Specialist Horizontal Directional Drilling Services
Since its adoption in the UK during the mid-eighties, Horizontal Directional Drilling has become a mainstay trenchless technique for installing water, gas, utility pipelines and electricity ducts, ranging in diameter from 25mm to over 1,000mm. It crosses under watercourses, runways, roads, and railways, mitigating environmental harm and overcoming topographical issues and congested sites.
The HDD Advantage
HDD can be performed in most ground conditions with minimal surface disruption, typically installing PE or steel pipes in lengths of up to 2km, subject to ground conditions and design.
It is a proven cost-effective alternative to open cut methods for laying small diameter pipes in streetworks, significantly reducing time, traffic management and reinstatement.
HDD handles horizontal and vertical curves, often removing the need for large launch and reception pits, and multiple crossings used in other trenchless techniques.
Utilising modern Forward Reaming and Direct Pipe techniques, it is possible to install outfalls with minimal marine works, making it the established method for wind farm connections.Â
Traditional Horizontal Directional Drilling Process
HDD begins with a small pilot hole drilled between designated entry and exit points. The hole is then expanded through pre-reaming passes until it is 130-150% of the pipe’s diameter. The drill pipe connects to prefabricated product pipe string laid on rollers. The drill pipe is then retracted back to the drilling rig, pulling the product pipe into the completed bore. Â
Due to the curves of HDD bores and the use of pressurised drilling fluid, it is critical to correctly plan crossings to reduce the risks of frac-out, drilling fluid loss, settlement and surface movement. Our Design and Engineering team can support bore design, risk assessment, drilling fluid planning and third-party approval submissions.Â
