Definition - What does Directional Drilling mean?
Directional drilling is the process of drilling a pilot hole along a planned route between two predetermined points. The pipe or cable is then installed by using the drill string to pull it through the excavated route back to the start point. Reaming is done, if necessary, to upsize the hole. In trenchless technology, directional drilling is a favored method of installing underground utilities with minimum disruption to surface structures.
Trenchlesspedia explains Directional Drilling
Directional drilling requires a few major components like:
- A directional drill rig based on the size of the installation
- Drill rods linked to form a drill string that advances the drill bits and pulls back reamers and products
- A transmitter to guide the drill using its location
- A mixing tank
- A pump for storing and circulating drill fluid
As the drill progresses through the planned track, it transmits its position to the operator who can divert the drill in case of obstructions or weak areas in the path. Once the pilot bore is completed, the drill is replaced with a back reamer to which the cable or pipe is attached. As the drill string is retracted, the pipe is installed. The drilling fluid is of prime importance in directional drilling, because in addition to lubricating and cooling, it contains polymers that help to bind and stabilize the surrounding earth.