Wellhead wicker repair tool

Abstract

A wicker repair tool lands on a casing hanger within a wellhead. The wicker repair tool engages cutters with the inner diameter of the wellhead and rotates to reform wickers in the wellhead. The wicker repair tool includes a tubular member having an upper end that couples to a tubing string. A tubular tool head is formed on a lower end of the tubular member. At least one cutter is coupled to the tool head and is radially moveable between an engaged and a disengaged position. The cutters are adapted to engage an inner diameter surface of a wellhead so that rotation of the tool head relative to the wellhead will reform the wickers.

1 . An apparatus for repairing wickers in a bore of a wellhead member in place at an upper end of a wellbore, the apparatus comprising:
 a tubular member having an upper end adapted to couple to a pipe string, the tubular member having an axis;   a tubular tool head coaxial with and formed on a lower end of the tubular member for landing in the bore of the wellhead member;   at least one cutter coupled to the tool head, the at least one cutter radially moveable relative to the tool head between an engaged and a disengaged position; and   while in the engaged position, the at least one cutter adapted to engage the wickers in the wellhead member so that rotation of the tool head relative to the wellhead member will re-cut and repair the wickers.   
     
     
         2 . The apparatus of  claim 1 , wherein the tool head comprises:
 a cylindrical extension extending from a lower portion of the tool head, the cylindrical extension defining an interior cavity for reception over a hanger located in the wellhead member;   the at least one cutter being carried on an exterior diameter portion of the cylindrical extension; and   a cutter actuation assembly secured to the tool head to selectively move the cutters between the engaged and disengaged positions.   
     
     
         3 . The apparatus of  claim 2 , the tool head further comprising:
 a centralizing plate having an exterior diameter less than the inner diameter of the cavity; and   the centralizing plate rotatably coupled to a lower portion of the tool head within the cavity so that the centralizing plate of the tool head lands on the hanger within the wellhead and locates the tool head coaxial with the hanger.   
     
     
         4 . The apparatus of  claim 3 , wherein a bearing is interposed between the centralizing plate and the tool head so that the tool head may rotate relative to the centralizing plate. 
     
     
         5 . The apparatus of  claim 1 , wherein the cutter actuation assembly comprises:
 a piston cavity defined by the tool head in an interior of the tool head axially beneath the tubular member;   a piston positioned coaxial with the tubular member within the piston cavity so that the piston moves in response to fluid pressure applied to the pipe string to move the cutter to the engaged position; and   at least one cutter actuator retained by the tool head proximate to the at least one cutter, the at least one cutter actuator engaging the at least one cutter and moving the cutter in response to fluid pressure applied by movement of the piston.   
     
     
         6 . The apparatus of  claim 5 , wherein:
 the at least one cutter actuator has a ramped surface facing the at least one cutter; and   the at least one cutter has a ramped surface facing the at least one cutter actuator so that when the at least one cutter actuator moves axially relative to the at least one cutter, the ramped surface of the at least one cutter actuator will slidingly abut the ramped surface of the at least one cutter, moving the at least one cutter radially in response.   
     
     
         7 . The apparatus of  claim 6 , wherein the cutter is biased to the disengaged position. 
     
     
         8 . The apparatus of  claim 5 , further comprising:
 a spring coaxial with the piston and positioned to bias the piston axially upward; and   hydraulic lines extending between hydraulic ports on an upper portion of the tool head and the piston and further extending between the piston and the cutters, an end of the at least one cutter actuator residing within the hydraulic lines.   
     
     
         9 . The apparatus of  claim 1 , further comprising:
 a hydraulically powered actuator carried in the tool head in engagement with the cutter for moving the cutter from the disengaged to the engaged position; and   a biasing spring carried in the tool head in engagement with the cutter for moving the cutter from the engaged to the disengaged position.   
     
     
         10 . A subsea wellhead comprising:
 a subsea wellhead having a bore containing a set of wickers;   a casing hanger landed on a shoulder in the bore of the subsea wellhead adjacent the wickers;   a wicker repair tool having an upper end that is threaded for coupling to a pipe string;   the wicker repair tool landing on an upper portion of the casing hanger so that a skirt portion of the wicker repair tool extends between the casing hanger and the subsea wellhead;   the wicker repair tool comprising:
 at least one cutter coupled to the wicker repair tool and radially moveable relative to the wicker repair tool between a disengaged position outward to an engaged position; and 
 the cutter having a plurality of teeth that engage the wickers while in the engaged position so that rotation of the wicker repair tool relative to the wellhead will re-cut the wickers. 
   
     
     
         11 . The system of  claim 10 , the wicker repair tool further comprising:
 a centralizing plate located within the skirt portion and landing on the hanger; and   the wicker repair tool centralizing plate being rotatable relative to a tool head of the wicker repair tool.   
     
     
         12 . The system of  claim 11 , wherein a bearing is interposed between the centralizing plate and the tool head. 
     
     
         13 . The system of  claim 10 , wherein the wicker repair tool further comprises a cutter actuation assembly to actuate the cutters between the engaged and disengaged positions in response to fluid pressure applied down the pipe string. 
     
     
         14 . The system of  13 , wherein the cutter actuation assembly comprises:
 a piston cavity adapted to be in fluid communication with the pipe string;   at least one cutter actuator retained by the tool head proximate to the at least one cutter, the at least one cutter actuator being axially moveable in response to movement of the piston and engaging the at least one cutter; and   a piston positioned within the piston cavity so that the piston moves downward in response to fluid pressure supplied from the pipe string.   
     
     
         15 . The system of  claim 14 , wherein the cutter actuation assembly further comprises:
 the at least one cutter actuator having a ramped surface facing the at least one cutter; and   the at least one cutter having a ramped surface facing the at least one cutter actuator so that when the at least one cutter actuator moves axially relative to the at least one cutter, the ramped surface of the at least one cutter actuator will slidingly abut the ramped surface of the at least one cutter, moving the at least one cutter radially in response.   
     
     
         16 . The system of  claim 15 , wherein the cutter actuation assembly further comprises:
 a spring coaxial with the piston and positioned so that the spring may resist axial motion of the piston; and   hydraulic lines extending between hydraulic ports on an upper portion of the tool head and the piston and further extending between the piston and the cutters, an end of the at least one cutter actuator residing within the hydraulic lines.   
     
     
         17 . A method for repairing wickers in a bore of a subsea wellhead, the method comprising:
 (a) running a wicker repair tool on a pipe string and landing the wicker repair tool on a casing hanger within the bore of the subsea wellhead;   (b) actuating a cutter of the wicker repair tool to engage the wickers of the subsea wellhead; then   (c) rotating the wicker repair tool to re-cut the wickers in the subsea wellhead.   
     
     
         18 . The method of  claim 17 , wherein step (b) comprises applying fluid pressure down the pipe string. 
     
     
         19 . The method of  claim 17 , wherein step (b) comprises dispensing a hydraulic fluid down a hydraulic line extending from a drilling rig to the wicker repair tool. 
     
     
         20 . The method of  claim 17 , wherein step (c) comprises rotating the pipe string.