A Kelly spinner, also known as a top drive spinner or rotary spinner, is a device used in drilling operations to facilitate the connection or disconnection of the Kelly to the drill string. It is typically mounted on the drilling rig's rotary table or top drive system. The function of a Kelly spinner is to rotate the Kelly during the process of making or breaking the connection between the Kelly and the drill string. The Kelly is a square or hexagonal pipe that serves as the uppermost part of the drill string. It transmits rotational torque from the rotary table or top drive system to the drill string and the drill bit. Here's how the Kelly spinner works and its key features: Connection Process: When making a connection, the Kelly spinner is used to rotate the Kelly, aligning it with the drill string below. The Kelly spinner is typically equipped with powered spinning rollers or jaws that grip the Kelly securely, allowing it to rotate. As the Kelly spins, the drill pipe below it is raised or lowered by the rig's hoisting system until the two components are properly aligned for connection. Disconnection Process: When breaking the connection, the Kelly spinner is used to rotate the Kelly in the opposite direction, unscrewing it from the drill string. The spinning action of the Kelly spinner helps release the threaded connection between the Kelly and the drill string, allowing them to be separated. Control and Safety: The Kelly spinner is operated by the rig crew using control buttons or switches. It allows for precise control over the spinning speed and direction. Additionally, the Kelly spinner is equipped with safety features, such as emergency stop buttons or mechanisms, to ensure the safety of personnel and equipment during operation. The use of a Kelly spinner simplifies the process of connecting and disconnecting the Kelly from the drill string, reducing the manual effort required by rig crew members. It improves efficiency, saves time during drilling operations, and helps reduce the risk of injuries associated with manual handling of heavy equipment. It's important to note that with the advancement of drilling technology, some modern drilling rigs are equipped with top drive systems instead of traditional rotary tables. In these rigs, the Kelly spinner function is incorporated within the top drive system itself. The top drive system serves as a motorized drilling tool that can rotate the drill string directly, eliminating the need for a Kelly and a separate Kelly spinner. Overall, the Kelly spinner is a valuable tool used in conventional drilling operations to facilitate the connection and disconnection of the Kelly to the drill string, improving the efficiency and safety of the drilling process.