Choosing a core bit configuration has always been considered to be a bit of a mystery, right up there with how to choose the right core bit. Because there are so many to choose from, drillers usually stick to a few of their favourites for as long as they provide good performance. When performance starts to suffer, they need to try something new.
Waterways can play an important role when considering the type of configuration to use. This is because waterways carry fluids and you want to make sure that these drilling fluids has enough
velocity to flush the rock cuttings from the bottom of the hole and to carry them up to the top of the borehole.
3 important factors
You should keep in mind that the number, shape and width of waterways will impact the amount of diamonds in the matrix. Fewer waterways and smaller widths allow for more space in the matrix for diamonds. The opposite case would be a turbo option that would cut the rock faster, but would also have fewer diamonds.
- Shape of waterways
There are many types of waterway shapes out there, depending on the manufacturer. You can choose from the tried and true standard option, which has been around for years, to other options like pie shaped, turbo pie-shaped and cyclone. They can be regular or deep, lateral and in some cases, blocked.
- Width of waterways
The width of the waterways on the configuration you choose should depend upon the type of ground in which you will be drilling.
When drilling in softer, unconsolidated ground you should consider wider waterways. When drilling in harder, competent ground, you should consider narrower waterways.
- Number of waterways
To obtain more cutting ability from the bit with less weight on the bit (WOB), you should consider adding more waterways to your configuration.
If you found what you’ve read interesting, make sure to check out our more comprehensive Fundamental Guide to Core Bit Configurations, packed with more details, tips and advice. It was created to make your life easier and to help improve your drilling performance.