FMS is an authorised Atlas Copco distributor of the Thiessen range of blasthole drill rod and adaptor products.When developing a rotary drilling system, most of the attention is usually given to the drill rig, the capital equipment that requires significant investment and hence a planned payback.The second priority in the system tends to be choice of rotary tricone drill bit – the Tricone.

However, to utilize the full power and capacity of the rig and the bit, and at the same time increase service life and productivity, consideration should also be given to the entire drill string. The optimal drill string includes a shock absorber at the top, a rotary deck bushing to centralize the drill string as it passes through the deck of the rig, strong and straight drill pipes and finally a hole stabilizing roller stabili-zer or bit sub-adaptor to optimize the performance. Giving the necessary attention to every part of the drill string will lead to the lowest total operating costs in rock excavation and fragmentation.

Close attention

When developing a rotary drilling system, most of the attention is usually given to the drill rig, the capital equipment that requires significant investment and hence a planned payback. The second priority in the system tends to be choice of rotary tricone drill bit – the Tricone. However, to utilize the full power and capacity of the rig and the bit, and at the same time increase service life and productivity, consideration should also be given to the entire drill string. The optimal drill string includes a shock absorber at the top, a rotary deck bushing to centralize the drill string as it passes through the deck of the rig,strong and straight drill pipes and finally a hole stabilizing roller stabili-zer or bit sub-adaptor to optimize the performance.Giving the necessary attention to every part of the drill string will lead to the lowest total operating costs in rock excavation and fragmentation.

The rotary drill string

The primary purpose of the drill string is to transmit the rotational torque and weight from the power source – the rotary head of the rig – to the rock breaking drill bit. As for every rock drilling method, the power must be transmitted as efficiently as possible, and return as few vibrations as possible,as these cause unnecessary wear on the rig and reduce penetration rates.

When selecting components for the drill string, attention must be given to the different roles of the support tools in the string.

Shock absorber

At the very top of the drill string  between the rotary head and drill pipe a shock absorber is commonly used.As the name indicates, the intention of this tool is to reduce the negative effects of harmful vibrations that travel back up the string as a result of the drilling
process.

The benefits of using a shock absorber include:

• improved torque control
• increased drilling penetration rates
• better drill rig availability and extended drill rig drive head and mast life
• longer service life of drill bits

Should you wish for more information please contact us