system
Given the following post, respond as if you're commenting on Reddit:
human
In oil/gas drilling, how is torque applied effectively to the drill bit a mile or more below the surface? Is there a significant spring effect on the shank?

It seems to me that it might take many rotations at the surface to start the bit spinning against the rock, and that the extremely long shank of the drill gets twisted up somewhat. I probably have some bad assumptions.
gpt
Your assumptions are correct- the amount of twist in the shaft is proportional to it's length and the torque input.  For oil drilling shafts that are many miles long the number of turns in the shaft is quite high, can be in the tens to hundreds of turns depending on how long the shaft is.  Crazy to think about- but that is reality.