What To Look For When Choose A Drilling Rig?

Underground diamond drilling is similar to surface drilling, but there are still some differences to consider. These differences may come into play when selecting drilling equipment.

Different objectives

Underground drilling involves defining drilling with a focus on production and speed - you don't want to slow down the extraction part of the operation. Given this focus, it is important to achieve optimal penetration rates. Coring bits that can cut the rock well and have good rotational speed can provide better penetration rates.

Unknown versus known ground

Most mines have been operating for many years, so the type of rock is not a mystery. Several holes have been drilled, so the team will know what to expect and there are few surprises. Instead of limiting their options to core bits for a wider range of ground, drillers can focus on bits developed for specific ground types. Additionally, since you know the type of ground, you could opt for a higher crown so the number of times you will need to change the bit will be reduced.

Rotary Well Drilling Rig     

Drilling depth

Most of the time in subsurface drilling, the hole is not as deep as, for example, 200 meters instead of 1,000 meters. This may lead drillers to choose conventional drilling methods instead of using cable drilling methods. The thinner cut found in coring bits used in conventional drilling can lead to better penetration rates.

Drill hole orientation

In subsurface drilling, the direction of the hole can be downward, upward, or inclined. These different orientations may mean that you may have to choose a different matrix for the core bit. In some drilling conditions, when drilling upward, you may need to change the matrix you normally use downhole and then drill a series upward. For example, if you are drilling a downhole, your drill bit will carry more weight due to the weight of the drill pipe. Once you drill in an upward hole, the weight of that rod goes away and you need to compensate with a softer matrix in a higher series, where the higher series core bit has a softer matrix that allows the diamond to be more easily exposed. This means that the coring bit stays sharper even without the required "bit weight" pressure.

CSD300 Rotary Drilling Rig    
   

Low Power Drilling Rigs

Typically, underground drilling provides less space for drilling rigs, so they tend to be smaller and less powerful. When drilling with low-powered rigs, especially in upper holes, you will need coring bits with softer substrates. As mentioned above, a softer matrix has easily exposed diamonds that will keep the coring bit sharp, cut well and provide good penetration even when using equipment that does not provide the required feed pressure.

We all realize that the choice of drilling equipment is the most important decision and will have a significant impact on your drilling performance. While the type of surface is an important factor, other factors need to be considered when drilling underground. Our technicians can provide other useful tips for underground drilling, such as: always trying to start with a used coring bit when beginning underground drilling. Cutting a hole in the ground can damage the bit, so avoid using a new bit and choose a bit that is already worn.