Subsidiary Shaft Drillers International (SDI) bought the equipment and assets of New South Wales contractor Zeni Drilling - which also hailed from the US - in December last year. The purchase gave SDI six blind shaft drilling rigs. The company has established a head office in Queensland.
A statement from the parent company, which commenced operating in 1984, said the purchase gave it an opportunity to transfer its "technological advancements in blind shaft drilling to the global mining industry".
The company had set itself apart from its competition by "systematically developing new technology, meeting customer cost requirements and successfully completing every project undertaken".
NAD is currently working on two 4.9m-diameter concrete-lined shafts in Kentucky, in the US. The shafts are part of a new thermal coal project.
NAD said a 6m coping section was installed through alluvial material, followed by 5.5m-diameter drilled shafts through virgin coal. The final 4.9m concrete lining was being installed with a slip form system from the bottom of the coping down to the coal seam at a depth of 100m.