Seal With Soft Material Inlay

Abstract

A wellhead assembly includes an inner wellhead member with wickers extending outwardly therefrom and an outer wellhead member with wickers extending inwardly therefrom. A seal assembly having an inner leg and an outer leg is inserted between the wellhead members. An energizing ring forces the legs radially apart from each other. An inlay is located along at least one of an inner diameter of the inner leg and an outer diameter of the outer leg, positioned to sealingly engage the wickers. The inlay is located in a single groove configured so that no part of the seal member body contacts an exterior wall of the inner wellhead member or an interior wall of the outer wellhead member. The inlay has a smooth outer surface flush with the diameter and is made of a material softer than the inner wellhead member, the outer wellhead member, and the seal member body.

What is claimed is: 
     
         1 . A wellhead assembly having an axis, comprising:
 an inner wellhead member that is tubular and has an exterior wall that includes a plurality of inner member wickers extending outwardly therefrom;   an outer wellhead member that is tubular and has an interior wall that includes a plurality of outer member wickers extending inwardly therefrom;   a seal assembly inserted between the inner and outer wellhead member, the seal assembly comprising:
 a seal member body having an inner leg and an outer leg circumscribing the inner leg and coupled to the inner leg by a base portion; 
 the inner leg having an inner diameter positioned adjacent the inner wellhead member; 
 the outer leg having an outer diameter positioned adjacent the outer wellhead member; 
 an energizing ring selectively located between the inner leg and the outer leg to force the legs radially apart from each other; and 
 an inlay located along a portion of at least one of the inner diameter and outer diameter, positioned to sealingly engage the wickers, the inlay being located in a single groove configured so that no part of the seal member body contacts the exterior wall of the inner wellhead member or the interior wall of the outer wellhead member, and having a smooth outer surface flush with the diameter and made of a material softer than the inner wellhead member, the outer wellhead member, and the seal member body. 
   
     
     
         2 . The wellhead assembly according to  claim 1 , wherein the inlay is located on both the inner diameter of the inner leg and the outer diameter of the outer leg. 
     
     
         3 . The wellhead assembly according to  claim 1 , wherein the inlay has a radial depth greater than a wicker bite depth of the wickers. 
     
     
         4 . The wellhead assembly according to  claim 1 , wherein the wickers include a plurality of parallel circumferential ridges and valleys the inlay completely fills the valleys along an axial length of the inlay. 
     
     
         5 . The wellhead assembly according to  claim 1 , wherein the inlay is on the outer leg and the inlay has an upper edge above an upper edge of the wickers and a lower edge below a lower edge of the wickers. 
     
     
         6 . The wellhead assembly according to  claim 1 , wherein the inner leg has a shorter axial length than the outer leg and the inlay is located on the inner leg with an upper edge of the inlay at an upper end of the inner leg. 
     
     
         7 . The wellhead assembly according to  claim 1 , wherein the wickers are formed of a material that has a tensile yield strength that is two to four times the yield strength of the material of the inlay. 
     
     
         8 . The wellhead assembly according to  claim 1 , wherein the seal member body is formed of a material that has a tensile yield strength that is two to four times the yield strength of the material of the inlay. 
     
     
         9 . A wellhead assembly having an axis, comprising:
 an outer wellhead member, the outer wellhead member being tubular and having an interior wall that includes a plurality of outer member wickers extending radially inwardly therefrom;   an inner wellhead member, the inner wellhead member being tubular and having an exterior wall that includes a plurality of inner member wickers extending radially outwardly therefrom, the inner wellhead member being operable to land within the outer wellhead member, defining an annular pocket between the inner wellhead member and the outer wellhead member;   a seal assembly located in the annular pocket, the seal assembly having a seal member body having an inner leg and an outer leg, the outer leg circumscribing the inner leg and coupled to the inner leg by a base portion;   an inner diameter of the inner leg positioned adjacent the inner wellhead member;   an outer diameter of the outer leg positioned adjacent the outer wellhead member;   an inner inlay located along a portion of the inner diameter of the inner leg and an outer inlay located along an outer diameter of the outer leg, each of the inlays having a smooth outer surface flush with the diameter and made of a material softer than the inner and outer wellhead members and softer than the seal member body;   an annular energizing ring selectively urging the inner inlay into sealing engagement with the inner member wickers and the outer inlay into sealing engagement with the outer member wickers; and wherein   at least one of the inlays has an axial length greater than an axial length of the wickers engaged by such inlay.   
     
     
         10 . The wellhead assembly according to  claim 9 , wherein the at least one of the inlays that has an axial length greater than an axial length of the wickers engaged by such inlay is the outer inlay. 
     
     
         11 . The wellhead assembly according to  claim 9 , wherein the inner inlay extends to an upper end of the inner leg. 
     
     
         12 . The wellhead assembly according to  claim 9 , wherein the wickers have a generally triangular shape in cross section. 
     
     
         13 . The wellhead assembly according to  claim 9 , wherein each of the inlays is located in a single groove having a cylindrical base. 
     
     
         14 . The wellhead assembly according to  claim 9 , wherein the wickers include a plurality of parallel circumferential ridges and valleys, and the inlays completely fill the valleys along an axial length of each of the inlays. 
     
     
         15 . The wellhead assembly according to  claim 9 , wherein the wickers and the seal member body are formed of a material that has a tensile yield strength that is two to four times the yield strength of the material of the inlay. 
     
     
         16 . A method for sealing an inner wellhead member to an outer wellhead member, the inner wellhead member being tubular and having an exterior wall that includes a plurality of inner member wickers extending outwardly therefrom, and the outer wellhead member being tubular and having an interior wall that includes a plurality of outer member wickers extending inwardly therefrom, the method comprising:
 (a) landing a seal assembly between the inner and outer wellhead members, the seal assembly having a seal member body with an inner leg with an inner diameter, and an outer leg with an outer diameter, the outer leg circumscribing the inner leg and coupled to the inner leg by a base portion;   (b) positioning an inner inlay located in a single groove along the inner diameter of the inner leg adjacent the inner wellhead member, and positioning an outer inlay located in a single groove along the outer diameter of the outer leg adjacent the outer wellhead member, each of the inlays having a smooth outer surface flush with the diameter and made of a material softer than the inner and outer wellhead members and softer than the seal member body; and   (c) urging the inner inlay into sealing engagement with the inner member wickers and the outer inlay into sealing engagement with the outer member wickers with an annular energizing ring so that no part of the seal member body contacts the exterior wall of the inner wellhead member or the interior wall of the outer wellhead member.   
     
     
         17 . The method according to  claim 16 , wherein the wickers include a plurality of parallel circumferential ridges and valleys, and wherein step (c) includes urging the inner inlay into sealing engagement with the inner member wickers and the outer inlay into sealing engagement with the outer member wickers until the inlays completely fill the valleys along an axial length of each of the inlays. 
     
     
         18 . The method according to  claim 16 , further comprising exposing the seal assembly to a high pressure to cause a material of the inlays to flow into the wickers. 
     
     
         19 . The method according to  claim 16 , further comprising selecting an inlay formed of a material with a tensile yield strength of 30 ksi to 70 ksi. 
     
     
         20 . The method according to  claim 16 , further comprising selecting an inlay formed of a material that is at least half as hard as the material of the wickers.