Horizontal directional drilling is a preferred method of installing cables, pipes, and conduits using a specialised drilling rig. The drilling process begins by creating a pilot hole at one end of the installation path. The drilling rig has corresponding accessories such as the drill pipe and drill bit which burrows underneath the ground surface to create a passageway for the pipes. Once the drill bit exits the other end of the path, pipes are drawn and pulled back into the hole. The process may also involve an additional step of enlarging the hold using a reamer to accommodate the size of the cables.


Is there a maximum diameter a rig can drill?


Horizontal directional drilling rigs have various capacities. The maximum diameter depends on the available fleet the drilling company owns. Typically, drill rigs can cut a hole up to a maximum of 60 inches in diameter.


What are the typical uses of horizontal directional drilling?


Horizontal directional drilling is a method used for utility cable installation. Some examples include internet fibre optics, water lines, main sewage connections, and underground electricity cables. This method allows for the complicated setup of pipes in urban areas or underneath obstructions such as rivers and streams.


What is drilling fluid and what are the types used?


Drilling fluids used in the process help the drill bit and pipe seamlessly move underground while tackling geothermal obstructions. These fluids are typically made using bentonite and a variety of additives and polymers. The specific composition depends on the soil condition as well as the intended outcome.


What are the preparations required before starting to drill?


It is crucial to maintain safety and ensure the structural integrity of the horizontal directional drilling installation. As such, there are preliminary steps needed to prepare the site before the project begins. If the drilling site is located in an urban area where there is already a network of pipes installed underneath the drill site, the drilling company needs to secure a blueprint of the underground layout of cables to determine the most suitable path for the new installation.


Another essential preparation before starting to drill is analysing the ground condition. Experts need to investigate the type of soil, geothermal formations as well as other factors which may impact the success of the project.


Can horizontal directional drilling tackle all kinds of obstructions?


Here are some specific scenarios where horizontal directional drilling is a suitable application:


  • Underneath ecologically sensitive locations such as rivers, streams, lakes, and wildlife sanctuaries.
  • Under highways, freeways, intersections, and golf courses.
  • Connections for residential communities and developed urban areas.
  • Installing pipelines into a marine environment such as a desalination plant.
  • Connecting pipelines for delivering utility in processing plants and factories.
  • Installing pipes in residential communities and cities.

Horizontal directional drilling is a more efficient method compared with open-cut trenching. Nevertheless, the compatibility of directional drilling as a feasible solution still depends on many factors. There are some instances, such as when the installation depth is shallow, where horizontal drilling is not always possible.


Image: Pixabay.com