Bits ‘n Pieces – The Driller’s Blog

In this blog, our last installment on handling core bits, we look at problems that can happen at the bottom of the bore hole when you’re adding or changing a new core bit. I always say that choosing the right core bit and bit configuration is one of the most important decisions you have to make to ensure you get the best drilling performance. You also need to make sure you handle them properly so that they get to the drill the ground they were chosen for.

Last week we looked at how experienced diamond drillers can get the best performance and longest life from their drilling equipment by avoiding common pitfalls in handling core bits. Often, core bits get damaged before they’re even used. You take the time to choose the right bit and the best configuration, so you want to get the longest bit life possible. Last week we looked at some problems that can happen above ground – this week we’ll examine common problems that happen all the way down, when you’re adding or changing a new core bit.

Experienced diamond drillers are always looking to get the best drilling performance and longest life from their drilling equipment. Sometimes core bits get damaged before they’re even used. After careful deliberation over choosing the right bit and the best core bit configuration, no one wants to ruin a bit before you start drilling. Let’s look at some problems that can happen above ground when you’re adding or changing a new core bit.

It’s been a while since we’ve done a blog on matrix troubleshooting. Core bits play an integral role in getting great drilling performance and many things can cause a bit to underperform. One of the best ways to determine what is off is to examine the wear profile of your bit crown and change drilling parameters if necessary. Today, we’ll look at burnt core bits, some of the causes and some of the solutions.

Losing equipment in a bore hole and having to go retrieve it is called fishing and no diamond driller wants go fishing. The equipment has become stuck, lost, or broken off but either way it is obstructing the bore hole.

Many of our previous blogs are about the importance of choosing the right core bit and the right core bit configuration. Recently I started discussing some of the reasons that core bits underperform, even if you have chosen the right ones. Some of the reasons involve changes in ground conditions or not using the best drilling parameters for the drilling project. One of the best ways to determine what is off is to examine the wear profile of your bit crown and change drilling parameters if necessary. An earlier blog looked at the problem of over exposed diamonds and this time we will look at core bits that are polished.

We’ve talked a lot in previous blogs about the importance of choosing the right core bit and the right core bit configuration, so I think it is time we talk about getting the most out of your core bit. 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 lack of experience.  One of the best ways to determine what is off is to examine the wear profile of your bit crown and change drilling parameters if necessary.

Unless you hear from another driller who has already drilled in your zone, there is no way to tell if you will encounter a problem with water circulation. Some areas are notorious for having voids, fractured ground or underground rivers. These include Nevada and the western USA, as well as a large part of South America. Large geological faults that run through these areas are often to blame for the ground conditions.

No matter how carefully you planned and drilled, bore holes are rarely straight. Many things can have an effect on the direction of the hole, such as weight on bit, poorly set up drill rig, fractures or voids in the ground formation, bedding planes, or ground that goes from hard to soft. Too often, the path of the bore hole needs to be corrected in order to reach a desired target and that is when you should consider using a wedge.

A surefire way to stall operations and lower productivity is to break a drill rod in a bore hole – a too common occurrence in diamond drilling.

A rod string can break, either from too much pressure or by being dropped, or the bit can melt and fuse to the rock. Certain ground conditions can lead to your equipment being jammed. Clay can swell enormously when water is introduced and this swelling can trap the rod and drill bit. Coming across sand can also be harmful as the sand can collapse around the drilling equipment.