Bit packer for dual tube drilling

Check valve sub

Continuous injection of an inert gas through a drill rig for dri

Coupling structure for a compound drill stem

Drill pipes and casings utilizing multi-conduit tubulars

Drill rod

Drill string component for drilling with a liquid driven drillin

Drilling apparatus

Hammer drill bit and sub-assembly

High pressure fluid apparatus

Hydraulic device for forming a cavity in a borehole

Locking a sample tube in a downhole hammer

Method for improving drill cuttings transport from a wellbore

Microtunnelling system and apparatus

Multi-walled drill string for exploration-sampling drilling syst

Reverse circulating tool

Reverse circulation down-the-hole drill

System for adapting top head drilling rigs for reverse circulati