Cutting drill costs

Olympic Dam is Australia's largest underground mine site with more than 450 kilometres of underground development, with Boart Longyear providing diamond core drilling services at the site.

Currently operating five LM75 diamond core rigs, it drills more than 55 000 metres a year. Diamond drilling is used to extract cores for analysis of the Olympic Dam ore body geometry and to collect geochemical information that will be used to create block models for planning and extraction of future resources.

Now Boart Longyear has developed and implemented the Drill Control Interface (DCi) to increase the efficiency, productivity and safety of the LM series of underground diamond core drill rigs.

The past introduction of rod handlers to the site reduced drilling contractors' exposure to the manual handling of rods, leading to a lower incidence of hand injuries, leading it to push for further innovations at the site.

It was able to introduce the DCi to not only increase productivity, but to also enhance safety for the drilling contractors.

Over a six-month period it used an LM75 drill rig with the DCi to drill a total of 5726 metres using a BQTK size diamond core bit.

This was an increase of 908 metres drilled over the previous six-month average, which resulted in a unit cost improvement of $2.90 per metre average and monthly productivity increase of 13.5 per cent.

With the deepest hole depth of 700 metres drilled on site, the DCi allowed Boart Longyear to continue drilling during crib breaks and shift changeover.

This is possible because the DCi incorporates a PLC system where a supervisor can pre-set parameters for drilling.

These parameters create a semi-autonomous drill system allowing the LM75 to achieve a three meter run in absence of a driller.

The DCi PLC system results in fewer hoses, fewer leaks and less clutter around the drill.

A supervisor can set drilling parameters for inexperienced operators, and an auto shutdown will occur when a drill run ends or programmed parameters are exceeded.

A laser proximity can also shut down the rig when breached – keeping drillers at a safe distance at all times.

A fully electronic user interface means the DCi has a lighter and more portable control cabinet compared to hydraulic controls, resulting in a 50 kilogram weight difference, while the limited number of components allows drillers to move the unit easier and faster.

"There are only three plugs to disconnect from the DCi and no hydraulic hoses," Boart Longyear stated.

The PLC allows one push of a button for unattended drilling.

By drilling within the pre-set parameters set by a supervisor, the LM75 can achieve greater equipment life and greater productivity from inexperienced drillers.

Its auto rod feed and pull system also results in less manual handling and a hands-free wireline descent.

The DCi provides real-time key performance data that is recorded, stored and easily downloaded for quick analysis, allowing drillers to make adjustments to the drill rig on the go.

Because the DCi provides significant instrumentation data, a system diagnostic can be run to determine rig performance and operator performance and detect early equipment failure.