Kelly bars are essential components in the execution of boreholes by hydraulic rotary drilling rigs. They serve as an extension to the excavator, providing increased reach and depth to the drilling hole. This article explores the function, types, features, material considerations, and noise reduction aspects of Kelly bars.
Key Facts
- Function: Kelly bars extend the reach and depth of a drilling hole by providing an extension to the excavator.
- Types: Kelly bars can be divided into two main types: friction kelly bars and interlocking kelly bars. Friction kelly bars have frictional contact between the rails of each element, while interlocking kelly bars have drive ribs welded with lock devices to transfer maximum torque.
- Features: Kelly bars can come with various additional features, including telescopic options, depth ranges from 10m to 110m, torque transfer capacity of 80kNm to 500kNm, high-quality seamless steel pipes, spring shock absorbers, and a square kelly box for connecting drilling tools.
- Material and Quality: It is important to look for Kelly bars made of high-quality steel with strong mechanical features. Origin and quality certificates can guarantee reliability and longevity.
- Noise Reduction: Some Kelly bars can be equipped with a damping noise system, which reduces disruptive, high-frequency noises during operation. This system consists of a phono-absorbent material applied to the outer scope of the Kelly bar, protected by steel plates.
Function of Kelly Bars
Kelly bars extend the reach and depth of a drilling hole by providing an extension to the excavator. They are inserted into the drill string and held in place by friction or interlocking mechanisms. The Kelly bar transfers torque and crowd force from the rotary drive to the drilling tool, enabling efficient drilling operations.
Types of Kelly Bars
Kelly bars are primarily classified into two types: friction Kelly bars and interlocking Kelly bars.
- Friction Kelly BarsFriction Kelly bars establish frictional contact between the rails of each element, allowing for torque transfer.
- Interlocking Kelly BarsInterlocking Kelly bars feature drive ribs welded with lock devices, ensuring maximum torque transfer to each scope.
Features of Kelly Bars
Kelly bars can be equipped with various additional features to enhance their functionality and performance. These features include:
- Telescopic OptionsTelescopic Kelly bars are collapsible, saving space during storage and transportation.
- Depth RangesKelly bars come with a range of depth options, typically from 10m to 110m, accommodating various drilling requirements.
- Torque Transfer CapacityKelly bars have a torque transfer capacity ranging from 80kNm to 500kNm, enabling them to handle demanding drilling conditions.
- High-Quality Seamless Steel PipesKelly bars are constructed using high-quality seamless steel pipes, ensuring durability and reliability.
- Spring Shock AbsorbersSpring shock absorbers can be incorporated into Kelly bars to mitigate vibrations and improve drilling efficiency.
- Square Kelly BoxA square Kelly box is provided for connecting drilling tools, ensuring secure and efficient transfer of torque and crowd force.
Material and Quality Considerations
When selecting a Kelly bar, it is crucial to consider the material and quality aspects.
- High-Quality SteelKelly bars should be made of high-quality steel with strong mechanical features to withstand the rigors of drilling operations.
- Origin and Quality CertificatesOrigin and quality certificates can guarantee the reliability and longevity of Kelly bars, ensuring they meet industry standards and specifications.
Noise Reduction
Some Kelly bars are equipped with a damping noise system to reduce disruptive, high-frequency noises during operation. This system comprises a phono-absorbent material applied to the outer scope of the Kelly bar, protected by steel plates.
Conclusion
Kelly bars play a vital role in drilling operations, extending the reach and depth of boreholes. They come in different types, with various features and material considerations. Noise reduction systems can also be incorporated to minimize operational noise. By selecting high-quality Kelly bars and implementing proper maintenance practices, drilling operations can be conducted efficiently and safely.
References
- Kelly Bars | Drilling Machinery | Tebco
- What Is a Kelly Bar? | Eiffel Trading
- Kelly Bar – Sip&T Foundation Drilling Tools
FAQs
Kelly Bars: Extending Reach and Depth in Drilling Operations
Introduction
Kelly bars are essential components in the execution of boreholes by hydraulic rotary drilling rigs. They serve as an extension to the excavator, providing increased reach and depth to the drilling hole. This article explores the function, types, features, material considerations, and noise reduction aspects of Kelly bars.
Function of Kelly Bars
Kelly bars extend the reach and depth of a drilling hole by providing an extension to the excavator. They are inserted into the drill string and held in place by friction or interlocking mechanisms. The Kelly bar transfers torque and crowd force from the rotary drive to the drilling tool, enabling efficient drilling operations.
Types of Kelly Bars