Friction reducing wear band and method of coupling a wear band to a tubular
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 and a second stop collars 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.
1. A stop collar for attachment to a tubular, the stop collar comprising:
a base configured to be disposed around the tubular, the base having a first axial end and a second axial end, wherein the base defines a plurality of slots extending radially entirely through the base and generally axially from the first axial end towards the second axial end such that a plurality of arcuate segments are defined circumferentially between the plurality of slots; and
a sleeve configured to be disposed around the tubular and to slide axially over the plurality of arcuate segments,
wherein, when the sleeve is positioned around the plurality of arcuate segments, the sleeve and the tubular entrain the plurality of arcuate segments therebetween and restrict the base from rotating relative to, and from axially translating relative to, the tubular and the sleeve.
2. The stop collar of claim 1 , wherein the plurality of arcuate segments are connected together by a portion of the base that is axially between the plurality of slots and the second axial end.
3. The stop collar of claim 2 , wherein the portion of the base has a first outside diameter, and wherein the plurality of arcuate segments define a second outside diameter, the first outside diameter being larger than the second outside diameter.
4. The stop collar of claim 3 , wherein the base comprises a shoulder extending radially from the first outside diameter to the second outside diameter.
5. The stop collar of claim 4 , wherein the shoulder provides a stop wall that bears against an end of the sleeve when the sleeve is fully received around the plurality of arcuate segments.
6. The stop collar of claim 2 , wherein the portion of the base and the plurality of arcuate segments are integrally formed.
7. The stop collar of claim 2 , wherein the portion of the base and the plurality of arcuate segments are separately formed and coupled together.
8. The stop collar of claim 1 , wherein the base defines a gap that extends axially from the first axial end to the second axial end.
9. The stop collar of claim 1 , wherein the plurality of arcuate segments each comprise a beveled end and a curved outer surface extending from the beveled end, the curved outer surface of each of the plurality of arcuate segments extending along at least a majority of an axial length of the arcuate segment, and wherein the curved outer surface defines a substantially constant outer diameter as proceeding axially along the arcuate segment.
10. An apparatus for securing to a tubular, the apparatus comprising:
means for gripping the tubular, the means for gripping the tubular comprising a base having a plurality of arcuate segments extending axially, the plurality of arcuate segments being separated apart by a plurality of slots extending at least partially axially across the base and radially entirely through the base; and
means for pressing the means for gripping into engagement with the tubular, the means for pressing comprising a sleeve configured to be slid over the plurality of arcuate segments so as to press the plurality of arcuate segments into engagement with the tubular.
11. The apparatus of claim 10 , wherein the means for gripping comprises means for allowing the plurality of arcuate segments to contract radially inwards.
12. The apparatus of claim 10 , wherein the plurality of arcuate segments extend axially from an end of the base, and wherein the plurality of axially-extending slots do not extend entirely axially across the base.
13. The apparatus of claim 12 , wherein the plurality of arcuate segments are integrally formed with a remainder of the base.
14. The apparatus of claim 10 , wherein the sleeve is configured to press the plurality of arcuate segments radially inwards when slid over the plurality of arcuate segments.
15. The apparatus of claim 10 , further comprising means for stopping the sleeve from sliding past the plurality of arcuate segments.
16. The apparatus of claim 15 , wherein the means for stopping comprises a stop wall that extends radially outwards from the plurality of arcuate segments.
17. A stop collar apparatus, comprising:
a base having a bore configured to be disposed around a tubular;
a plurality of arcuate segments coupled to or integral with the base and extending axially therefrom, wherein the plurality of arcuate segments are separated apart by a plurality of slots that extend radially entirely through the base, and wherein a radial-inside surface of the plurality of arcuate segments is configured to engage the tubular; and
a sleeve configured to be slid axially onto the plurality of arcuate segments, to press the radial-inside surface of the plurality of arcuate segments radially inwards, to grip the tubular.
18. The stop collar apparatus of claim 17 , wherein the base defines a first outside diameter and the plurality of arcuate segments define a second outside diameter, the second outside diameter being smaller than the first outside diameter.
19. The stop collar apparatus of claim 18 , wherein the base comprises an axial face that extends between the first and second outside diameters.
20. The stop collar apparatus of claim 19 , wherein the axial face provides a stop wall against which the sleeve is configured to bear, to prevent the sleeve from sliding further in at least one axial direction relative to the plurality of arcuate segments.
21. The stop collar apparatus of claim 17 , wherein the base and the plurality of arcuate segments are integrally formed, and wherein at least one of the plurality of slots does not extend across the base.