Directional drilling is the process of installing underground conduit and pipelines while keeping excavations to an absolute minimum.
The procedure is carried via a surface mounted directional drilling rig capable of pushing, rotating and pulling a string of steel drilling rods. The drill string is guided along a predetermined borepath from the drilling rig to an exit pit excavation, where the steering head is removed and a hole opener (reamer) attached. The pipeline or conduit (usually a PE or PVC material) can then be directly connected behind the hole opener via a swivel.
During both the guidance and hole opening process the native ground material is cut into fine particles and suspended in a drilling slurry for transportation out of the borehole.
Through the use of trenchless equipment and methods, environmental and social impacts of infrastructure installations can be kept to an absolute minimum. The technology also allows for installations under rivers, structures, swamps, protected trees and at depths unachievable using traditional open-cut methods.
CDS New Zealand Limited operate a fleet of DitchWitch® directional drilling rigs that range from 120KN to 358KN of pullback capability. Our rigs are capable of trenchless installations of pipelines and conduit ranging in from 32mm to 1.2m in diameter. Our largest Drilling rig has a proven capability of a single installation of 1.2km in length.