Horizontal directional drilling: a valuable service defined

At Master Bore, LLC we believe it’s important to define our terms so our customers understand exactly what it is they’re getting when they pay for our services. Sometimes we might not even be sure we need something until we know what it is and have taken the time to understand it. While one of our main focuses is trenchless sewer line repair, we also offer a wide range of other services.

That’s why we wanted to take the time to explain one of our less utilized, but extremely valuable, services: directional drilling. We’ll tell you what it is and when you might need it.

What is horizontal directional drilling and when do I need it?

Horizontal directional drilling is often used to install pipes in areas where traditional open cut construction is difficult. During this process, all the drilling is done underground. This means if it’s done properly, no damage should occur to the things above ground. Not only does the drilling itself have little effect on what is going on surface-level, it also requires minimal job site disturbance on the entry and exit sites. This type of drilling is especially beneficial in the cases where the job requires drilling over long distances, particularly in urban areas.

There are three parts in the horizontal directional drilling process:

Creating a pilot hole

This first stage is creating a pilot hole. A pilot hole is made by drilling a hole that’s small in diameter. Start and finish of the drilling line must be pre-planned as well the route the drill is going to take. This is especially important if there could be other underground pipes or cables in the way.

One a drilling pit is created — this is especially important as this is where the drilling fluids are contained — the drilling process begins. A steering tool is located near the drill head and sends signal to the engineer. This allows those above ground to know exactly where their drill is headed and to make corrections if needed.

Getting the hole to the right size

The next step in the process is called pre-reaming. This involves getting the hole to a large enough size that piping or whatever else can be installed properly and safely. This is typically 1.5 times the size needed for whatever is being installed.

In order to do this, engineers will attach a reamer and pull it back through the exit hole and back through the entrance. The reamer rotates and pumps drill fluid to cut through solids and widen the hole.


The last stage in this process is the installation of the pipe. This is simply pulled into place by the directional drill rig. Drilling fluid is often used to provide the lubrication needed to successfully complete the installation job.

Master Bore, LLC provides solutions for an unconventional markets

We hope this post has helped clear up some of the questions you have about horizontal directional drilling and allowed you to see some of its value.

If you’re interested in learning more about our directional drilling services, call or contact us today.