Wellhead isolation tool including an abrasive cleaning ring

Abstract

A wellhead isolation tool includes a lower mandrel sized and shaped for insertion through a wellhead into a length of wellbore tubing. The wellhead isolation tool includes an improved sealing assembly connected to the lower end of the mandrel. The sealing assembly includes a conventional elastomeric cup deployed about a cup carrier for sealingly engaging an inner surface of the tubing. The sealing assembly further includes an abrasive cleaning ring deployed below the cup (e.g., between the cup carrier and the bull nose). Corrosion products, scale, and/or other debris may be advantageously removed from the tubing via the abrasive action of the cleaning ring, thereby promoting a better seal between the cup and the tubing.

1 . A wellhead isolation tool comprising:
 a main body portion;   a mandrel deployed in the main body portion, the mandrel having an external end extending outward from main body portion; and   a sealing assembly connected to a lower end of the mandrel, the sealing assembly including a cup carrier having an elastomeric cup deployed thereabout, the cup disposed to move axially on the cup carrier;   a tube cleaner deployed distal from the mandrel as compared to the cup, the tube cleaner including an abrasive outer surface disposed to abrade an inner surface of a tube into which the mandrel is deployed.   
   
   
       2 . The wellhead isolation tool of  claim 1 , wherein the abrasive outer surface comprises at least one raised thread. 
   
   
       3 . The wellhead isolation tool of  claim 2 , further comprising a bull nose connected to the cup carrier, the at least one thread being formed on an outer surface of the bull nose. 
   
   
       4 . The wellhead isolation tool of  claim 1 , wherein:
 the wellhead isolation tool further comprises a bull nose connected to the cup carrier; and   the tube cleaner includes a cleaning ring deployed between the cup carrier and the bull nose.   
   
   
       5 . The wellhead isolation tool of  claim 4 , wherein the cleaning ring includes at least one raised thread formed on an outer surface thereof. 
   
   
       6 . The wellhead isolation tool of  claim 4 , wherein the cleaning ring includes at least one wickered thread formed on an outer surface thereof. 
   
   
       7 . The wellhead isolation tool of  claim 4 , wherein the cleaning ring is fabricated from a material selected from the group consisting of elastomeric materials and plastic materials. 
   
   
       8 . A sealing assembly configured to be coupled to a mandrel on a wellhead isolation tool, the sealing assembly comprising:
 a cup carrier having an elastomeric cup deployed thereabout, the cup disposed to move axially on the cup carrier;   a tube cleaner deployed distal from the mandrel as compared to the cup, the tube cleaner including an abrasive outer surface disposed to abrade an inner surface of a tube into which the mandrel is deployed.   
   
   
       9 . The wellhead isolation tool of  claim 8 , wherein the abrasive outer surface comprises at least one raised thread. 
   
   
       10 . The wellhead isolation tool of  claim 9 , further comprising a bull nose connected to the cup carrier, the at least one thread being formed on an outer surface of the bull nose. 
   
   
       11 . The wellhead isolation tool of  claim 8 , wherein:
 the wellhead isolation tool further comprises a bull nose connected to the cup carrier; and   the tube cleaner includes a cleaning ring deployed between the cup carrier and the bull nose.   
   
   
       12 . The wellhead isolation tool of  claim 11 , wherein the cleaning ring includes at least one raised thread formed on an outer surface thereof. 
   
   
       13 . The wellhead isolation tool of  claim 11 , wherein the cleaning ring includes at least one wickered thread formed on an outer surface thereof. 
   
   
       14 . The wellhead isolation tool of  claim 11 , wherein the cleaning ring is fabricated from a material selected from the group consisting of elastomeric materials and plastic materials. 
   
   
       15 . A wellhead isolation tool comprising:
 a main body portion;   a mandrel having an external end extending outward from the main body portion;   a sub connected to the external end of the mandrel;   a cup carrier connected to the sub;   an elastomeric cup deployed about the cup carrier, the cup disposed to slide axially on the cup carrier between a shoulder on the sub and an enlarged diameter portion of the cup carrier;   a bull nose connected to the cup carrier; and   a cleaning ring deployed between the cup carrier and the bull nose, the cleaning ring including an abrasive outer surface.   
   
   
       16 . The wellhead isolation tool of  claim 15 , wherein the abrasive outer surface of the cleaning ring comprises a plurality of raised threads. 
   
   
       17 . The wellhead isolation tool of  claim 15 , wherein the abrasive outer surface of the cleaning ring comprises a plurality of wickered threads. 
   
   
       18 . The wellhead isolation tool of  claim 15 , wherein the cleaning ring is fabricated from a material selected from the group consisting of elastomeric materials and plastic materials. 
   
   
       19 . In a wellhead isolation tool including a sealing assembly connected to an external end of a mandrel, the sealing assembly operative to form a substantially pressure tight seal with an inner surface of a tube, the sealing assembly including a bull nose connected to a cup carrier, the sealing assembly further including an elastomeric cup deployed about the cup carrier, the cup disposed to sealingly engage the inner surface of the tube, an improvement comprising:
 a cleaning ring deployed between the cup carrier and the bull nose, the cleaning ring including at least one thread formed on an outer surface thereof, the at least one thread disposed to abrade an inner surface of the tube upon insertion of the mandrel in the tube.   
   
   
       20 . The improvement of  claim 19 , wherein the at least one thread is wickered such that the thread is not disposed to abrade the inner surface of the tube upon removal of the mandrel from the tube.