4 ms·

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 an

by Retric 2y ago

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 2y ago
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 2y ago
  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 2y ago
    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 2y ago
      They need to be able to steer drills for all kinds of reasons: https://www.youtube.com/watch?v=JAhdb7dKQpU 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 https://news.ycombinator.com/item?id=43371776
  - BriggyDwiggs42 2y ago
    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.
    - deleted 2y ago
      [deleted]
    - Retric 2y ago
      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 https://news.ycombinator.com/item?id=43371776
      - BriggyDwiggs42 2y ago
        Ah yep that does explain it well.
- ada1981 2y ago
  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 2y ago
    That's exactly what they do. It just takes a while since there's tens of thousands of feet of drillstring.
    - ada1981 2y ago
      Then what’s the jive about needing to drill around the old bits?
      - Retric 2y ago
        Removing many miles of pipe to swap out a drill bit at the end is slow and seems rather inefficient. Which suggests just leaving the old drill bit somewhere in the ground. But currently doing that would also involve removing the pipe, as to why: https://news.ycombinator.com/item?id=43371776 https://news.ycombinator.com/item?id=43371776
      - ufmace 2y ago
        That was answering silly speculation about intentionally leaving worn-out drill bits behind. There are actually workable procedures for drilling around things, but it's far more cumbersome and time-consuming than replacing a bit normally. Those procedures used for things like the drillstring getting stuck due to hole collapse; nobody would do that just for a worn-out drill bit. The actual way to avoid the problem is by using bits whose design lifetime in the formation you're drilling is at least as long as the hole section you're planning to drill.
cnote337 2y ago
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 2y ago
  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 2y ago
    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.

by Retric 2y ago

CorrectHorseBat 2y ago

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 2y ago
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 2y ago
  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 2y ago
    They need to be able to steer drills for all kinds of reasons: https://www.youtube.com/watch?v=JAhdb7dKQpU 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 https://news.ycombinator.com/item?id=43371776
- BriggyDwiggs42 2y ago
  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.
  - deleted 2y ago
    [deleted]
  - Retric 2y ago
    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 https://news.ycombinator.com/item?id=43371776
    - BriggyDwiggs42 2y ago
      Ah yep that does explain it well.
ada1981 2y ago
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 2y ago
  That's exactly what they do. It just takes a while since there's tens of thousands of feet of drillstring.
  - ada1981 2y ago
    Then what’s the jive about needing to drill around the old bits?
    - Retric 2y ago
      Removing many miles of pipe to swap out a drill bit at the end is slow and seems rather inefficient. Which suggests just leaving the old drill bit somewhere in the ground. But currently doing that would also involve removing the pipe, as to why: https://news.ycombinator.com/item?id=43371776 https://news.ycombinator.com/item?id=43371776
    - ufmace 2y ago
      That was answering silly speculation about intentionally leaving worn-out drill bits behind. There are actually workable procedures for drilling around things, but it's far more cumbersome and time-consuming than replacing a bit normally. Those procedures used for things like the drillstring getting stuck due to hole collapse; nobody would do that just for a worn-out drill bit. The actual way to avoid the problem is by using bits whose design lifetime in the formation you're drilling is at least as long as the hole section you're planning to drill.

cnote337 2y ago

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 2y ago
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 2y ago
  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.