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

A traditional drilling rig has no ability to push, and the first joint of pipe or two will be special, super heavy weighted stuff called drill collars.

The rig is used to pull up on the pipe, and as the hole gets deep this pulling force can be a hundred tons. That leaves just a little weight on the bit, just enough to do it’s job.

Yes, the pipe is like a wet noodle, and spinning the top takes just a bit to make it to the bottom, winding up the pipe. Same happens when the rig lifts the pipe, it stretches.