In geotechnical drilling, your project performance often depends on the drill bit you choose. So, picking the right drill bit can save time and improve the quality of your boreholes. In this blog, we’ll discuss PCD, TCI, and drag drill bits used in geotechnical and exploration drilling. Moreover, understanding them can help you make informed choices for your drilling operations in 2025.
PCD Drill Bits
Polycrystalline Diamond (PCD) bits are known because they are strong and long-lasting. PCD drill bits are made to drill sandstone, limestone, and cemented soils. Over time, these bits stay sharp, reducing the frequency of bit changes and delays.
Further, PCD bits are typically used in projects where surface finish is critical. Their strength makes them perfect for water boreholes in hard areas. Although PCD drill bits may cost more at first, their durability and long-term savings make them valuable.
TCI Drill Bits
Tungsten Carbide Insert (TCL) drill bits are known for their impact resistance and work well for medium to hard-rock formations. The carbide pieces provide strength and toughness, allowing the bit to easily drill hard rock.
These rigs are effective in geotechnical drilling rigs, where the ground has both soft soil and hard rock. They are popular with geotechnical drilling companies because of their versatility and reliability. Moreover, TCI bits are compatible with most drill rig tools and equipment, making them easy to use for everyday operations.
Drag Bits
Drag bits have a simple design and work best for clay, sand, and loose soil. Instead of breaking rock, they work by dragging material from the hole. These bits are most effective for shallow and small-diameter boreholes, such as exploration drilling or compact site projects.
Drag bits are easy to handle. They also require less rotational force compared to PCD or TCI bits and are often used on drill rigs or for exploration in small spaces. While they do not work for soft soil, they are ideal for geotechnical drill rigs.
Choosing the Right Drill Bit
Selecting the right drill depends on:
Formation Type: Hard, medium, or soft rock decides if a PCD, TCI, or Drag bit should be used.
Project Scope: For large-scale projects, strong and fast bits are critical. For small, shallow borings, simple drag bits are best.
Drilling Rig Compatibility: Check that the bit works with your drilling rig setup. Some need specific speed or torque.
Cost Efficiency: Weigh the upfront cost against long-term savings from fewer replacements and faster drilling.
You should also think about the tools and equipment available for the drill rig. High-quality bits with compatible tools minimize the risk of damaging the borehole.
How to use Drill Bits Correctly?
Regularly inspect parts for damage or wear prior to use in order to avoid any problems in the course of the project.
Proper Lubrication: Make sure the driller is using appropriate fluids or water in order to decrease the friction and increase heat.
The correct speed for rotation: Follow the manufacturer's instructions to prolong the lifespan of the bit.
Matching the Bit to the Material. The wrong bits, like hard rock bits in soft soil or soft bits found in hard rock, decrease efficiency and could increase the cost of production.
By following these tips, Drilling operators can prolong the lifespan of their bits as well as ensure the highest-quality drilling operation.
Conclusion
Understanding PCD, TCI, and Drag bits is essential for any geotechnical drilling project. Each bit has unique strengths for different project requirements. PCD bits perform best in hard abrasive layers, TCI bits work on mixed and medium-hard rock, and Drag bits are simple work fast in soft soils.
MetaDrill helps operators get the correct tools for every project. For anyone serious about geotechnical drilling in 2025,MetaDrill is the go-to solution.
Question to the public:
Learn about PCD, TCI, and drag drill bits, their uses, and how to choose the right bit for geotechnical drilling projects in 2025.