For borehole drilling, it looks simple. But if you really want to get perfect borehole, it will need a lot of professional knowledge. Such as selecting most suitable drill rigs and drill tools. Any of them is not chosen properly, it will cause issues on hole quality.

Below is some tips we learned in the past and share here, hopefully it will be helpful.

Quality holes are……

  • Drilled in correct position
  • At the right angle
  • To required depth

Rig set up and collaring technique are critical operations for successful quality hole drilling,  in below picture, it is Hardrock Mining Drill Rigs

 

 

 

 

 

Hole Deviation Classification

  • Inclination error
  • Collaring error
  • Hole depth error
  • Deflection

 

 

 

 

 

 

 

 

 

 

 

 

 

Issues will be caused by above deviation

  • Fly Rock
  • Oversize
  • Secondary Blasting
  • Underbreak

Deviation caused by Hardrock Regular Drill Bit, the deviation is 1.4m for 15m depth with Dia. 64mm hole.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Deviation caused by Hardrock Special Drill Bit,  it is only 0.4m deviation for 15m depth and Dia.64mm hole

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Button shape and sharpness influence drilling accuracy- Sharp buttons drill better than blunt buttons

 

 

 

 

 

Hardrock Guide tubes for rod drilling – Used as first rod in string to improve accuracy

 

Below is the hole deviation drilled between with Guide Tube and Hardrock MF Rod – with guide tube has much better borehole quality

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Above is just a few experience our engineer had accumulated during past years in drilling business area, we will share more and more practical and theoretical knowledge here.