 of pressurized pipelines, like the one pictured here, transporting carbon dioxide in the U.S. alone.){kind=spacer}
CO2 PIPELINE: There are already some 3,100 miles (4,988 kilometers) of pressurized pipelines, like the one pictured here, transporting carbon dioxide in the U.S. alone.
Image: Courtesy of Denbury Resources, Inc.
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Editor's Note: This is the fourth in a series of five features on carbon capture and storage, running daily from April 6 to April 10, 2009.
The Scurry Area Canyon Reef Operators Committee oil field, better known as SACROC, near Snyder, Tex., has slurped 140 million metric tons of liquid carbon dioxide (CO2) since 1972—80 million metric tons of which has stayed trapped in the reservoir. Pumping all that CO2 down has meant pumping more oil out.
For 36 years, oil services companies like Denbury Resources and Kinder Morgan have piped carbon dioxide from naturally occurring reservoirs in Colorado to the declining oil fields of the Permian Basin in West Texas.
The U.S. has at least 100 such projects like SACROC and 3,100 miles (5,000 kilometers) of CO2 pipelines. All told, companies have injected some 10.8 trillion cubic feet of the greenhouse gas since the 1970s, according to petroleum engineer R. Tim Bradley, Kinder Morgan's president of CO2, to raise the yield from oil fields by some 650,000 extra barrels a day—more than 10 percent of daily U.S. total production.
Most important with respect to carbon capture and storage (CCS), the Great Plains Synfuels Plant in North Dakota has pumped as much as two million metric tons of carbon dioxide a year to the Weyburn oil field in Saskatchewan since 2000.
"The Dakota gasification project is creating synthetic gas and taking the CO2 from that process," then pipelining it to the Weyburn oil field, observes carbon storage development coordinator Kurt Waltzer of the Boston–based environmental group the Clean Air Task Force. "In effect, you have demonstrated all the components of doing a CCS project."
In all of these projects, the CO2 basically scours more hydrocarbons out of the oil field. When injected into the oil reservoir, it mixes with the oil and mobilizes more of it—like turpentine cleaning paint—and then allows it to be pumped to the surface.
Using carbon dioxide to churn out more fossil fuels—and permanently storing some of the CO2 in the process—might sound counterproductive to limiting climate change because those fuels, when burned, put more CO2 into the atmosphere. But it does reduce overall emissions by at least 24 percent, calculates petroleum engineer Ronald Evans, Denbury's senior vice president of reservoir engineering: every recovered barrel of oil eventually puts 0.42 metric ton of CO2 into the atmosphere, but 0.52 to 0.64 metric ton are injected underground recovering it. In fact, Kinder Morgan's Bradley estimates that enhanced oil recovery in the U.S. could reduce CO2 emissions by 4 percent, if done correctly.
The great fear commonly associated with carbon sequestration is that trapped CO2 might suddenly escape to the surface with deadly consequences, as happened in 1986 at Lake Nyos in Cameroon. That volcanic lake had naturally accumulated two million metric tons of carbon dioxide in its cold depths; one night it spontaneously vented, displacing the oxygenated air, and suffocated more than 1,000 nearby villagers.
Yet in all three decades of commercial use of CO2 for EOR, there have been no dangerous leaks. CO2 from leaks and ruptured injection wells has always dispersed too quickly to pose a threat.
For example, prospectors in Utah drilling for natural gas in 1936 accidentally created a CO2 geyser. It still erupts a few times a day as pressure builds but is "so unhazardous that it's a tourist attraction, not a risk," says hydrologist Sally Benson, director of the global climate and energy project at Stanford University. In fact, air concentrations of carbon dioxide have to build up to more than 10 percent to be hazardous, which is difficult to achieve, according to modeling from Lawrence Livermore National Laboratory (LLNL).
The reason is that CO2 belching from a volcanic lake creates conditions very different from those of the gas escaping from a wellhead or seeping into a basement, explains Julio Friedmann, leader of the carbon management program at LLNL. At Lake Nyos, an abrupt release of the CO2 allowed dangerous concentrations to pool in low-lying surrounding areas. Pressurized gas escaping from a wellhead or crack simply mixes rapidly with the atmosphere, presenting no danger, much as the use of a fire extinguisher is not hazardous. In situations where atmospheric mixing is minimal, such as for a slow leak into a basement, the problem can be eliminated by simply installing a sensor and a fan, as in apartment buildings today near natural CO2 seepages in Italy and Hungary.
The greatest risk is from the wellheads themselves leaking: one in 12,000 injection wells leak, according to LLNL. And, not unlike a vase that is glued back together, a wellhead provides the crack where a new break will most likely form, particularly if CO2 is injected too fast and too much pressure builds up deep underground.
Most wellheads, though, seem to hold up. For example, oil wells drilled in 1944 near Cranfield, Miss., are not reacting to extra pressure from injected CO2, according to geologist Susan Hovorka of the University of Texas at Austin, who is running the test. "I'd like to congratulate the roughnecks that drilled those wells," she says, "because they seem to be holding pressure just fine."
At a demonstration project in Japan, even a magnitude 6.8 earthquake didn't shake injected CO2 loose from a deep saline aquifer; the wellheads did not so much as leak. Big earthquakes might cause leakage, but in many cases, they will not, Friedmann says.
The U.S. Environmental Protection Agency (EPA), under the terms of the Safe Drinking Water Act of 1974, is currently crafting new measures to regulate wells for CO2 injection—final rules are set to be adopted by 2011 to protect groundwater sources from CO2 in the subsurface, according to Stephen Heare, director of the EPA's drinking water protection division. "There are 800,000 wells out there injecting almost everything imaginable," Heare says. "We think the technology is there and we can move ahead safely."
Nevertheless, "the first CCS project that is done badly is the last CCS project that will be done," warns Mark Brownstein, New York-based managing director of business partnerships in the climate and air program at the Environmental Defense Fund. "In this respect, it is very similar to nuclear power."
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14 Comments
Add Comment>>The U.S. oil business has been using carbon dioxide to pump extra oil out of reservoirs for 36 years--and permanently storing some CO2 in the process<<
Reply | Report Abuse | Link to thisI can't believe you really said that...
The CO2 is NOT stored permanently: it is stored only until the rock formation is punctured: either by an earthquake or by some innocent or not-so-innocent drilling a hole in it...
Then the CO2, which will be in the form of gas, since it is above it's triple point in the "repository", although it may have been liquid when pumped down, will come bubbling out...
Yes, it "co2" may escape into the air, a colorless oderless gas, that plants love ,even at six times the present levels. We must quit drinking Rv Jones' community activists cool aid.
Reply | Report Abuse | Link to thisI have been following the companies involved in enhanced oil recovery for several years now. Denbury Resources (DNR) is the poster child for doing things the right way, but keep your eyes on Enhanced Oil Resources (EORIF), they own the St. Johns Dome helium and CO2 field in Arizona and New Mexico. It is the largest natural CO2 dome in the United States and has the potential to unlock 100s of millions of barrels of oil in the Permian Basin.
Reply | Report Abuse | Link to thisfishman says: >>Yes, it "co2" may escape into the air, a colorless oderless gas, that plants love ,even at six times the present levels. We must quit drinking Rv Jones' community activists cool aid.<<
Reply | Report Abuse | Link to thisI would like to suggest that fishman try breathing the stuff. It doesn't support life, any more than carbon monoxide does. And yes, SOME plants can exist in higher concentrations of CO2: note that the operative word is EXIST, not THRIVE.
And finally: fishman seems to be denying anthropogenic global warming: I would suggest that he actually READ SciAm: Antarctica is in an "interesting" state right now: trembling on the verge of instability.
I do wish that some of the people in the SciAm discussions would learn some basic chemistry and physics, and not sound like Republicans.
The main problem with CCS is that it will take decades to implement on new plant and do nothing for most existing technology. Furthermore, it will do nothing for excess CO2 actually in the atmosphere. So better to invest in biochar technology, which can actually clean up the air....
Reply | Report Abuse | Link to thisSee www.EPRIDA.com for full details.
comment:eoleen- you need to check out the research into the first lifeforms on the earth- and there have been many studies done on plants in high levels of co2, if you check it out, you would find that the plants can have 30 to 40 percent growth increase.
Reply | Report Abuse | Link to thisIf you are falling for the GW scam, you must check the mean temp loss, from the high, the ocean temp has lost its' grain and sunk 1.2 c in the last two years- gee let us not let the hard evidence get in the way.
Last, so, if I don't fall for unproven info I am a Republican.
If you are so smart, read about the search for "Leakey man" and find how science can make the worng conclusions.
Fishman, all I can say is that your understanding of physics, chemistry, etc., etc., etc., is on a par with your spelling.
Reply | Report Abuse | Link to thisAnd just what do you mean about searching for "Leakey man"? Are you perchance referring to Louis Leakey the paleoanthropologist>\?
As far as EPIDRA goes, I think that we are in for another dot.com bubble, or maybe another Bernie Madoff...
The most important point is - where does the oil company get the CO2 from?
Reply | Report Abuse | Link to thisIf it is extracted from air, then yes, it is a step towards reducing greenhouse emissions per barrel of oil.
Most likely, however, is that they purchase liquid CO2 from a gas supply company, who generate it by burning carbon or by dissociating Calcium carbonate.
Good point, Runesmith. Who knows? I'm pretty damn sure they don't get it from the air: at 386 ppm it's damn thin on the ground: they'd have to run a lot of atmosphere through a liquefaction and fractional distillation process to get the amounts of CO2 they are talking about...
Reply | Report Abuse | Link to thisI would like to see an energy budget for these "Carbon-capture-and-Entombment" proposals. My admittedly very crude estimates result in, at best, a wash: it takes as much energy to dispose of the CO2 as you generate by burning the coal, oil, etc. which produces it. Being more pessimistic with my estimates of efficiencies results in net LOSS of energy...
And even if it is 50% efficient, over all: it takes only 50 BTU's to dispose of the CO2 from generating 100BTU's, then is is economically feasible? I somehow don't think so...
I do wish that an understanding of physics and chemistry was a pre-requisite for public office...
eoleen- too bad you didn't understand the improper conclusions about "Leakey Man", if you make assumptions from a few spelling errors then Edison, Ford, Einstein and Firestone would not meet your standards for relative intelligence.
Reply | Report Abuse | Link to thisAt least I am keeping good company.
If you can't get "flawed conclusions in science" then bantering with you is a waste of time.
CO2 injection for enhanced oil recovery has been supplied by natural gas production that include a significant and natural proportion of CO2, including Bravo and McElmo domes in the Rocky Mountain region and Jackson Dome in Mississippi. This process has historically reduced CO2 emmissions in that the CO2, having been separated from the valuable methane, would have otherwise been vented. No disassociation of calcium carbonate required runesmith... It is correct that industrial sources of CO2 are quite dilute and so CO2 must be "captured" at considerable cost - $20+ per tonne. It could well be that clean coal will cost as much as solar and fuel cels. I beleive that nano tech will improve efficiencies such that solar and thermal generators actually work. But in the end, the free market is in the best position to pick the winners and loosers. Biofuels have proven yet again that the government can't. I am skeptical about the government's ability to set up a market for carbon without corruption, but it is a better option than direct subsidy of alternative energy winners. O yea, and I'm a Republican.
Reply | Report Abuse | Link to thisEoleen, I know, I know! At present most CO2 comes from gas wells, often helium wells in Colorado. So, from the earth and back to the earth equals no net effect. In fact a lot is lost when the CO2 saturated oil is produced, unless they cleaned that up since I was at an "enhanced field". The big exception mentioned in the article is the Weyburn field project, which uses CO2 from the syngas project. Of course the syngas is produced from coal so there is still a big net increase in CO2 when that gas is burned, but less than if the coal were burned. If the well is properly sealed, there isn't much chance of a return of the CO2 in any time relevant to the human species. Recall that gas fields trap methane, a less viscous gas, for tens of millions of years. Not to say that problems don't or won't happen. A big blowout on a windless night could kill many people living in a valley near the well, since CO2 is denser than air. We have been lucky so far and the technology improvements should improve our luck.
Reply | Report Abuse | Link to thisI would agree that it is unfortunate that right wing radical no-nothings like Fishman have to spew their denialist nonsense on forums like this, but it is a free country, even for idiots. By the way, I'm a geophysicist working in the petroleum business and I understand that the science is very much settled about global warming, whether it is in my economic interest or not. And the oceans aren't cooling off: http://www.osdpd.noaa.gov/data/sst/anomaly/2009/anomnight.11.2.2009.gif
Thx, eco-steve
Reply | Report Abuse | Link to thisLook like promising, I like it.
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