Why Unidrill kelly bar is your better choice?

As the first and only company in the industry to fully apply five-layer interlocking kelly bars to ultra-deep hard rock formation construction, Unidrill rotary drilling rig kelly bars have greatly expanded the market share of ultra-large rotary drilling rigs in pile foundation construction of super-large bridge projects.

1. Better raw materials

- Steel pipe: high-strength steel pipe (safety factor of interlocking kelly bar under compression-torsion combined load is above 2.0, and torsional safety factor of friction kelly bar is above 1.8)

Advantages:

1) Improve bearing capacity and stability

High-strength steel pipes have high yield strength and tensile strength, and can withstand the huge pressure and torque during drilling. This ensures that the rotary kelly bar can maintain a stable working state when drilling into hard formations, and is not prone to bending or breaking. At the same time, the good toughness of high-strength steel pipes also helps to improve the overall stability of the kelly bar and ensure the smooth progress of drilling operations.

2) Enhance wear resistance and corrosion resistance

During drilling operations, the kelly bar will rub and contact with rocks, soil and other media in the formation. High-strength steel pipes usually have good wear resistance and corrosion resistance, which helps to extend the service life of the kelly bar and reduce the frequency of replacement due to wear or corrosion. At the same time, good corrosion resistance can also ensure the normal operation of the kelly bar in harsh environments and improve the safety and efficiency of drilling operations.

3) Adapt to complex and changing drilling needs

Rotary drilling rigs are usually used in various complex and changing geological environments, such as soft soil, hard rock, frozen soil, etc. The excellent mechanical properties of high-strength steel pipes enable the kelly bar to adapt to these different drilling needs. For example, when drilling hard rock, high-strength steel pipes can withstand greater impact and friction; when drilling soft soil, their good toughness and stability help maintain drilling accuracy and efficiency.

4) Improve drilling efficiency and economy

The rotary kelly bar using high-strength steel pipes can complete drilling tasks more quickly and accurately. This helps to improve drilling efficiency, shorten construction period, and reduce construction costs. At the same time, the excellent performance of high-strength steel pipes also helps to reduce the failure rate and maintenance cost of kelly bars, further improving the economy of drilling operations.

- External key strip: High-strength wear-resistant key strip (HRC42-45, impact energy above 90)

1) Enhance torque transmission efficiency

High-strength wear-resistant key strips play a key role in transmitting torque in rotary kelly bars. Through precise matching and locking mechanisms, they ensure that the torque generated by the power head can be efficiently transmitted to the drill bit, thereby driving the drill bit to perform rotary cutting operations. The key strips made of high-strength wear-resistant materials can reduce torque loss caused by friction and wear and improve overall transmission efficiency.

2) Improve the stability and service life of the kelly bar

kelly bars need to withstand huge pressure and vibration during drilling, and high-strength wear-resistant key strips can enhance the structural strength of the kelly bar and improve its bending and torsion resistance. This helps to maintain the stability of the kelly bar during drilling and reduce the failure rate caused by vibration and deformation. At the same time, the use of wear-resistant materials can also extend the service life of the key strip, reduce the frequency of replacement, and reduce maintenance costs.

3) Adapt to complex and changing drilling environments

Rotary drilling rigs are usually used in various complex and changing geological environments, such as soft soil, hard rock, frozen soil, etc. In these environments, kelly bars and key strips need to withstand different stresses and wear conditions. High-strength wear-resistant key strips have excellent mechanical properties and wear resistance, and can adapt to these different drilling needs to ensure the smooth progress of drilling operations.

4) Improve drilling efficiency and economy

Rotary kelly bars using high-strength wear-resistant key strips can complete drilling tasks more quickly and accurately. This helps to improve drilling efficiency, shorten construction periods, and reduce construction costs. At the same time, the excellent performance of high-strength wear-resistant key strips also helps to reduce the failure rate and maintenance costs of kelly bars, further improving the economy of drilling operations.

- Forgings: Key stress points are made of high-strength forgings or castings

Advantages:

1) Improve mechanical properties

High strength: Forging or casting parts are processed by specific processes, and their internal structure is denser and the strength is significantly improved. This allows the key stress points of the rotary drilling drill pipe to remain stable when subjected to huge torque and axial force, and is not prone to deformation or breakage.

Good toughness: High-strength forgings or castings usually have good toughness, which helps the key stress points of the rotary drilling drill pipe resist impact and vibration during drilling and maintain a stable drilling state.

2) Enhance wear resistance and corrosion resistance

Improved wear resistance: Special treatment of the surface of forged or cast parts, such as carburizing, quenching, etc., can significantly improve their wear resistance. This reduces wear and extends the service life of the key stress points of the rotary drilling drill pipe when drilling in hard formations.

Enhanced corrosion resistance: For rotary drilling rigs working in harsh environments, the use of high-strength forgings or castings supplemented with anti-corrosion treatment can effectively resist the erosion of corrosive media and keep the key stress points of the kelly bar in good condition.

3) Improve processing accuracy and fit

Improved processing accuracy: Forging or casting processes can accurately control the size and shape of parts, so that the various components of the rotary drilling rig can fit closely, improving overall work efficiency and stability.

Improved fit: The precise fit of high-strength forgings or castings helps reduce energy loss and vibration during drilling and improve drilling efficiency.

4) Adapt to complex and changing drilling needs

Rotary drilling rigs are usually used in various complex and changeable geological environments, such as soft soil, hard rock, frozen soil, etc. High-strength forgings or castings have excellent mechanical properties and adaptability to meet the needs of these different drilling environments. For example, when drilling hard rock, high-strength forgings or castings can withstand greater impact and friction; when drilling soft soil, their good toughness and stability help maintain drilling accuracy and efficiency. .

5) Improve the safety and reliability of drilling operations

The rotary kelly bar made of high-strength forgings or castings has higher load-bearing capacity and stability, which helps to reduce the failure rate and accident risks during the drilling process. At the same time, good wear resistance and corrosion resistance also help to maintain the drill pipe in good condition and improve the safety and reliability of drilling operations.

- Welding wire: Use high-strength and low welding stress welding wire.

Advantages:

1) Improve the strength and toughness of the weld

High-strength, low-stress welding wire has high tensile strength and yield strength, which means that the weld of the rotary drilling pipe welded with this welding wire can withstand greater external forces without breaking easily. At the same time, high-strength welding wire can also provide good toughness, so that the weld can maintain integrity when subjected to impact or vibration, and it is not easy to crack or break.

2) Reduce welding residual stress

During the welding process, due to the action of the heat source, the weld and its surrounding areas will produce thermal expansion and contraction, thereby generating residual stress in the weld. These residual stresses may cause cracks or deformation in the weld during service. High-strength, low-stress welding wire can effectively reduce the generation of residual stress during welding by optimizing the welding process and welding wire composition. This helps to maintain the overall stability of the rotary drilling pipe and reduce failures caused by residual stress.

3) Improve welding efficiency and quality

High-strength, low-stress welding wire usually has good welding properties, such as high deposition efficiency and stable arc. This helps to improve welding efficiency and shorten welding cycle. At the same time, due to the optimization of the welding wire composition, the weld quality of the welds welded with this welding wire is generally higher and has fewer defects, thereby improving the overall quality and reliability of the rotary kelly bar.

4) Adapt to complex and changeable drilling environments

Rotary drilling rigs are usually used in various complex and changeable geological environments, such as soft soil, hard rock, frozen soil, etc. In these environments, the kelly bar needs to withstand different stresses and wear conditions. High-strength and low-stress welding wire has excellent mechanical properties and adaptability, which can meet the needs of these different drilling environments. It can improve the durability and reliability of the kelly bar under complex geological conditions and ensure the smooth progress of drilling operations.

5) Extend the service life of the kelly bar

Due to the above advantages of high-strength and low-stress welding wire, rotary kelly bars welded with this welding wire usually have a longer service life. This helps to reduce the replacement frequency and maintenance costs of the kelly bar and improve the economy of drilling operations.

- Integral high-strength steel forged kelly box

- The kelly box, core steel pipe and forging disc form a multi-rigidity reinforcement structure

- Key strip and disc are directly connected

- Kelly box + reinforced core rod forged and strengthened

Above 4 designings enhance the durability of the kelly box and core rod to prevent cracking of the kelly box and core rod.

2. More scientific structure

- Inner key strip → outer key strip → outer key strip support plate forms a closed structure, enhances the strength of the pipe end, and reduces the cracking failure rate of the lower pipe

- The inner key strip is formed by hot pressing high-strength plate as a whole, and the new process of local heat treatment can improve the overall performance of the inner key strip while ensuring the local wear resistance.

- Improve the verticality of the hole

Improve the force on the lower pipe mouth and reduce the failure rate of lower pipe cracking

Improve the stability of the drill pipe pressure rod

Increase the width of the retaining ring to prevent the pipe mouth from deformation

3. More professional production process

4. More strict inspection technology

5. More comprehensive product portfolio

6. More engineering cases

The optimal combination of kelly bars, drilling tools and drilling processes can be used to improve construction efficiency and safety, and increase customer satisfaction to the product.