Thursday, June 24, 2010

Natural Gas and a Waltz

Reading my fellow-bloggers posts recently, I was struck by the fact that I spend almost no time talking about fossil fuels. Jason Ribeiro at Pro-Nuclear Democrats took on natural gas, and Nuclear Fissionary compared coal to nuclear. I did no comparisons.

I'm changing that, but not in a depressing way. We'll have music and maybe dancing while we discuss fossil fuels. Even though the Sierra Club has come out for natural gas, and the CLF has invested heavily in natural gas, well, natural gas has its problems.

So I'm going to steal a video clip about natural gas from a post by blogger Jason Ribeiro at Pro Nuclear Democrats. (Jason, imitation is the sincerest form of flattery, as well as the most annoying.)

Fracking Shale

Most natural gas is found in sandstone formations, but the big excitement now is finding gas in shale formations. Fracking shale for natural gas means injecting a nasty mix of chemical underground to open up paths for the gas to travel to the gas wells. These chemicals can contaminate aquifers that are used for drinking water. The gas companies will not reveal which chemicals are being injected. A recent Scientific American article explores some of the problems. The City of New York has set a moratorium against fracking beneath its watershed lands.

Is fracking shale really a problem? In many cases, I think that concerns about energy technologies are overblown. There is no free lunch, no form of energy without its drawbacks. Furthermore, people have stimulated ordinary (sandstone-based) gas wells with injection for a long time. Oil and gas wells have been stimulated with hydraulic fracturing since 1947. The technology should be well known and (hopefully) controllable. Perhaps the outcry against fracking the Marcellus shale is another environmental-scare-of-the-month story?

I don't think so. The Marcellus shale is a shale, not a sandstone. Sandstones are the usual reservoir for oil and gas reserves. Fracking shale is not the same thing as stimulating a traditional gas well.

My Friend Shale

In my opinion, shale is our friend. Sandstones have high porosity and high permeability. Shale can have high porosity (holes) but has low permeability (few connecting holes). Therefore, shale is the barrier between different types of water-containing layers. For example, a groundwater aquifer may contain agricultural run-off and be unsuitable for drinking water. However, that shallow aquifer is usually separated by a layer of shale from a deeper drinking-water aquifer. The impervious rock that defines an artesian aquifer is usually shale.

If you fracture sandstone, you can hope for a layer of shale to protect local aquifers from the fracturing chemicals. If you fracture shale, on the other hand, you can expect no protection of aquifers. As a matter of fact, you are destroying that protection by making the impermeable shale permeable.To fracture shale, you have to add permeability to a rock that basically doesn't have any. It's harder than stimulating sandstone. You have to try harder, blast harder, use more chemicals. All that stuff.

All in all, fracking shale is dangerous for aquifers. It's a good idea to have a moratorium on fracking the Marcellus shale.

Singing and Dancing

When anti-VY activists do their song and dance how we don't need VY, they often say that we have recently found lots of local natural gas.

They are talking about shale. They are talking about possibly destroying our aquifers.

It's kind of like the Tom Lehrer song about Wernher Von Braun. In this song, Werner explains that the consequences of his rockets are "not my department."

Once Vermont Yankee is closed, who cares where the energy comes from? From the point of view of an anti-VY activist: "It's not my department." Using Marcellus shale to substitute for VY will be a problem for everyone in Vermont, New Hampshire, and Massachusetts. It won't be a problem for the anti-VY activists. It's not their department.


Jason Ribeiro said...

Thanks Meredith, you're information about shale vs sandstone fracturing is very interesting. People need to learn about where our energy comes from so I encourage the spread and copy of good stories.

Steve Aplin said...

Beautiful analogy, Meredith! Once the [fracking] rockets are up, who cares where they come down -- even if it's into a local aquifer. The anti-nuke (pro-gas) crowd should consider that long and hard.

Tom Lehrer was a genius. Somebody more talented than me should do a Renewables version of the Vatican Rag -- the "Renewables Rag."

Meredith Angwin said...

Jason and Steve.

Thank you. I was in geothermal and I was familiar with stimulating oil and gas wells. It was done all the time, and it didn't seem to be a big deal. Steam injection was a bigger deal, because they just burned whatever they wanted to burn (poor-quality oil) to raise steam, and they made a lot of unregulated sooty pollution.

Anyhow, I resolved to figure out if this Fracking issue was a real problem or a scare-of-the-week story.

I realized that they key point is that they are fracturing SHALE. That makes such a huge difference. I can't begin to emphasize it enough.

Thank you for your comments on my post.

Mike said...

The gas producing shale layers sits several thousands of feet below drinking water aquifers. In between these layers are thousands of feet of impermeable rock, that’s what has kept the gas down there for millions of years in the first place. The only mode of contamination from fracking comes from damage to a well head casing … and that has been document in one case out of 100,000 wells.

You have to understand that the hear and soul of the hardcore environmental activist is an end to industrial society. The piss and moan about VY saying that there is all this clean gas to supplant it but I guarantee you the moment VY goes off line and someone tries to build a gas fired plant, the very same people will oppose that and the necessary gas wells to fuel it.

With your advocacy of nuclear power as well as your understanding of the motivations and technical illiteracy of its opponents, I would have hoped that you would be a shade more skeptical of Gasland and the plethora of anti-shale gas activists.

Meredith Angwin said...


Thank you for your comment. I was very skeptical, and I thought this might be the "environmental scare story of the week." Especially since in geothermal and oil and gas wells (which share similar technologies) "stimulating wells" by fracturing was truly no big deal.

Still, I am more concerned with fracking to open paths in shales (which have almost no natural permeability) than with opening sandstones (increasing existing permeability). However, your point is well taken, and I do not mean to buy into a scare story of the week.

My current opinion is that the problems of fracking shale are NOT just a scare story, but I am open to changing my mind. For example, in a longer snippet from Gasland, some of the affected people say that their neighbors hate them, because the neighbors hope to make money from gas leases. Clearly, if the gas-to-harm correlation was one-to-one (lease gas on property EQUALS get really really sick) the neighbors wouldn't be eager to lease.

I do not think it is just a scare story, but I am capable of changing my opinion later. You are right. If VY closes down, people will fight the natural gas plants. The same people, probably.