Horizontal Collector Wells (HCW)
Horizontal collector wells are used to collect ground water from higher aquifers through drilled filter strings. A drilling machine was specially designed for this purpose by Anger’s. This horizontal drilling machine injects horizontal strings into ground water aquifers with a pushing force of up to 1500 kN. As a rule, several horizontal filter strings are produced from one vertical, impermeable shaft.
Vertical filter wells are not always suitable for all geological conditions, at least not from an economical point of view. Often aquifers are found in limited horizontal layers. In this case, several vertical filter wells would be needed to develop these thin, but productive deposits. Besides, these vertical wells pass through several layers of aquifers so that ground waters of different quality can get mixed.
A possible solution to these special demands can be the construction of a horizontal collector well, such as Anger’s has constructed for some years now.
The development and construction of a horizontal drilling machine has opened up a completely new field of activity to Anger’s. The special thing about our plant is this: the machine is powered entirely by water hydraulics. Consequently, no oil-substances are used and, thus, sensible ecosystems in the surroundings of aquifers are protected. Furthermore, the device is also a genuine innovation when it comes to occupational safety: there is no necessity to carry out works under hanging loads anymore.
Technical data of our horizontal drilling unit:
- pushing force up to 1500 kN at 160 bar
- horizontal filter strings at an angle of up to 360°
- filter strings can be arranged radially and at different layers of depth
- strings with a borehole diameter of up to 464 mm
- closed water-hydraulic cycle
- integrated crane-/ lift-system for handling of materials
The following projects were handled with the new horizontal drilling technique:
- Munich-Feldmoching (redevelopment): 1 strand in the gravel jack process DN 200, 3 m length
- Oberhausen-Buschhausen: 1 HFB with 4 strands in the gravel jacket process, DN 200, from 74 m to 80 m in length
- Schwertberg (A): 3 strands in the gravel jacket process, DN 250, 1 * 36 m, 2 * 40 m in length
- Senftenberg: 2 HFB in dry installation with altogether 11 strands in the gravel jack method, DN 200, each 60 m in length
In addition, inventory determinations (e.g., TV surveys, performance tests) and replacements were performed on existing HFBs:
- (Dresden, Hoyerswerda (HFB in dry installation), Duisburg, Leipzig, Mainz, Oberhausen, Porta Westfalica)