When drilling like 12 km deep into the ground, how is it possible that a 12 km long pipe (drill string) is able to turn the drill bit AND be pushed down enough to drill??

Question

A 12 km long pipe seems like a ridiculous length for any of that to be possible. Isn’t it like trying to drill a hole with a 258 ft long piece of spaghetti?

In: 1335

Answer 1

Mud motors are a thing. They rotate on the end on a drill string (pipe). The fluid that is pumped down hole (mud) to clean it out is used to turn a turbine of sorts in the mud motor or “drill bit” but this is mostly used to provide directional drilling. That being said, the drill isn’t actively “pushed” the pipes are put together such that gravity provides the “pushing” force. You put heavier pipe at the beginning to provide more weight after a while you end up with kilometers of heavy steel pipe that provides all the weight you need. The fluid “mud” l, is pumped into the center of the pipe all the way to the bottom and back up again. You track your torque and such and adjust your fluid to ensure the tailings “dirt,rock etc” makes it back to the surface and doesn’t bind everything up down hole. The drill rigs I worked on were “table drive”, the pipe would pass through the floor of the rig and interface with the table and be rotated by either big diesel motors or diesel electric set ups.