Just in case people aren’t aware of this, drilling wells the “old fashioned way” is a very advanced technology. Typically a mechanically complex diamond-tipped tungsten carbide drill bit grinds its way down, while a fluid with precisely calibrated density and reactivity is circulated down the center of the drill string and back up the annulus between the drill string and edges of the hole, sweeping the drill cuttings up the borehole to the surface. A well 4 miles long and 8 inches wide has a volume of over 200,000L, meaning that’s the volume of rock that has to be mechanically removed from the hole during drilling. So that’s the volume of rock you would have to “blow” out of the hole with compressed air. You can see why using a circulating liquid with a reasonably high viscosity is more efficient for this purpose.
The other important thing about drilling fluid is that its density is calibrated to push statically against the walls of the hole as it is being drilled, preventing it from collapsing inward and preventing existing subsurface fluids from gushing into the wellbore. If you tried to drill a hole with no drilling fluid, it would probably collapse, and if it didn’t collapse, it would fill with high pressure groundwater and/or oil and/or explosive natural gas, which would possibly gush straight to the surface and literally blow up your surface facilities. These are all things that would almost inevitably happen if you tried to drill a hole using microwaves and compressed air.
tl;dr, drilling with microwaves might sense if you’re in space drilling into an asteroid, but makes so no sense for this application.
ertical holesYes: conventional drilling requires much less energy—but takes 30 times longer!
To ensure stability—the two vertical boreholes and the bundle of connecting boreholes of the “heat exchanger” for the closed loop system must be installed in solid granite! - - Advance there: conventional 1 to 1.5 m/h—with evaporation 35 to 40 m/h (for Diameter ~2 inch). For a 1 GW-construct 4m /hr are realistic - so one of the two vertical holes can be drilled in 4000 hrs - nearly half of a year ! Limit for rotation drilling is regulary at 9000 m !
Note additional : with increasing depth, the temperature increases by approx. 40k per km. At 12 km it is already almost 500°C—plus the heat for the drilling process 150-200°C.
The heat for the drill head is then almost 700°C - ! No material can withstand that for a long time.
And: even the best diamond drill head wears out within a few days—then the entire string has to be completely pulled out EVERY TIME to change the bit.
Drilling are NOT be done with air, but with inert gas—e.g. liquid CO2 - in the heat on site it gasifies and thus increases its volume by almost 600 times (under normal pressure) and there is also the enormous increase in volume of the vaporized granite. This means that the gasified rock does not have time to attach itself to the wall when it condenses until it has cooled down to simple dust!
Bringing the microwave power to the drill head is certainly a problem. The attenuation is actually enormous, especially since there is currently no concept for a FLEXIBLE wave guide several kilometers long.
An existing slim version of the gyrotron will probably have to be modified in such a way that it can be dragged a few 10 meters behind the drill head (heat protection).
Then all that is needed is the inert gas and the power cable to achieve this length - - - intermediate inert gas pumping stations can also be supplied with power via the cable. Since the diameter will be greater than 15 inches for an appropriate flow rate of supercritical water, there is sufficient cross-section for pumps and cables—as well as return flow.
There are certainly still problems to be solved - - and therefore the world’s specialized scientific institutions should definitely focus on these problems with the highest priority and appropriate financial resources! If it weren’t for the enormous volume of orders with the insane profit of several hundred billion when converting the economy to wind & PV with the subsequent ruin and the even more profitable reconstruction of the economy - !
Because drilling into natural grown granite (stock) it is almost impossible to come across a gas or oil deposit—and since THIS non-contact drilling (no vibrations !) allows continuous sonar measurement, cavities and faults in the rock can be largely avoided!
Due to the fact that must be drilled in Granite - THIS rock does NOT flow into the borehole . And if Granite will be vaporated, than any fluid anyway - that would be a coocking kettle .
And if the rock will be vaporated—the wall is melting and will get a thick and stabile rock glaze ! That stabilisizes and seals same time like an intruded tube!
Just in case people aren’t aware of this, drilling wells the “old fashioned way” is a very advanced technology. Typically a mechanically complex diamond-tipped tungsten carbide drill bit grinds its way down, while a fluid with precisely calibrated density and reactivity is circulated down the center of the drill string and back up the annulus between the drill string and edges of the hole, sweeping the drill cuttings up the borehole to the surface. A well 4 miles long and 8 inches wide has a volume of over 200,000L, meaning that’s the volume of rock that has to be mechanically removed from the hole during drilling. So that’s the volume of rock you would have to “blow” out of the hole with compressed air. You can see why using a circulating liquid with a reasonably high viscosity is more efficient for this purpose.
The other important thing about drilling fluid is that its density is calibrated to push statically against the walls of the hole as it is being drilled, preventing it from collapsing inward and preventing existing subsurface fluids from gushing into the wellbore. If you tried to drill a hole with no drilling fluid, it would probably collapse, and if it didn’t collapse, it would fill with high pressure groundwater and/or oil and/or explosive natural gas, which would possibly gush straight to the surface and literally blow up your surface facilities. These are all things that would almost inevitably happen if you tried to drill a hole using microwaves and compressed air.
tl;dr, drilling with microwaves might sense if you’re in space drilling into an asteroid, but makes so no sense for this application.
Also, polycrystalline diamond (PDC) bits are pretty common these days.
ertical holesYes: conventional drilling requires much less energy—but takes 30 times longer!
To ensure stability—the two vertical boreholes and the bundle of connecting boreholes of the “heat exchanger” for the closed loop system must be installed in solid granite!
- - Advance there: conventional 1 to 1.5 m/h—with evaporation 35 to 40 m/h (for Diameter ~2 inch).
For a 1 GW-construct 4m /hr are realistic - so one of the two vertical holes can be drilled in 4000 hrs -
nearly half of a year ! Limit for rotation drilling is regulary at 9000 m !
Note additional : with increasing depth, the temperature increases by approx. 40k per km.
At 12 km it is already almost 500°C—plus the heat for the drilling process 150-200°C.
The heat for the drill head is then almost 700°C - ! No material can withstand that for a long time.
And: even the best diamond drill head wears out within a few days—then the entire string has to be completely pulled out EVERY TIME to change the bit.
Drilling are NOT be done with air, but with inert gas—e.g. liquid CO2 - in the heat on site it gasifies and thus increases its volume by almost 600 times (under normal pressure) and there is also the enormous increase in volume of the vaporized granite.
This means that the gasified rock does not have time to attach itself to the wall when it condenses until it has cooled down to simple dust!
Bringing the microwave power to the drill head is certainly a problem. The attenuation is actually enormous, especially since there is currently no concept for a FLEXIBLE wave guide several kilometers long.
An existing slim version of the gyrotron will probably have to be modified in such a way that it can be dragged a few 10 meters behind the drill head (heat protection).
Then all that is needed is the inert gas and the power cable to achieve this length - - - intermediate inert gas pumping stations can also be supplied with power via the cable. Since the diameter will be greater than 15 inches for an appropriate flow rate of supercritical water, there is sufficient cross-section for pumps and cables—as well as return flow.
There are certainly still problems to be solved - - and therefore the world’s specialized scientific institutions should definitely focus on these problems with the highest priority and appropriate financial resources!
If it weren’t for the enormous volume of orders with the insane profit of several hundred billion when converting the economy to wind & PV with the subsequent ruin and the even more profitable reconstruction of the economy - !
Because drilling into natural grown granite (stock) it is almost impossible to come across a gas or oil deposit—and since THIS non-contact drilling (no vibrations !) allows continuous sonar measurement, cavities and faults in the rock can be largely avoided!
Due to the fact that must be drilled in Granite - THIS rock does NOT flow into the borehole .
And if Granite will be vaporated, than any fluid anyway - that would be a coocking kettle .
And if the rock will be vaporated—the wall is melting and will get a thick and stabile rock glaze !
That stabilisizes and seals same time like an intruded tube!