The Raise Boring (upward drilling) system originated from the upward drillings performed in mining operations in order to connect galleries at different levels and improve both ventilation and ore extraction.
The system is based on the drilling of a downward, small diameter pilot hole that penetrates into a lower-level gallery. At this point the tricone is replaced by a widening drill with the required diameter and then an upward reaming operation (“raise”) is performed. An advantage of this system is that the drilling debris falls to the lower gallery due to gravity.
GEOSA has a long experience using the Raise Boring technique.
Our Company presently owns the following equipment for execution of these techniques:
There are very compact machines, ideal for work in enclosed spaces and highly adaptable to underground environments.
With them, GEOSA has carried out approx. 75 drilling projects, totaling over 6,000 m in length. Worthy of special notice are 17 Raise Boring projects at an angle of 38 degrees, with a length ranging from 120 to 170 m each.
Since 2005, there has been an increase in horizontal drilling for civil works, especially in diameters ranging from 400 to 600 mm, using both the classic raise boring technique or through consecutive extensions.