Hanger assembly

Abstract

A hanger assembly and a method for supporting a string of tubular members in a wellhead assembly are disclosed wherein the hanger assembly is supported within the wellhead assembly by a single landing shoulder in the wellhead assembly and a seal member is independently, sealingly engaged with a portion of the string of tubular members.

We claim:  
     
         1 . A hanger assembly for use in a wellhead housing and for supporting a string of tubular members, the hanger assembly comprising: 
 a hanger slip bowl housing, having an upper end, a lower end, and an outer wall surface, adapted to be supported by a portion of the wellhead housing;    a hanger slip bowl, having an upper end and a lower end, disposed within the hanger slip bowl housing;    at least one slip disposed within the hanger slip bowl and adapted for contacting a portion of the string of tubular members;    at least one seal member adapted to sealingly engage about a portion of the string of tubular members, the at least one seal member having an upper surface, a lower surface, and an outer wall surface, the outer wall surface being substantially coplanar with the outer wall surface of the hanger slip bowl housing; and    the hanger slip bowl housing having a substantially cylindrical cross-sectional configuration with only one beveled surface provided at the lower end of the hanger slip bowl housing, the only one beveled surface adapted for engagement with a single mating, inwardly extending, landing shoulder provided in the wellhead housing, whereby the wellhead housing requires only a single landing shoulder to support the hanger assembly and the string of tubular members.    
     
     
         2 . The hanger assembly of  claim 1 , including a casing hanger seal member upper support plate provided above the at least one seal member, and a casing hanger seal member lower support plate provided below the at least one seal member, the upper and lower support plates each having an outer wall surface, and the outer wall surfaces of each support plate are substantially coplanar with the outer wall surface of the hanger slip bowl housing.  
     
     
         3 . The hanger assembly of  claim 2 , wherein the lower support plate is supported upon the upper end of the slip bowl housing.  
     
     
         4 . The hanger assembly of  claim 3 , wherein the lower support plate is in an abutting relationship with the upper end of the slip bowl housing.  
     
     
         5 . The hanger assembly of  claim 2 , wherein the upper and lower support plates and the at least one seal member are each provided with at least one opening, the at least one opening of each of the upper and lower support plates and the at least one seal member, mating with adjacent openings to provide at least one passageway, through which each at least one passageway a bolt is passed; the bolt having an end threadedly received within the hanger assembly, whereby upon the bolt being threaded into the hanger assembly, the at least one seal member is compressed into sealing engagement about a portion of the string of tubular members.  
     
     
         6 . The hanger assembly of  claim 5 , wherein the bolt has an upper end and a lower end, the upper end being received within the upper support plate, and the lower end is threadedly received within the hanger assembly.  
     
     
         7 . The hanger assembly of  claim 6 , wherein the lower end of the bolt is threadedly received within the upper end of the hanger slip bowl.  
     
     
         8 . The hanger assembly of  claim 1 , wherein the hanger slip bowl housing has an interior wall surface and the hanger slip bowl has an outer wall surface, and a portion of the outer wall surface of the hanger slip bowl is in sliding engagement with a portion of the interior wall surface of the hanger slip bowl housing.  
     
     
         9 . The hanger assembly of  claim 8 , wherein the lower end of the hanger slip bowl housing has an inwardly extending ledge portion which restrains downward movement of the hanger slip bowl within hanger slip bowl housing.  
     
     
         10 . The hanger assembly of  claim 9 , wherein the lower end of the hanger slip bowl has a reduced diameter portion which provides a radial shoulder formed in the outer wall surface of the hanger slip bowl, whereby downward movement of the hanger slip bowl within hanger slip bowl housing is restrained by the radial shoulder abutting the ledge portion of the hanger slip bowl housing.  
     
     
         11 . The hanger assembly of  claim 5  wherein an anti-extrusion ring is disposed about each bolt, and the anti-extrusion ring overlies each of the at least one openings formed in the at least one seal member.  
     
     
         12 . The hanger assembly of  claim 11 , wherein two anti-extrusion ring are disposed about each bolt with an anti-extrusion ring in engagement with the upper surface of the at least one seal member and an anti-extrusion ring is in engagement with the lower surface of the at least one seal member.  
     
     
         13 . The hanger assembly of  claim 2 , wherein the upper and lower support plates each have annular shaped ridge member which are matingly received by corresponding annular shaped grooves found in the upper and lower surfaces of the at least one seal member.  
     
     
         14 . The casing hanger of  claim 1 , wherein downward movement of the string of tubular members within hanger slip bowl does not automatically cause compression of the at one least seal member.  
     
     
         15 . A method for supporting a string of tubular members in a wellhead assembly having at least one landing shoulder, comprising the steps of: 
 providing a hanger assembly having a hanger slip bowl housing with an outer wall surface, a hanger slip bowl, at least one slip disposed within the hanger slip bowl, and at least one seal member with an outer wall surface;    disposing a portion of the string of tubular members within the hanger assembly;    disposing and supporting the hanger assembly within the wellhead assembly by placing the hanger assembly in abutting engagement with only one landing shoulder of the wellhead assembly;    permitting downward movement of the at least one slip member within the hanger slip bowl to cause the at least one slip member to be forced inwardly to grip a portion of the string of tubular members; and    compressing the at least one seal member by exerting a compressive force upon the at least one seal member to cause it to sealingly engage about a portion of the string of tubular members.    
     
     
         16 . The method of  claim 15 , wherein the compressive force to the at least one seal member is provided by threading at least one bolt into the hanger assembly, the bolt being operatively associated with the at least one seal member.  
     
     
         17 . The method of  claim 16 , including the step of associating at least one anti-extrusion ring with the at least one bolt.  
     
     
         18 . The method of  claim 15 , including the step of disposing the outer wall surfaces of the hanger slip bowl housing and the at least one seal member substantially co-planar to each other.