The DoE is trying to convert some of the millions of abandoned oil and gas wells for geothermal energy.

[freebeard]

Kilometers-deep bore holes are above my pay grade. I was thinking of the backyard DIY. Maybe black iron pipe?

[freebeard]

Anton Petrov did Quaise today:

Creating Deepest Hole on Earth For Geothermal Energy Revolution

54,808 views at the time of posting.

[Piotrsko]

Originally Posted by aerohead

The steam provided to the turbine must be exceptionally clean and dry, in order to not erode the super-expensive turbine blades.
Seems like it would have to be in its own closed-loop, as in any thermal-powered power plant, traveling to and from the heat source via a heat-exchanger, or the hot well working fluid traveling from the bore-hole to and from the heat-exchanger.
Carson City, Nevada sits atop a super-volcano caldera, and they tap this as a source of 'shallow' heat.
Seems like these 'shallow', thin lithosphere locations, close to the magma, would be the 1st-choice locations. They'd require the minimum drilling and completion costs, plus get into service the quickest, all else being equal.

Really: Carson City?? Ormat is at the southish end of Washoe county about 15 miles from Carson and I believe there are no commercial thermal operations in Carson except for home heating in a limited way.

https://thermalzones.com/usa/nevada/...city-nv510/map

The other super volcano is under Mono lake/and or Bishop Mammouth mountain which is a bit farther south. Same distance north west is mt Lassen.

Bunches of thermal east and around Elko. If I want, a 500 ft deep well gives me 150f water as there are numerous geothermal houses in my neighborhood but the city won't issue a permit..

400 500 & 800 series of stainless pipe, good to 600f, inconel and hastelloy good to 1800-2200f as used in jet engines aft sections

[JSH]

Seems that nobody actually read the article. The DOE isn't looking to get steam to turn a turbine and make power. They are pumping 150F hot water out of an old well and using it to directly heat two schools in the winter. In the summer they use that same hot water to run an absorption heat pump for cooling. The goal is 1 MW of power per year from the test project.

Another option is to use the water that comes up with the oil and use it to power rankine cycle engines to produce modest amounts of power for the oil field before injecting it back into the ground.


Xist - having just driven cross-country on I-70; There are plenty of old wells next to one another. It was interesting crossing Kansas to see new energy production (large wind farms) sited next to oil energy production (old oil fields with pumpjacks barely pumping or sitting idle)

[freebeard]

Well look at the way it was presented:

I think that it is an interesting idea, but I didn't think the common knowledge and politics in the first couple paragraphs were relevant, nor did I see any details worth sharing,

I'd mentioned Quaise elsewhere, is why I went off on a tangent. Then there was confusion about 150° water vs 500° supercritical steam.

The ideal would be old wells in or near a coal-fired power plant, for the infrastructure.

[rmay635703]

Originally Posted by aerohead

We should look at 'what works' ( Matt Damon ).
I can't envision vertical, multi-mile length copper pipe. I don't think it has the tensile strength to survive.
Pex, as with Poly Vinyl Chloride couldn't hold up to the heat.

If you have ever used a hose to empty a gas tank…,

If you pull it up and maintain a seal it can be easily pumped up and back down to the same level, you could then directly use the heat differential between it and ambient using a PEG or similar, no turbines required

Although I can’t find the article there are new designs for aerospace that can work at near 100% efficiency and extremely high temperatures.

https://www.science.org/content/arti...at-electricity

[freebeard]

Xist -- About permalink #4, I found this on Hacker News.

www.lamag.com/citythinkblog: 4 Oil Wells Hidden in Plain Sight in L.A.



They cluster 40-50 wells at one location. Presumably with slant drilling.

The only problem is that they are still productive.

[Xist]

Apparently when oil companies frack they pump the wastewater into the ground, which is causing earthquakes in Texas!

[freebeard]

That's what fracking is. IIRC there was a case of geothermal injection casing an earthquake but I'm not going back to find it.

[freebeard]

Here's a good one:

Carbon Dioxide Removal from our oceans. Can we achieve 20 BILLION tonnes per year?

It makes sense to remove CO2 from the oceans and let them rob it from the atmosphere. The oceans have 150x the atmosphere and it can be recovered in a single step.

He concludes with the sensible suggestion that it not be taken for an excuse for 'business as usual'.

But.... they're suggesting scraping the limestone off a steel mesh drum and dropping it back in the ocean. If their 'flow reactor' were a build chamber filled with steel mesh armatures they could produce building components ....or ashtrays, or anything that could be made out of seashell material.

Done right, it could have the microscale structure of abalone.