The origin of the horizontal directional drilling lies in the oil industry. In the beginning of the 70’s, the technique was used only for the construction of oil and gas pipelines. Since the 90’s this technique is also used to construct water pipes, electricity cables and other pipes.
Horizontal directional drillings have relatively little impact on the surface environment. Drilling can be carried out under existing infrastructure, waterways, ditches or other obstacles.
Phases of an HDD bore
The first phase of an HDD bore is the implementation of a pilot bore. During this pilot a rig (this is the drilling machine) pushes a drilling head, followed by a hollow pipe, through the ground. Drilling fluid is applied to prevent the borehole from collapsing.
The second phase of an HDD bore is the expansion of the borehole. During this phase, the rig pulls a reamer through the borehole. A duct is placed behind this reamer. Through this duct, drilling fluid is applied. Depending on the desired diameter of the production pipe, this process is repeated several times.
The final step in an HDD bore is the withdrawal of the production pipe. The reamer is disconnected from the rig and production pipe is attached. The rig pulls the pipe slowly through the hole. With the withdrawal of the final duct, the drilling fluid is pushed out.
Visser & Smit Hanab
Visser & Smit Hanab was the developer of the technique of wellbores and is now ‘leading’ in this area. A specialized department carries out long and complex HDD bores all around the world.