Bits ‘n Pieces – The Driller’s Blog

Directional drilling technology has certainly come a long way in the mineral exploration world, with Gyro-guided tooling and the ability to core while steering the borehole.  There have never been so many options and methods of steering a hole. One of the oldest methods of directing a borehole - wedging - remains an important tool in the drillers box!  Wedges are commonly used to kick the hole trajectory back on line or to scoot past lost tooling in the hole. For one of our customers, the Prism directional wedge was the perfect tool for their needs.

Finding reliable staff in the diamond drilling industry has always been a challenge. Many of the challenges we hear about from our customers involve problems with training. Some prominent drilling companies are investing in training of upwards of 100 employees per month and only end up with 10% of them moving the next phase of training.

In this blog we have provided a lot of information about how to choose equipment and how to take care of it properly. Every once in a while, it’s a good idea to look beyond the equipment part of the job and focus on how to do the job, or in the case of this blog, how not to do the job.

Drilling parameters are really important when it comes to achieving great drilling performance and extended equipment life. While it is important to choose the right equipment, once drilling conditions change, you need to adjust your parameters to maintain good drilling performance. Understanding how to adjust drilling parameters can help drillers improve performance in difficult drilling situations.

In our last blog, we looked at the expression “pushing a block”, what it meant and why drillers should never try to advance in a hole when the core is blocked. However, in many parts of the world, especially where dry hole drilling is common, or when the hole is very deep, different advice and procedures should be followed. We are going to look at these different situations and the recommended procedures.

Bore hole deviation is one of those things that occur despite all the preventative measures and precautions that diamond drillers may take. Deviations may occur due to equipment that is lost and stuck in the bore hole or it may be intentional because the geologist has requested a new trajectory. A deflection wedge is one of the oldest and simplest ways to steer the bore hole. There are other choices for directional drilling and you can read about them in this blog.

Our technical team in Northern Ontario had an interesting request a while ago during an onsite visit. The mining company they were visiting was a longtime customer with multiple mines. The mine was one of the largest in the world and a large player in the area. With a lot business already done, and an excellent relationship developed over 25 years, the customer would often consult with us when it came to anything to do with coring challenges. During this particular visit, they asked if we could come up with a procedure and the necessary tooling to be able to get core using unconventional drill rigs such as a jumbo drill or a bolter.

It has been a while since we did a blog on matrix troubleshooting where we examine the different wear patterns on a bit crown. By looking at the wear profile, you can get clues as to why your core bit may be underperforming. There are many variables that can cause a really good core bit to underperform. It can be a change in ground conditions, drilling parameter or simply a lack of experience.

Drilling parameters are really important when it comes to drillers achieving great drilling performance and long bit life. They help guide a driller avoid burning bits or damaging other drilling equipment. Diamond drillers have learned that there is a relationship between the drilling parameters and all others factors in drilling, such as the diameter of the equipment of you’re using, rock hardness or ground variability.

In a previous blog, we discussed some of the issues you encounter when drilling in soft rock. This time, we’ll look at the opposite end of the spectrum: hard rock. Hard rock is defined as being over 6 on the Mohs scale of hardness. Common types of hard rock included kimberlite, granite, chert, quartz and silicified rock.