The problem is finding a porous medium which is sealed on all sides, so that it doesn’t leak. You need a good sealing “cap rock” over the entire upper surface, and seals on the outer perimeter – due to an anticlinal structure or sealing faults or some other mechanism. A good sealed structure is a relatively rare phenomenon. Petroleum geophysicists and geologists often find promising structures which when drilled are empty (no oil or gas) because of an “incompetant seal”, so the hydrocarbons leaked out over time.

Finding a structure which has stood the test of time is relatively rare. In all the petroleum exploration to date, people have found a total of about 0.3 trillion tonnes of available voidage which has been competantly sealed to keep the oil in place over a long period of time.

The only way of knowing whether a porous volume is competantly sealed, would be to pump fluid in and test pressures over a long period of time (to test for pressure decline due to leakage), or pump in fluids with tracers (e.g. radioactive tracers) and then drill extra holes to monitor its movement through the porous medium over time (e.g. movement towards areas of leakage).

This is a very expensive and lengthy process (e.g. monitoring wells cost $millions and tracer studies take many years to yield useful results). You can bet your last rouble that hasn’t been done for the ENORMOUS volumes the CCS are blandly talking about, namely in the order of 2300 trillion tonnes.

So far we have a PROVEN storage volume of 0.3 trillion tonnes or so, from ALL known oilfields.

You can even bet that the CCS lobby hasn’t proven up double that volume, i.e. 0.6 trillion tonnes. What about the rest???

Excuse me, but what bloody scientific literature on CCS which “proves” all this huge volume of permanent storage capacity? Please point us to a series of detailed studies somewhere, not just the vague posturings of the coal industry?

Remember, we are talking of a proposed extra 100 years at around 23 trillion tonnes/year, i.e. 2,300 tonnes of storage.

We have a bunch of geologists (usually in the pay of the coal lobby) saying that there are skads of assorted porous strata around the place.

That is NOT a proof positive that these strata are suitable, and permanently sealable, in the quantity required.

Fran:
Let the coal industry do so if they think it’s viable. So far they haven’t.

As I’ve pointed out a number of times on this thread, they are. The fossil fuel industry has contributed billions towards CCS with projects such as Coal21 and the Gorgon project.

No problem then …. let the government withdraw the subsidy if this is all that is needed.

I trust the judgement of IPCC scientists on climatology.

I wouldn’t be hanging my hat on their ability with reservoir engineering topics, which is essentially the discipline needed for studying pumping CO2 underground.

The IPCC CCS report is written by different people with different areas of expertise than the IPCC Scientific Basis report. And far more importantly, it is simply a review of the scientific literature.

Fran:

Let the coal industry do so if they think it’s viable. So far they haven’t.

As I’ve pointed out a number of times on this thread, they are. The fossil fuel industry has contributed billions towards CCS with projects such as Coal21 and the Gorgon project.

I trust the judgement of IPCC scientists on climatology.

I wouldn’t be hanging my hat on their ability with reservoir engineering topics, which is essentially the discipline needed for studying pumping CO2 underground.

That was a very aggressive spray LO. If you bothered to read more carefully, you would see that I started by saying “I would offer this, in partial answer”. To accuse me of trying to be “clever” because I give a reasoned argument says something about you.

What I was trying to show, was that the cavalier assertions, by the coal lobby and the various pollies, about “clean coal” and CCS/geosequestration being the way forward were grossly overstated.

“Your line seems to be – because CCS can’t solve the problem on its own, it can’t make a contribution. Nice logic.”

I was showing that pumping CO2 into old oilfields would probably not even meet 1% of total future CO2 emissions. The discussion was offered in direct response to a challenge to David, about exactly that point.

Of course you can argue that not all emissions would be “cleaned up” by CCS, and that there are other means. That was NOT the point. I wasn’t being “clever”, I was presenting some data which others may not have examined in enough detail to have a clear idea.

The point is that CCS is being OVERSOLD as a solution. People need to consider some real data, as a counterpoint to the coal propaganda story.

I would suggest that you realise this perfectly well LO, and have resorted to playing the person and not the issue. Very clever of you.

In the meantime we should be pushing on with the alternatives to provide an incentive for the fossil fuel industry to get on with it.

Unless one blieves that there is some prospect of CCS being commercially viable within a realistic time frame, spending any money on R&D is a waste. Let the coal industry do so if they think it’s viable. So far they haven’t.