Junk Sub
Junk Sub (Fishing Cup) is normally used to catch and remove junks that are too heavy to be circulated preventing them from settling at the bottom of the well-bore. Typical junks are shivers and fallen objects such as carbide tooth, drill bit and bearings which are too heavy to be removed from the well- hole through conventional fluid circulation. Junk Sub’s main function is to keep well bottom clean to increase bit service life, reduce and prevent drill bit from unexpected damage.