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!!
You'd need to trip out of hole for it, but that isn't really a problem. I know the video acts like tripping is the end of the world, but it's a standard day to day practice offshore. Everytime something breaks or dies down hole, or you finish a section of hole you need to case, you have to trip.
So yes, you could swap the two out. But we already have bits that are good at drilling hard rock (granites, etc) they're called tricone bits. They more so crush the rock than cut it. And they look badass.
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.
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.
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.