Drilling operations are a vital part of the oil and gas industry, enabling the extraction of valuable resources from deep beneath the earth's surface. To ensure efficient and safe drilling, various equipment and tools are utilized, including the hex.kelly 6 5/8" REG. This article aims to shed light on the significance of this particular tool in drilling operations, its features, and its role in enhancing productivity and safety.

    1. Hex.Kelly: An Overview:

    The hex.kelly is a crucial component of the drilling string that connects the rotary table to the drill pipe during drilling operations. It serves as the primary force transmission point, allowing the rotation of the drill string and bit. The hex.kelly is characterized by a hexagonal cross-section, which offers enhanced stability and torque transmission capabilities compared to round kellys.

    2. Understanding 6 5/8" REG:

    The 6 5/8" REG refers to the connection size of the hex.kelly. The 'REG' stands for regular, which indicates a standard thread connection used in the industry. The 6 5/8" measurement refers to the outside diameter of the hex.kelly. It is essential to choose the appropriate connection size based on the specific drilling requirements and the compatibility with other drilling tools.

    3. Features and Benefits:

    a. Enhanced Torque Transmission: The hexagonal shape of the hex.kelly allows for improved torque transmission between the rotary table and the drill pipe. This ensures optimal power transfer, facilitating efficient drilling and reduced wear on the equipment.

    b. Stability and Alignment: The hexagonal cross-section provides increased stability and alignment during drilling operations. It minimizes the risk of wobbling or misalignment, enhancing drilling accuracy and reducing the chance of accidents or equipment damage.

    c. Durability: Hex.kellys are manufactured using high-quality materials, such as alloy steel, ensuring durability and resilience. This robust construction allows them to withstand the harsh conditions encountered during drilling, including high pressures, vibrations, and variable temperatures.

    d. Compatibility: The 6 5/8" REG connection size is widely used and compatible with various drilling tools and equipment, making it a versatile choice for drilling operations. It allows for easy integration into the drilling string, ensuring smooth operations and reducing downtime.

    4. Importance in Drilling Operations:

    a. Efficient Power Transmission: The hex.kelly's ability to transmit torque efficiently is crucial for drilling operations. It enables the rotary table to transfer the required rotational force to the drill string and bit, facilitating effective penetration into the geological formations. This efficient power transmission aids in increasing drilling speed and productivity.

    b. Safety and Stability: The hex.kelly's hexagonal shape enhances stability and alignment, minimizing the risk of accidents and equipment failures. The precise alignment between the rotary table and the drill string reduces vibrations, preventing potential damage to the equipment and ensuring a safer working environment for the drilling crew.

    c. Versatility and Compatibility: The 6 5/8" REG connection size of the hex.kelly allows for compatibility with various drilling tools, including subs, drill collars, and bottom-hole assemblies. This versatility enables seamless integration within the drilling string, optimizing drilling efficiency and reducing operational complexities.

    d. Maintenance and Repair: Hex.kellys are designed to facilitate easy maintenance and repair. Their standardized connection sizes and compatibility with common drilling tools simplify the replacement process. This reduces downtime, enhances operational efficiency, and helps minimize costs associated with equipment repairs.


    The hex.kelly 6 5/8" REG is a critical tool in drilling operations, offering enhanced stability, torque transmission, and compatibility. Its hexagonal shape and standard connection size make it a reliable and versatile choice for connecting the rotary table to the drill pipe. By ensuring efficient power transmission, safety, and ease of maintenance, the hex.kelly plays a pivotal role in optimizing drilling operations in the oil and gas industry.