VIBRATION DAMPER SYSTEMS FOR DRILLING WITH CASING

摘要

Apparatus and methods are provided for reducing drilling vibration during drilling with casing. In one embodiment, an apparatus for reducing vibration of a rotating casing includes a tubular body disposed concentrically around the casing, wherein tubular body is movable relative to the casing. Preferably, a portion of the tubular body comprises a friction reducing material. In operation, the tubular body comes into contact with the existing casing or the wellbore instead of the rotating casing. Because the tubular body is freely movable relative to the rotating casing, the rotating casing may continuously rotate even though the tubular body is frictionally in contact with the existing casing.