Burnishing assembly systems and methods

Abstract

A technique facilitates formation of a burnished region, e.g. a seal region, via plastic deformation of an internal surface. The technique utilizes a burnishing assembly which may comprise a stem sized for insertion into a tubular region. The stem may be combined with an actuator and a plurality of rolling elements mounted on the actuator. When the actuator is actuated to a radially outward position, the plurality of rolling elements may be moved into engagement with the internal surface until plastic deformation occurs. The stem may then the rotated to force the plurality of rolling elements along the internal surface so as to form a region of plastic deformation. The plastic deformation may be located to form a seal, for example, between adjacent components.

What is claimed is: 
     
         1 . A method of sealing, comprising:
 mounting rolling elements on a piston;   coupling the piston to a stem;   moving the stem along an interior metal surface within a subsea component until the rolling elements are located proximate a seal area;   actuating the piston to move the rolling elements outwardly into engagement with the interior metal surface at the seal area to plastically deform the interior metal surface at the seal area; and   forming a seal by rotating the stem to form a ring of plastic deformation along the seal area.   
     
     
         2 . The method as recited in  claim 1 , further comprising moving the stem longitudinally while rotating the stem to form a wider ring of plastic deformation. 
     
     
         3 . The method as recited in  claim 1 , wherein forming comprises forming the seal between two flanges. 
     
     
         4 . The method as recited in  claim 1 , wherein the subsea component comprises a subsea tree and wherein forming comprises forming the seal between a choke body flange of the subsea tree and a mating flange. 
     
     
         5 . The method as recited in  claim 1 , wherein mounting rolling elements comprises mounting ball elements on the piston. 
     
     
         6 . The method as recited in  claim 1 , wherein mounting rolling elements comprises mounting a plurality of sets of rolling elements on a plurality of pistons. 
     
     
         7 . The method as recited in  claim 1 , wherein actuating the piston comprises hydraulically actuating the piston. 
     
     
         8 . The method as recited in  claim 1 , wherein actuating the piston comprises electrically actuating the piston. 
     
     
         9 . The method as recited in  claim 1 , wherein forming the seal comprises rotating the stem with a remotely operated vehicle (ROV). 
     
     
         10 . A system, comprising:
 a sealing assembly for forming an internal seal along a seal area where two tubular components are joined, the seal being formed via plastic deformation of an internal metal surface, the sealing assembly comprising:
 a stem sized for insertion into at least one of the two tubular components; 
 an actuator mounted to the stem for actuation between radially inward and radially outward positions; and 
 a plurality of rolling elements mounted on the actuator such that actuation of the actuator to the radially outward position causes the plurality of rolling elements to move into engagement with and to plastically deform the internal metal surface, the stem being rotatable to force the plurality of rolling elements to form a ring of plastic deformation at the seal area. 
   
     
     
         11 . The system as recited in  claim 10 , wherein the stem is longitudinally movable while rotating to form a wider ring of plastic deformation at the seal area. 
     
     
         12 . The system as recited in  claim 10 , wherein at least one of the two tubular components comprises a mounting flange of a subsea tree. 
     
     
         13 . The system as recited in  claim 10 , wherein the actuator comprises a pair of opposed pistons. 
     
     
         14 . The system as recited in  claim 13 , wherein the plurality of rolling elements comprises at least one set of rolling elements mounted on each opposed piston of the pair of opposed pistons. 
     
     
         15 . The system as recited in  claim 10 , wherein the plurality of rolling elements comprises a plurality of ball elements. 
     
     
         16 . The system as recited in  claim 15 , wherein ball elements of the plurality of ball elements are formed of a hardened steel. 
     
     
         17 . The system as recited in  claim 15 , wherein ball elements of the plurality of ball elements are formed of a ceramic material. 
     
     
         18 . A method, comprising:
 mounting rolling elements to an actuator to form a burnishing assembly;   moving the burnishing assembly into a tubular region of a component;   actuating the actuator to move the rolling elements into a wall forming the tubular region until the material forming the wall is plastically deformed; and   moving the rolling elements along the wall until a region of plastic deformation is formed.   
     
     
         19 . The method as recited in  claim 18 , further comprising forming the region of plastic deformation in a ring along a seam between two components to form a metal seal between the two components. 
     
     
         20 . The method as recited in  claim 18 , further comprising mounting the actuator on a stem and rotating the stem via an ROV to form the ring of plastic deformation.