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I think the idea is to use a traditional drilling technique to start the whole until they are past any gas pockets, then use the beams after that. The beam dril

by Mizza 4y ago

I think the idea is to use a traditional drilling technique to start the whole until they are past any gas pockets, then use the beams after that. The beam drilling doesn't require fluid, and the process itself creates a glass wall/lavatube on the side of the hole. They drill quite slowly relative to traditional drilling to evacuate the ash and fumes, but they don't need to replace the drill head so the overall process is faster.

ufmace 4y ago
Still sounds rather dubious. I dunno about this whole thing about the beam creating a protective glass wall, but I'll give them a pass on that. Also on how they'd actually evacuate all the fluid and how they'd extract ash and fumes without it. The most critical part sounds like heat. It's very hot down there, and we're also presumably running megawatts of electrical power for this beam, which all goes to more heat. Ambient temps at those depths may be over 300 F / 150C, and that's before we pump in megawatts of extra heat with no way to extract it. I helped design and operate lots of oilfield electronics for those depths and temperatures. MTBF for the most hardened electronics we could get our hands on at temps over 150C was in the neighborhood of 200 hours max. Drilling slowly with much more sophisticated and unproven electronics, I expect they'll be dropping like flies if they ever work at all. And that's with extremely generous assumptions on the heat loads. MTBF of electronics drops exponentially as temperature goes up.
- jasamer 4y ago
  The plan seems to be to have the gyrotron that generates the drilling beam on the surface, so the electronics don't have to withstand any heat at all. The "only" need to manage to get a beam that's clean enough that it reaches 20km into the ground.
  - ufmace 4y ago
    Curiously, the other people who responded all think it'll be downhole. Anyways, this does make the device heat practical to handle, but now you have to figure out how you're going to get the vaporized rock out and shoot your microwave laser thing through 20km of rock vapors. And we're also presuming you can keep 20km of borehole exposed to atmospheric pressure with only this supposedly glass wall thing preventing formation fluids from flooding the borehole. If that cracks anywhere and floods it with high pressure hydrocarbons, maybe you could seal it up before all of your surface hardware gets blown up, but what do you do next? Oil wells have procedures for how to circulate heavier fluid back in to get the well back under control, but I have no idea how you fix a failed glass wall thing.
- yetihehe 4y ago
  Problem with traditional drilling is that your drill has to contact with hot rocks. With gyrotron, it doesn't have to. If you pump lot's of water down to your electronics, it can be used to cool electronics, then gyrotron, then be dumped outside head where it flashes into steam (thanks to megawatts of energy that is melting rocks already) and helps to evacuate ash while also cooling it and preventing recondensation on walls of already drilled tube. Walls will still be glassy because they were just melted.
  - ufmace 4y ago
    That doesn't sound practical at all. It doesn't matter if you have direct contact or not, everything down there is that hot, so you're gonna be that hot. Existing oilwells already flow fluid through at a fairly high flowrate - high enough that eroding parts is a concern - and it's not enough to get the temperature down much. You're gonna need something a lot better than "just pump some water though" to cool things down enough to get the MTBF back up. And that's before accounting for how much heat this rock melting microwave laser thing plus it's power transmission lines is adding to the environment.

by Mizza 4y ago

ufmace 4y ago

Still sounds rather dubious. I dunno about this whole thing about the beam creating a protective glass wall, but I'll give them a pass on that. Also on how they'd actually evacuate all the fluid and how they'd extract ash and fumes without it. The most critical part sounds like heat. It's very hot down there, and we're also presumably running megawatts of electrical power for this beam, which all goes to more heat. Ambient temps at those depths may be over 300 F / 150C, and that's before we pump in megawatts of extra heat with no way to extract it. I helped design and operate lots of oilfield electronics for those depths and temperatures. MTBF for the most hardened electronics we could get our hands on at temps over 150C was in the neighborhood of 200 hours max. Drilling slowly with much more sophisticated and unproven electronics, I expect they'll be dropping like flies if they ever work at all. And that's with extremely generous assumptions on the heat loads. MTBF of electronics drops exponentially as temperature goes up.

jasamer 4y ago
The plan seems to be to have the gyrotron that generates the drilling beam on the surface, so the electronics don't have to withstand any heat at all. The "only" need to manage to get a beam that's clean enough that it reaches 20km into the ground.
- ufmace 4y ago
  Curiously, the other people who responded all think it'll be downhole. Anyways, this does make the device heat practical to handle, but now you have to figure out how you're going to get the vaporized rock out and shoot your microwave laser thing through 20km of rock vapors. And we're also presuming you can keep 20km of borehole exposed to atmospheric pressure with only this supposedly glass wall thing preventing formation fluids from flooding the borehole. If that cracks anywhere and floods it with high pressure hydrocarbons, maybe you could seal it up before all of your surface hardware gets blown up, but what do you do next? Oil wells have procedures for how to circulate heavier fluid back in to get the well back under control, but I have no idea how you fix a failed glass wall thing.
yetihehe 4y ago
Problem with traditional drilling is that your drill has to contact with hot rocks. With gyrotron, it doesn't have to. If you pump lot's of water down to your electronics, it can be used to cool electronics, then gyrotron, then be dumped outside head where it flashes into steam (thanks to megawatts of energy that is melting rocks already) and helps to evacuate ash while also cooling it and preventing recondensation on walls of already drilled tube. Walls will still be glassy because they were just melted.
- ufmace 4y ago
  That doesn't sound practical at all. It doesn't matter if you have direct contact or not, everything down there is that hot, so you're gonna be that hot. Existing oilwells already flow fluid through at a fairly high flowrate - high enough that eroding parts is a concern - and it's not enough to get the temperature down much. You're gonna need something a lot better than "just pump some water though" to cool things down enough to get the MTBF back up. And that's before accounting for how much heat this rock melting microwave laser thing plus it's power transmission lines is adding to the environment.