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

It works like a basic hand drill. Except driven by gigantic motors instead of hand.

The drill is rotated while being pushed down, both by gravity and machine. It is a relatively slow process. This causes a hole to form and the material drilled to be moved up along the shaft. As it gets deeper, sections of pipe/tubing are added.

Typically for wells, this is done with a specialized fluid for lubrication and to help bring the debris drilled up to the surface. The fluid is often called mud. The mud slurry is pumped down and filtered when it comes back up with drilled material.

A casing is pushed down along the sides of the well to maintain its structure and prevent contamination in and out of the well bore hole.

Then a pump system is installed and production begins.