Canada will not be able to stop that since industry owns the science using our taxpayer subsidies to pay for developing it.
Reply | Report Abuse | Link to this71 nations currently have tarsands they could exploit. The Madagascar Tarsand project is expected to become the world's worst for pollution. What we're doing in Canada is advancing a science that could generate funds for terrorism, corrupt governments etc. Do we really want to advance further to open up these international security risks or are we going to be responsible enough to stop what we're doing and take a new path toward clean, morally ethical energy solutions for our nation's needs?
You are reporting on two conflicting studies, conducted by different teams of scientists. The original study was prompted by what seem to be anomalous animal deaths etc., the response by the goal to "deliver the framework necessary to encourage implementation of CO2 geological storage on a worldwide basis." Note that the second study does not conclusively show that the results of the first one are wrong, but that argues that it is based on insufficient data.
Reply | Report Abuse | Link to thisStrangely, only one group of scientists get called "scientists", or "experts". So, some consultants conduct a study, and "scientists" (without a qualifier) push back against it. We even learn that "many scientists and engineers" support CCS, without being told that the majority of scientists in the field remain skeptical towards CCS.
Thus, the article strikes me as strangely biased, even if the results of the original study are not sufficiently substantiated.
you are a tool.
Reply | Report Abuse | Link to thisOf course it's leaking. Long term, everything leaks. Rocks are porous to gasses. The question is how fast, and how much.
Reply | Report Abuse | Link to thisThe area near the site has around 5X more CO2 than areas further away. OK. Now, if the environment can metabolize the CO2 as fast as it leaks out, then the plan works. Otherwise, it's back to the drawing board.
The attempt to say that the gas couldn't have traveled 2 KM is laughable. Transmission is by cracks in the rock. It will move sideways at least as much as it moves upward. Direction and extent will be random.
Sequestration will buy us a little time, that's all.
The only real solutions will involve a different way of powering civilization. So far, bio fuels don't appear to be compatible with providing food. Food or fuel, pick any one. Solar and wind are only minor contributors. Most folks don't realize yet the environmental costs of those. Hydro is maximized in most areas. Fusion still doesn't work, after almost 80 years of trying. It looks more and more like Nuclear is the only workable option.
The Article is an attempt to whitewash the leaks.
The article states:
Reply | Report Abuse | Link to this"Cenovus uses CO2, which arrives via pipeline from North Dakota, for enhanced oil recovery—a technique in which the greenhouse gas (GHG) is injected into an oil reservoir to coax out extra oil."
I didn't find any more about where this co2 comes from (a pipe from N. Dakota): is it being extracted from some coal fired power plant, or simply being extracted from underground as a byproduct of some mining operation?
More importantly, is sounds like the co2 is simply being pumped into old oil wells in Canada to repressurize them, improving their production, so that additional fossil fuel will be burned, increasing atmospheric co2.
There was no indication of any attempt to actually sequester the co2 within any sort of mineral or other chemical compound, making it less likely to escape as a gas.
It sounds to me like this is simply a situation where an oil company had some unproductive wells that needed some way to increase their internal pressure and a power company needed some way to reduce its atmospheric co2 releases. Making money is the most likely catalyst here, not altruistic ecological concerns.
What result should be expected when gas is a pumped into subterranean wells that have already been drilled out? It would seem that reliable gas storage should certainly not be expected.
Whilst it is evidently true that the oil has lain trapped for millions of years, a new parameter is that the pumping of the oil can create relaxation in the rocks, leading to micro and macro fissuration which could slowly extend its way to the surface. Only time will tell, or an extensive program of monitoring boreholes.
Reply | Report Abuse | Link to thisIf there is a C02 leak underground, are there temperature differences in the leak area versus area without leak?
Reply | Report Abuse | Link to thisWe used the same concept for groundwater location and isolated areas for biologists. Here is a link to show you. http://www.thermoguy.com/groundwater.html
We did some amazing work this year showing global warming contributing to climate change without emissions produced.
Reply | Report Abuse | Link to thisBuilding development is supposed to reflect or protect from solar radiation or the building development will be radiated because of a paint job or lack of shade. Here is a link showing buildings on a -12 C day over
50 C with solar exposure. These buildings are cooking the atmosphere without producing emissions and in the summer will produce massive emissions responding to the symptoms of a radiated building. http://www.thermoguy.com/urbanheat.html
I am very much against storing compressed carbon dioxide below the earth's surface. It is far too vulnerable to being released back into the atmosphere. A gas is highly mobile, whilst a solid with a very high melting point is virtually immobile.
Reply | Report Abuse | Link to thisI suppose it's considered to be achieving two objectives by using carbon dioxide under pressure in natural gas wells to enhance the release of the natural gas to the surface (crude oil, too, I would guess), and to leave the carbon dioxide down there, supposedly permanently. But the latter idea has been criticised, which is likely to become more vociferous.
Leaving aside the use of the carbon dioxide to enhance the release of natural gas or crude oil, I would have thought that going back to nature would have been a considerable improvement, ie store the carbon dioxide in solid form. No, of course not to solidify it and store at very low temperature - that's useless as you get nearer to the earth's white hot centre! But develop an energy-economic chemical process to convert the carbon dioxide to carbon and oxygen. The oxygen is released back into the atmosphere, and the particulate carbon is compressed and sintered into solid blocks, for storage well underground, possibly in worked out mine tunnels.
After all, coal has remained down there very successfully for some 2 billion years, undisturbed, until man decided to mine it. (So, too, has crude oil, but not all the natural gas that was ever produced). Plate tectonics has played some minor havoc with coal storage, of course, bringing some of the coal near to the surface in some places. (It also had to get down there in the first place, but that's a story for another occasion).
At least as a continuous conversion process, even if plate tectonics brings some coal up to the surface, or it subducts it into volcanic areas, then being released into the atmosphere as carbon dioxide, a continuous process of carbon dioxide conversion on a large enough scale might possibly counteract its rate of production from coal caught in volcanoes.
Mike, I am by no means a specialist in this area, so this is a request for information. If the CO2 were stored in very deep, depleted oil wells, then the wells plugged up competently, would it be subject to the dangers you warn of?
Reply | Report Abuse | Link to thisFurthermore, if we were to solidify it into solid blocks, would it need to be sequestered very deep? Could it be used as construction materials?
Pazuzu, the sintered carbon blocks would not need to be permanently stored further down than in typical coal mines, but not in those near to the surface. You want a good number of 10s to 100s of millions of years for weathering not to open them up to the atmosphere. It might not be quite so easy to predict what plate tectonics might do, though, in such long timescales.
Reply | Report Abuse | Link to thisA problem with using solid carbon blocks as a construction material is its flammability. Two good demonstrations of how synthetic solid carbon (graphite, actually) easily burns were the Windscale accident and Chernobyl disaster. I have no idea of the strength of sintered graphite. But I wouldn't expect it to be brilliant, though.
In some regions it might be possible to store compressed carbon dioxide deep down, After all, natural gas is still associated with a number of oilfields, and natural gas contains methane which is considerably more diffusible through relatively porous rock than carbon dioxide is, and we all know that there are natural gasfields. The same goes for a number of coal mines, those where methane leaks are a serious explosion hazard. But certainly not all oil fields and coal mines are impervious to the diffusion of natural gas into the atmosphere. It would be a risk, especially if one is hoping that the carbon dioxide will stay permanently down there for a 10s to 100s of millions of years. But then can one predict many thousands of years hence that massive earthquakes won't open up huge cracks in the rock strata through which the carbon dioxide will leak back into the atmosphere. Conclusion: can do, but pretty risky for our descendants!
So you point out that thousands of bird fall dead out of the sky where carbon is not being sequestered and use that as an excuse to criticize carbon sequestering? I know clinically diagnosed morons with better logic than that. Sure enough, carbon sequestering has risks much the way pumping oil from the ground has risks. How about we focus on finding the real dangers through properly performed science instead of jumping on a rather questionable bandwagon.
Reply | Report Abuse | Link to thisThe oil didn't escape. It was forcibly extracted. If there is an additional hole in the reservoir then the gas will escape quickly. If there is no other hole it won't. What the alarmists are missing is that the reservoir probably fractured as oil was removed and that allowed a wide range of other gasses that are usually contained to escape into the atmosphere. Those gasses are known to be deadly.
Reply | Report Abuse | Link to thisCO2 makes plants grow. This is a simple fact. In view of this fact one must wonder if the odd things that the locals want explained includes more abundant plant growth. If it doesn't, I'd look to other causes.
Who is a tool and why? Please be specific so you don't seem to be a jerk.
Reply | Report Abuse | Link to thisSince carbon is a valuable material for all manner of things, why not capture it as pure carbon and use it for industrial functions such as say, maybe diamonds or carbon nano-whatevers? That would be much better than stuffing it underground. Would concentrating it into a solid form be economically viable?
Reply | Report Abuse | Link to thisResponding to "bucketofsquid's" point, certainly the separated carbon could be used to produce industrial mini-diamonds, especially for use as an abrasive, although there are, of course, other industrial uses.
Reply | Report Abuse | Link to thisBut some considerable care would need to be considered in converting that carbon into jewelly-grade diamonds, otherwise the market would be rapidly and totally overwhelmed, and their value would fall dramatically. The ladies wouldn't be very pleased!
Also, think of all those miners, or whatever they're called in the goldfields, who would be put out of work if only synthetic jewellery grade diamonds were to be available!
Now, a totally different aspect of using CO2 to pressurise oil and gas fields has occurred to me. CO2 is a heavy gas. There are a few volcanic regions in the world with very substantial CO2 leaks, and if this heavy gas flows into sealed valleys or geological "bowls", there's a danger of the CO2 accumulating to levels which asphyxiate animals - and humans - due to lack of oxygen.
It is not unknown for tectonic activity and the settling of rock strata to cause minor earthquakes, let alone major earthquakes. In particular, causing impervious rock strata to crack, through which gas under pressure can leak. If such leaks were to be substantial, and into enclosed valleys or geological bowls, once again we could run into a situation where the atmosphere is unable to support life.
Perhaps there's geologist out there who could tell us whether or not this situation could be a possibility in the use of CO2 for pressurising oil and gas fields.
Nobody has yet studied the existence of life-forms in deep aquifers. We know that life-forms can exist in extreme locations such as undersea volcanic vents. The effect of CCS on deep aquifers needs to be evaluated.
Reply | Report Abuse | Link to thisTwo like gas particles literally exist to separate to infinity from each other. Entropy alone, regardless of all other physical efforts to contain matter will see to it that “long-term safe and reliable CO2 sequestration” is an oxymoron.
Reply | Report Abuse | Link to thisScience's most well designed gas containers cannot contain gases indefinitely. This is true of tires, acetylene and oxygen tanks to Space Shuttle quality gas containment cylinders. The general rule of thumb for any practitioner is to use stored gas productively as fast as possible to minimize loss to leakage that occurs over time. Any professional metal fabricator knows this.
It is only our desperate hope for a solution to our addiction to fossil fuel consumption that clouds our scientific and uninformed minds alike to the point that we are willing to acquiesce to the fossil fuel industry's clever "out of sight, out of mind" scam. To the industry, the solution to CO2 emissions is found in psychology and perception, not in physical science.
We cannot predict even the smallest earthquake. If we could predict them we can do nothing to stop them. Mass CO2 leakage can have immediate and deadly consequences. Longer term global warming problems loses importance when a city or town is dying in a cloud of CO2.
Remember Lake Nyos, Cameroon 1986.
Government and fossil fuel industry representatives stand up in town hall meetings and, selling underground CO2 sequestration projects, assure attendees that CO2 is not toxic to Humans. But whenever I challenge them to hold their breath for, say, four minutes none accept my challenge. It is the buildup of CO2 in the oxygen breathing organism (that’s us) that kills us. The lack of oxygen is a secondary factor. Again, remember Cameroon 1986. In Cameroon it was not an earthquake but a rainstorm that is believed to have released a CO2 gas bubble from the bottom of Lake Nyos. Over 1,700 people and 3,500 cattle died in within minutes of the deadly release.
One tiny earthquake creating a breach of a so-called safe and reliable "stone" underground storage unit could essentially belch a CO2 plume that would crawl over the nearby landscape killing every oxygen breathing organism in its path.
I tried to explain this to Medicine Bow, Wyoming citizens in a town hall meeting last year. Some got it, but then Governor Dave Freudenthal’s folks and industry represents scoffed. I am certain the rest of the gathering noticed that no one accepted my challenge to attempt holding their breath for four full minutes.
Don't be fooled by out of sight - out of mind psychology.
I have written a great deal about the false promise of underground CO2 sequestration. One point I have made repeatedly is that underground CO2 sequestration comes with inherent advantages to the industry. One of these advantages is playing out as described in this article. A coal fired electric energy plant generates CO2 emissions that can be reliably and accurately monitored at the emissions leave a discrete and finite smokestack. In the case of underground CO2 sequestration, smokestacks do not exist. The "smokestacks" come in the form of literally an infinite number of pores in the bedrock and landscape atop the bedrock vessel containing the sequestered CO2. This fact renders the monitoring of leaking CO2 essentially impossible. At any given monitoring site only a minuscule faction of the whole can be measured, unlike the smokestack scenario where the sum of all emissions can be directly measured and calculated if necessary. The aspiring CO2 sequestration industry promotes underground "storage" of CO2 because first, it offers the industry an advantaged relating to public perception or rather, non-perception meaning the underground aspect of this bad idea lend itself to an "out of sight - out of mind" public psyche. Secondly, pressurized CO2 (when pumped underground) leaks back into the atmosphere via literally an infinite number of tiny porous "smokestacks" over a vast escape zone rendering leakage measurements and reliable calculations impossible (thus the controversy discussed in the article prompting all these comments). As stated in my last comment, the fossil fuel industry has abandoned even the most basic gas laws and physical science in its search for a solution to CO2 emissions. Instead they have devised a "solution" that relies on the human psyche and its weaknesses. Out of sight - Out of mind is a powerful tool when appeasing the public... as is the case with an infant. The industry has chosen to bury CO2 much like we bury our dead. Burial is closure in the human mind. But CO2 will rise from its grave one way or another. CO2 will rise slowly in an almost imperceptible manner (as described in this article) or should that small or large earthquake occur, in a plume that will kill every oxygen breathing organism in its path, humans included. We must not behave as the infant, allowing the CO2 underground sequestration industry to fool us with their "out of sight - out of mind" pseudo-solution to CO2 emissions.
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