Coring drilling Problems and Solutions

1.Segment Cracking 

Cause: Bond is too hard for material being drilled 

Remedy: Use softer bond 

Cause: Drill rig is not firmly secured

Remedy: Secure drill rig - tighten anchor, check vacuum system 

2.Glazing 

Cause: Too much feed pressure 

Remedy: Open bit, reduce feed pressure 

Cause: Aggregate is too hard 

Remedy: Use a softer bond 

Cause: Too much water, flushing slurry away 

Remedy: Open bit, reduce water flow 

3.Core Hangs Up 

Cause: Insufficient water flow causing slurry to bind core in bit 

Remedy: Increase water flow 

Cause: Dented core barrel 

Remedy: Repair core barrel and increase water flow

4.Loss of Segments 

Cause: Snagging on steel reinforcement (rebar) 

Remedy: Reduce drilling pressure, use higher grade bit 

Cause: Insufficient water flow 

Remedy: Increase water flow 

Cause: Drill rig is not firmly secured 

Remedy: Secure drill rig - tighten anchor, check vacuum system

5.Bent Segments 

Cause: Too much feed pressure and insufficient water 

Remedy: Reduce feed pressure and increase water flow 

Cause: Aggregate is too hard 

Remedy: Use a softer bond

6.Barrel cracking 

Cause: Too much feed pressure 

Remedy: Reduce feed pressure 

Cause: Aggregate is too hard 

Remedy: Use a softer bond