US 12,291,932 B2
Method and system for detecting a loosened joint of a drill string
Gustav Mörtzell, Örebro (SE); and Thomas Adolfsson, Örebro (SE)
Assigned to EPIROC ROCK DRILLS AKTIEBOLAG, Örebro (SE)
Appl. No. 18/551,208
Filed by EPIROC ROCK DRILLS AKTIEBOLAG, Örebro (SE)
PCT Filed Mar. 10, 2022, PCT No. PCT/SE2022/050234
§ 371(c)(1), (2) Date Sep. 19, 2023,
PCT Pub. No. WO2022/203564, PCT Pub. Date Sep. 29, 2022.
Claims priority of application No. 2150366-9 (SE), filed on Mar. 26, 2021.
Prior Publication US 2024/0159115 A1, May 16, 2024
Int. Cl. E21B 19/16 (2006.01)
CPC E21B 19/166 (2013.01) 19 Claims
OG exemplary drawing
 
1. 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.