Circumferential wear bands for oilfield tubulars

Abstract

A wear band assembly for a pipe string operating inside a casing string includes a fixed cylindrical wear band made from a non-metallic, abrasion-resistant, low-friction material (such as but not limited to a glass-reinforced thermal polyurethane) injection-moulded onto a pipe joint or sub incorporated into the pipe string, and optionally having a circumferential wear indicator groove. In an alternative embodiment, the wear band assembly includes a rotatable wear band comprising mating cylindroid sections rotatably disposed within an annular recess formed in a circumferential collar injection-moulded onto the pipe or sub. The rotatable wear band initially projects radially beyond the collar and is rotatable relative to the pipe or sub, allowing the wear band to rotate relative to the casing when in rotational contact therewith, thereby reducing resultant wear to the wear band, and reducing torque in the pipe string due to contact with the casing.

What is claimed is: 
     
         1 . A wear band assembly comprising:
 (a) a tubular member;   (b) a generally cylindrical collar coaxially disposed around, and bonded to, a selected portion of the length of the tubular member, wherein:
 the collar has an annular wear band retention groove coaxial with the tubular member; and 
 the wear retention groove has a cylindrical circumferential surface; and 
   (c) a generally cylindrical wear band rotatably and coaxially disposed within the wear band retention groove so as to be coaxially rotatable around the cylindrical circumferential surface of the wear band retention groove.   
     
     
         2 . A wear band assembly as in  claim 1  wherein the wear band comprises a plurality of cylindroid wear band sections. 
     
     
         3 . A wear band as in  claim 2  where the cylindroid wear band sections are removably retained within the wear band retention groove by retention means selected from the group consisting of bolted connections between circumferentially-adjacent cylindroid wear band and snap-on connections between circumferentially-adjacent cylindroid wear band sections. 
     
     
         4 . A wear band assembly as in  claim 1  wherein the cylindrical collar is bonded to the tubular member by injection moulding. 
     
     
         5 . A wear band assembly as in  claim 1  wherein the cylindrical collar is made from a material selected from the group consisting of polyketone, HDPE (high-density polyethylene), PEX (cross-linked polyethylene), Fortron® (polyphenylene sulfide), fiberglass, Amodel® (polyphthalamide), Ryton® (polyphenylene sulfide), PE-RT (polyethlene of raised temperature), UHMW-PE (ultra-high molecular weight polyethylene), TPU (thermal polyurethane), and glass-reinforced TPU. 
     
     
         6 . A wear band assembly as in  claim 1  wherein the wear band is made from a material selected from the group consisting of polyketone, HDPE (high-density polyethylene), PEX (cross-linked polyethylene), Fortron® (polyphenylene sulfide), fiberglass, Amodel® (polyphthalamide), Ryton® (polyphenylene sulfide), PE-RT (polyethlene of raised temperature), UHMW-PE (ultra-high molecular weight polyethylene), TPU (thermal polyurethane), and glass-reinforced TPU. 
     
     
         7 . A wear band assembly as in  claim 1  wherein the tubular member comprises a steel pipe section having an upset end. 
     
     
         8 . A wear band assembly as  claim 7  wherein the cylindrical collar is located proximal to the upset end of the steel pipe section. 
     
     
         9 . A wear band assembly as in  claim 7  wherein the outer diameter of the wear band is greater than the outer diameter of the upset end of the steel pipe section. 
     
     
         10 . A wear band assembly as in  claim 1  wherein:
 (a) the wear band is made from a material comprising a glass-reinforced TPU containing between about 5% and 25% glass by weight; and 
 (b) the wear band is formed with one or more longitudinal debris channels and a circumferential wear indicator groove. 
 
     
     
         11 . A wear band assembly as in  claim 10  wherein the glass-reinforced TPU contains approximately 10% glass by weight. 
     
     
         12 . A wear band assembly comprising:
 (a) a tubular member; and   (b) a generally cylindrical wear band disposed circumferentially around and bonded to a selected portion of the length of the tubular member.   
     
     
         13 . A wear band assembly as in  claim 12  wherein the wear band has a circumferential wear indicator groove. 
     
     
         14 . A wear band assembly as in  claim 12  wherein the wear band is bonded to the tubular member by injection moulding. 
     
     
         15 . A wear band assembly as in  claim 12  wherein the wear band is made from a material selected from the group consisting of polyketone, HDPE (high-density polyethylene), PEX (cross-linked polyethylene), Fortron® (polyphenylene sulfide), fiberglass, Amodel® (polyphthalamide), Ryton® (polyphenylene sulfide), PE-RT (polyethlene of raised temperature), UHMW-PE (ultra-high molecular weight polyethylene), TPU (thermal polyurethane), and glass-reinforced TPU. 
     
     
         16 . A wear band assembly as in  claim 13  wherein the tubular member comprises a steel pipe section having an upset end. 
     
     
         17 . A wear band assembly as  claim 16  wherein the wear band is located proximal to the upset end of the steel pipe section. 
     
     
         18 . A wear band assembly as in  claim 16  wherein the outer diameter of the wear band is greater than the outer diameter of the upset end of the steel pipe section. 
     
     
         19 . A wear band assembly as in  claim 12  wherein:
 (a) the wear band is made from a material comprising a glass-reinforced TPU containing between about 5% and 25% glass by weight; and 
 (b) the wear band is formed with one or more longitudinal debris channels and a circumferential wear indicator groove. 
 
     
     
         20 . A wear band assembly as in  claim 19  wherein the glass-reinforced TPU contains approximately 10% glass by weight.