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Comment by Animats | Hacker News Reader

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...

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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.

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.

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.

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?

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.

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

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

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.

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

Ah yep that does explain it well.

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?

That's exactly what they do. It just takes a while since there's tens of thousands of feet of drillstring.

Then what’s the jive about needing to drill around the old bits?

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

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.

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.

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?

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.

How dare you Scumberger! (Me sitting in a scumberger wireline unit rn)

You're completely right doodlebug, our MD is around 30,000 with a TVD of about 26,000' (ballparking here so i'm not violating any contracts).

I also appreciate your other comments here!

They earned any moniker that I apply. Hopefully none of the people that I worked with are still there.

I can't edit that other comment any more. I did once because I had a long anecdote trying to give context to the pet name I apply to them. After I reread it I felt like it was too long and meandering.

So I wrote a longer, more meandering reply to explain the other one. I'm deleting that one too. Too much stuff. Suffice to say that my time with them was interesting, not fun, full of organizational dysfunction on levels I never thought possible. I hope you are having a nice career with them. I cut mine short to save my own sanity and everything else that I loved and cared about.

Oh I don't work for them, just with them. I'm an independent contractor now after 5 years with exxonmobil. Cut my career short there for the exact same reasons. Talk about organizational dysfunction!!

I totally get that too. Right after I struck out as an independent contractor a long time ago, I did some stuff for ExxonMobil. Very smart people there. Very tight, collaborative structure. It was easy to see how they had been so successful for so long. Lots of things working in sync. Totally unlike the situation at Scumbagger where you advanced quickly if you could get your snout far enough up the FSM's ass. If you were like me and came from an oilfield culture where ass-kissing could get your ass whooped before they fired you (seismic field crews never put up with any bullshit), then it didn't work for me at all. My FSM actively held me back and denied promotions that I had earned, moving the goalposts every time I hit the expected target. I wasn't the only one. He openly bragged that his payroll burden was the lowest in Anadrill for all regions globally because he had the least number of SFEs on his payroll. He said that he delayed promotions at all levels to keep his numbers low. He had come out of college with an MBA on a fast-track to management.

Life is full of new experiences. Every day finds you at another node on the decision tree that will ultimately define and document your life to others. Pick the wrong path and your options at the next node will be less attractive than those behind you. Pick the right path and you can continue like branches on a hackberry, making the most of every opportunity to continue growing toward the light.

Had I followed the path that vengeful rage had offered me I would never have had the opportunities to polish my skills and grow my career into a successful consultancy. They got off easy because I chose to take the long view for my family's sake and chose to let it slide while taking every opportunity to find another job. If I had let it be personal then a lot of things would be different.

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

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

> 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...

Microwaves are a longer wavelength of light which makes them less precise. So people don’t use them to cut stuff for the reason lithography swapped to ultra violet light.

This wants to dump a lot of heat into a large area, and there’s industrial uses for that: https://industrialmicrowave.com/industrial-microwave-heating...

You also have a device at home that uses microwaves for heating larger volumes of material…

We do use conventional drilling for geothermal!

We just have to be more selective with the location to ensure that there is heat nearer the surface. They're right, if you drill deep enough, it's hot everywhere. Even in non-geothermal oil and gas wells, we commonly have temperatures that exceed 250 degrees Fahrenheit. Our tools that we send down whole are commonly rated for 300-350 degree temperatures. Plenty of temperature down there!

Although I admit, I'm an oil and gas guy and don't really have any industry knowledge of geothermal.

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.

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