| 摘要 |
In one embodiment, a wear band comprises a rotating element having a bore receivable on a tubular, the bore comprising first and second bore portions slidably receiving first and second sleeve bearings. Outer surfaces of the sleeve bearings slidably engage the bore portions and the bores of the sleeve bearings slidably engage the tubular. A first stop collar and a second stop collar may be received on the tubular to together straddle the rotating element and sleeve bearings to longitudinally secure the rotating element in a position on the tubular. The tubular may be included within a tubular string run into a borehole or into the bore of an installed casing, such as in casing while drilling. The rotating element provides stand-off between a tubular and the wall of a bore, reduces frictional resistance to longitudinal sliding and also to rotation of the tubular string within the bore. |
