Improving your rate of penetration will have a direct impact on profitability as it will increase productivity and lead to recuperating more core. How to achieve better penetration is a challenge for many drillers but there are several methods that will help.
First and foremost, you need to pick the right core bit for the type of ground you will be drilling. You should refer to a matrix selection chart to help narrow down your choices.
Once you have an idea of the matrix you need, you will also need to consider the type of waterway configuration. You will need to look at the pattern, the number of waterways as well as the width between the waterways as all of these play a role.
For example, when drilling in broken ground that is not very hard (3-5 on the Moh scale), you could choose a Hero 3 with a cyclone configuration. Other options could include core bits that are self-sharpening, such as the Hero 11 Abrasive. This kind of core bit has a matrix that has been developed to provide excellent penetration rates.
A core bit with a higher crown impregnated with diamonds, such as the Vulcan, may also help improve penetration rates by reducing the number of times you need to change your bit. However, care must be taken to choose a Vulcan with a matrix that is suitable for the type of ground you will be drilling. As a Vulcan typically lasts up to 33% longer than a normal core bit, it should be used in ground that is not variable.
For example, let’s say you have chosen a Vulcan with a matrix for medium ground. You are drilling and after 100 meters the ground changes to a very hard ground, the Vulcan will not be suitable and you risk prematurely wearing the Vulcan or burning it. While it is a tool that can offer great results, you must be certain of the hardness and the type of ground.
Finally, other considerations include the use of drilling additives which can cool the bit and help flush cuttings so that coring is faster and wear on the drill bit is reduced. The type of drill rig can also play an important role. If you are approaching your drill rigs’ performance capacity in terms of diameter and depth, a larger hydraulic drill rig may be the solution.