Ardent Underground has an exclusive relationship with Abergeldie Complex Infrastructure to provide shaft construction for Ardent Underground hydrogen storage. Abergeldie is an Australian-owned company and a world leader in blind bore shaft drilling with a proven track record of drilling the world's largest diameter deep shafts.
What is blind boring?
Blind boring is a construction method used for over 70 years in the mining industry for the construction of vertical access or ventilation shafts to underground mines. Abergeldie is one of the few companies in the world with this capability and the leading proponent in Australia.
The Abergeldie blind boring method involves drilling from the surface using a large diameter rotating heavy weighted head that breaks rock using disc cutters similar to those used in tunnel construction. The drilled shaft is maintained full of water during drilling. This allows a positive pressure to be applied to the drilled shaft and for the drill cuttings to be removed through the drill pipe to the surface by reverse circulation.
BLIND BORING DRILLING RIGS
Abergeldie has designed and manufactured in-house its fleet of three 450t blind bored rigs and has successfully delivered 15 blind bored shafts in Australia over the last 15 years with shaft depths ranging from 165m to 517m and finished diameters ranging from 3.5m to 6.5m. The majority of the completed shafts have a diameter of around 5m and are drilled to a depth of around 300 metres.
LINER INSTALLATION
Once the shaft reaches the intended total depth, the shaft is lined with the steel reinforced concrete composite liner sections. The casing segments are installed from the surface by ‘floating’ them into the flooded shaft. Each liner section is lowered over the shaft and supported at ground level, aligned, and welded to the preceding section before being lowered into the shaft in a carefully controlled process. Once the liner has been lowered to the final depth the annulus between steel liner and the rock is then grouted along its full length and the water in the shaft is removed.
