How many kinds of drilling tools for rotary drilling are there?

Drilling tools are key components in rotary drilling. What roles are they play in drilling process? The torque and pressure output by the drilling rig act on the drill teeth on the drilling tool to cut and break the geology, and the drilled residue is contained in the drill bucket in different ways and lifted out. outside the hole.

There are 6 main types for drilling tools: Drilling bucket, Core barrel, Drilling auger, Centrifugal bucket, Belling bucket and Cleaning bucket.

• Drilling bucket

Drilling buckets are frequently used in foundation work, such as creating boreholes or piles for buildings, bridges, and other structures. The buckets can handle different soil and rock types, ensuring stable and load-bearing foundations.

The working principle of a drilling bucket involves its use as a cutting tool to excavate soil or other materials during drilling operations. Drilling buckets are commonly used in construction, foundation work, and deep excavation projects. The primary goal is to create holes or shafts in the ground while removing the excavated material. Here's an overview of the working principle of a drilling bucket:

- Attachment to the Kelly Bar: The drilling bucket is typically attached to the lower end of a drilling rig's kelly bar. The kelly bar is a telescopic or segmented shaft that extends into the ground and transmits torque and downward force to the drilling bucket.

- Rotation: The kelly bar, along with the attached drilling bucket, is rotated using the drilling rig's machinery or equipment. The rotation applies torque to the drilling bucket, causing it to turn.

- Cutting Teeth: The drilling bucket is equipped with cutting teeth or cutting edges on the base. These cutting teeth are designed to cut into the soil or rock, depending on the geological conditions.

- Material Excavation: As the drilling bucket rotates, the cutting teeth engage with the ground, and the soil or other material is broken up and cut away from the surrounding area. The cutting teeth create a hole or shaft by removing material in a cylindrical pattern.

- Bucket Shell: The material that is cut and dislodged by the cutting teeth is collected within the cylindrical bucket shell, which surrounds the cutting teeth. The bucket shell retains the excavated material as it is removed from the ground.

- Bottom Door or Gate: At the bottom of the drilling bucket, there is usually a hinged or removable bottom door or gate. This door is opened when the drilling bucket is lifted out of the drilled hole, allowing the collected material to be released and deposited outside the hole.

- Lifting and Emptying: After the material is released, the drilling bucket is lifted out of the hole using the kelly bar. The excavated material is emptied, and the drilling process can continue.

The working principle of a drilling bucket involves the combination of rotary motion and cutting action to create holes in the ground and simultaneously remove the material, which is especially important for deep foundation work. The design and choice of the drilling bucket, including the type and arrangement of cutting teeth, depend on the specific geological conditions at the drilling site, ensuring efficient excavation and the creation of stable foundations or boreholes.

• Core barrel

In piling and deep foundation construction, a core barrel is a specialized tool used to create holes or boreholes in the ground and extract core samples, particularly in challenging geological conditions.

Here's the working principle of a core barrel in piling:

- Attachment to Drilling Equipment: The core barrel is typically attached to the bottom of a drilling rig's kelly bar, which is a telescopic or segmented shaft that extends into the ground. The drilling rig provides the necessary force, rotation, and downward pressure for the drilling process.

- Penetration and Rotation: The drilling equipment, including the core barrel, is lowered into the ground, and the drilling rig's machinery provides the required rotational force. This rotation causes the core barrel to cut into the subsurface material.

- Core Bit: At the base of the core barrel is a core bit, which is a cutting tool designed to extract a cylindrical core from the ground. The core bit typically has a hollow center, allowing the core to enter and be collected inside the core barrel.

- Collection of Core: As the core barrel penetrates the ground, the core bit cuts a cylindrical core, which is collected within the hollow core barrel. The core is held in place as long as the core barrel remains within the ground.

- Lifting and Retrieval: Once the drilling reaches the desired depth or when a sufficient core is collected, the drilling equipment is lifted, and the core barrel is removed from the ground.

• Drilling auger

The working principle of a drilling auger for piling, often referred to as an auger piling rig or a piling auger, involves using a specialized auger tool to create holes in the ground, particularly in the construction of foundation piles. Auger piling is a common method for creating cylindrical holes or shafts in the ground to support structures such as buildings, bridges, and other heavy loads.

Here's how it works:

- Attachment to Drilling Equipment: The drilling auger is typically connected to the drilling rig's kelly bar or an auger drive, depending on the specific equipment used. The kelly bar is a telescopic or segmented shaft that extends into the ground, transmitting torque and downward pressure to the auger.

- Rotation and Penetration: The drilling equipment, which can be a hydraulic rig or other machinery, provides the necessary rotational motion to the auger. The auger bit, the cutting tool at the base of the drilling auger, is driven into the ground.

- Cutting Action: The auger bit has a helical, screw-like shape, with cutting edges, which enables it to cut into the soil or other material. As the auger bit turns, it drills into the ground, creating a cylindrical borehole.

- Material Removal: The helical design of the auger bit helps remove the excavated material as the auger penetrates the ground. The cut material is conveyed up the spiral flighting, a spiral section of the auger, to the surface.

- Hole Creation: The continuous rotation of the auger bit creates a hole or shaft in the ground. The size and depth of the hole depend on the dimensions of the auger bit and the drilling equipment's capabilities.

- Control and Precision: The operator controls the drilling process, guiding the auger to ensure the hole is created accurately in terms of depth and diameter. The rotational speed, direction, and downward pressure are managed to suit the material and the required specifications of the foundation pile.

- Pile Installation: Once the hole is created, it is typically filled with concrete or another structural material to form the pile. Reinforcement bars (rebar) may be added, and any necessary pile casings are placed for added stability.

The working principle of a drilling auger for piling is focused on the efficient creation of cylindrical holes in the ground for the installation of foundation piles. The auger's helical design aids in material removal and hole creation, and it can be adapted to suit different soil and geological conditions. The size, design, and specifications of the auger bit, as well as the drilling equipment used, are selected to meet the specific requirements of the piling project.

• Centrifugal bucket

The centrifugal bucket is similar to drilling bucket mentioned upon. The special point is the bucket body can be opened to 2 parts by rotating it. So centrifugal bucket is suitable for small piling diameter projects with sticky soil layer.

• Belling bucket

A belling bucket, also known as a belling auger, is a specialized tool used in foundation construction, particularly for creating bell-shaped enlargements at the base of drilled holes, often in the context of pile foundations. The belling bucket serves to increase the bearing capacity and stability of foundation piles.

Here's the working principle of a belling bucket in piling:

- Attachment to Drilling Equipment: The belling bucket is typically connected to the bottom of a drilling rig's kelly bar, a telescopic or segmented shaft that extends into the ground. The drilling rig provides the necessary force, torque, and downward pressure for drilling.

- Rotation and Penetration: The drilling equipment, often a hydraulic rig, provides the rotational motion to the belling bucket. The belling bucket is lowered into the ground, and the rotation allows it to penetrate the soil or rock.

- Cutting Action: The belling bucket is equipped with cutting teeth or blades at the base, and it is specifically designed to create a bell-shaped enlargement at the bottom of the drilled hole. These cutting teeth cut into the soil or rock as the bucket rotates.

- Belling Process: As the belling bucket penetrates the ground, the cutting teeth create an enlarged, bell-shaped bottom section of the hole. This is achieved by cutting and displacing the material outward to create the desired shape. The exact size and shape of the bell can vary depending on the design of the belling bucket.

- Material Removal: The displaced material from the belling process is often left in place, contributing to the increased bearing capacity and stability of the foundation pile.

- Lifting and Retrieval: Once the belling process is complete and the bell-shaped enlargement is created, the drilling equipment is lifted, and the belling bucket is removed from the ground.

- Pile Installation: After the belling bucket is removed, the enlarged hole is typically filled with concrete or another structural material. The pile reinforcement or rebar can also be added, ensuring that the enlarged bottom section is part of the pile structure.

• Cleaning bucket

A cleaning bucket, also known as a clean-out or bottom clearing drill bucket, is a specialized tool used in foundation drilling and deep foundation construction to remove loose materials or debris from the bottom of a drilled hole or shaft before concrete is poured or piles are installed. The working principle of a bottom clearing drill bucket involves efficiently cleaning the bottom of the borehole, ensuring it is free of obstructions and debris.

Here's how it works:

- Attachment to Drilling Equipment: The bottom clearing drill bucket is typically attached to the drilling rig's kelly bar, which extends into the drilled hole or shaft. The kelly bar transmits the necessary torque, rotational force, and downward pressure to the bucket.

- Rotation and Penetration: The drilling equipment, often a hydraulic drilling rig, provides the rotational motion to the bottom clearing drill bucket. The bucket is lowered into the drilled hole, and the rotation allows it to penetrate the material at the bottom.

- Cutting Action: The bottom clearing drill bucket is equipped with cutting teeth, blades, or other mechanisms at the base. These cutting elements are designed to cut through and remove any loose soil, debris, or obstructions at the bottom of the hole.

- Material Removal: As the bucket rotates and penetrates, the cutting elements loosen and remove any material or debris that may have accumulated at the bottom of the hole. This material is brought up by the bucket and typically falls into the open borehole above.

- Cleaning Process: The cleaning process continues until the bottom clearing drill bucket has effectively cleared the hole's bottom of any obstructions or loose material, leaving a clean, debris-free surface.

- Lifting and Retrieval: After the cleaning process is complete, the drilling equipment is lifted, and the bottom clearing drill bucket is removed from the hole.

- Concrete Placement or Pile Installation: With the hole's bottom cleaned and prepared, it is now ready for the placement of concrete in the case of drilled shafts or the installation of piles. A clean hole bottom ensures that the structural element can be properly seated and supported.

The working principle of a bottom clearing drill bucket is essential for ensuring the integrity and load-bearing capacity of the foundation or structural elements that will be placed in the drilled hole. By removing debris and loose material, it creates a stable and clean foundation for subsequent construction work.