[HN Gopher] Can a Geothermal Startup Vaporize Rock to Drill the ...
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Can a Geothermal Startup Vaporize Rock to Drill the Deepest Holes?
Author : wallflower
Score : 53 points
Date : 2025-03-11 17:49 UTC (4 days ago)
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| nayuki wrote:
| A relevant video by Real Engineering: "Geothermal Energy is
| Changing" https://www.youtube.com/watch?v=b_EoZzE7KJ0 (21m53s)
| [2025-03-01]
|
| The company being discussed is Quaise Energy:
| https://www.quaise.energy/ , https://en.wikipedia.org/wiki/Quaise
| stringl45 wrote:
| One thing that video left me wondering is what happens to the
| vaporized rock; how are we collecting or transporting it so it
| doesen't immediately re-solidify, stringify and block the hole?
| cassepipe wrote:
| It's true that it's not entirely clear but it seems there's a
| nitrogen gas that pushes the gasses back up ? It's also not
| clear how much of the rock mass actually resolididy instead
| going away as gas but for the part that does, it seems to be
| do so in a fashion that resembles mineral wool.
| doodlebugging wrote:
| That's a valid question. As the vaporized rock cools it needs
| to be directed to the annular walls of the borehole being
| drilled. If it flutters chaotically up the along the
| drillstring and sticks itself to the drillstring then you are
| effectively blocking the borehole as you drill. Even if you
| rotate the drillstring the cumulative effect is that the
| drillstring becomes a long length of sandpaper or a vertical
| grinder, grinding the fused rock from the annulus above where
| you are currently drilling.
| cassepipe wrote:
| It is only shortly mentionned in the video but it seems like
| one of the main issues is what happens when water starts
| infiltrating your hole (it's unclear how much the glassified
| walls of the holes are a protection against that) and then you
| waste a lot of energy vaporizing liters and liters of water.
|
| Unless... you close the hole at the top to collect the steam
| and have it turn a turbine to recoup electricity expenditures ?
| LadyCailin wrote:
| If the hole is 2 miles long, I assume the steam would
| condense before reaching the top. And I guess lowering the
| pressure again, so I don't know if that's possible. But I'm
| not a physics expert.
| doodlebugging wrote:
| At depth, natural gas is in the liquid phase in the
| reservoir due to high temperatures and overburden pressure.
| Once the drillbit penetrates the seal of the formation
| containing natural gas or other liquids then the gas will
| begin to be carried up the annulus of the well in the
| drilling mud to the surface. As it moves closer to the
| surface it expands and crosses into the bubble point into
| the gas phase which is the dangerous condition that leads
| to blowouts and the loss of the well and potentially lives
| at the surface.
|
| It is important to be able to detect the formation
| boundaries and to have the mud weight tailored to the
| expected pressures within the target zones so that blowouts
| can be avoided. Pre-drill predictions of downhole pressures
| are made from seismic data and can be extremely accurate,
| especially when correlated with borehole data from regions
| with similar geologic history.
|
| I did pre-drill pressure predictions as a geophysicist.
| Very interesting stuff.
|
| Here is a little info about well control and gas kicks.[0]
|
| [0]https://www.drillingmanual.com/gas-kick-behavior-
| expansion-m...
| Animats wrote:
| Wasn't Quaise on HN before, years ago? They've been talking this
| up since 2018.
|
| The competing technology is diamond drill bits.[1][2]. As
| synthetic diamonds have become cheaper, drill bits have improved.
| The old Hughes-style bits with what looked like big bevel gears
| now have a competitor. The key question is how much drilling you
| can do before you have to back out the whole drill string. That's
| a slow process, which gets slower as the drill string gets
| longer. Polycrystalline diamond bits now sometimes last for 3000+
| meters. Maybe longer.
|
| Comments from anyone in the drilling industry?
|
| [1] https://okbit.com/choose-a-geothermal-drill-bit/
|
| [2] https://www.slb.com/products-and-services/scaling-new-
| energy...
| Retric wrote:
| Quaise is also aiming for faster drilling not just longer
| lasting drills.
|
| Anyway, seems like the obvious solution is to stack multiple
| drill bits at the end and detach ones that get used up.
| Obviously this doesn't work, but it's not clear to me why it
| shouldn't.
| CorrectHorseBat wrote:
| Well, where are the used up drill bits supposed to go to in a
| hole just as wide as the bits itself except for up and out?
| Retric wrote:
| Again going for obvious solution, drop it, back up a few
| meters and drill around. Alternatively, have pre drilled
| side paths for drill bit drop off.
| cassepipe wrote:
| How do you pre-drill side paths ? Isn't being able to
| drill the hard part ? I am not saying it's dumb but from
| what I know about the industry (almost nothing) it does
| not seem simple at all
| Retric wrote:
| They need to be able to steer drills for all kinds of
| reasons: https://www.youtube.com/watch?v=JAhdb7dKQpU
|
| Actual answer seems to be drilling side holes also
| involves removing the pipe.
| https://news.ycombinator.com/item?id=43371776
| BriggyDwiggs42 wrote:
| The drill is on the end of what amounts to a several km
| long rope. I'm pretty sure a side hole would introduce
| friction with the side that wasn't there before, making
| it easy to stick going in and out. I think if the obvious
| solution worked then people would already be doing it,
| cause they'd save multiple millions of dollars.
| Retric wrote:
| They can do side drills, but apparently that also
| requires removing the pipe which is the bit I was
| missing.
|
| https://news.ycombinator.com/item?id=43371776
| ada1981 wrote:
| Why don't they just retract the bits and change them like I
| would on a regular drill that needs a new bit?
|
| Is the failure mode they always or often fall off the shank
| into the hole and they can't be extracted?
| ufmace wrote:
| That's exactly what they do. It just takes a while since
| there's tens of thousands of feet of drillstring.
| cnote337 wrote:
| Main reason it wouldn't work is that once a bit is lost in
| the bottom of the hole, that portion of hole is done, el fin.
| These bits are diamond impregnated PDC bits and you cannot
| drill or mill through them. Once you've dropped one, it would
| be a required side track.
|
| Now you might ask, cool so just drill around it.
|
| The problem is that with current technology, you HAVE to pull
| back to the surface first in order to do this. You need to
| cement the bottom of the current hole and depending on the
| circumstances, you also need to set a 'whipstock' in order to
| assist in drilling out of the original hole. Side tracking is
| a long and arduous process that involves numerous trips out
| of the hole.
|
| So regarding your lower comment, that's why we can't just
| have multiple bits and drill around them, or drop them off in
| their own sidetrack. It's not a bad idea, it's just that the
| realities of drilling at these depths are harsh and not
| completely intuitive.
|
| My Creds - currently in the gulf of mexico drilling a well
| with a total depth of 30,012 feet.
| giarc wrote:
| On a recent podcast, I believe the founder said that at 6
| miles (close to your 30k well) that this technology could
| be used anywhere. However, I think they could only get 3-4
| mile wells at this point. So if we already have the ability
| to drill 6 miles with conventional tech, why not just do
| geothermal with conventional drilling?
| doodlebugging wrote:
| He is probably on a rig drilling a deviated well to 30k+
| total depth (TD) so that it is not a vertical well 30k+
| feet deep or 30k' true vertical depth (TVD), it is
| instead a deviated well with a long vertical section
| before the kickoff point which deviates the drillbit to
| the target at some horizontal displacement from the
| vertical borehole with the total length of the
| drillstring being 30k+ feet when they reach TD (total
| depth). With horizontal drilling and use of steerable mud
| motors you aren't rotating the drill string constantly as
| you drill the deviated section and this allows one to
| push the bit through the formations until you reach the
| target.
|
| Drilling 6 miles vertically without using a media to
| conduct cuttings to the surface would be a major change
| in how things work. I don't think that glassing the
| inside of the borehole by fusing cuttings as you drill
| will create a durable borehole. We used to have problems
| with electronics desoldering at depth in our MWD tools.
| It gets hot and the pressures can be enormous.
|
| Former Scumbagger MWD engineer here.
| MostlyStable wrote:
| My understanding from earlier encounters with reporting
| about this company, is not that we can't do geothermal
| drilling without it, it's that it's not always cost-
| effective. Drilling is expensive and the cost is a
| significant fraction of the total capital investment in a
| geothermal energy plant. In order to make geothermal cost
| effective everywhere, drilling needs to be made less
| expensive. This company is not about doing what is
| currently impossible, it's about doing what is currently
| possible cheaper
| ufmace wrote:
| The technology being discussed hasn't actually drilled
| much of anything yet. Their latest press release with
| actual numbers[0] gives depths drilled in inches. Nice
| progress, yeah, but they're not anywhere near competitive
| with even water wells, much less the current generation
| of conventional oilfield drilling technology.
|
| Geothermal power is indeed cool, but to get it usable
| anywhere on Earth instead of a few places where magma
| currents happen to be near the surface, we'll probably
| need several orders of magnitude deeper and wider holes
| than we're currently capable of drilling just for
| starters. Can these guys do the job? Maybe, but let's
| just say I'm not planning to invest in them.
|
| [0] https://www.quaise.energy/news/from-lab-to-field-
| testing
| Animats wrote:
| > The technology being discussed hasn't actually drilled
| much of anything yet. Their latest press release with
| actual numbers[0] gives depths drilled in inches.
|
| That's what bothers me about this. If drilling with
| microwaves works, why aren't there industrial
| applications? Laser cutters are widely used, from little
| ones that engrave plastic to big ones that cut steel
| plate. Yet nobody seems to be selling microwave cutters.
| In industrial applications, you don't even have to fit
| the microwave generator into the hole and keep it working
| in a hostile environment.
|
| The idea was suggested back in 2002, but seems to have
| gone nowhere.
|
| [1] https://www.researchgate.net/publication/11075717_The
| _Microw...
| Retric wrote:
| Thank you for the detailed answer. I figured there was
| something wrong with the idea but didn't know enough about
| the subject to understand why.
| grumbelbart wrote:
| Drilling is essentially an O(N^2) method. You need to replace
| your drill bit every X meters, and the time it takes to replace
| it about linear in the current depth.
| ufmace wrote:
| Note that diamond (usually called PDC) drill bits have been in
| common use in the oilfield industry for decades now. Search PDC
| on your favorite search engine, and you'll find dozens of
| manufacturers actively selling them, each with a big selection.
|
| Exactly how long you can drill with one varies widely based on
| a bunch of factors. You do have to pull the whole drill string
| to change one. It's slow, but not that slow. Most actual oil
| wells drilled have in the neighborhood of 10 or so trips in and
| out with drilling tools for the whole operation for various
| reasons. Varies widely of course depending on a bunch of
| factors, but that's usually the ballpark. Plus a few more for
| casing and cementing runs.
| ninetyninenine wrote:
| I feel the energy spent vaporizing the rocks is more then the
| energy gained.
| littlestymaar wrote:
| They plan to use just a megawatt of power to drill, it's not
| even close.
| victorbjorklund wrote:
| No, if it works as planned then the energy is cheap in
| comparison to the total cost of drilling a hole.
| nonelog wrote:
| Actually, the _real_ trick is to invent the technology that
| eliminates the need to drill so _deep_. But for that invention to
| be made /found, we need to go a bit more "quantum".
| cnote337 wrote:
| I'm a geologist. I work on well sites for a living. My biggest
| concerns about what have been talked about in the video are with
| regards to rock removal, and hole stability. But those are always
| my concerns.
|
| The oil and gas industry currently uses "mud" either oil based or
| water based, in order to keep their holes from collapsing on
| themselves. Holes collapse. It's what they want to do, this is a
| factor of overburden - the collective weight of the rock above
| the hole 'pushing' down. It is also the primary means of
| communication with downhole tools through mud pulse telemetry,
| and the primary means of removing rocks - currently in the form
| of cuttings.
|
| There is no mention of this mud system or other alternative (an
| innovation that would also need to be ground breaking for the
| industry) that will 1) keep the hole from collapsing 2) remove
| the volume of rock required to continue going down and 3) allow
| communication with your downhole tools.
|
| It feels like this is a massive hole in the logic.
| svantana wrote:
| I think the idea is that the heat from the radiation turns the
| walls of the hole into a very hard glass structure, which
| should be hard enough to withstand the pressure.
| aurizon wrote:
| at 10,000 feet in a thermal area the rock is very hot. Hot
| rock is ductile and holes will gradually close. Some deep
| hard rock mines in Northern Ontario encounter this problem
| where mine working gradually close under extreme pressure
| over time. The closure can be instant = rock-burst = a local
| micro-quake. Often there is lateral shear as well. The
| deepest gold mines in Witwatersrand in South Africa are over
| 160 degrees in places and workers wear vented/cooled suits.
| They also have refrigerated cold rooms they can jump into to
| get cool and get back to another work session.
| mcswell wrote:
| There's an old SciFi story here: https://www.gutenberg.org/ca
| che/epub/30797/pg30797-images.ht... that uses that idea as
| part of the plot. The hole is not very deep, maybe 150 feet,
| so the "glass" walls would presumably be strong enough. Much
| deeper, though, and the walls would almost certainly not be
| able to withstand the pressure.
|
| What I was wondering when reading the story, though, was what
| happened to all the rock that was vaporized. It has to leave
| the hole, else it will prevent the energy beam (in the case
| of the story, a laser beam) from getting to the bottom of the
| hole. If you've ever seen smoke (or even steam) coming out of
| a smoke stack, you have to wonder how the efficiency of the
| beam would not be cut to zero after the first few feet.
| ufmace wrote:
| That's their idea yes, but it's only an idea, and I am
| extremely dubious. It's much more like handwaving speculation
| by people who have no experience in drilling deep wells than
| a practical proven solution.
|
| They're expecting the hole to be open air, with nothing at
| all to push back against formation pressure. It has to be,
| for the radiation system to work. But that means that this
| supposedly fused glass wall has to withstand all of the
| formation pressure all the way through the borehole
| perfectly. And they seem to be expecting this to happen from
| the vaporized material just condensing on the borehole walls.
| One little crack anywhere, and the whole borehole could flood
| with water or oil, possibly even blowing out at the surface.
| How do they recover from that? They'd have to figure out
| where the failure was, seal it, then get all the water out,
| each of which seems practically impossible.
| svantana wrote:
| Yes that does seem worrying, and might explain why they've
| only (publicly) drilled a few inches here & there. Maybe
| they could give the waveguides some outer grid or fins or
| whatnot to give extra support?
| ufmace wrote:
| Physical support isn't actually that important -
| conventional wellbores are not physically supported
| either until they are cased and cemented, and mostly
| don't have too much trouble with collapsing. What they
| need is a seal tight against liquid and gas to prevent it
| from leaking into the wellbore.
|
| Conventional wellbores accomplish this with the hydraulic
| pressure of the drilling fluid. These guys can't have any
| fluid though, so they would have to rely entirely on this
| condensed rock stuff to both support against the pressure
| and seal against any leaks. Seems very unlikely,
| considering that it isn't deliberately created by any
| kind of process, just randomly condensed from rock
| vapors.
|
| Note also that they won't really start to run into
| trouble with this until they get at least a few hundred
| feet down.
|
| Also, you definitely aren't going to drill more than 6
| inches while attempting to physically support the
| wellbore with any part of the drillstring or waveguide or
| whatever they're calling this thing.
|
| People should also understand that oil drilling is a
| highly competitive multi-trillion dollar industry
| employing tens of thousands of smart people all around
| the world. Absolutely everything that anyone could think
| of has already been tried, and adopted if it worked and
| abandoned if it didn't.
| ufmace wrote:
| Oh, I just thought of another issue too. A liquid well-
| control incident with this thing would indeed suck for the
| reasons given, but there's a lot of gasses down there too.
| What happens if there's a gas well-control incident?
|
| It could be flammable natural gas. It may or may not burn
| or explode in the wellbore, since there's not going to be
| much oxygen down there. How about at the surface though?
| Flammable gas erupting out your wellbore with this system
| sounds very not fun. They have megawatts of electricity
| flowing around, do you think all of that meets industry
| standards for avoiding explosions in an environment of
| flammable gasses? I think there's high potential for a very
| big boom, and maybe the whole well turning into a giant
| blowtorch you have no way to control.
|
| Or it could be a poisonous gas like H2S. Poisonous gasses
| billowing out of your wellbore with this system also sounds
| like a major pain.
|
| So, who wants to come up with a practical way for this
| thing to deal with that too? The oilfield has proven
| methods for preventing it in the first place and dealing
| with it if it happens anyways. Trip your annular blowout
| preventer, evacuate the rig, and circulate heavy kill mud
| until the gas stops flowing.
|
| Maybe these guys could flood the well to stop it. Which
| means they also need to keep many tankers full of fluid on-
| hand, and after it works, they're back in the initial
| situation of needing to figure out how to seal the leak and
| evacuate the fluid again. I seriously can't think of a good
| way to do any of that.
| MathMonkeyMan wrote:
| A massive hole!
| doodlebugging wrote:
| Geophysicist and former MWD engineer here. I agree. Even if you
| fuse everything that you penetrate to the annulus of the
| borehole, the material properties of the fused annular ring
| will vary as you cross formation boundaries based on the
| mineral composition of the formations being drilled. You may
| have some nice silicon glasses through a clean sandstone that
| transition quickly to inhomogeneous glass from a silicon-poor
| limestone. That has to create zones of weakness along the
| annulus and as you drill (zap) deeper it becomes even more
| critical to stabilize the borehole.
|
| I can see this being a lot like conventional drilling to a
| point with several bit trips or casing runs necessary until you
| reach a point where the borehole tends to collapse due to
| overburden pressure, especially in overpressured environments
| where well control is critical, and it is no longer possible to
| trip out and run casing before the borehole collapses in the
| newly drilled interval.
|
| What happens if your proposed well encounters salt or other
| evaporites? A lot of questions could use answers and those
| answers only come from poking holes in the ground so maybe if
| they throw enough money at it they can determine where this
| method can be useful. That would be the most valuable result of
| all this.
|
| This looks useful for near surface stuff but for ultradeep
| wells looks like it needs some experimentation.
| pavel_lishin wrote:
| Are there places on Earth where it's mostly-homogenous "good
| stuff" all the way down? Could they avoid some of these
| problems - salt pockets, limestone - by being very picky
| about where they drill, avoiding (e.g.) places where there
| used to be ocean?
| jofer wrote:
| Even if it's homogenous, you have steadily increasing
| stresses with depth. This occurs for perfectly uniform
| materials as well. If you can't offset these to keep the
| hole open, it collapses.
|
| Rocks are very weak in tension, despite being very strong
| in contraction. It's the reason you can break rock with a
| hammer or the reason ancient quarries were able to work by
| pouring water on wood pegs in rocks. It's also the reason
| concrete needs rebar to reinforce it (steel is very strong
| in tension, so the two combined are exceptionally strong).
| Keeping a hole open requires strength in tension as well as
| strength in compression.
|
| Drilling mud accomplishes this by being roughly the same
| density as the rock, so it offsets the stresses that are
| trying to close the borehole that steadily increase with
| depth due to the increasing amount of rock above. Drilling
| mud keeps the borehole open until you can put in casing to
| support it.
|
| This is exactly the same reason why it's difficult to build
| a submarine that can go to very large depths in the ocean.
| To put up steel walls (casing) to keep it open, you have to
| stop drilling and cement in casing - you can't do that as
| you drill. So drilling mud is a key part of being able to
| drill efficiently. Otherwise, you'd need to stop every few
| tens of meters and spend _days_ setting casing before being
| able to drill again.
|
| Regardless, there is nowhere on earth where things are
| homogenous over very long distances. Simply put, even
| relatively uniform rocks can have very significant
| variations in physical properties. Many relevant properties
| (e.g. permeability - how well fluids can move through) vary
| over _tens of orders of magnitude_ naturally. So "uniform"
| can still mean "only varies by a few orders of magnitude".
| There are places where you can reasonably avoid non-
| silicates, but you're going to hit tons of other issues due
| to fundamental heterogeneity.
| gosub100 wrote:
| Could you avoid the problem by drilling down a fixed length,
| carving out a room or supply area, drilling laterally, and
| then drill vertically again?
| bilsbie wrote:
| If you're vaporizing you'd simply use fans to pull the
| vaporized material out?
| amluto wrote:
| I don't know anything about geology in particular, but:
| vaporized rock is vaporized rock, not air. It's going to cool
| off as it travels up a relatively cool shaft, and some or all
| of it will condense and/or solidify into something that will
| be, in the best case, fine dust. The gasses in the shaft will
| need to be moving upward faster than the terminal velocity of
| the removed material for the material to continue moving
| upward.
|
| In the worst case, I can imagine the vaporized rock
| depositing (directly in the strict chemistry sense or
| indirectly via a liquid intermediate) into the walls of the
| shaft higher up.
| lazide wrote:
| Additionally, keeping the vapor from cooling/depositing
| will also require keeping it above the vapor point of rock
| - which is well above any metals they might make anything
| from.
| ufmace wrote:
| Another thing that occurred to me after watching some of their
| videos - how do they plan to control rate of penetration?
|
| Their radiation head thing has to be a certain distance from
| the rock face it's cutting / vaporizing, but it isn't actually
| touching anything. So how do they know how fast they're
| actually vaporizing more hole and how fast to advance?
|
| I'm sure you know this, but for the rest of the audience,
| conventional drilling rigs use the measured weight of the
| drillstring to determine how much weight is on the bit and how
| fast to advance. I don't see any good way for these guys to do
| anything like that.
| a12k wrote:
| I feel like you're underestimating the power of SV moving fast
| and breaking things to learn quickly. Your attitude is why
| we've stopped hiring SMEs and PhDs in my underwater space
| launch / space elevator bio startup.
| cmrdporcupine wrote:
| Damn you I was hovering over downvote until the last clause
| of your sentence.
| SequoiaHope wrote:
| Perfect Silicon Valley comment.
| LargoLasskhyfv wrote:
| Will there be
| https://en.wikipedia.org/wiki/Sea_Dragon_(rocket) s?
| marcosdumay wrote:
| Well, they do talk about it, just not on those terms.
|
| Their "drill" is unable to distinguish mud from rock, so
| inserting mud is a complete no-starter.
|
| They expect to stabilize the hole by hardening the rocks on the
| walls. If you just ignored this because it obviously can't
| work, well, I agree, but that's still their claim. The only
| conclusion I can take from it is that they either know a
| solution and won't tell us, or haven't thought of anything and
| hope to solve it in production.
|
| They also talk about residue removal. They say it will just gas
| away from the hole. Again, if you decided to ignore it because
| it obviously can't work...
|
| That said, I'm with doodlebugging here. As long as it's not my
| money that they are betting, I just want to see what
| interesting problems and solutions will come out from this.
| K0balt wrote:
| So, you're saying they -do- have a massive hole in their geo-
| logic formation?
| worldvoyageur wrote:
| Eavor is a Canadian geothermal company that does closed loop
| systems with diamond drills and insulated drill pipe.
| https://www.eavor.com/technology/
|
| Closed loop and insulated pipe allows a geothermal project to be
| drilled into hot rock, which is pretty much everywhere, even if
| there is no water.
|
| They have a demonstration project in Alberta, a 'commercial'
| project in Geretsried, Germany (4500 meters, 64MW thermal, 8.2MW
| electric) and a deep demonstration project in New Mexico (5500
| meters, no news since early 2023).
|
| From the company website, it looks like the projects work though
| Eavor doesn't give any data on their projects that would help
| calculate the economics. The heavy presence of government in
| their media suggests that, at least for now, significant
| government involvement is required to get projects built.
| thinkcontext wrote:
| Hype for this is extremely premature, they've only drilled inches
| in a lab.
| giarc wrote:
| Founder was on What's Your Problem podcast recently [1] and I
| seem to recall them having much deeper wells already complete.
|
| https://www.pushkin.fm/podcasts/whats-your-problem/harnessin...
| thinkcontext wrote:
| This article from 2 days ago says they have a test rig that
| is drilling outside. They don't say exactly how deep they
| have drilled but mentions they have another site where they
| will attempt to drill up to 100 feet.
|
| So sounds like they are at the very beginning of piloting.
| I'm not going to listen to an hour podcast to see if it is
| claiming anything different, if you have a text source I'd be
| interested.
|
| https://www.canarymedia.com/articles/geothermal/the-smell-
| of...
| istjohn wrote:
| I transcribed the podcast for you, but I think you're
| right.
|
| https://pastebin.com/raw/PG5JdAKv
| lightedman wrote:
| Why not just use a laser? I vaporize rock instantly with an 80w
| CO2. vacuum the dust up and blow it out the other end, done.
| Throw it on a galvo, you can control where it aims and fires.
| HPsquared wrote:
| I don't know much about lasers, but this seems a very "dirty"
| environment for that sort of thing. Wouldn't the lenses etc get
| all fouled up?
| mcswell wrote:
| Dust? Vaporized rock going through a vacuum is not going to be
| kind to the inside of that vacuum.
| avsteele wrote:
| your beam waist is going to increase (and intensity is going to
| drop) after a few hundred meters. you'd have to lower the whole
| laser down the hole
| bilsbie wrote:
| Maybe use adjustable lenses?
| notorandit wrote:
| Some maths.
|
| 1 squared meter surface times 10 km in depth yields ... 10,000
| cubic m of mass to be vaporized and then "dispersed" into the
| atmosphere.
|
| At a density of 5.5 kg/dm^3 it would weight about ... 55
| thousands metric tonnes of rock.
|
| To vaporize 1 kg of liquid water it takes 2250 kcal of energy.
|
| If that mass was water it would require 1.23e11 kcal of energy.
|
| I suspect that both the amount of energy needed and the amount of
| pollution added would be unbearable.
|
| And this is for a hole that's "just" 10 km deep.
| foobarian wrote:
| 1 m^2 x 10,000 m = 10,000 m^3
|
| 10 km^3 = 10 x 1,000 x 1,000 x 1,000 m^3 != 10,000 m^3
| notorandit wrote:
| Correct! I fixed my numbers too. Still a lot of stuff.
| istjohn wrote:
| Your cross section area is off by two orders of magnitude. They
| currently are drilling a 0.008 m2 hole at one meter per hour
| with 1 MW of power. They hope to scale that up to a 0.032 m2
| hole while maintaining the same rate of depth penetration and
| energy use per meter [0].
|
| 0. https://m.youtube.com/watch?v=b_EoZzE7KJ0&t=500s
| itishappy wrote:
| Think you're somewhat off. Quaise says they intend to allow
| their tech to be "plugged into existing oil rigs," and most
| boreholes are 5-20 in wide.
|
| 20 in down 7.6 mi is 0.2 m^2 down 12321 m. This gives 2500 m^3
| or 2.5e-6 km^3 of rock.
|
| Google says "rocks are generally between 1600 kg/m^3
| (sediments) and 3500 kg/m^3 (gabbro)" so going with 2500 km/m^3
| that would be 6240000 kg, 6.24 Gg, or 6.24 thousand metric
| tons.
|
| Heat of vaporization of water is roughly 2250 kJ/kg, or 537
| kcal/kg, so if the mass was water it would need 14e9 kJ, 14 TJ,
| or 3.35e9 kcal to vaporize.
|
| For a 5 in borehole divide all the above by 16. This ignores
| the heat required to actually change the temperature of the
| water, but I'm betting you can get a lot of that back via
| condensation, and for this reason I'd also assume that much of
| the rock will not end up in atmosphere. These assumptions also
| go entirely out the window of there's an inflow of material,
| but unfortunately I'm betting that's exactly what will happen.
|
| Edit: Fixed post after I confused radius and diameter. Someone
| should probably check my math as well.
| api wrote:
| I have always thought that very deep geothermal is a massive
| potential source of renewable energy that gets far too little
| attention.
|
| If we can make it work, we have a source of "limitless" (at
| terrestrial human scale) energy that doesn't require expensive
| battery backup and is dispatchable. It could also be used as a
| source of industrial process heat, cogeneration (if it's safe to
| do near or inside city limits), etc. I've even seen proposals to
| make methane or liquid fuels by injecting CO2 and H2 or H2O down
| there and using it as a thermally driven in situ synfuel reactor.
|
| Solar is one way of using a ready-made natural nuclear reactor.
| This is another. Some geologists believe the Earth's core is a
| natural fission reactor, and a few people have proposed other
| even more exotic possibilities:
|
| https://www.nature.com/articles/srep37740
| WalterBright wrote:
| I read about this years ago on HN and then ... nothing. Glad to
| see it back in the news. It really would be tremendous if it
| works.
| actionfromafar wrote:
| Don't tell the Evangelicals, they will believe you are drilling a
| hole to hell.
|
| (And the oil companies will view the competition as from Satan?)
| foobarian wrote:
| <armchair geologist hat on>
|
| Wonder if they could drill a stable hole with a honeycomb
| arrangement of lasers like engines on the Starship, but with
| smaller radius. It wouldn't strictly be an empty hole but just a
| bundle of small diameter holes. Whatever the laser hits,
| vaporizes until it's out or turns into glass on the side.
| Whatever caves in just keeps getting vaporized.
| dhosek wrote:
| 63 comments and no one brings up Betteridge's Law of Headlines:
| "Any headline that ends in a question mark can be answered by the
| word no."
|
| (The 63 comments essentially support Betteridge.)
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