Underground Intersect Drilling Pioneered by Prime Horizontal
Prime pioneered underground intersect drilling, recently completing the first pre-survey PLANNED underground intersect in Europe and in the United States. To date Prime's track record is 100% success in underground intersect drilling. Prime has completed projects for handling heavy gravels on both sides of a crossing, for lowering annular pressures in alluvial formations and for successfully completing long reach HDD projects.
New Micro-Coil Magnetic Source Developed by Prime Horizontal for Freeze Hole Drilling of Tunnel Bores
In July 2004, the Netherlands Office of Prime Horizontal developed a new magnetic source called Micro-Coil to enable the freeze drilling of tunnel bores for the creation of the underground metro system, in Naples city centre, by Pizzarotti & C S.P.A. Prime's part of the project was to provide the magnetic guidance during the construction of the Metro Station in Piazza Garibaldi, opposite the main train station of Naples.
Extremely high levels of magnetic interference prohibited the use of conventional techniques, causing Pizzarotti to bring Prime Horizontal into the project as consultant in replacment of the original HDD contractor.
Prime developed a narrow, 50 m length coil with a measurement system for highly precise horizontal alignment to be placed in a sacrificial bore hole drilled through the middle of the tunnel gallery. This source was then used to track all the surrounding bore holes in that tunnel gallery.
Overall, the ParaTrack Micro-Coil is considered a resounding success, saving both time and expense for the freeze drilling contractor. The ease of setting up and using the equipment meant that after a few weeks of instruction, the contractor, who had no previous experience in using such a system, was able to operate the ParaTrack-2 system entirely unaided.
Once again, Prime Horizontal, when consulted about a specific application, was able to adapt a
novel solution to a difficult guidance problem, giving the drilling contractor the confidence to expand into technical directions previously thought too difficult.
