The deepest hole we have ever dug(bbc.com)
bbc.com
The deepest hole we have ever dug
https://www.bbc.com/future/article/20190503-the-deepest-hole-we-have-ever-dug
118 comments
Well ackshually... :)
Shout out for the deepest hand dug well: https://www.mybrightonandhove.org.uk/places/utilities/woodin...
Shout out for the deepest hand dug well: https://www.mybrightonandhove.org.uk/places/utilities/woodin...
That page says the well was 1285 feet (~390 meters). So, the Mir mine (525 meters) does seem deeper.
-True, but at some point I believe it is safe to say that the Soviets started using heavy machinery - an option denied the workhouse inmates who dug the well.
(This is where the 'deepest hole dug' contest gets a whiff of 'No true Scotsman...')
On some levels I find the well more impressive than the mine, though. A 4ft diameter hole dug 1285ft deep means some 400 cubic meters of dirt was removed. By hand. That's an awful lot of blisters by anyone's standards.
(This is where the 'deepest hole dug' contest gets a whiff of 'No true Scotsman...')
On some levels I find the well more impressive than the mine, though. A 4ft diameter hole dug 1285ft deep means some 400 cubic meters of dirt was removed. By hand. That's an awful lot of blisters by anyone's standards.
Sure - I did specify well.
What criteria are you using for that? I argue any excavation counts as a hole so my first instinct is that surely the Africans hold the title with their crazy mines. They go very deep looking for gold (& diamonds from what I recall).
I doubt the borehole in the original article goes straight down. Boreholes tend to list left and right.
https://en.wikipedia.org/wiki/List_of_deepest_mines
I doubt the borehole in the original article goes straight down. Boreholes tend to list left and right.
https://en.wikipedia.org/wiki/List_of_deepest_mines
While I am no authority on the subject of holes, I'd argue that a borehole is not dug as such, hence any borehole is disqualified from the 'deepest hole dug' contest.
A mine of the crazy deep variety, then, in my book, is more of a tunnel than a hole in the strict sense - hence it, too, is disqualified.
YMMV. :)
A mine of the crazy deep variety, then, in my book, is more of a tunnel than a hole in the strict sense - hence it, too, is disqualified.
YMMV. :)
TIL there are reactionary hole digging experts.
https://www.motor1.com/news/313750/top-gear-hole-digging-con...
>"I was almost physically sick watching this last night," said Mark Stevens, chartered safety and health practitioner at The Building Safety Group. "In fact, I had to turn over straight away I couldn’t watch it anymore."
https://www.motor1.com/news/313750/top-gear-hole-digging-con...
>"I was almost physically sick watching this last night," said Mark Stevens, chartered safety and health practitioner at The Building Safety Group. "In fact, I had to turn over straight away I couldn’t watch it anymore."
I dont know the context where ‘reactionary’ is right here. Unsupported holes or trenches are crazy dangerous. Its been a while since ive done construction but 3-4’ deep is where you’ll kill someone. A partial collapse traps the victim and compresses/crushes the thorax or diaphragm. The victim will suffocate before you can extract them, even if theyre only partially buried. I ‘opt in’ to some dangerous activities. A wet 6’ hole is not one Id get in to.
This is a real example of what I was alluding to. Environmental impact isn't all polar ice caps and methane gas. An unprofessionally dug hole is a LIABILITY.
But personally attacking strangers on the internet is acceptable too.
But personally attacking strangers on the internet is acceptable too.
Apparently there are also reactionary hole digging trolls.
The deepest open pit mine is the Bingham Canyon mine, at over 1200 m. The deepest mine is TauTona in South Africa, at 3900 m.
These were done using power equipment, but they aren’t boreholes.
https://en.m.wikipedia.org/wiki/Mining
These were done using power equipment, but they aren’t boreholes.
https://en.m.wikipedia.org/wiki/Mining
The latest project to drill through the mantle...
The deep sea drilling vessel Chikyu will drill through the crust where it is the shallowest using tech which wasn't available in any of the previous attempts. Looking forward to this one starting!
https://www.jstage.jst.go.jp/article/jscejam/71/2/71_I_3/_ar...
The deep sea drilling vessel Chikyu will drill through the crust where it is the shallowest using tech which wasn't available in any of the previous attempts. Looking forward to this one starting!
https://www.jstage.jst.go.jp/article/jscejam/71/2/71_I_3/_ar...
My wife and I were talking about this borehole a few weeks ago and wondering why similar projects hadn't been undertaken with newer technology. So thanks for this, interested to see how it turns out!
Link to Lotte Geevan’s recording in the German borehole. According to the article the rumbling sound recorded was unexpected.
https://vimeo.com/80266870
https://vimeo.com/80266870
> It’s not clear exactly what you hear on Geeven’s recording. She guesses it could be something small like a data transmission that is resonating, but she can’t be sure. In a Heisenberg-ian twist, it seems possible that some of the sounds were created by the devices themselves. "Exactly knowing what it is is not important I believe," she says. "Mysteries are important. They act as engines for new thoughts and ideas."
Were are you pulling that link from? I'm interested to learn more about this - I'm also interested in the technical details about things like what dB the sound was originally. That's quite the rumble - I suspect there was quite a bit of amplification involved.
Thanks!
> "I later learned that blind people can 'hear' thunderstorms because the low frequency can be sensed in the body"
Huh. Amazing no one has commented on that.
> "I later learned that blind people can 'hear' thunderstorms because the low frequency can be sensed in the body"
Huh. Amazing no one has commented on that.
I suppose she meant deaf people? Not too surprising - a loud thunderclap rattles windows, and seems likely to have low enough tones to be sensed internally. I remember reading about deaf sports teams using low-frequency gongs in place of whistles.
Yeah, I assume deaf as well. Just funny that neither she nor wired caught it.
So it's goopy pseudoscience?
nah. this is more like art.
the Goopists are actually telling lies
the Goopists are actually telling lies
Sounds like the ocean.
So if you drill through the crust to the mantle, will magma come up the hole? Will you create a little volcano?
First off, this borehole isn't that deep. Over the continents, you'd need to drill to 40-70km to reach the mantle (sometimes even 100km). However, oceanic crust is much thinner. It is technically feasible to drill into the mantle in ocean basins, where the mantle can be only a few km below the seafloor.
Regardless, the mantle isn't molten. It's different types of rocks, but they're still rocks.
In fact, the mantle is exposed at the surface in a handful of locations (and a good chunk of the ocean floor). We have learned a lot from what's exposed at the surface, but these rocks have been significantly chemically alerted. Many of the minerals we expect to be there are unstable at near surface conditions. We'd learn a _lot_ from "fresh" mantle rocks
If you were to maintain the same temperature but drop the pressure to surface conditions, yes, deep mantle rock would melt. A hole with nothing in it going deep enough would cause a volcano (even if it didn't hit the mantle). However, not all of the mantle is hot enough for that to occur. (Again, the mantle is quite shallow beneath the oceans) We also have to keep the pressure at the bottom of the hole the same as the rock around it, so a well doesn't usually release pressure.
At any rate, in any case where you'd try to drill into the mantle, it would be impossible for a volcano to form.
All that having been said, geothermal drilling in Iceland has hit magma chambers by accident and caused a "mini volcano".
Regardless, the mantle isn't molten. It's different types of rocks, but they're still rocks.
In fact, the mantle is exposed at the surface in a handful of locations (and a good chunk of the ocean floor). We have learned a lot from what's exposed at the surface, but these rocks have been significantly chemically alerted. Many of the minerals we expect to be there are unstable at near surface conditions. We'd learn a _lot_ from "fresh" mantle rocks
If you were to maintain the same temperature but drop the pressure to surface conditions, yes, deep mantle rock would melt. A hole with nothing in it going deep enough would cause a volcano (even if it didn't hit the mantle). However, not all of the mantle is hot enough for that to occur. (Again, the mantle is quite shallow beneath the oceans) We also have to keep the pressure at the bottom of the hole the same as the rock around it, so a well doesn't usually release pressure.
At any rate, in any case where you'd try to drill into the mantle, it would be impossible for a volcano to form.
All that having been said, geothermal drilling in Iceland has hit magma chambers by accident and caused a "mini volcano".
If the hole is not wide enough, like less than 1m in diameter, then rising magma would likely cool off and seal the shaft long before the flow would reache the surface.
To be fair, it probably isn't the easy approach to drill so thin. Paradoxically (or not), the bigger ones are less of a hassle to manage as you dig deeper.
Kola Borehole diameter is just 23cm
In Indonesia they managed to create a “mud volcano”. And it has been running for years. At peak the daily flow has been 180.000m3 of mud per day.
https://en.m.wikipedia.org/wiki/Sidoarjo_mud_flow
https://en.m.wikipedia.org/wiki/Sidoarjo_mud_flow
No, and no.
The mantle is solid. You would have to drill way deep into the mantle before you encountered liquid rock.
Volcanoes don't work like that. Even if you drilled directly into a magma chamber, not much would happen. This has been done inadvertently a handful of times. https://phys.org/news/2009-06-scientists-drill-magma.html Basically volcanoes only happen when there's an extreme amount of pressure from below.
The mantle is solid. You would have to drill way deep into the mantle before you encountered liquid rock.
Volcanoes don't work like that. Even if you drilled directly into a magma chamber, not much would happen. This has been done inadvertently a handful of times. https://phys.org/news/2009-06-scientists-drill-magma.html Basically volcanoes only happen when there's an extreme amount of pressure from below.
I wonder if by the time it gets through 3KM of the relatively thin diameter borehole if it cools and hardens enough to just plug the hole with rock?
It's interesting what they said near the end... Most of the cost of a project like this isn't going to be spent on the actual drilling. Most of it will go into supporting the people who are supporting the infrastructure that enables the drill team to do the work of doing the actual drilling...
I've just finished applied for a government grant, and am starting to realize just how inefficient these projects need to be to support the people doing the work.
I've probably underestimated my own costs by a lot, and allocated too much toward the actual science I'll be doing.
I've just finished applied for a government grant, and am starting to realize just how inefficient these projects need to be to support the people doing the work.
I've probably underestimated my own costs by a lot, and allocated too much toward the actual science I'll be doing.
I was under the impression that the Kora borehole went unfinished because the drill broke due to temperature (7 miles down and you're talking hundreds of degrees C), not the breakup of the Soviet Union.
While the article says the time at which drilling was stopped was after the breakup, it gives the reason as the high temperatures encountered.
"Then it was the turn of the Kola Superdeep Borehole. Drilling was stopped in 1992, when the temperature reached 180C (356F). This was twice what was expected at that depth and drilling deeper was no longer possible."
"Then it was the turn of the Kola Superdeep Borehole. Drilling was stopped in 1992, when the temperature reached 180C (356F). This was twice what was expected at that depth and drilling deeper was no longer possible."
Sure, but the funding needed to fix and continue wasn't available as the country was collapsing
How long does it take to dig a hole to the mantle? Could we drop nuclear waste in such a hole?
I think you inspired the other front page story lol
You absolutely can, and probably should if your intent is to go really, really deep — sort of a "nuclear jackhammer". The usual concerns are a little bit shifted in that context, you're likely to explode your stuff into billions of tons of e.g. mercury (some heavier-than-earth compound) to help with extraction of dirt... good times in perspective.
Have fun with it, https://youtu.be/jZQP2oNDkAM?t=525 (he talks specifically about nukes at 8:45, but I really recommend watching the whole if you're into this kind of 'crazy-but-great' ideas. ;-)
Have fun with it, https://youtu.be/jZQP2oNDkAM?t=525 (he talks specifically about nukes at 8:45, but I really recommend watching the whole if you're into this kind of 'crazy-but-great' ideas. ;-)
I don't think heating up nuclear waste would be a good idea. Even if you don't reach the mantle, it's hundreds of degrees (celsius) down there already.
That said, putting nuclear waste deep underground and sealing the hole is probably the best best.
That said, putting nuclear waste deep underground and sealing the hole is probably the best best.
I would like to argue that waiting for partitioning and transmutation technology to mature and temporarily storing the waste until then makes more sense than putting nuclear waste into a place where we can not easily (or at all!) reach it when we can use it (and thereby actually solve the problem).
Some half-lifes are so long that just any progress over a fraction of these time-scales should be be enough to be better off to wait for the tech to be ready than to bury the material.
Some half-lifes are so long that just any progress over a fraction of these time-scales should be be enough to be better off to wait for the tech to be ready than to bury the material.
"temporarily storing the waste" is mostly what the US have done since the late 70s. https://en.wikipedia.org/wiki/Dry_cask_storage#United_States
Yucca Mountain was supposed to be the solution this temporary storage; but the budget for Yucca Mountain got suspended, so the US are back to the temporary solution.
But postponing forever in the hope of a better solution is a bad solution; because in the meantime they are in unsafe locations.
Yucca Mountain was supposed to be the solution this temporary storage; but the budget for Yucca Mountain got suspended, so the US are back to the temporary solution.
But postponing forever in the hope of a better solution is a bad solution; because in the meantime they are in unsafe locations.
Not forever, just for 200-500 years.
Transmutation technology is inherently more dangerous than simple uran fission plants due to the problem of proliferation. A lot of nasty stuff, e.g., weapon-grade Plutonium, be cooked up in these transmutation plants on demand, AFAIK.
Nuclear waste is already used to being hot in the reactor core (way hotter than the temperatures in the article), and are still hot after removal from a reactor. That's why spent rods are put into a cooling pool for a year or more after removal from a core.
Still, the idea of dumping waste that deep doesn't sound like a good one.
Still, the idea of dumping waste that deep doesn't sound like a good one.
The concept is described here
https://en.wikipedia.org/wiki/Deep_borehole_disposal
But the article sounds like a sales pitch
https://en.wikipedia.org/wiki/Deep_borehole_disposal
But the article sounds like a sales pitch
It tracks that I would not be the first person to think of this, but long term nuclear "waste" storage came to my mind immediately when I read the article.
Really dumb question, but can spent nuclear rods still be used to generate electricity (from the heat)?
Thanks
Thanks
Not a dumb question. With your parenthetical, "from the heat", no. A crude measure of "potential electrical energy" is the difference in "temperature" (really, enthalpy) between the coldest water coming in contact with the spent fuel at the bottom and hottest water/steam leaving the top (natural convection), and while each rod's heat generation is significant enough to require water cooling so it doesn't melt, it isn't enough heat in enough time to generate enough steam to move a X00 MW turbine or two.
Cool, thanks for answering!
We already have deep spaces underground for storing nuclear waste. We don’t, however, have a way to transport said waste to said holes.
What could possibly go wrong...
There's a movie about that...
https://www.imdb.com/title/tt0059065/
https://www.imdb.com/title/tt0059065/
Would drilling holes deep enough theoretically allow us to harvest thermal energy on a meaningful scale?
I wonder as well. The self-proclaimed world's largest spa, Therme Erding [1], is the result of an oil drilling attempt hitting a hot sulphur/fluoride spring instead at ~2.3km depth. Today, it powers the entire spa and close by communities with geothermal energy.
Just need a way to efficiently extract the heat from whatever depth and convert it to electricity by usual means.
[1] https://en.wikipedia.org/wiki/Therme_Erding
Just need a way to efficiently extract the heat from whatever depth and convert it to electricity by usual means.
[1] https://en.wikipedia.org/wiki/Therme_Erding
The city of Beppu and especially it's Kannawa district is pretty much this & has been this way from Ancient times:
https://en.wikipedia.org/wiki/Beppu
It's really an almost surreal experience, with encrusted hot spring water pipes and steam everywhere in the district. Sometime you even need to be careful where you step to avoid to be scolded by steam coming up from the ground, likely due to overflow from the hot water boreholes flowing to the rainwater drainage system.
And it's not just the modern hot water boreholes they use to supply the hot spring baths & other users. One time we even saw a traffic code & couple sandbags placed on a random hillside next to the road, as there was steam escaping out of it. :D
https://en.wikipedia.org/wiki/Beppu
It's really an almost surreal experience, with encrusted hot spring water pipes and steam everywhere in the district. Sometime you even need to be careful where you step to avoid to be scolded by steam coming up from the ground, likely due to overflow from the hot water boreholes flowing to the rainwater drainage system.
And it's not just the modern hot water boreholes they use to supply the hot spring baths & other users. One time we even saw a traffic code & couple sandbags placed on a random hillside next to the road, as there was steam escaping out of it. :D
I've had an idea that is probably impractical and/or impossible, but seems like it would be neat: Every house should have a super deep hole drilled in their back yard, and a small self-contained Stirling engine [1] generator lowered into it, with wires up to the house. Free electricity on a micro scale, 24/7. I'm sure the idea has been explored by people with a much better grasp of physics and engineering than myself. But we've done crazier things as humans - like covering half of the ground in asphalt and stringing wires point to point around the globe, so it doesn't seem unreasonable to me.
1. https://en.m.wikipedia.org/wiki/Stirling_engine
1. https://en.m.wikipedia.org/wiki/Stirling_engine
For any heat engine - including a stirling engine - you need a heat difference between the hot and cold side, ideally as big as possible. If you put the stirling engine at the bottom of the hot hole, the whole machine will be hot, there will be no difference in temperature and it will not run.
This also discounts stuff like the need for maintenance, that is hard to achieve at the bottom of a hot & likely very humid if not water filled borehole.
For that reason, most geothermal systems pump water down & then back up again (possibly using multiple wells) & have the heat engines at the surface, where they can be easily serviced & a good heat differential can be achieved, via air or water cooling.
This in the end, is generally an industrial operation though, not really something suitable for every single house. Still helps with maintenance, as you can provide energy for many houses & don't hat to maintain the geothermal power production equipment for each house separately.
This also discounts stuff like the need for maintenance, that is hard to achieve at the bottom of a hot & likely very humid if not water filled borehole.
For that reason, most geothermal systems pump water down & then back up again (possibly using multiple wells) & have the heat engines at the surface, where they can be easily serviced & a good heat differential can be achieved, via air or water cooling.
This in the end, is generally an industrial operation though, not really something suitable for every single house. Still helps with maintenance, as you can provide energy for many houses & don't hat to maintain the geothermal power production equipment for each house separately.
Lots of potential uses indeed — also for travel, potential megastructures, and mining beyond the wildest hopes of asteroids but it's likely to be harder to get the stuff (gold, iron, etc) down there than it is to travel millions of kilometers out there through the void and radiations...
And yes, potentially much more heat than we'd know what to do with currently.
Interesting hard sci-fi (well, basic physics principles mostly) about it by Isaac Arthur: https://youtu.be/jZQP2oNDkAM
Disclaimer: absolutely not affiliated with the man but deeply hoping that such perspectives become maintream, normal expectations. Not holding my breath, but one hacker at a time, we'll get there!
And yes, potentially much more heat than we'd know what to do with currently.
Interesting hard sci-fi (well, basic physics principles mostly) about it by Isaac Arthur: https://youtu.be/jZQP2oNDkAM
Disclaimer: absolutely not affiliated with the man but deeply hoping that such perspectives become maintream, normal expectations. Not holding my breath, but one hacker at a time, we'll get there!
Yes. The problem is that the thermal conductivity of rock isn't great, so it needs to be in a "hot" area and to have some kind of underground fracturing allowing water to spread out and heat up.
An example: https://www.cnbc.com/2018/11/06/drilling-to-start-at-the-uks...
Not quite there yet: https://www.uniteddownsgeothermal.co.uk/future-programme
In both construction time and cost it's a bit meh compared to wind/solar, its only advantage is dispatchability.
An example: https://www.cnbc.com/2018/11/06/drilling-to-start-at-the-uks...
Not quite there yet: https://www.uniteddownsgeothermal.co.uk/future-programme
In both construction time and cost it's a bit meh compared to wind/solar, its only advantage is dispatchability.
It must be easier to get environmental permits for geothermal since it has such a small footprint compared to wind and solar and won’t kill any birds, make noise, make pulsing light, etc.
Let me check Wikipedia for you: "The Earth's geothermal resources are theoretically more than adequate to supply humanity's energy needs, but only a very small fraction may be profitably exploited. Drilling and exploration for deep resources is very expensive. Forecasts for the future of geothermal power depend on assumptions about technology, energy prices, subsidies, plate boundary movement and interest rates."
https://en.wikipedia.org/wiki/Geothermal_energy
https://en.wikipedia.org/wiki/Geothermal_energy
When the article mentioned that the temperature was twice what they had expected, I wondered the exact same thing.
Could they cover the hole, pour water into it and use air pressure changes in the hole to generate electricity? There must be a way to make the hole air tight. I suspect that the rock near the bottom of the hole would already be air tight.
Also I never understood why steam engines release all the hot stream into the air? Doesn't that waste energy to let the hot steam out? Isn't it better to keep the heat trapped inside the system and generate electricity from the pressure only?
Could they cover the hole, pour water into it and use air pressure changes in the hole to generate electricity? There must be a way to make the hole air tight. I suspect that the rock near the bottom of the hole would already be air tight.
Also I never understood why steam engines release all the hot stream into the air? Doesn't that waste energy to let the hot steam out? Isn't it better to keep the heat trapped inside the system and generate electricity from the pressure only?
Isn't it better to keep the heat trapped inside the system and generate electricity from the pressure only?
Steam engines are old technology. They've been replaced by modern steam turbines, in which the steam is either cooled and recirculated, or used for other processes, or both.
Geothermal steam turbines typically use a heat exchanger and release the original steam, as geothermal steam tends to be very corrosive.
Steam engines are old technology. They've been replaced by modern steam turbines, in which the steam is either cooled and recirculated, or used for other processes, or both.
Geothermal steam turbines typically use a heat exchanger and release the original steam, as geothermal steam tends to be very corrosive.
Steam is very corrosive in general.
> Also I never understood why steam engines release all the hot stream into the air?
They don't. All practical steam engines have condensers that recover most of the water and as much of the heat as current technology and the laws of thermodynamics allow.
They don't. All practical steam engines have condensers that recover most of the water and as much of the heat as current technology and the laws of thermodynamics allow.
In steam trains it is often injected to the chimney to increase draft, forcing more air through the firebox, improving combustion. This of course uses up a massive amount of water.
For this reason most steam engines in ships and elsewhere generally did have condensers & reused the steam as feedwater, as you describe.
For this reason most steam engines in ships and elsewhere generally did have condensers & reused the steam as feedwater, as you describe.
I was thinking that if the steam had to travel up 10km to the surface, that would give it more time to cool down. Maybe in cold countries, they could use outside air temperature to cool rising steam before it reaches the top of the hole.
You don't necessarily have to go that deep to get useful amounts of heat. This varies by location of course. https://arstechnica.com/science/2019/06/report-geothermal-co...
If you want a single project at a huge scale, check out https://news.ycombinator.com/item?id=15596350
If you want a single project at a huge scale, check out https://news.ycombinator.com/item?id=15596350
Yes, but not at a viable cost. Drilling is extraordinarily expensive and complicated.
There's the added issue that rock's thermal conductivity is low, and any thermal borehole would have a limited effective lifespan as it reduced the temperature of adjacent material.
Geothermal energy is a viable and widely tapped energy resource, where it's available. In almost all such locations, it's been substantially exploited, with two notable exceptions: the African Rift Valley (mostly in Kenya), and the Yellowstone supervolcano, a national park in the US.
Substantial developments exist in California (The Geysers), Hawaii, Iceland, Japan, the Philippines, New Zeland, and quite probably elsewhere. 1GW+ plants are possible, comparable with the largest practical thermal and nuclear power plants (generally 1-4 GW, though multiple plants or reactors may be co-located). Worldwide capacity as of 2015 is about 12.5 GW.
The two principle variants are standard and enhanced geothermal. A standard plant utilises naturally-occurring steam, and is far less expensive to develop. "Enhanced geothermal" involves boreholes and often water injection to provide power generation.
I'd followed the case of one such project in Australia, the Geodynamics Habanero project. I'd first read of that in 2014 through a grossly misleading and fatuously optimistic report which struck me as both odd and curiously fact-free. Digging showed that in reality the project was running years late, at 1/50th originally-planned capacity, well over budget, and with significant technical challenges.
https://old.reddit.com/r/dredmorbius/comments/1wpa90/how_not...
Checking now, it appears the firm plugged the remaining wells in 2015 and cancelled the project.
http://www.thinkgeoenergy.com/geodynamics-plugging-wells-and...
Even had the project gone as initially scoped, the wells would have had a useful life of about 20-40 years, after which all available useful thermal energy would have been extracted, and would have to be replenished over ... long time, possibly centuries or more. There's a reason the Earth's interior remains molten -- rock is a very good insulator.
I'm not an opponent of geothermal power -- where appropriate it's highly useful, dependable, safe, and proven. In Africa it stands to make a tremendous difference, where even a small plant would make a tremendous increase in the availability (and probably reliability) of electricity. I'd encourage consideration of developing even such normally off-limits natural park resources such as Yellowstone (specifically excluded from a USGS geothermal resource survey I'd checked on some years back).
But enhanced development through borehole-based wells looks like a very long shot.
Wikipedia's treatment of geothermal is good:
https://en.wikipedia.org/wiki/Geothermal_power
There's the added issue that rock's thermal conductivity is low, and any thermal borehole would have a limited effective lifespan as it reduced the temperature of adjacent material.
Geothermal energy is a viable and widely tapped energy resource, where it's available. In almost all such locations, it's been substantially exploited, with two notable exceptions: the African Rift Valley (mostly in Kenya), and the Yellowstone supervolcano, a national park in the US.
Substantial developments exist in California (The Geysers), Hawaii, Iceland, Japan, the Philippines, New Zeland, and quite probably elsewhere. 1GW+ plants are possible, comparable with the largest practical thermal and nuclear power plants (generally 1-4 GW, though multiple plants or reactors may be co-located). Worldwide capacity as of 2015 is about 12.5 GW.
The two principle variants are standard and enhanced geothermal. A standard plant utilises naturally-occurring steam, and is far less expensive to develop. "Enhanced geothermal" involves boreholes and often water injection to provide power generation.
I'd followed the case of one such project in Australia, the Geodynamics Habanero project. I'd first read of that in 2014 through a grossly misleading and fatuously optimistic report which struck me as both odd and curiously fact-free. Digging showed that in reality the project was running years late, at 1/50th originally-planned capacity, well over budget, and with significant technical challenges.
https://old.reddit.com/r/dredmorbius/comments/1wpa90/how_not...
Checking now, it appears the firm plugged the remaining wells in 2015 and cancelled the project.
http://www.thinkgeoenergy.com/geodynamics-plugging-wells-and...
Even had the project gone as initially scoped, the wells would have had a useful life of about 20-40 years, after which all available useful thermal energy would have been extracted, and would have to be replenished over ... long time, possibly centuries or more. There's a reason the Earth's interior remains molten -- rock is a very good insulator.
I'm not an opponent of geothermal power -- where appropriate it's highly useful, dependable, safe, and proven. In Africa it stands to make a tremendous difference, where even a small plant would make a tremendous increase in the availability (and probably reliability) of electricity. I'd encourage consideration of developing even such normally off-limits natural park resources such as Yellowstone (specifically excluded from a USGS geothermal resource survey I'd checked on some years back).
But enhanced development through borehole-based wells looks like a very long shot.
Wikipedia's treatment of geothermal is good:
https://en.wikipedia.org/wiki/Geothermal_power
How long would it take to fall 40,230 feet? I'm guessing the drill doesn't go straight down, but it's still a fun thought experiment.
This free-fall calculator[1] (with air resistance) reports a fall duration of 229 seconds (3m49s) with 121mph velocity for a 72kg mass with the default air resistance coefficient as used in skydiving.
[1] https://keisan.casio.com/exec/system/1231475371
This free-fall calculator[1] (with air resistance) reports a fall duration of 229 seconds (3m49s) with 121mph velocity for a 72kg mass with the default air resistance coefficient as used in skydiving.
[1] https://keisan.casio.com/exec/system/1231475371
I imagine that if the hole isn't that wide then it would be harder to displace air, meaning that you should fall slower.
There is, as they say, an XKCD for every situation: https://xkcd.com/1330/
And showing relative depths -- it always surprises me that modern oil wells aren't actually _all_ that shallower: https://xkcd.com/1040/
And showing relative depths -- it always surprises me that modern oil wells aren't actually _all_ that shallower: https://xkcd.com/1040/
The Kola borehole:
> reached 12,262 metres (40,230 ft; 7.619 mi) in 1989
While Deepwater Horizon's deepest drill:
> In September 2009, the rig drilled the deepest oil well in history at a vertical depth of 35,050 ft (10,683 m) and measured depth of 35,055 ft (10,685 m)
> reached 12,262 metres (40,230 ft; 7.619 mi) in 1989
While Deepwater Horizon's deepest drill:
> In September 2009, the rig drilled the deepest oil well in history at a vertical depth of 35,050 ft (10,683 m) and measured depth of 35,055 ft (10,685 m)
My understanding is that the well is measured from the point at which drilling starts -- so the Deepwater Horizon started lower down, and one can therefore argue that the depth they reached (as opposed to the depth they drilled) is 11,944m.
It's maybe not a useful technical measure, but it's a lot closer in "depth" than I imagined it would be given the amount of attention given to the Kola borehole, and especially the tales of the difficulties they faced. Makes me think that one of the big oil companies could probably beat the record if they wanted.
It's maybe not a useful technical measure, but it's a lot closer in "depth" than I imagined it would be given the amount of attention given to the Kola borehole, and especially the tales of the difficulties they faced. Makes me think that one of the big oil companies could probably beat the record if they wanted.
We did something like /1330/ in Terraria. We drained the ocean directly into the Underworld. It worked beautifully :)
> it always surprises me that modern oil wells aren't actually _all_ that shallower
There is a theory that oil is actually generated as a by product of the mantle itself, not by buried prehistoric plants.
If that's the case, oil could truly be a limitless resource, which is bad news for the climate.
There is a theory that oil is actually generated as a by product of the mantle itself, not by buried prehistoric plants.
If that's the case, oil could truly be a limitless resource, which is bad news for the climate.
> There is a theory that oil is actually generated as a by product of the mantle itself, not by buried prehistoric plants.
Sounds like more like alchemy than actual science. What magical process transmutes rock into long chain hydrocarbons?
Sounds like more like alchemy than actual science. What magical process transmutes rock into long chain hydrocarbons?
I'm not saying I believe it, but the mantle does contain natural hydrocarbons and it's not just "rock" - it's a very slow moving liquid under immense temperatures and pressures. Who knows what kinds of reactions might happen on mantle-crust (or other) boundaries.
And it helps to remember that hydrogen is the most common element in the solar system. Its not common on the surface, but huge amounts of it are trapped in the earth's interior.
It's not hydrogen that's the limiting factor, it's the carbon. Carbon, like silicon (in rock), tends to bind to oxygen whenever possible. So long-chain hydrocarbons would have to in highly anoxic regions. And there's also the issue of reacting with all that abundant hydrogen to form methane, although I'm not sure offhand which direction the binding energy difference favors on that one.
It is primordial methane that is transformed into long chain hydrocarbons by pressure and heat, according to “The Deep, Hot Biosphere” by Thomas Gold.
Normally this happens in the opposite direction. Complex hydrocarbons are broken down by heat and time into lighter and gassier hydrocarbons.
Well, there's a theory the earth is hollow and inhabited by dinosaurs and aliens, too. ;)
I think the best argument against abiogenic petroleum in the mantle is that if the theory had any merit Exxon would have figured out a way to bore into the mantle decades ago.
I think the best argument against abiogenic petroleum in the mantle is that if the theory had any merit Exxon would have figured out a way to bore into the mantle decades ago.
That XKCD was great.
“What was clear for the experience of the Russians was that you have to drill as vertical as possible because otherwise you increase torque on the drills and kinks in the hole,” says Uli Harms. “The solution was to develop vertical drilling systems...”
Great article, but does anyone have any insight as to what those techniques were?
Great article, but does anyone have any insight as to what those techniques were?
Instead of turning the bit by turning the entire string of pipe, you can turn only the bit with a mud-motor.
https://en.wikipedia.org/wiki/Mud_motor
https://en.wikipedia.org/wiki/Mud_motor
I'm guessing directional drilling techniques. I'm not sure exactly how they work, but I know that they are often used when drilling oil and gas production wells so that you can penetrate a reservoir laterally rather than drilling a bunch of more or less vertical wells. Especially useful if your reservoir is fairly thin but wide.
I suspect that's obsolete now that directional drilling has become widespread - it's routine to curve into different parts of a field from the same rig.
Did you know the hole's only natural enemy is the pile?
https://www.youtube.com/watch?v=DERjNPnr31Q
https://www.youtube.com/watch?v=DERjNPnr31Q
Video is an Onion parody of info-tainment shows done by investigating a "big hole."
I hadn't seen the Onion video parodies before, so I'm glad someone is holding a mirror up to that crap, but truth be told, it is as equally unwatchable as the originals.
I hadn't seen the Onion video parodies before, so I'm glad someone is holding a mirror up to that crap, but truth be told, it is as equally unwatchable as the originals.
Anyone else click on the link thinking it was an article about Brexit?
Obligatory, some forward-looking ('hard' sci-fi) physics and observations about drilling to the Earth core, by Isaac Arthur.
https://youtu.be/jZQP2oNDkAM
Warning: nerd alert!
https://youtu.be/jZQP2oNDkAM
Warning: nerd alert!
Cards Against Humanity got people to donate more than $100,000 to dig a big hole for no reason at all. Maybe scientists should try funding a deep bore hole for science by live streaming it.
https://www.independent.co.uk/news/world/americas/cards-agai...
https://www.independent.co.uk/news/world/americas/cards-agai...
Figure out how to get a camera that can see the walls of the borehole as it goes down and many people would be interested.
Set it up so the digger's progress only continues with a donation so you can "buy" a foot of the depth.
Set it up so the digger's progress only continues with a donation so you can "buy" a foot of the depth.
I want to know what the environmental impact on that hole...i mean where is the humor in destroying the planet just because we can?
That hole makes me unnervingly angry. And I can't be the only one.
That hole makes me unnervingly angry. And I can't be the only one.
https://holidayhole.com/
>Is the hole bad for the environment?
>No, this was just a bunch of empty land. Now there’s a hole there. That’s life.
>Why aren’t you giving all this money to charity?
>Why aren’t YOU giving all this money to charity? It’s your money.
>Is the hole bad for the environment?
>No, this was just a bunch of empty land. Now there’s a hole there. That’s life.
>Why aren’t you giving all this money to charity?
>Why aren’t YOU giving all this money to charity? It’s your money.
I have a feeling that for a project funded by Cards _against_Humanity_, such a study would just be seen as a way to reveal methods to maximize harm.
You're not alone. It feels something like releasing hundreds of rubber balloons into the air, pointless and arrogant.
From the picture it looks like the hole is maybe 30 feet across so the environmental impact is non existent
This is extremely reactionary to the point you must be trolling.
"Destroying the planet"? Come on. It's a hole in the ground. We make a hole ten times bigger than this every time we build a building.
"Destroying the planet"? Come on. It's a hole in the ground. We make a hole ten times bigger than this every time we build a building.
I am not trolling.
this is the same forum where people minimize their consumer garbage output to one bag a year and reduce aviation usage to reduce carbon footprint. I find it EXTREMELY condescending that you ridicule my opinion. Whats the scope for scales of environmental impact that matters?
Every single construction project in an area where an endangered species lives, the USAF must conduct an environmental impact study for said species from the project, even if its a toilet.
I am very much extremely reactionary, this is a news forum. People post news and react to it.
this is the same forum where people minimize their consumer garbage output to one bag a year and reduce aviation usage to reduce carbon footprint. I find it EXTREMELY condescending that you ridicule my opinion. Whats the scope for scales of environmental impact that matters?
Every single construction project in an area where an endangered species lives, the USAF must conduct an environmental impact study for said species from the project, even if its a toilet.
I am very much extremely reactionary, this is a news forum. People post news and react to it.
One environmental impact of the hole is that it just caused you to unnervingly outgas huge quantities of hot carbon dioxide and stinky methane into the atmosphere, years after it was dug, and expose yourself as a troll.
Why don't you donate some money to charity to offset your fake moral outrage?
What I don't understand is why you're so clearly and idealistically virtue signaling, and taking other people's commentary so deeply personally, while your profile says:
>This is my avatar for participating in a community full of idealists, virtue signallers, hardworkers, and paid advertisers.
>To take personal any of my commentary is a folly of the reader.
You sound like a troll to me.
PS: You misspelled "signalers" and "hard workers", and just forgot two apostrophes. Did you know that your web browser has a built-in spelling checker and corrector? Look for misspelled words with squiggly red lines underneath them, then click the right mouse button on them to pop up a menu with correct spellings. Also, you should brush up on the simple easy-to-remember apostrophe rules -- it will improve your trolling:
https://grammar.yourdictionary.com/punctuation/apostrophe-ru...
Why don't you donate some money to charity to offset your fake moral outrage?
What I don't understand is why you're so clearly and idealistically virtue signaling, and taking other people's commentary so deeply personally, while your profile says:
>This is my avatar for participating in a community full of idealists, virtue signallers, hardworkers, and paid advertisers.
>To take personal any of my commentary is a folly of the reader.
You sound like a troll to me.
PS: You misspelled "signalers" and "hard workers", and just forgot two apostrophes. Did you know that your web browser has a built-in spelling checker and corrector? Look for misspelled words with squiggly red lines underneath them, then click the right mouse button on them to pop up a menu with correct spellings. Also, you should brush up on the simple easy-to-remember apostrophe rules -- it will improve your trolling:
https://grammar.yourdictionary.com/punctuation/apostrophe-ru...
I want to tag on the remainder of my profile for you, since you conveniently skipped it in your hate speech.
>Live long and prosper.
I hold a genuine desire for strangers to live a fruitful life.
Please, consider revisiting the source of your anger and hate to a stranger and ask yourself "what is the effect I aim to have?" If you are aiming to hate as a cathartic release, I suggest writing a journal. If you are aiming to hate as a means of cruelty to a stranger online, do it anonymously without your real name attached to it.
>Live long and prosper.
I hold a genuine desire for strangers to live a fruitful life.
Please, consider revisiting the source of your anger and hate to a stranger and ask yourself "what is the effect I aim to have?" If you are aiming to hate as a cathartic release, I suggest writing a journal. If you are aiming to hate as a means of cruelty to a stranger online, do it anonymously without your real name attached to it.
Everything about this comment is a personal attack and sidesteps my real concern--the flagrant disregard for the environment just because someone can do it.
And Don I have to tell you, I am not a troll and I have to ask what crime did I commit expressing myself?
Was the post script necessary?
Maybe I get heated because this forum claims a standard is being held while I see bias persist
Maybe i believe it is important in a healthy democracy that the right conversations happen.
Maybe I hate bullies. You def. Are being a bully.
You disregard a real talking point on how little liability we hold people to disrupting land, and just attack me, AND YOU CLAIM YOU CAN BC YOU PERCEIVE ME AS A TROLL.
I stand by my profile description bc this is a diverse community.
I have a question for you, what is your purpose of your rant? To make me feel bad and you feel superior?
And Don I have to tell you, I am not a troll and I have to ask what crime did I commit expressing myself?
Was the post script necessary?
Maybe I get heated because this forum claims a standard is being held while I see bias persist
Maybe i believe it is important in a healthy democracy that the right conversations happen.
Maybe I hate bullies. You def. Are being a bully.
You disregard a real talking point on how little liability we hold people to disrupting land, and just attack me, AND YOU CLAIM YOU CAN BC YOU PERCEIVE ME AS A TROLL.
I stand by my profile description bc this is a diverse community.
I have a question for you, what is your purpose of your rant? To make me feel bad and you feel superior?
Oh, boo hoo. Bullying and hate speech, huh? You're the only one brought any "hate" into this conversation: you just used that word five times, called me a bully, and said you hate bullies (therefore you hate me). That clinches it. You're definitely an angry reactionary troll. Keep digging that fine hole you've made for yourself there.
PS: That's "PostScript" (TM Adobe).
PS: That's "PostScript" (TM Adobe).
Dear Don, please go easier. You don't know your own strength sometimes.
When the Russians started to drill they claimed they had found free water – and that was simply not believed by most scientists. There used to be common understanding among Western scientists that the crust was so dense 5km down that water could not permeate through it
The deepest hole we have ever dug (bbc.com) = Doctor Who, season 12.
(j/k)
(j/k)
etxm(2)
The deepest hole we've dug is probably the Mir diamond mine in Siberia, at 525m [0]
(A quick internet search will probably say that the Bingham copper mine in the US is deeper, but that was dug at the bottom of an existing canyon, giving it a head start; the Mir mine started... Well, basically with a bunch of guys with shovels in the middle of the tundra.
[0] https://www.atlasobscura.com/places/mir-diamond-mine