Rathole

Drilling Equipment & Components

The rathole is another hole in the rig floor, used specifically to store the kelly and swivel when they are not in use (typically during tripping operations). Stowing the heavy, suspended kelly in the rathole clears the derrick floor for other activities.

On top drive rigs, the term is less relevant for storage, but 'rat hole' can also refer to the extra depth drilled at the bottom of the open hole to accommodate logging tools or junk that might settle, ensuring the casing can be landed at the correct depth.