Kelly

Kelly is on the top of the drill stem.Kelly is main driver of the whole drill string. It transmits drill stem weight and torsional energy from the rotary table through the drill string to the bit at the bottom of the hole.

When assembled with down hole motor and Turbodrill tools, Kelly should bare the stem weight and Reverse torque,it will Measure the depth of a well and provide a circulation channel.

Kelly consists of a driving part (square or hexagonal), upper joint (LH connection) and lower joint (RH connection).