November 21, 2005 11:47 AM PST

To curb greenhouse gases, put them underground

DOHA, Qatar--Tony Espie, storage technology manager for BP Exploration, believes one of the primary tools for solving global warming lies beneath our feet.

Storing carbon dioxide in underground caves that once held oil and gas is shaping up to be one of the more promising techniques for reducing the amount of greenhouse gases that get pumped into the atmosphere, he said during a presentation at the International Technology Petroleum Conference taking place here this week.

"Gas fields have the attraction of natural seals. They have held gasses for millions of years," Espie said. "Storage in geological formations is one of the cheapest options."

Trials for the concept are already under way in Algeria and Canada. Commercial development could begin within the next five years. Ideally, storage facilities would keep carbon dioxide underground for at least 1,000 years and hopefully 10,000 or more.

The carbon problem comes as a direct result of fuel consumption. Since the industrial revolution, the amount of carbon dioxide has increased dramatically, paralleling a spike in global temperatures, Espie said. In the 20th Century, average temperatures rose about 0.6 degrees Celsius. While that doesn't sound like a lot, scientists say that a rise of 2 degrees Celsius will cause significant disruptions to water supplies and agriculture.

Currently, about 25 billion tons of carbon dioxide are injected into the atmosphere each year, of which about 7 billion tons make it into the atmosphere. That's close to the maximum, Espie said.

Fossil fuel demand, however, is rising rapidly too. By 2050, the emissions figure will double if preventative action isn't taken, according to Espie.

"By 2050, storage could provide about half of what is needed," he said. The other half could be accomplished through storing it in underground deposits of saline water.

Carbon storage involves a two-step process. First, carbon should be sequestered during the combustion process, either through industrial scrubbers or technologies like oxyfuels. With oxyfuels, fuel is ignited in a pure oxygen environment, rather than in air, which contains nitrogen. The reaction leads to wet carbon dioxide.

The carbon dioxide can then be compressed and stored. In some nations, the cost could be subsidized under an emissions credit plan. Carbon dioxide storage could also be used to extract more oil out of depleted fields; by pumping in C02, the added pressure would force out remaining oil that's been otherwise difficult to extract.

Significant risks, of course, exist. A rupture in an underground cavern can lead to a bubble of carbon dioxide. If people were to walk through the bubble, they would probably die of suffocation, Espie said. That problem, however, is fairly localized. Sensors placed in the area can provide some warning.

A large earthquake could also create a fault that would let carbon dioxide escape over a broader area. "In that case, you'd probably have to take the CO2 out," he said.

If the gas escaped into a water supply, the result would be carbonated water, but health officials would be concerned about any deleterious chemical reactions.

Still, the geochemical and geophysical data show that the concept has promise. In some cases, carbon dioxide storage could prove beneficial by redistributing minerals and making the cavern stronger, Espie said.

The biggest roadblock ultimately could be public acceptance of the idea. To that end, he suggested the industry share the data of these projects.

Administrative bodies also need to be created. Companies don't last 1,000 years, he said.


Join the conversation!
Add your comment
CO2 Sequestration
The 'Oxyfuels' aspect seems a very attactive
Combustion with Pure Oxygen significantly increases of fuel efficiency, and eliminates formation of NitrousOxide.

. . . carbon should be sequestered during the combustion process, either through industrial scrubbers . . .
What is the purity of the Carbon extracted via 'Industrail Scrubbers'?
What is the cost/efficiency (quantity of Carbon removed) via 'Industrial Scrubbers'?

Our 'Air Quality' is not improving!

Compare The cost of:
'Doing Nothing'
To the 'probable' catastrophic results of doing nothing; especially if human activity is precipitating the apparent alteration of Our Global Climate!

Roy Stewart
Phoenix AZ
Posted by Roy Stewart (4 comments )
Reply Link Flag
No caves, no caverns
"Storing carbon dioxide in underground caves that once held oil and gas is shaping up to be one of the more promising technique ..."

Wrong, there are no caves or caverns or other large void spaces underground. This is a common misconception and CNET should not contribute to its spread.

Underground oil and gas are trapped in relatively porous rock formations, such as sandstone, capped by impermeable rock. When tapped by a well, these materials -- under the weight of the earth -- are forced into the well and up to the surface, but they leave behind the porous rock, as well as residual gas and oil. Carbon dioxide pumped back into these formation would presumably also be trapped by the impermeable rock.
Posted by thalen (7 comments )
Reply Link Flag
Probably Another Oil Company Scam
My favorite part of the article was that very short line in the middle
saying that this technology will also pump out more oil. I wonder
why this BP scientist was studying this "environmental" project?
Sounds like a great way for them to get more oil and silence
critiques. Isn't there a big problem with the fact that if one of
these things break, a lot of things are going to die... possibly
Posted by flopster325 (2 comments )
Reply Link Flag
Trees need carbon dioxide
Studies have shown that trees thrive on a carbon dioxide enriched environment. This means they produce more oxygen for people and other animals.
Posted by dshenry (1 comment )
Reply Link Flag
Trees need nature's balanced percentage of CO2... not a bunch of hot air.
Trees thrive best in a balanced environment, including a balanced atmosphere... a relatively undisturbed balance they have enjoyed for millions of years... until, that is, the invention of the internal combustion engine. Just one century into the industrial age, the balance is being tilted to produce known and certainly unknown harmful environmental effects.

Rationalization of problems doesn't mean they go away nor does sweeping them under the rug or in this case, hiding them (temporarily) underground.

"Adults who continue to live with a childlike "out of sight - out of mind" mentality are generally considered the latter." Duane Short - August 12, 2006

Given the thoughtfulness of our society I am not surprised that the public (and even scientists) are accepting the fossil fuel industry's claims at face value.

For reference:
These processes acting sequentially and simultaneously appear to have produced the delicate balance of 78% nitrogen (N2) and 21% oxygen (O2) we observe today.

source: <a class="jive-link-external" href="" target="_newWindow"></a>


The atmosphere is comprised of gases which are considered to be permanent (gases which remain essentially constant by percent) and gases considered to be variable (gases which have changing concentrations over a finite period of time).

PERMANENT gases in the atmosphere by percent are:

Nitrogen 78.1%
Oxygen 20.9%

(Note that these two permanent gases together comprise 99% of the atmosphere)

Other permanent gases:

Argon 0.9%
Neon 0.002%
Helium 0.0005%
Krypton 0.0001%
Hydrogen 0.00005%

VARIABLE gases in the atmosphere and typical percentage values are:

Water vapor 0 to 4%
Carbon Dioxide 0.035%
Methane 0.0002%
Ozone 0.000004%

So you see, there is little margin for error in the amount of CO2 we anthropogenically produce and release into the atmosphere.

Duane Short
Posted by CO2 Bad (2 comments )
Link Flag
This is lunacy
So THIS is acceptable?

&gt; Significant risks, of course, exist. A
&gt;rupture in an underground cavern can lead
&gt;to a bubble of carbon dioxide. If people were
&gt;to walk through the bubble, they would probably
&gt;die of suffocation, Espie said. That problem,
&gt;however, is fairly localized.

Great, "fairly localized" meaning if you're in a neighborhood where this is forced on you, your SOL.
Posted by R. U. Sirius (745 comments )
Reply Link Flag
I was wondering when they were going to get around to this.
Personally I think that CO2 sequestration is the only intelligent option we have. Most oil deposits are significantly below ground and as pointed out earlier (in another comment) they are basically pourous rock with an impermiable rock covering. Nature is good at packing these gases away. In fact there are several CO2 fields in the southern central states already. (These are natural fields). As far as using the technology to recover more oil, it sure makes more sence (at least to me) then pumping our pottable water supply down the hole to bring the gas field pressure up. (SAGD- Steam Assisted Gravity Drainage) SAGD water is not expected to be seen again for 80-100,000 years.

One comment brought up trees as a way to get rid of CO2. Recent studies I have read suggest that very few trees will adapt to higher CO2 levels by absorbing more CO2. Further, for the purpose of climate change, trees are considered very short term traps for CO2. Wood burns or decomposes releasing the CO2 back into the atmosphere in short order.

Well thats my 4 cents worth (inflation)
Posted by firebate (15 comments )
Reply Link Flag
Halliburton calling?
I'm curious as to who would fund this. Would it be the oil industry, the most profitable subsidized industry in the world, or will we taxpayers hold both the 1000 year maintenance responsibility and purse strings as well? I'm guessing the latter if history is any measure.

What also seems to be missing is a realistic collection method. Any CO2 generation facility would likely be where higher concentrations of those gasses exist, but often those metropolitan areas are a great distance from the oil fields. The facilities would need to be able to trap an incredible amount of CO2 to make even a measurable dent in emissions levels. How will they be able to circulate "fresh" CO2-rich air to a facility in basin regions like LA, where a lack of currents are one of the problems to begin with?

Oxygenated fuels - that ought to work well, as long as we don't mind a fate worse than global warming. MTBE is a current additive used to oxygenate fuels to help reduce cold weather emissions, but it pollutes groundwater at extremely minute quantities, affecting both taste and odor, as well as being a known carcinogen. Pure oxygen is likely too dangerous to be widely available for public use (smoking next to the O2 tank - think it won't happen?), and fuels that generate their own oxygen are extremely toxic.

I'm not hoping for a miracle cure to our energy problems, free energy, or a magic wand for pollution, but there has got to be a better way to spend research money than this.
Posted by Titos 2 Cents (18 comments )
Reply Link Flag
Hideously stupid idea
Anyone recall the lake in Africa that "inverted" and released a huge amount of carbon dioxide a few years ago? Hundreds of people died and thousands of animals. I saw recently that lake is at risk of doing it again and how plans were being made to release the carbon dioxide from that lake in a controlled fashion to prevent another catastrophe.

Now imagine creating hundreds of new places where a catastrophic release of carbon dioxide were possible! This has got to be one of the worst ideas ever. If you want to sequester carbon dioxide then do it the way nature does by creating calcium carbonate.
Posted by aabcdefghij987654321 (1721 comments )
Reply Link Flag
Lake turnover
The gas invovled was hydrogen sulfide, not carbon dioxide. The H2S formed from rotting vegitation at the bottom of the stagnant lake. When enough pressure accumulated, a huge bubble escaped and broke the surface. The non-exsistant wind and location of the village (in a valley) combined to kill several hundred people. (H2S kills quickly -in seconds- at concentrations of less than 1000 ppm.

CO2 sequestration is a technological solution to a technological problem. Is it the only solution? Probably not. But it could help.

If any non-profit idealists out there have any other ideas, bring them forth, don't just sit there and whine.

BTW, the oil companies "huge" profits amount to about 10% over their costs.
Posted by Jimm1 (11 comments )
Link Flag
Technical BS
1. It will probably take as much fuel to collect the CO2 as is being
burned in the first place.

2. Oil companies would love to have the CO2 to pressurize their
fields and to enhance oil recovery. They win three ways - sell the
oil, store the CO2, and recover more oil.

3. The whole idea is just idiotic.
Posted by Earl Benser (4310 comments )
Reply Link Flag
How about reducing CO2 emissions, drastically increasing fuel efficiency, and investing in renewable energy? Losing our addiction to oil wouldn't hurt. This seems like it will just be used as an excuse to harvest more oil while really doing nothing for the problem.
I guess the Bush administration doesn't help, of course since they have ties to the oil industry they refuse to do anything that would decrease the amount of oil consumed. Typical corruption.
Posted by jdbwar07 (150 comments )
Link Flag
Just put the CO2 back into the air where it came from
Just put the co2 back into the air where it came from in the first place. It will have the effect of increasing crop yields and help to prevent starvation in the third world.
Posted by lingsun (482 comments )
Reply Link Flag
It's already in the air....
... too damn much of it. And the vegetation isn't using it fast
enough to create cellulose. Besides, it's hard to increase crop yields
and prevent starvation when the air temperature starts going over
120 degrees.

We need better ideas than "just put the CO2 back in the air where it
came from". This one approaches stupid.
Posted by Earl Benser (4310 comments )
Link Flag
It's the carbon that matters, not the dioxide part
The earth has a solution that works already:
Plants sequester the carbon in their sugars and cellulose fiber and release oxygen back into the atmosphere. As long as we burn cellulose thus formed, the amount of greenhouse gases stays fixed and in balance. Natural recycling. What burning oil and coal does is to add more carbon to the air that has to be turned back into cellulose. And that new added carbon has to be turned back (or buried as someone is proposing) ton for ton and barrel for barrel in order to maintain the balance. The obvious and better solution is to burn cellulose directly or ferment it into alcohols. Leave the coal and oil for plastics.
Posted by InterestedVoter (2 comments )
Reply Link Flag
The obvious and better solution....
.... just doesn't work. The annual production of cellulose (and
sugars) across the earth is nowhere near the amount needed to
replace coal and oil as fuels. We passed that possible balancing
point sometime around the Dark Ages. Just consider where all the
trees in Europe and America went - mostly into stoves and
Posted by Earl Benser (4310 comments )
Link Flag
Destructionist mentality
When are people going to wake up and understand we don't have to destroy the enviroment in order to live in harmony with it and use it. More of the same.

Burn eco-friendly fuels only. And modify the rest.

Also, fuel cell tech is promising. Storage is not a solution, it will just cause more environmental damage and is anti-recycling.

How about just burning something that's eco-friendly. Pretty simple eh???
Posted by Blito (436 comments )
Reply Link Flag
Just what exactly, ....
.. is 'eco-friendly'???? Other that hydrogen, any fuel is a
hydrocarbon and is definitely not ;eco-friendly'. And fuel cells are
no solution, they still use fuels.

Not so simple after all.
Posted by Earl Benser (4310 comments )
Link Flag
Real inovation
<a class="jive-link-external" href="" target="_newWindow"></a>
Posted by 208774626618253979477959487856 (176 comments )
Reply Link Flag
Analysis of the Obvious
CO2 is a gas, as in... not a liquid. How long can even the least porous stone contain a given volume gas? If pressurized? How long can a tightly sealed soda bottle contain CO2? What happens if the seal or bottle breaks or cracks?

What mere mortal can guarantee any given spot on earth will not crack or break tomorrow or anytime?

Even if earthquakes would cease to occur (and they won't, of course) CO2 gas will not be contained by earth's highly fragmented crust or the oceans' depths.

Concerning CO2 sequestration, this overwhelmingly industry owned and therefore industry biased scientific community is silent on the basic matter of gas laws and gas physics. Gases will eventually leak from the best manmade containers. This is why gases are considered a "volatile" state of matter relative to liquids and solids. To further confound the empty promise of CO2 sequestration is the fact that CO2 is made about 20 times more soluble when combined with water or even moisture. Wet or dry, rocks and minerals cannot reliably contain CO2 gas. Rocks and minerals may break down and absorb some of CO2 but under natural conditions this process can take millennia and in the meantime the CO2 gas leaks (undetectably) from countless unidentifiable microsource points.

This is the industry/political scheme behind the CO2 sequestration dream! Remove a single source point (such as a smoke stack) from which CO2 can be accurately measured and the industry is off the hook. CO2 will leak into the atmosphere in minute amounts at any given locus but in huge, undetectable amounts over vast areas of land or water. The leakage will be spread so far and wide it will be impossible to measure.

To make this a bit more pedestrian I offer this analogy. Removing the single source point i.e., smoke stack, from which CO2 gas is analyzed and allowing, in effect, an undefinable expanse of landscape or water surface area become CO2's exhaust is the difference between having one's fart collected in a tube and evaluated (sniffed) and trying to evaluate that same fart released randomly in a cave under a 40 acre field.

In both cases the same amount of gas is eventually released to atmosphere. In the first case the gas is detectable, the latter undetectable.
It requires a very unusual mind to undertake the analysis of the obvious.
Alfred North Whitehead (1861-1947) English philosopher and mathematician.

I discuss CO2 Sequestration in more detail at my REALITICS blog:

<a class="jive-link-external" href="" target="_newWindow"></a>
Posted by CO2 Bad (2 comments )
Reply Link Flag

Join the conversation

Add your comment

The posting of advertisements, profanity, or personal attacks is prohibited. Click here to review our Terms of Use.

What's Hot



RSS Feeds

Add headlines from CNET News to your homepage or feedreader.