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What is horizontal directional drilling?

The horizontal directional drilling process is a method developed in the United States. This has revolutionized the complicated installation of pipelines that were initially done using conventional dredging methods or otherwise diverted over long distances.

zlconn 60ton HDD machine working in india
zlconn 60ton HDD machine working in india

What is horizontal drilling?

Horizontal Directional Drilling (HDD) is a construction technique that involves drilling a tunnel under a waterway or other designated area. Where a pipeline or other fitting is then installed through this underground tunnel.

This horizontal drilling is often used for installing the following types of underground infrastructures: water pipes, telecommunications cables, electrical cables, gas and oil pipelines. The underground tunnel follows a specific curve from the entrance point, continues downwards under the special crossing area and then emerges again on the other side.

How does horizontal directional drilling work?

Horizontal directional drilling is done in three phases:

horizontal directional drilling process
horizontal directional drilling process

Test drilling

During the first phase, a drill bit that is hollow on the inside is pushed through the ground via a rigging. A Bentonite vacuum system is then used to keep the borehole open. It is therefore immediately possible to remove all excess soil.

Enlarging the borehole

After test drilling, the drill is removed and replaced by a reamer. This reamer is then used to widen the borehole. During this process, the reamer pulls a pipeline supplied with drilling fluid behind it to prevent it from collapsing.

Pulling the production pipe

In the final phase, the production line is drawn. As soon as the reamer has done its job, it is replaced by the production line and a final reamer. During this procedure, the pipe is often provided with a ballast pipe to absorb possible excessive pressure.

The advantages of horizontal directional drilling

There are a number of benefits that come from using this trenchless drilling method.

Faster installation . Using this horizontal drilling method works a lot faster compared to digging a trench for underground work. Digging a trench underground to add a pipe system causes much more damage to the ground as well. Plus it also takes a lot of time to replace all the removed soil.

However, using the directional drilling method only requires one pilot hole and a special machine to install these underground pipes.

Lower costs . Directional drilling is much more cost-effective compared to digging a trench to install an underground pipe. After all, much less machine and manpower is used compared to the regular method. This automatically means much lower costs.

Less disruption . HDD uses only one machine and one pilot hole that it uses to complete the entire project and therefore often has much less or no impact on the environment. This is not just about the amount of landscaping that is disrupted, but also the amount of time it takes to complete the project.

When to consider the horizontal drilling method

According to the Horizontal Directional Drilling explanation , you should consider this trenchless drilling technology if two or more of the questions below are answered YES:

  • Is the pipeline 1.5 meters deep or more?
  • Is the pipe below the groundwater table?
  • Is the ground unstable?
  • Is the subsurface overloaded with other utilities?
  • Is the installation used in an urban area?
  • Will the installation take place under a roadway, railway line or river?
  • Is the installation in a residential area?
  • Is the length of the pipe to be installed longer than 60 meters?

HDD drilling is a unique method for installing underground pipelines, cables and service lines using trenchless methods. It uses a directional drill and associated attachments to drill accurately along the chosen drilling path.

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