Horizontal Directional Drilling: All You Want To Know

Horizontal Directional Drilling: All You Want To Know

Pipe installation is made easy on sensitive surfaces using the HDD process. The article explains all aspects related to horizontal directional drilling.

Getting the perfect bore path from the ground surface for various purposes is never a small project. Any mistake and loophole in the process can cause havoc. The wrong drilling for the telecommunication power cable or water, sewage, and gas pipe installation means the time and money invested, went to waste.

Therefore, the horizontal directional drilling method is the only comparatively safe method to choose for such activities. This drilling has minimal impact on surface area. It is the best method for environmentally friendly surface areas such as utilities, under roadways, waterways, or developed landscapes.

If you are considering getting the pipelines installed and a land bored, then horizontal drilling is the best option. The article explains all the information about the horizontal directional drilling process you should know before opting for it.


What Is Horizontal Directional Drilling?

Horizontal directional drilling is a trenchless construction method used to dig for pipe installation without disturbing the ground surface. The process is launched from the designed bore path’s starting point and retrieved at the desired endpoint. The whole process is carried underground except for the launch and retrieve points.

HDD has become a preferable choice over the conventional pipe-laying methods that involve opening the earth surface to the depth where the pipes are aimed to install for the entire pipeline route.

Process Of Horizontal Directional Drilling

The drilling is a three-step process

Pilot holes


Pipe pullback

Pilot Hole

The first step in the process is drilling a pilot hole using a steerable guided drill along the planned path. The pilot hole is usually 1 to 5 inches wide along the proposed centerline of the desired path of pipe alignment. When the drill of the pilot hole reaches the endpoint only then the second step is initiated.


The second step is to attach a reamer of approximately the same diameter as the pipe to the end of the drill and drill it to the end of the drill bit and pull it back to the end. Pre-reaming speed depends on the conditions of existing soil conditions and the number of cuttings removed from the ground. Usually, several passes are required to achieve the desired bore diameter.

Pipe Pullback

The final step is to pull back the pipe within the pre-reamed hole. The drill rod and reamer are attached to the swivel, to decrease the torsional stress produced by the rotating drill string and the product line. As the product pipe is drilled into the pipe, during the process, drill fluid is pumped downhole to provide lubrication to the product pipe.

Equipment Used

The process needs special attention and the involvement of specialized tools and equipment. The equipment used in the horizontal drilling generally are;

Specialized drill bits

Mud motors

Bottom hole assembly

Multi-shot cameras

Rotary steerable systems

Custom whipstocks

Networked or wired pipe

Benefits Of HDD

HDD offers many advantages, making it the best choice for drilling and installations in modern urban environments.

Horizontal directional drilling is a minimum impact method, especially useful for environmentally sensitive areas such as wetlands, rivers, lakes, roadways, etc.

The process is continuously monitored and controlled. This allows the workers to navigate in the constrained places in the existing utility lines.

It is a quick and accurate method. This allows the operators to accomplish creditable accuracy even when the paths are difficult with complicated crossings.

This can carry the drilling at greater depths and bypass existing pipelines and utilities altogether.

It only requires one launching shaft at the starting point and one reception shaft at the endpoint.

HDD is less surface disturbing, cost-effective, and less invasive as compared to the open-cut excavation. Moreover, you can take help from a trusted hydrovac excavation company such as Ghost Hydrovac .