Assembly

Abstract

A downhole transport assembly ( 100, 101 ) having first and second members ( 10, 20 ) having a common longitudinal axis, at least one of the members ( 10, 20 ) being rotatable about the longitudinal axis and movable along the longitudinal axis relative to the other member, the rotatable member having at least one engaging member ( 60 ), the or each engaging member ( 60 ) being configured and/or disposed on the rotatable member so that rotation of the rotatable member about the longitudinal axis causes the first and second members ( 10, 20 ) to move with respect to each other in opposite directions along the longitudinal axis.

1 . An assembly for transport through an outer structure, the assembly having
 first and second members having a common longitudinal axis;   at least one of the members being rotatable about the longitudinal axis and movable along the longitudinal axis relative to the other member,   the rotatable member having at least one engaging member,   the or each engaging member being configured and/or disposed on the rotatable member so that rotation of the rotatable member about the longitudinal axis causes the first and second members to move with respect to each other in opposite directions along the longitudinal axis.   
     
     
         2 . An assembly as claimed in  claim 1 , wherein the outer structure is a generally tubular outer structure and wherein the or each engaging member is configured to engage the outer structure so that rotation of the rotatable member about the longitudinal axis causes the engaging member to engage the outer structure so that the engagement of the engaging member with the outer structure causes traction between the outer structure and the engaging member whereby the engaging member causes the rotatable member and other member to move with respect to each other in opposite directions along the longitudinal axis. 
     
     
         3 . An assembly as claimed in  claim 1 , wherein the rotatable member has a second mode of rotation and the or each engaging member is configured and/or disposed on the respective rotatable member so that in the second mode of rotation, rotation of the rotatable member about the longitudinal axis causes the assembly to advance along the longitudinal axis. 
     
     
         4 . An assembly as claimed in  claim 3 , wherein the or each engaging member is configured to engage the outer structure, so that rotation of the rotatable member about the longitudinal axis causes the engaging member to engage the outer structure so that the engagement of the engaging member with the outer structure causes traction between the outer structure and the engaging member whereby, in the second mode of rotation the engaging member causes the rotatable member and other member to advance along the longitudinal axis. 
     
     
         5 . An assembly as claimed in  claim 1 , wherein the engagement of the or each engaging member with the outer structure also causes the entire assembly to rotate as a unit about the longitudinal axis. 
     
     
         6 . An assembly as claimed in  claim 1 , wherein each of the first and second members comprises one or more engageable members. 
     
     
         7 . An assembly as claimed in  claim 1 , wherein each of the first and second members is rotatable. 
     
     
         8 . An assembly as claimed in  claim 1 , wherein the rotatable members are independently rotatable about the longitudinal axis. 
     
     
         9 . An assembly as claimed in  claim 7 , wherein the relationship between the engaging members and the rotatable members is such that rotation of the rotatable members in the same first direction about the longitudinal axis causes the rotatable members to move towards each other; and wherein rotation of the rotatable members in the same second direction about the longitudinal axis causes the rotatable members to move away from each other. 
     
     
         10 . An assembly as claimed in  claim 1 , wherein the relationship between the or each engaging member and the respective rotatable member is such that relative rotation of the rotatable member and the other member in the first opposite directions about the longitudinal axis causes the first and second members to move towards each other, whereas relative rotation of the rotatable member and the other member in the second opposite directions, about the longitudinal axis causes the movement of the first and second members away from each other. 
     
     
         11 . An assembly as claimed in  claim 1 , wherein the arrangement of the or each engaging member defines a rotational pattern having a rotational direction. 
     
     
         12 . An assembly as claimed in  claim 11 , wherein each of the first and second members comprises one or more engageable members, wherein the rotational directions of the rotational patterns of the engaging members of the first and second members are opposite each other. 
     
     
         13 . An assembly as claimed in  claim 12 , wherein each of the first and second members is rotatably mounted and rotation of the rotatable members in the same first direction about the longitudinal axis causes the rotatable members to move towards each other, wherein rotation of the rotatable members in the same second direction about the longitudinal axis causes the rotatable members to move away from each other. 
     
     
         14 . An assembly as claimed in  claim 12 , wherein relative rotation of the rotatable member and the other member in the first opposite directions about the longitudinal axis causes the first and second members to move as a unit in a first direction along the longitudinal axis, whereas relative rotation of the rotatable member and the other member in the second opposite directions about the longitudinal axis causes the movement of the first and second members as a unit in a second opposite direction along the longitudinal axis. 
     
     
         15 . An assembly as claimed in  claim 11 , wherein each of the first and second members comprises one or more engageable members, wherein the rotational directions of the rotational patterns of the engaging members of the first and second members are the same. 
     
     
         16 . An assembly as claimed in  claim 15 , wherein each of the first and second members is rotatably mounted and rotation of the rotatable members in the same first direction about the longitudinal axis causes the rotatable members to move as a unit along the longitudinal axis in a first direction, wherein rotation of the rotatable members in the same second direction about the longitudinal axis causes the rotatable members to move as a unit along the longitudinal axis in a second direction, opposite to the first direction. 
     
     
         17 . An assembly as claimed in  claim 15 , wherein relative rotation of the rotatable member and the other member in the first opposite directions about the longitudinal axis causes the first and second members to move toward each other along the longitudinal axis, whereas relative rotation of the rotatable member and the other member in the second opposite directions about the longitudinal axis causes the movement of the first and second members away from each other along the longitudinal axis. 
     
     
         18 . An assembly as claimed in  claim 1 , wherein the or each engaging member is helically arranged around the rotatable member. 
     
     
         19 . An assembly as claimed in  claim 18 , wherein a plurality of engaging members are helically arranged around the rotatable member. 
     
     
         20 . An assembly as claimed in  claim 18 , wherein the rotational direction of the rotational pattern of the or each engaging members of one member is clockwise and the rotational direction of the rotational pattern of the or each engaging members of the other member is anti-clockwise. 
     
     
         21 . An assembly as claimed in  claim 1 , wherein the rotatable member is rotatably mounted on a shaft member. 
     
     
         22 . An assembly as claimed in  claim 21 , wherein the shaft member connects the first and second members. 
     
     
         23 . An assembly as claimed in  claim 1  comprising a jarring mechanism. 
     
     
         24 . An assembly as claimed in  claim 23 , wherein the jarring mechanism is provided between the first and second members and is activated by rotation of the first and second members with respect to each other. 
     
     
         25 . An assembly as claimed in  claim 23 , wherein the jarring mechanism is provided within the shaft member. 
     
     
         26 . An assembly as claimed in  claim 1  wherein the or each rotatable member is connected to and is driven by a drive means. 
     
     
         27 . An assembly as claimed in  claim 26 , wherein the or each rotatable member is independently driven by the drive means. 
     
     
         28 . An assembly as claimed in  claim 1 , wherein the or each engaging member comprises a roller member which is arranged to rotate. 
     
     
         29 . An assembly as claimed in  claim 28 , wherein the or each engaging member rotates around an axis perpendicular to the axis of rotation of the respective rotatable member. 
     
     
         30 . An assembly as claimed in  claim 28 , wherein the or each roller member is independently rotatable. 
     
     
         31 . An assembly as claimed in  claim 1 , wherein the assembly is a transport assembly. 
     
     
         32 . An assembly as claimed in  claim 1 , wherein the assembly is adapted for use in a wellbore. 
     
     
         33 . An assembly as claimed in  claim 1 , wherein the assembly comprises an attachment member attachable to a downhole tool. 
     
     
         34 . An assembly as claimed in  claim 33 , wherein the rotatable member is connected to the attachment member. 
     
     
         35 . An assembly as claimed in  claim 1 , wherein the or each engagement member is attached to a surface of the respective rotatable member. 
     
     
         36 . An assembly as claimed in  claim 1 , wherein the or each engaging member is disposed on an outer surface of the respective rotatable member. 
     
     
         37 . An assembly as claimed in  claim 1 , wherein a plurality of engaging members are attached to the rotatable member. 
     
     
         38 . An assembly as claimed in  claim 1 , wherein the or each engaging member is attached to the rotatable body via an arm linkage; the arm linkage and the engaging member forming a hub assembly. 
     
     
         39 . An assembly as claimed in  claim 38 , wherein the arm linkage is pivotally mounted on the rotatable member and is pivotally connected to the respective engaging member. 
     
     
         40 . An assembly as claimed in  claim 38 , comprising a plurality of hub assemblies each comprising at least one arm linkage mounted on the rotatable member. 
     
     
         41 . An assembly as claimed in  claim 38 , wherein the or each hub assembly has a second arm linkage, also pivotally mounted to the rotatable member and pivotally connected to the same engaging member of that hub assembly so that the engaging member is connected to the rotatable member by two arm linkages. 
     
     
         42 . An assembly as claimed in  claim 41 , wherein the first and second arm linkages of the or each hub assembly pivot in the same plane as each other and extend on the same side of the rotatable member. 
     
     
         43 . An assembly as claimed in  claim 38 , wherein the rotatable member may be provided as two rings which are independently axially moveable with respect to each other. 
     
     
         44 . An assembly as claimed in  claim 43 , wherein the first arm linkage of each hub assembly is mounted to the first ring of the rotatable member and the second arm portion of each hub assembly is mounted to the second ring of the rotatable member. 
     
     
         45 . An assembly as claimed in  claim 38 , wherein at least one of a proactive and a reactive mechanism is provided to move the engaging member from a relatively retracted radial position to an extended radial position. 
     
     
         46 . An assembly as claimed in  claim 38 , wherein a resilient element is mounted around an outer side of the rotatable member between the rotatable member and the attachment member. 
     
     
         47 . An assembly as claimed in  claim 1 , wherein at least one retaining member is disposed between the engaging members and the rotatable member and is operable to resist separation of the engaging members from the rotatable member.