Downhole seal

Abstract

A downhole seal assembly for establishing a seal against a bore wall includes a mandrel, a seal element mounted on the mandrel, a setting support member mounted on the mandrel, and at least one setting element mounted on the mandrel axially between the seal element and the setting support member. Relative axial movement between the seal element and the setting support member over a first actuation distance causes the seal element to be deflected radially outwardly by an axially adjacent setting element. Relative axial movement of the seal element and the setting support member over a subsequent actuation distance causes radial expansion of at least one setting element to further expand the seal element.

1 . A downhole seal assembly for establishing a seal against a bore wall, comprising:
 a mandrel;   a seal element mounted on the mandrel;   a setting support member mounted on the mandrel; and   at least one setting element mounted on the mandrel axially between the seal element and the setting support member,   wherein relative axial movement between the seal element and the setting support member over a first actuation distance causes the seal element to be deflected radially outwardly by an axially adjacent setting element, and relative axial movement of the seal element and the setting support member over a subsequent actuation distance causes radial expansion of at least one setting element to further expand the seal element.   
     
     
         2 . (canceled) 
     
     
         3 . The seal assembly according to  claim 1 , configured such that the seal element preferentially expands by being radially deflected by the primary setting element, prior to radial expansion of the at least one setting element. 
     
     
         4 . The seal assembly according to  claim 1 , wherein the seal element is configured to be deflected radially outwardly and over an outer surface of the adjacent setting element such that the seal element and the adjacent setting element become radially stacked. 
     
     
         5 . The seal assembly according to  claim 1 , wherein the seal element is configured to define a cup or lip seal when in an expanded configuration. 
     
     
         6 . The seal assembly according to  claim 1 , wherein the seal element comprises a fixed region which is radially fixed, and a free end region which is configured to be radially expanded by being deflected radially outwardly by the adjacent setting element. 
     
     
         7 . The seal assembly according to  claim 6 , wherein at least one of:
 the fixed region is positioned intermediate opposing ends of the seal element;   the fixed region is positioned at one end region of the seal element, opposite the free end region; and   the fixed region of the seal element is sealingly engaged with the mandrel.   
     
     
         8 - 9 . (canceled) 
     
     
         10 . The seal assembly according to  claim 1 , wherein the seal element and the adjacent setting element are generally arranged axially relative to each other in end-to-end relationship, when the seal element is in the retracted configuration. 
     
     
         11 . The seal assembly according to  claim 1 , wherein at least one of:
 the seal element and the adjacent setting element define a seal deflection interface therebetween configured to permit the seal element to be deflected radially outwardly by the adjacent setting element during relative axial movement between the seal element and the setting support member;   the seal element and the adjacent setting element define a seal deflection interface therebetween configured to permit the seal element to be deflected radially outwardly by the adjacent setting element during relative axial movement between the seal element and the setting support member, the seal deflection interface comprising an interengaging ramp structure; and   the seal element and the adjacent setting element each define a ramp surface to facilitate deflection of the seal element.   
     
     
         12 - 13 . (canceled) 
     
     
         14 . The seal assembly according to  claim 1 , wherein said at least one setting element is at least one of:
 axially compressible during relative axial movement between the seal element and the setting support member over the subsequent actuation distance to be radially expanded; and   radially expanded by being radially deflected outwardly during relative movement between the seal element and the setting support member over the subsequent actuation distance.   
     
     
         15 . (canceled) 
     
     
         16 . The seal assembly according to  claim 1 , comprising a deflecting member for use in radially deflecting at least one setting element. 
     
     
         17 . The seal assembly according to  claim 16 , wherein at least one of:
 the deflecting member is defined by the setting support member;   the deflecting member is defined by a further setting element;   the deflecting member and at least one setting element define a setting deflection interface therebetween configured to permit the at least one setting element to be deflected radially outwardly by the deflecting member;   the deflecting member and at least one setting element define a setting deflection interface therebetween configured to permit the at least one setting element to be deflected radially outwardly by the deflecting member, and wherein the setting deflection interface comprises an interengaging ramp structure; and   the setting element and the deflecting member each define a ramp surface to facilitate deflection of the setting element.   
     
     
         18 - 21 . (canceled) 
     
     
         22 . The seal assembly according to  claim 16 , wherein one of:
 the seal element and the adjacent setting element define a seal deflection ramp interface therebetween, and the adjacent setting element and the deflecting member define a setting deflection ramp interface therebetween; and   the seal element and the adjacent setting element define a seal deflection ramp interface therebetween, and the adjacent setting element and the deflecting member define a setting deflection ramp interface therebetween, and wherein the seal deflection ramp interface and the setting deflection ramp interface each define a ramp angle relative to a longitudinal axis of the mandrel, wherein the seal deflection ramp interface defines a shallower ramp angle than the setting deflection ramp interface.   
     
     
         23 . (canceled) 
     
     
         24 . The seal assembly according to  claim 1 , wherein one of:
 both of the setting support member and the seal element are axially moveable relative to the mandrel, such that movement of both the setting support member and the seal element establishes relative axial movement therebetween; and   one of the setting support member and the seal element is axially moveable relative to the mandrel, and the other of the setting support member and the seal element is axially fixed relative to the mandrel.   
     
     
         25 . (canceled) 
     
     
         26 . The seal assembly according to  claim 1 , comprising an actuator arrangement for establishing relative axial movement between the seal element and the setting support member. 
     
     
         27 . The seal assembly according to  claim 1 , wherein the seal element defines an annular gap with the mandrel, at least when the seal element is in its retracted configuration. 
     
     
         28 . The seal assembly according to  claim 1 , comprising an actuation ring mounted on the mandrel and axially adjacent the seal element. 
     
     
         29 . The seal assembly according to  claim 28 , wherein at least one of:
 the actuation ring axially supports the seal element;   the actuation ring radially retrains one end region of the seal element;   a seal arrangement is provided between the mandrel and the actuation ring;   the actuation ring is secured to the seal element by at least one of integrally forming, fusing, adhesive bonding and interference fitting; and   the actuation ring comprises an outer retaining structure extending along a portion of the outer surface at one end region of the seal element.   
     
     
         30 - 33 . (canceled) 
     
     
         34 . The seal assembly according to  claim 28 , wherein the actuation ring comprises an inner actuation structure extending along a portion of the inner surface of the seal element. 
     
     
         35 . The seal assembly according to  claim 34 , wherein at least one of:
 when the seal element is in its retracted configuration the inner actuation structure of the actuation ring is axially separated from at least one setting element, and during relative axial movement between the seal element and the setting support member the inner actuation structure of the actuation ring eventually engages the at least one setting element;   when the seal element is in its retracted configuration the inner actuation structure of the actuation ring is axially separated from at least one setting element, and during relative axial movement between the seal element and the setting support member the inner actuation structure of the actuation ring eventually engages the at least one setting element, and wherein engagement between the at least one setting element and the inner actuation structure of the actuation ring defines the full extent of the first actuation distance;   the inner actuation structure of the actuation ring is configured to actuate a setting element following engagement therewith to cause said setting element to be radially expanded;   the inner actuation structure is configured to axially compress a setting element; and   the inner actuation structure is configured to axially move the setting element to permit said setting element to be radially deflected.   
     
     
         36 - 39 . (canceled) 
     
     
         40 . The seal assembly according to  claim 1 , comprising a back-up arrangement configured to provide axial support to the seal element when said seal element is in the extended configuration. 
     
     
         41 . The seal assembly according to  claim 1 , comprising first and second sealing arrangements mounted on the mandrel, wherein each sealing arrangement comprises:
 a seal element mounted on the mandrel;   a setting support member mounted on the mandrel; and   at least one setting element mounted on the mandrel axially between the seal element and the setting support member.   
     
     
         42 . The seal assembly according to  claim 41 , wherein the first and second sealing arrangements are at least one of;
 mounted adjacent each other on the mandrel;   configured to be actuated by a common actuation event; and   arranged in a front-to-front orientation relative to each other such that respective free ends of the seal elements face each other.   
     
     
         43 - 44 . (canceled) 
     
     
         45 . The seal assembly according to  claim 1 , wherein the setting support member comprises at least one of;
 a rigid material;   a metal material;   an elastic material; and   an elastomeric material.   
     
     
         46 - 48 . (canceled) 
     
     
         49 . A method for establishing a seal against a wall of a bore, comprising:
 locating a seal assembly within the bore, wherein the seal assembly comprises a seal element and a seal support element, wherein a maximum unconstrained expansion of the seal element is achieved by a combination of radial deflection of the seal element by the setting element, and subsequent radial expansion of the setting element; and   expanding the seal element to sealingly engage a wall of the bore.   
     
     
         50 . A method for establishing a seal within a bore, comprising:
 (a) running a mandrel into a bore, wherein the mandrel carries a seal element, a setting support member; and at least one setting element positioned axially between the seal element and the setting support member; and   (b) causing relative axial movement between the seal element and the setting support member over a first actuation distance to cause the seal element to be deflected radially outwardly by a setting element.   
     
     
         51 . The method according to  claim 50 , wherein in the event that step (b) does not result in sealing engagement of the seal element with a bore wall, the method comprises:
 (c) causing relative axial movement of the seal element and the setting support member over a subsequent actuation distance to cause radial expansion of at least one setting element to further expand the seal element.   
     
     
         52 . The method according to  claim 50 , comprising the further step of:
 (d) axially compressing the seal element to establish or improve sealing engagement with a bore wall.   
     
     
         53 . A downhole seal assembly for establishing a seal against a bore wall, comprising:
 a seal element;   a setting support member; and   a setting element mounted axially between the seal element and the setting support member,   wherein the seal element is configured to be radially expanded by at least one of radial deflection by the setting element and radial expansion of the setting element.   
     
     
         54 . The seal assembly according to  claim 53 , wherein the setting support member comprises at least one of:
 a rigid material;   a metal material;   an elastic material; and   an elastomeric material.   
     
     
         55 - 57 . (canceled) 
     
     
         58 . A downhole seal assembly, comprising:
 a radially expandable seal element;   a radially expandable setting element; and   an actuator configured to radially stack at least portions of the seal element and the setting element, and to radially expand the setting element.