Forgive me, couldn't help sharing this harvested from wikipedia:
Air is almost 1% argon. Argon is 38% more dense than air.
Argon is used in fluorescent glow starters.
Argon has approximately the same solubility in water as oxygen and is 2.5 times more soluble in water than nitrogen
Argon can form clathrates with water when atoms of argon are trapped in a lattice of water molecules
About 700,000 tonnes of argon are produced worldwide every year.
Argon is inexpensive, since it occurs naturally in air and is readily obtained as a byproduct of cryogenic air separation in the production of liquid oxygen and liquid nitrogen: the primary constituents of air are used on a large industrial scale.
All the dark-matter detectors are currently operating with liquid argon.
Argon is sometimes used as the propellant in aerosol cans.
Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects .
Argon has also been used experimentally to replace nitrogen in the breathing or decompression mix known as Argox, to speed the elimination of dissolved nitrogen from the blood (commercial diving) .
Argon is also used in technical scuba diving to inflate a dry suit because it is inert and has low thermal conductivity.
Argon is used for thermal insulation in energy-efficient windows.[47]
Argon is used as a propellant in the development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR).
Compressed argon gas is allowed to expand, to cool the seeker heads of some versions of the AIM-9 Sidewinder missile and other missiles that use cooled thermal seeker heads. The gas is stored at high pressure
Argon has been used by athletes as a doping agent to simulate hypoxic conditions. In 2014, the World Anti-Doping Agency (WADA) added argon and xenon to the list of prohibited substances and methods, although at this time there is no reliable test for abuse.
"For the application in EGS drilling, this device uses a metallic waveguide to carry the
millimeter wave (MMW) beam to a standoff distance from the crystalline rock. Argon gas is
used as the waveguide fill medium due to its ability to stay transparent to MMW’s at such
deep depths and thus higher pressures [12]. Purge gas is also used to pump out the excess
material that has been transformed into smaller particles (Figure 2.4). "
As a former geologist involved in drilling, thats going to get real expensive, real fast, in terms relative to regular mechanical drilling thanks to the requirement for argon. Perhaps theres an economically efficient changeover point at depth as mechanical drilling becomes less capable due to increasingly plastic deformation.
You don't need a significant flow of argon, just enough to keep unwanted gasses out of the waveguide.
It's possible there exists a material that is transparent to mm waves, airtight, and can survive the conditions at the bottom of the hole. In such a case they could cap the waveguide and prevent any gas leakage.
I'm quite sure Quaise is well aware that Argon isn't cheap and are already exploring multiple avenues for reducing its usage.
It is interesting that they have to use Argon instead of the more typical Nitrogen or SF6. A waveguide with such a significant pressure differential is decidedly unusual and a unique challenger for what they are doing.
If the goal is to simply purge the content of the hole, compressed air is typically sufficient. That said, the wider the hole, and the deeper it is, the harder it is to lift material on air.
To be clear though, I'd love to have one of these rigs on my old project and compare rate of progression and hole quality. Particularly when establishing the hole in sedimentary gravels and clays. I imagine casing will still be required.
One thing that I'd be concerned about is the ability to collect samples if most of the material is being vaporised or melted. Similarly, the cooking of the side of the hole on the way down could make geophysical responses much more difficult to interpret. Sonic velocity would probably increase, televised would probably be harder to interpret, harder to spot hydrothermal infill in sedimentary cover, would it affect gamma tools (probably not)
Edit: also wondering how the hole holds up around aquifers. Does the super heating cause wall instability immediately above the non geothermal aquifers as superheated steam is created? How does this affect the hole stability if we are not casing?
Edit 2: if we are not casing, how does the hole hold up around aquifer sands, loose fill, fractured or brecciated mass?
Edit 3: Also! Do we ream open the top of the hole to down past the last aquifers before the geothermal horizon? If not, how are we stopping stopping aquifers interplay and interaquifer contamination?
perhaps, but usually things like "which fossil species are present" are also utilized to figure out what's going on near the drill bit, like if you're trying to reach oil deposits right along the edge of an old riverbed.
Some shale formations in Michigan, for example, sometimes requires drilling to a 4" thick target. You don't know the exact depth because the depth of that 4" thick layer can vary by many feet from an another spot 100m north/south.
I'm aware that if you search "thickness of Antrim shale" or "thickness of Collingswood shale", Google will happily tell you that it's 20-40 feet thick, but for modern drilling techniques, the economics of the well depend on hitting a much more narrow target than that, which can be delicately guided in by analyzing fossils that come up.
Yeah, they say in their launch video for Project Obsidian (https://www.youtube.com/watch?v=xmrna_r_b3A) that they'll drill the first 3km using conventional rotary drilling and mmWave beyond that.
I'd be curious if anyone (perhaps the parent) knows why – my assumption is that it's more expensive and/or not as reliable to drill higher up with mmWave, not least because the ground might be uneven materials, etc., and then it becomes something predictable and harder to rotary drill lower down, incl. as you would spend more time doing things like replacing bits low down and sending things up and down?
Naively, I wonder how much the density of argon gas helps here, in terms of being able to recover and reuse the argon gas in a relatively closed-loop system.
Forgive me, couldn't help sharing this harvested from wikipedia:
Air is almost 1% argon. Argon is 38% more dense than air.
Argon is used in fluorescent glow starters.
Argon has approximately the same solubility in water as oxygen and is 2.5 times more soluble in water than nitrogen
Argon can form clathrates with water when atoms of argon are trapped in a lattice of water molecules
About 700,000 tonnes of argon are produced worldwide every year.
Argon is inexpensive, since it occurs naturally in air and is readily obtained as a byproduct of cryogenic air separation in the production of liquid oxygen and liquid nitrogen: the primary constituents of air are used on a large industrial scale.
All the dark-matter detectors are currently operating with liquid argon.
Argon is sometimes used as the propellant in aerosol cans.
Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects .
Argon has also been used experimentally to replace nitrogen in the breathing or decompression mix known as Argox, to speed the elimination of dissolved nitrogen from the blood (commercial diving) . Argon is also used in technical scuba diving to inflate a dry suit because it is inert and has low thermal conductivity.
Argon is used for thermal insulation in energy-efficient windows.[47]
Argon is used as a propellant in the development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR).
Compressed argon gas is allowed to expand, to cool the seeker heads of some versions of the AIM-9 Sidewinder missile and other missiles that use cooled thermal seeker heads. The gas is stored at high pressure
Argon has been used by athletes as a doping agent to simulate hypoxic conditions. In 2014, the World Anti-Doping Agency (WADA) added argon and xenon to the list of prohibited substances and methods, although at this time there is no reliable test for abuse.
From the thesis: https://www.proquest.com/openview/624989df3cdd8055a6cee9affc...
"For the application in EGS drilling, this device uses a metallic waveguide to carry the millimeter wave (MMW) beam to a standoff distance from the crystalline rock. Argon gas is used as the waveguide fill medium due to its ability to stay transparent to MMW’s at such deep depths and thus higher pressures [12]. Purge gas is also used to pump out the excess material that has been transformed into smaller particles (Figure 2.4). "
As a former geologist involved in drilling, thats going to get real expensive, real fast, in terms relative to regular mechanical drilling thanks to the requirement for argon. Perhaps theres an economically efficient changeover point at depth as mechanical drilling becomes less capable due to increasingly plastic deformation.
Why mmwave instead of ultrasonic? FWIU 28 kHz shreds the quartzite in granite?
You don't need a significant flow of argon, just enough to keep unwanted gasses out of the waveguide.
It's possible there exists a material that is transparent to mm waves, airtight, and can survive the conditions at the bottom of the hole. In such a case they could cap the waveguide and prevent any gas leakage.
I'm quite sure Quaise is well aware that Argon isn't cheap and are already exploring multiple avenues for reducing its usage.
It is interesting that they have to use Argon instead of the more typical Nitrogen or SF6. A waveguide with such a significant pressure differential is decidedly unusual and a unique challenger for what they are doing.
You mean the argon gas used as medium specifically? I assume the purge gas is something else, cheaper?
If the goal is to simply purge the content of the hole, compressed air is typically sufficient. That said, the wider the hole, and the deeper it is, the harder it is to lift material on air.
To be clear though, I'd love to have one of these rigs on my old project and compare rate of progression and hole quality. Particularly when establishing the hole in sedimentary gravels and clays. I imagine casing will still be required.
One thing that I'd be concerned about is the ability to collect samples if most of the material is being vaporised or melted. Similarly, the cooking of the side of the hole on the way down could make geophysical responses much more difficult to interpret. Sonic velocity would probably increase, televised would probably be harder to interpret, harder to spot hydrothermal infill in sedimentary cover, would it affect gamma tools (probably not)
Edit: also wondering how the hole holds up around aquifers. Does the super heating cause wall instability immediately above the non geothermal aquifers as superheated steam is created? How does this affect the hole stability if we are not casing?
Edit 2: if we are not casing, how does the hole hold up around aquifer sands, loose fill, fractured or brecciated mass?
Edit 3: Also! Do we ream open the top of the hole to down past the last aquifers before the geothermal horizon? If not, how are we stopping stopping aquifers interplay and interaquifer contamination?
Great response! I'm just a layman here (former material scientist) but it's fun to think about this stuff!
Maybe you could hook up a mass spectrometer to the purge gas to get real time composition.
perhaps, but usually things like "which fossil species are present" are also utilized to figure out what's going on near the drill bit, like if you're trying to reach oil deposits right along the edge of an old riverbed.
Some shale formations in Michigan, for example, sometimes requires drilling to a 4" thick target. You don't know the exact depth because the depth of that 4" thick layer can vary by many feet from an another spot 100m north/south.
I'm aware that if you search "thickness of Antrim shale" or "thickness of Collingswood shale", Google will happily tell you that it's 20-40 feet thick, but for modern drilling techniques, the economics of the well depend on hitting a much more narrow target than that, which can be delicately guided in by analyzing fossils that come up.
i think they plan to drill with a traditional rig until they get deep/hot enough to necessitate a switch to mm wave
There is definitely an economic changeover point, I’m sure I read they will use conventional drilling down to a certain depth, before switching to MMW
I doubt argon is the purge gas.
Yeah, they say in their launch video for Project Obsidian (https://www.youtube.com/watch?v=xmrna_r_b3A) that they'll drill the first 3km using conventional rotary drilling and mmWave beyond that.
I'd be curious if anyone (perhaps the parent) knows why – my assumption is that it's more expensive and/or not as reliable to drill higher up with mmWave, not least because the ground might be uneven materials, etc., and then it becomes something predictable and harder to rotary drill lower down, incl. as you would spend more time doing things like replacing bits low down and sending things up and down?
Naively, I wonder how much the density of argon gas helps here, in terms of being able to recover and reuse the argon gas in a relatively closed-loop system.
This company was previously featured on a video by Real Engineering: https://www.youtube.com/watch?v=b_EoZzE7KJ0
Impressive, but how long did it take to drill 100 meters? I didn't see a mention of that.
They mentioned about 1 hour per meter at 1 MW.
I think we can use 1 Gulf War for units
Does it vaporize the granite?
Fwiw, I'll share some surfing:
Nice article on an earlier demo: https://newatlas.com/energy/quaise-energy-millimeter-wave-dr... ; linked from this (nice but lots lots of ads): https://newatlas.com/energy/quaise-energy-millimeter-wave-dr... .
Company https://www.quaise.com/ on YT https://www.youtube.com/@quaise
MS thesis (2024; browsable) on the vitrified wall, for that and its intro: https://www.proquest.com/openview/624989df3cdd8055a6cee9affc...
Search for papers "Millimeter Wave Drilling for Deep Geothermal Energy Production" https://scholar.google.com/scholar?hl=en&as_sdt=0%2C33&q=Mil...
Wow. That's interesting. Thats tx of 300ghz.
Very interesting application of radio waves.
They made the laser drill from The Core IRL?
Except that it is not a laser but a high power radio transmitter made with a vacuum tube (gyrotron).
For generating the highest possible power of radio waves, vacuum tubes remain the only solution.
This drilling method resembles more a microwave oven (which uses a magnetron), than a laser.