Horizontal Directional Drilling
Directional Drilling is a technique which can be used for the installation of pipelines and ducts of varying diameters over short or long distances. Advances in drilling rig design and st eering techniques have made this method of construction extremely flexible. Diameters of 100mm and above can be installed by Directional Drilling and lengths of 2000m and more are possible in one drill shot.
A pilot bore is installed by pushing a line of steel rods through the ground. A “shoe” at the leading end of the rods enables steering of the line to be carried out. A sonde within the shoe transmits a signal which is received by a tracker at ground level. The line of pilot rods follows a pre-determined course until the installation between launch and receiving pits is complete. The pilot roads are then pulled back to the launch pit with a reamer attached. Several reaming passes may be required until the hole is large enough for the final product pipeline. A drilling mud, usually bentonite based, is used to carry the arisings and to prevent collapse of the hole. Finally, the product pipe is pulled in behind the last reamer to form the complete installation.
The technique is applicable for ducts and pipelines beneath roads, rivers and railways, and often forms and economical alternative to open trench pipelaying techniques under roads.
Terra Solutions have many years experience of the ownership and operation of directional drilling equipment. The very latest drilling muds are available through sister company Drilling Supplies Ireland Ltd. This integrated approach is an essential factor in the success of our Directional Drilling contracts.