Epiroc Rock Drills Aktiebolag

Thomas Adolfsson

Gustav Mörtzell

The invention relates to a method for determining the state of a joint joining a first and a second drill string component. A drill rig includes a rotation unit for rotating the drill string and means for determining a representation of a torque applied by the rotation unit. A joint loosening mechanism distinct from the rotation unit apply a joint loosening torque acting on the drill string when loosening a joint. The method includes applying a torque in a joint loosening direction by means of the rotation unit, and applying a joint loosening torque acting on the drill string by means of the joint loosening mechanism.

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Örebro, Sweden

Thomas Adolfsson