Performing a horizontal directional drilling requires a lot of knowledge and expertise, as does the construction of a drinking water well. Both activities have been performed successfully for many years. However, combining them was long thought to be impossible.
The HDDW technique combines both activities and results in a perfect, horizontal drinking water well.
The following steps are required for the construction of an HDDW:
- Performing a pilot drill
A rig (that is a drilling machine) accurately pushes the drill head through the soil, through the desired soil package. A hollow pipe behind the drill head fills the drill hole with drilling fluid to keep it from collapsing.
- Clearing the drill hole
To clear the drill hole, a drilling rig pulls a clearing device through the drill hole. Depending on the desired diameter, this process takes place once or several times. To this end, the diameter of the clearing device increases in the process. The use of drilling fluid keeps the drill hole from collapsing.
- Installation of filter system
When the drill hole is large enough, a mantle pipe is drawn in. The filter pipe is placed inside this temporary mantle pipe. Subsequently, (if required) the artificial screen is applied. The temporary mantle tube is removed, the required pumps are installed and the filter system is ready.
- Development of the source
In order to put the HDDW into use, the source must be developed. This means that the drilling fluid in the system must be removed and the soil composition must be optimised.
Only after development is the HDDW ready for use.
Watch the video and see how an HDDW is actually constructed.