Downhole Drilling Assemblies Mean?
A downhole drilling assembly is all the equipment from the end of the drilling string to the face of the tunnel. It includes the drill bit, directional control and monitoring equipment, a mud motor and associated equipment. The purpose of the downhole drilling assembly is to advance the drill through the ground by cutting away at the tunnel face.
Trenchlesspedia Explains Downhole Drilling Assemblies
The downhole drilling assembly is actually a collection of equipment which forms the active drilling part of a Horizontal Directional Drilling machine. Due to the high stress environment involving torque provided by the drill string, the weight of the equipment pushing against the tunnel face and the presence of drilling fluid, the downhole assembly must be very robust. At the same time, high tech components to monitor and control the direction as well as measuring systems for analysing drill rate and efficiency are also present and must be protected from the harsh conditions. Downhole drilling assemblies are an expensive part of the drilling equipment.