One (1) hole was abandoned and re-collared due to drill hole deviation
Production drill hole deviation
had been an ongoing issue at Cracow for some time.
Here are the most common factors in hole deviation
and general fixes.
was monitored by multi-shot down hole camera and a representative population probed with a gyroscopic tool for QA/QC purposes.
In cases where a weak rock mass is present or where discontinuities in the rock are persistent, open and frequent, "unanticipated" drill hole deviation
The LS600 rig claims to deliver more accurate core sampling, less than 1 percent hole deviation
, reduced waste, and faster penetration than conventional methods.
The strong effect of the diameter size on the hole deviation
is evident, with a confidence level of more than 99%.
Step-less control of feed and percussion pressure avoids overfeeding and excessive tightening of connections that contribute to hole deviation
and accessory wear.
Furthermore, although the forces on the tool are somewhat reduced, significant mechanical force is still required, bringing back the problems of bit wear and hole deviation
"The initial trials of which have seen our clients reduce their average blast hole deviation
by up to 60%, which has in turn delivered an estimated reduction in dilution of up to 30%," Beilby said.
You begin to talk with the blaster or the powder salesman and they keep offering the same answer, "geology." Questioning how geology could cause these problems, you get the typical answers, such as mud seams and structures, one might even explain how drill hole deviation
could have been worsened by the "new" structure that only occurred in the middle of the pattern.