Engineering & Mining Journal

MAY 2017

Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr

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Page 47 of 59

46 E&MJ • MAY 2017 SUPPLIERS REPORT New drill rig technology, claimed to have the potential to drastically cut exploration costs, has undergone successful field tri- als in outback South Australia, according to a report published by the joint Austra- lian government/mining industry research organization that originated the concept. RoXplorer, a coiled tubing drill rig, was developed by the Deep Exploration Tech- nologies Cooperative Research Centre (DET CRC) in South Australia and under- went its first extensive, field drilling trials in late February and early March. According to DET CRC, the trial site, 20 kilometers (km) west of Port Augusta, was adjacent to a hole previously drilled by con- ventional (diamond) drilling methods and provided a typical example of the thick cover sequence of the Olympic Iron-Oxide-Copper- Gold (IOCG) Province of South Australia. Coiled tubing drilling differs from con- ventional drilling in that the drill string is a continuous, malleable steel coil, as op- posed to individual steel rods that must be connected and disconnected. This, says DET CRC, not only helps make the process fast and cheap but also offers a substantial improvement in safety because individual rods do not need to be manually handled. DET CRC CEO Richard Hillis said, "It is a revelation to watch rapid drilling with no rotation, no one near the drill string, no rod handling and no fluids on the sur- face. When going well it is wonderfully dull. When tripping in and out of the hole it is wonderfully quick." The RoXplorer first drilled, cased with steel pipe and cemented the top 30 m of the hole. The main hole was then drilled through the cement and into open forma- tion with a DTH hammer and percussion bit powered by a downhole motor. The rig drilled 367 meters (m) in four successive 12-hour (h) shifts, for an aver- age of 92 m per shift and at an average penetration rate when drilling of 15 m/h. This compared with about 25 m per shift at an average penetration rate of three m/h for diamond drilling in the adjacent hole. DET CRC said the RoXplorer rig and CT drilling system also offers environmen- tal benefits because drilling fluids are ful- ly recycled using an above-ground AMC Solids Removal Unit (filters and centri- fuges) and no sump is required. The rig weighs about 15 metric tons and can be transported without the need for special permits. The project is a collaborative effort with support from Boart Longyear, CSIRO, Curtin University, the Geological Survey Rodless Exploration Drill Rig Rolls Toward Commercialization During recent field trials the RoXplorer rodless drill rig, pictured here, produced better meters-per-shift and average penetration rates than a conventional diamond drill rig when boring holes under similar conditions. The RoXplorer rig cases drillholes in a conventional manner, but employs a coil of thick, malleable steel cable to sink the hole instead of individual steel rods.

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