Adaptive reuse of abandoned oil and gas wells

[ACtrafficengr]

Pardon me if this has already been discussed, but I think this is interesting. In addition to providing cooling and heating, it could employ former roughnecks, and recover some value from what are basically stranded assets. On the other hand, I'm not sure it has potential to be a major player in the overall energy market.

They are talking about geothermal heat pumps and geothermal electrical generation. At the depths they are talking about, the temperature is about 150˚F. This would be great for heating, if there are buildings near by to use the heat. There are urban oil wells in Los Angeles, Luling, Texas, and probably some other cities. Geothermal electricity could be transmitted longer distances, but it's reportedly a lot less efficient.

This is well out of my area, so I'd be interested in hearing from those that know more about it.


Geothermal from old oil wells

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http://xkcd.com/319/

 

[TugboatEng]

The issue with 150°F energy is that there simply isn't enough potential to make it's recovery efficient. Perhaps you could run a sterling engine on it but is that worth having to deal with the arsenic and hydrogen sulfide being brought to the surface at the same time?

I have had the fortune of touring a large geothermal power plant here in California. Their wells are all running dry after short time in operation. Wastewater injection is being used to stimulate dying wells but it's a crapshoot as sometimes the injection quenches the well and further reduces capacity.

 

Could work, but housing doesn't tend to be located near oil wells, new or old.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[ACtrafficengr]

Are the well shafts large enough to insert closed-loop fluid conduits, rather than extracting existing groundwater plus contaminants?

My glass has a v/c ratio of 0.5

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[TugboatEng]

At 150°F I don't think you're going to offset the pumping losses with energy recovery. The energy available in sensible heat is low and at 150°F it won't be able to be flashed to steam.

Keep in mind that the well bore is small. There just isn't much surface area for heat transfer to occur. Geothermal works because the the volume surrounding the well bore is like a sponge and is permeable to steam. There is a great deal of heating available in the "sponge" (sorry, I don't know geological terminology) and there is pressure to push the steam in to the well bore. Injecting water into a well bore doesn't expose the water to much of the "sponge" before the water flows back out of the well bore.

 

[JoshPlumSE]

I'm with Tug on this one. I think the temperatures difference is not great enough to deal with the other draw backs / risks. Heat recover is technically possible for locations nearby. But, when you factor in the danger of toxic gas or such, I don't see how it would be feasible.

Now, geothermal power generation is a wonderful and clean method of energy generation (just ask Iceland). But, my impression is that this is really only feasibly for locations where there is some volcanic behavior and you're generating lots of steam.

 

[Compositepro]

The word is permeability, and fracking technology has taken care of that problem.

Geothermal power is not extracted from 150F wells. More like 300F. Old shallow wells would not be good candidates.

 

[TugboatEng]

When I was at the geo powerplant they had a conveyor loading sulfur into a 40ft dump trailer. The operators weren't very enthusiastic about where it was going. They said it was going to China, probably to be burned in a power plant. Mind you, this was way back in 2005.

 

[IRstuff]

150°F is basically about 10°F hotter than the setting on my water heater; whatever energy I might be able to pull from that is going to be fairly non-energetic

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[ACtrafficengr]

So, if there happened to be some heated facilities near to an old well, you could use it for heat.

Electric generation would probably not be more than a niche market. If you had some small devices to power, couldn't get a utility hookup, and solar or wind weren't viable for some reason, it might work. Would there be enough buyers to be worth it?

My glass has a v/c ratio of 0.5

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[Pud]

Here in UK heat extraction from old flooded mine workings in going ahead in several places.

https://www.gov.uk/government/colle...contained,Council-owned buildings in Felling.

Politicians like to panic, they need activity. It is their substitute for achievement.

 

[EdStainless]

Old shallow wells make a good source for heat pumps to use, but not so much power gen.
It really takes 200C to drive much, and there is a plant in Mexico that has 350C inlet.
You can build an ORC (organic Rankine cycle) plant with 120-150C input if all you need is kW power levels.
It is ironic that the low temp ORC plants have no emissions.
The hotter plants actually flash the fluid that comes up the wells and then drives turbines with the steam.
In doing this they release CO2 that is in the well fluid, it isn't much though.

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