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Aps Technology, Inc.

Mark Hutchinson

William Evans Turner

Carl Allison Perry

Mark Ellsworth Wassell

Martin E Cobern

Dirk Bosman

An apparatus and method for damping vibration, especially torsional vibration due to stick-slip, in a drill string, Sensors measure the instantaneous angular velocity of the drill string at one or more locations along the length of the drill string. One or more vibration damping modules are also spaced along the length of the drill string. When torsional vibration above a threshold is detected, the damping module imposes a reverse torque on the drill that dampens the torsional vibration. The reverse torque can be created by imparting a frictional resistance to the rotation of the drill string. The frictional resistance can be created externally, by extending friction pads from the damping module so that they contact the bore hole wall and drag along the bore hole as the drill string rotates, or internally by anchoring a housing mounted on the drill string to the wall of the bore hole and then imposing frictional resistance on a fluid, such as a magnetorheological fluid, flowing within the drill string.

Apparatus and method for damping vibration in a drill string

An apparatus for determining the weight on a drill bit and axial forces along a drill string drilling though an earthen formation. The apparatus comprising an LVDT incorporated into a torsional bearing of a magneto-rheological damping system such that the LVDT senses the relative displacement and accelerations between a bearing mandrel portion and a bearing casing portion of the torsional damper. The LVDT is calibrated with respect to a spring in the damping system that resists relative motion between the bearing mandrel and bearing casing such that the output of the LVDT can be transformed into the force associated with the weight on the drill bit, and the same LVDT accelerations combined with the mass distribution along the drill string to determine axial stresses.

Apparatus and method for determining axial forces on a drill string during underground drilling

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Meriden, CT, United States of America

Mark Hutchinson