IN-SEAM DRILLING TO PLOT COAL MINING
Pike River Coal Limited has started its scheduled in-seam drilling through
the Brunner coal seam under the Paparoa Ranges to plot the best road map for
its heavy mining machinery to cut coal.
Pike River has contracted an experienced Australian in-seam drilling company
to drill five in-seam boreholes, totalling approximately 7 kilometres in the
Brunner coal seam.
These holes will have regular directional deflections or ''branches'' into the
seam roof and floor, to better outline the geometry of the coal-seam and
assist with controlled drainage of in-seam coal-bed gas ahead of mining.
In-seam drilling involves placing a drilling machine underground and drilling
horizontally within the coal seam rather than vertically from the surface.
This is far more effective in collecting accurate in-seam data than drilling
from the surface and with no impacts on the surface.
The drill-rig is comprised of a track-mounted unit along with a power pack
and can safely be deployed wherever required. The motor, located within the
drill hole just behind the drill bit, allows the driller to steer the hole in
a pre-determined direction. It can drill forward up to 2000 metres.
The drill-rig has been established at the end of the 2.3 km access tunnel and
the first hole is now being drilled parallel to the northwards tunnel
extension to the ventilation shaft location. Later holes drilled from this
same location will radiate out in a fan pattern and delineate the pit bottom
area and further.
End CA:00174066 For:PRC Type:MINE Time:2008-12-11:11:31:10