Method and system for detecting a loosened joint of a drill string
AssigneeEpiroc Rock Drills Aktiebolag
InventorsGustav Mörtzell, Thomas Adolfsson
Life of this patent
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Abstract
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.
Claims19
A method for determining loosening of a joint of a drill string of a drill rig, the joint joining a first and a second drill string component, the drill rig comprising:
- a rotation unit for rotating the drill string during drilling;
- means for determining a representation of a torque applied to the drill string by the rotation unit;
- a joint loosening mechanism, the joint loosening mechanism is distinct from the rotation unit and is configured to:
- when loosening the joint, apply a first joint loosening torque acting on the drill string;
- the method comprising, when loosening the joint of the drill string:
- applying a torque in a joint loosening direction by means of the rotation unit;
- applying the first joint loosening torque acting on the drill string by means of the joint loosening mechanism;
- monitoring the representation of the torque applied by the rotation unit during the applying of the first joint loosening torque by means of the joint loosening mechanism;
- determining whether the joint is loosened based on the monitored representation of the torque applied by the rotation unit;
- and
- generating a signal representing a loosened joint when the determining indicates that the joint has been loosened.
A system for determining loosening of a joint of a drill string of a drill rig, the joint joining a first and a second drill string component, the system comprising:
- a rotation unit for rotating the drill string during drilling;
- means for determining a representation of a torque applied to the drill string by the rotation unit;
- a joint loosening mechanism, the joint loosening mechanism is distinct from the rotation unit and is configured to, when loosening the joint, applying a joint loosening torque acting on the drill string;
- means for, when loosening the joint of the drill string:
- applying a torque in a joint loosening direction by means of the rotation unit;
- applying a joint loosening torque acting on the drill string by means of the joint loosening mechanism;
- monitoring the representation of the torque applied by the rotation unit during the applying of the joint loosening torque by means of the joint loosening mechanism;
- determining whether the joint is loosened based on the monitored representation of the torque applied by the rotation unit;
- and
- generating a signal representing a loosened joint when the determining indicates that the joint has been loosened.
Dependencies are inferred from the claim text.