Seal element

Abstract

A sealing element ( 10 ) for use in establishing a seal in an annulus ( 50 ) between a mandrel ( 52 ) and a bore wall ( 54 ) comprises an annular body ( 12 ) which defines a through bore ( 14 ) to permit mounting of the sealing element ( 10 ) on a mandrel ( 52 ), and further defines an inner surface ( 16 ), an outer surface ( 18 ) and opposing axial ends ( 20, 22 ). A pair of inner circumferential grooves ( 24, 26 ) are formed in the inner surface ( 16 ) of the annular body ( 12 ), wherein each groove ( 24, 26 ) is defined by first and second opposing ramp surfaces ( 224 a, 24 b, 26 a, 26 b ) extending from the inner surface ( 16 ) of the annular body ( 12 ), wherein the first ramp surface ( 24 a, 26 a ) defines a shallower ramp angle than the second ramp surface ( 24 b, 26 b ). The ends ( 20, 22 ) of the body ( 12 ) are configured to receive an axial setting force to axially compress the annular body ( 12 ) and cause radial expansion thereof to, in use, establish a seal between the inner surface ( 16 ) and the mandrel ( 52 ), and the outer surface ( 18 ) and a bore wall ( 54 ).

1 . A sealing element for use in establishing a seal in an annulus between a mandrel and a bore wall, comprising:
 an annular body defining a through bore to permit mounting of the sealing element on a mandrel, and further defining an inner surface, an outer surface and opposing axial ends, wherein the ends are configured to receive an axial setting force to axially compress the annular body and cause radial expansion thereof to, in use, establish a seal between the inner surface and the mandrel, and the outer surface and a bore wall; and   a pair of inner circumferential grooves formed in the inner surface of the annular body, wherein each groove is defined by first and second opposing ramp surfaces extending from the inner surface of the annular body, wherein the first ramp surface defines a shallower ramp angle than the second ramp surface.   
     
     
         2 . The sealing element according to  claim 1 , wherein at least one of:
 the first and second ramp surfaces of each groove extend from the inner surface towards a groove trough;   the first ramp surface defines a ramp angle relative to a longitudinal centre axis of the annular body which is less than the corresponding ramp angle of the second surface;   the difference in ramp angles of the first and second opposing ramp surfaces defines a lateral asymmetry within each groove.   
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The sealing element according to  claim 1 , wherein at least one of:
 the form of the grooves facilitates a preferential transmission of an axial setting force through the annular body;   the form of the circumferential grooves permits an axial setting force to be transmitted in such a manner that the annular body is preferentially expanded both radially outwardly and inwardly;   the form of the circumferential grooves preferentially establishes a radial force component from an axial setting force in both outwardly and inwardly radial directions to preferentially cause the annular body to be extended both radially outwardly and inwardly;   the form of the grooves permits a preferential asymmetry of the established radial force components to be achieved.   
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . The sealing element according to  claim 1 , wherein at least one of:
 the form of the circumferential grooves permits an axial setting force to be transmitted in such a manner that the annular body is controllably buckled during setting;   the annular body is configured to be subject to a combination of bucking and material expansion upon application of an axial setting force.   
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . The sealing element according to  claim 1 , wherein at least one of:
 the form of the circumferential grooves encourage a central region of the annular body to extend radially outwardly before end regions of the body;   the first ramp surface of each groove extends a greater axial distance than the associated second ramp surface;   the first and second ramp surfaces extend from portions of the inner surface of the annular body which define a common inner diameter.   
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The sealing element according to  claim 1 , wherein at least one of:
 the grooves are arranged in back-to-back relationship with each other;   the second ramp surfaces of the grooves are arranged in back-to-back relationship with each other.   
     
     
         16 . (canceled) 
     
     
         17 . The sealing element according to  claim 1 , wherein at least one of:
 the pair of circumferential groves define a circumferential band therebetween;   the second ramp surface of each groove are located adjacent the circumferential band;   axially directed end faces of the circumferential band are defined by the respective second ramp surfaces of the grooves;   the form of the grooves cause the circumferential band to bulge radially inwardly when the annular body is exposed to an axial setting force;   the circumferential band is located within a central region of the annular body, between the opposing axial ends.   
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . The sealing element according to  claim 17 , wherein the circumferential grooves divide the inner surface of the annular body into at least first, second and third inner surface regions, wherein the second region is interposed between the grooves, the second inner surface region being provided on the circumferential band defined between the grooves. 
     
     
         23 . The sealing element according to  claim 22 , wherein at least one of:
 at least one of the first, second and third inner surface regions define cylindrical surfaces;   two or more of the first, second and third inner surface regions define substantially equivalent inner diameters;   the first inner surface region extends from one axial end of the annular body;   
       the first inner surface region extends from one axial end of the annular body;
 the third inner surface region extends from an opposite axial end of the annular body; 
 the grooves are arranged such that the first ramp surfaces of the grooves extend from a respective one of the first and third inner surface regions, and the second ramp surfaces extend from the intermediate second inner surface region. 
 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . (canceled) 
     
     
         27 . (canceled) 
     
     
         28 . The sealing element according to  claim 1 , comprising one or more further circumferential grooves defined in the inner surface of the annular body. 
     
     
         29 . The sealing element according to  claim 1 , wherein at least one of:
 the sealing element comprises one or more relief ports extending between inner and outer surfaces of the annular body to permit fluid communication between inner and outer surfaces and allow release of fluid during setting of the seal element;   a relief port extends from at least one circumferential groove;   a relief port extends from an inner surface region of the body which is outside the grooves.   
     
     
         30 . (canceled) 
     
     
         31 . (canceled) 
     
     
         32 . The sealing element according to  claim 1 , wherein at least one of:
 at least one of the opposing axial ends of the annular body define an annular surface which is perpendicular relative to a longitudinal centre axis of the annular body;   at least one of the opposing axial ends of the annular body define a tapered surface, so as to be obliquely aligned relative to a longitudinal centre axis of the annular body;   at least one of the opposing axial ends of the annular body define a tapered surface, so as to be obliquely aligned relative to a longitudinal centre axis of the annular body, the tapered surface providing a preferential transmission of an axial setting force into the annular body through the ends;   at least one of the opposing axial ends of the annular body taper inwardly of the annular body;   the surface of at least one axial end of the annular body is aligned generally perpendicular relative to the first ramp surface of at least one circumferential groove.   
     
     
         33 . (canceled) 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . (canceled) 
     
     
         37 . The sealing element according to  claim 1 , wherein at least one of:
 the annular body comprises or defines one or more reinforced regions;   the annular body comprises one or more integrally formed reinforced regions;   the annular body includes one or more separate components which are arranged with the annular body to define reinforced regions.   
     
     
         38 . (canceled) 
     
     
         39 . (canceled) 
     
     
         40 . The sealing element according to  claim 1 , comprising a circumferential spring arrangement provided in one end region of the annular body. 
     
     
         41 . The sealing element according to  claim 1 , wherein at least one of:
 the sealing element comprises one or more outer circumferential grooves provided in the outer surface of the annular body;   
       any outer circumferential groove is axially offset from one or each inner circumferential groove. 
     
     
         42 . (canceled) 
     
     
         43 . The sealing element according to  claim 1 , wherein at least one of:
 at least one of the inner circumferential grooves are free from any insert material;   at least one of the inner circumferential grooves receive an insert material.   
     
     
         44 . (canceled) 
     
     
         45 . The sealing element according to  claim 1 , wherein the annular body comprises an elastomeric material. 
     
     
         46 . The sealing element according to  claim 1 , wherein the annular body comprises a swellable material which is configured to swell upon appropriate exposure to an activating medium. 
     
     
         47 . The sealing element according to  claim 1 , configured for use with a seal back-up assembly for providing support to the sealing element. 
     
     
         48 . The sealing element according to  claim 1 , wherein at least one groove of the annular body is configured to permit a fluid to become trapped therein to define a fluid pressure seal. 
     
     
         49 . A sealing assembly comprising a mandrel and a seal element according to  claim 1  mounted on the mandrel. 
     
     
         50 . A method for establishing a seal within an annulus between a mandrel and a bore wall, comprising:
 locating a sealing element between a bore wall and a mandrel, wherein the sealing element comprises an annular body defining opposing axial ends, an outer surface and an inner surface which includes a pair of inner circumferential grooves each defined by first and second opposing ramp surfaces extending from the inner surface of the annular body, wherein the first ramp surface defines a shallower ramp angle than the second ramp surface; and   applying an axial compression force through the opposing axial ends of the annular body to axially compress the annular body and cause radial expansion thereof to establish a seal between the inner surface and the mandrel, and the outer surface and a bore wall.   
     
     
         51 . A sealing element for use in establishing a seal in an annulus between a mandrel and a bore wall, comprising:
 an annular body defining a through bore to permit mounting of the sealing element on a mandrel, and further defining an inner surface, an outer surface and opposing axial ends, wherein the ends are configured to receive an axial setting force to axially compress the annular body and cause radial expansion thereof to, in use, establish a seal between the inner surface and the mandrel, and the outer surface and a bore wall; and   at least one circumferential groove formed in at least one of the inner and outer surfaces of the annular body, wherein the groove is configured to trap fluid between the groove and a bore wall or mandrel during setting of the annular body, such that the trapped fluid defines a circumferential fluid seal.   
     
     
         52 . A bore seal system comprising:
 a bore wall;   a mandrel;   a seal element mounted on the mandrel and radially extended by axial compression thereof to extend between the mandrel and the bore wall, wherein the seal element defines at least one circumferential groove defining a space between the groove and one of the bore wall and the mandrel: and   a pressurised fluid trapped within the groove to define a circumferential fluid seal.   
     
     
         53 . A method for establishing a seal within an annulus between a bore wall and a mandrel, comprising:
 locating a sealing element between a bore wall and a mandrel, wherein the sealing element comprises an annular body defining an inner surface, an outer surface and opposing axial ends, and including at least one circumferential groove formed in at least one of the inner and outer surfaces of the annular body;   applying an axial compression force through the opposing axial ends of the annular body to axially compress the annular body and cause radial expansion thereof to establish a seal between the inner surface and the mandrel, and the outer surface and a bore wall; and   trapping and pressuring a fluid within the at least one circumferential groove during setting of the sealing element to provide a circumferential fluid seal.   
     
     
         54 . A sealing element for use in establishing a seal in an annulus between a mandrel and a bore wall, comprising:
 an annular body defining a through bore to permit mounting of the sealing element on a mandrel, and further defining an inner surface, an outer surface and opposing axial ends, wherein the ends are configured to receive an axial setting force to axially compress the annular body and cause radial expansion thereof to, in use, establish a seal between the inner surface and the mandrel, and the outer surface and a bore wall; and   a pair of laterally asymmetric inner circumferential grooves formed in the inner surface of the annular body.   
     
     
         55 . (canceled) 
     
     
         56 . (canceled) 
     
     
         57 . (canceled)