2 ms·

For those curious, for all of history, mankind has probably only dug a few dozen or so holes a mile deep or deeper. It’s not easy

deleted 2y ago
[deleted]
yxhuvud 2y ago
Keeping things cool at that depth also seems like a challenge.
- shagie 2y ago
  Which would then suggest the alternate approach of just push down cold water and get back hot water without any nuclear reactor at the bottom of the hole. We're not talking hot hot everywhere, but possibly still useful. https://www.researchgate.net/figure/The-average-temperature-gradient-for-planet-Earth-is-20-per-kilometre-In-many-areas_fig2_352197150 https://www.researchgate.net/figure/The-average-temperature-... > The average temperature gradient for planet Earth is 20 °C per kilometre. In many areas around the world the gradient is higher, and the temperature increases at a faster rate with depth below the ground. With a temperature gradient of between 50 and 100 °C geothermal resources are more readily accessible. Above 20 °C geothermal waters can be used for direct uses like greenhouses, aquaculture and district heating applying heat pumps. Above 75 °C the water is hot enough to be used for electricity generation using binary cycle technology. Above 160 °C flash steam generation can be used to produce clean, renewable electricity. Source: Geothermal Resources Council
SkyPuncher 2y ago
This data suggests that 1 mile is common for oil wells: https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm Obviously, that’s not a meter wide hole, but it’s clearly possible.
n1b0m 2y ago
What are the challenges involved which makes it so difficult?
- batch12 2y ago
  Off the top of my head: rocks, water, debris, inconsistent medium, length of the drill bit needed, tool breakage
Bedon292 2y ago
Are you separating digging holes from drilling holes? Digging out something like a mine for people to be in to that depth is definitely hard and you are right there is a very limited number of those. That is not really what the article is discussing though. They are talking about putting it down a drilled hole, and a mile is a very common depth for drilling. In a USGS publication summarizing deep wells in the US through 1998 [1], it talks about a dataset of more than 20,000 wells over 15,000ft (4,572 m), more than 1,000 wells over 20,000ft (6,096 m), and 52 over 25,000ft (7,620 m). [1] https://pubs.usgs.gov/dds/dds-067/CHB.pdf https://pubs.usgs.gov/dds/dds-067/CHB.pdf

deleted 2y ago

[deleted]

yxhuvud 2y ago

Keeping things cool at that depth also seems like a challenge.

shagie 2y ago
Which would then suggest the alternate approach of just push down cold water and get back hot water without any nuclear reactor at the bottom of the hole. We're not talking hot hot everywhere, but possibly still useful. https://www.researchgate.net/figure/The-average-temperature-gradient-for-planet-Earth-is-20-per-kilometre-In-many-areas_fig2_352197150 https://www.researchgate.net/figure/The-average-temperature-... > The average temperature gradient for planet Earth is 20 °C per kilometre. In many areas around the world the gradient is higher, and the temperature increases at a faster rate with depth below the ground. With a temperature gradient of between 50 and 100 °C geothermal resources are more readily accessible. Above 20 °C geothermal waters can be used for direct uses like greenhouses, aquaculture and district heating applying heat pumps. Above 75 °C the water is hot enough to be used for electricity generation using binary cycle technology. Above 160 °C flash steam generation can be used to produce clean, renewable electricity. Source: Geothermal Resources Council

SkyPuncher 2y ago

This data suggests that 1 mile is common for oil wells: https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm https://www.eia.gov/dnav/pet/pet_crd_welldep_s1_a.htm Obviously, that’s not a meter wide hole, but it’s clearly possible.

n1b0m 2y ago

What are the challenges involved which makes it so difficult?

batch12 2y ago
Off the top of my head: rocks, water, debris, inconsistent medium, length of the drill bit needed, tool breakage

Bedon292 2y ago

Are you separating digging holes from drilling holes? Digging out something like a mine for people to be in to that depth is definitely hard and you are right there is a very limited number of those. That is not really what the article is discussing though. They are talking about putting it down a drilled hole, and a mile is a very common depth for drilling. In a USGS publication summarizing deep wells in the US through 1998 [1], it talks about a dataset of more than 20,000 wells over 15,000ft (4,572 m), more than 1,000 wells over 20,000ft (6,096 m), and 52 over 25,000ft (7,620 m). [1] https://pubs.usgs.gov/dds/dds-067/CHB.pdf https://pubs.usgs.gov/dds/dds-067/CHB.pdf