Definition of drill string in English:

drill string


  • A structure consisting of coupled lengths of pipe or casing, which occupies the hole made in drilling for oil or gas.

    • ‘Vibration of the drill string may also reduce the friction between the drill string and the hole, resulting in lower torque requirements.’
    • ‘Mud is injected into the drill string, up a borehole and through the blowout preventor adjacent the sea floor.’
    • ‘You keep adding to the drill string until you reach the total depth of the well.’
    • ‘The first end of the shaft is connectable to the drill string of a horizontal boring machine.’
    • ‘A 400-ton heave compensator keeps the drill string stable relative to the sea floor.’