HDD Drilling
History
The technique of a horizontal directional drilling was taken from the oil industry in the 1970s. In the beginning, the technique was only used to install petroleum pipes and natural gas pipes. Since the 1990s, water pipes, cables and other pipes are laid in this way as well.
Horizontal directional drillings have relatively little impact on the aboveground environment. Drillings can be performed underneath existing infrastructure, watercourses, dikes or other obstacles.
Standard steps in an HDD drilling
The first phase of an HDD drilling is the pilot drill. During the pilot drill, a rig (that is a drilling machine) pushes a drilling head, followed by a hollow pipe, through the ground. Drilling fluid is applied through the hollow pipe to prevent the drill hole from collapsing.
The second phase of an HDD drilling is the clearance of the drill hole. In this phase, the rig pulls a clearing device through the drill hole. Behind the clearing device is a pipe with which drilling fluid can be applied to the drill hole directly. Depending on the desired diameter of the production pipe, this process is repeated several times.
The final step of an HDD drilling is drawing in the production pipe. The clearing device is disconnected from the rig and the production pipe is attached. The rig slowly pulls the pipe through the drilling hole. When the permanent pipe is pulled in, the drilling fluid is pushed out.
Visser & Smit Hanab
Visser & Smit Hanab has been involved in the developments surrounding this technique from the very beginning, and has become a leading authority in the field. A specialised department performs HDD drillings on long and complex lines all over the world.
Watch the video to see an HDD drilling in practice.