Friction lock assembly and retaining ring for wellhead

Abstract

A locking assembly and a retaining ring for retaining the locking assembly within a bore of a wellhead component are provided. In one embodiment, a system includes an inner component disposed within a bore of a wellhead component and a locking assembly disposed within the bore to secure the inner component within the bore. The locking assembly includes a lock ring that extends into a recess in a wall of the bore of the wellhead component and an actuator radially disposed between the inner component and the lock ring. The system also includes a retaining ring that limits movement of the actuator along the inner component and maintains the actuator between the inner component and the lock ring to retain the lock ring within the recess. The actuator and the retaining ring have mating tapered surfaces that inhibit movement of the actuator out of engagement with the lock ring.

1 . A system comprising:
 a wellhead component having a bore;   an inner component disposed within the bore of the wellhead component;   a locking assembly disposed within the bore between the inner component and the wellhead component to secure the inner component within the bore of the wellhead component, the locking assembly including:
 a lock ring that extends into a recess in a wall of the bore of the wellhead component; and 
 an actuator radially disposed between the inner component and the lock ring; and 
   a retaining ring positioned within the bore of the wellhead component so as to limit movement of the actuator along the inner component and maintain the actuator between the inner component and the lock ring to retain the lock ring within the recess, wherein the actuator and the retaining ring have mating tapered surfaces that inhibit movement of the actuator out of engagement with the lock ring.   
     
     
         2 . The system of  claim 1 , wherein the actuator includes a flange, and the flange and the retaining ring have the mating tapered surfaces that inhibit movement of the actuator out of engagement with the lock ring. 
     
     
         3 . The system of  claim 1 , wherein the retaining ring is a multi-piece mechanism including an outer sleeve and an inner sleeve, and the actuator and the inner sleeve of the retaining ring have the mating tapered surfaces that inhibit movement of the actuator out of engagement with the lock ring. 
     
     
         4 . The system of  claim 1 , wherein the actuator includes an inner sleeve radially disposed between the inner component and the lock ring and an outer ring positioned about the inner sleeve, and the outer ring and the retaining ring have the mating tapered surfaces that inhibit movement of the actuator out of engagement with the lock ring. 
     
     
         5 . The system of  claim 4 , wherein the outer ring is carried on a shoulder of the inner sleeve. 
     
     
         6 . The system of  claim 1 , wherein the retaining ring is a landing ring of a packoff. 
     
     
         7 . The system of  claim 1 , wherein the retaining ring is positioned within the bore on the lock ring of the locking assembly. 
     
     
         8 . The system of  claim 1 , wherein the actuator has an interference fit with the inner component to inhibit movement of the actuator between the lock ring and the inner component. 
     
     
         9 . The system of  claim 1 , wherein the inner component is a wellhead hanger. 
     
     
         10 . The system of  claim 1 , comprising a bearing ring between the lock ring and a shoulder of the inner component. 
     
     
         11 . A system comprising:
 a locking assembly to secure a device in a bore of a wellhead component, the locking assembly including:
 a lock ring; and 
 an actuator configured to be radially disposed between the device and the lock ring such that the actuator can be moved axially in a first direction along the device to drive the lock ring radially outward to a locked position in which the lock ring secures the device within the bore of the wellhead component; and 
   a retaining ring, wherein the retaining ring and the actuator having mating tapered surfaces that, when installed in the bore of the wellhead component, limit axial movement of the actuator in second direction, opposite the first direction, along the device so as to facilitate retention of the actuator in engagement with the lock ring in the locked position.   
     
     
         12 . The system of  claim 11 , wherein the mating tapered surfaces limit axial movement of the actuator in the second direction by cooperating with one another so as to apply an increasing retention load on the actuator as the actuator moves in the second direction. 
     
     
         13 . The system of  claim 11 , wherein the lock ring and the actuator have additional mating tapered surfaces, and the mating tapered surface of the actuator and the additional mating tapered surface of the actuator are tapered in opposite directions. 
     
     
         14 . The system of  claim 11 , wherein the actuator includes an outer ring carried on an inner sleeve, and the outer ring and the retaining ring have the mating tapered surfaces such that engagement of the mating tapered surfaces causes the outer ring to contract inwardly about the inner sleeve in response to axial movement of the actuator in the second direction. 
     
     
         15 . The system of  claim 11 , comprising the device, wherein the device includes a wellhead hanger. 
     
     
         16 . A method comprising:
 running a locking assembly into a bore of a wellhead component, the locking assembly including a lock ring and an actuator;   driving the lock ring into engagement with the wellhead component by moving the actuator between the lock ring and an additional wellhead component to a locked position so as to secure the additional wellhead component within the bore;   lowering a retaining ring into the bore of the wellhead component; and   positioning the retaining ring along the actuator such that a tapered interface between the retaining ring and the actuator opposes movement of the actuator along the additional wellhead component toward an unlocked position.   
     
     
         17 . The method of  claim 16 , wherein driving the lock ring into engagement with the wellhead component by moving the actuator between the lock ring and the additional wellhead component to the locked position so as to secure the additional wellhead component within the bore includes wedging the actuator between the lock ring and the additional wellhead component so as to secure the additional wellhead component within the bore via an interference fit of the additional wellhead component with the actuator. 
     
     
         18 . The method of  claim 16 , comprising running the additional wellhead component into the bore with the locking assembly. 
     
     
         19 . The method of  claim 18 , wherein running the additional wellhead component into the bore includes running a wellhead hanger carrying the locking assembly into the bore. 
     
     
         20 . The method of  claim 16 , wherein lowering the retaining ring into the bore includes lowering a packoff having the retaining ring into the bore.