Retrievable setting tool for well plugs

Abstract

The present disclosure relates to a well plug setting tool having a retrievable dog assembly, which replaces a mule shoe structure used in a state-of-the-art setting tool. The well plug setting tool according to the present disclosure reduces the amount of drillable or dissolvable material used for setting well plugs.

1 . An apparatus for use in a wellbore, comprising:
 a mandrel including a first section and a second section; and   a dog assembly movably coupled to the mandrel, wherein the dog assembly comprises two of more dog members, the first section of the mandrel is operable to receive and support the dog assembly at an extended arrangement, and the second section of the mandrel is operable to receive and support the dog assembly in a retracted arrangement.   
     
     
         2 . The apparatus of  claim 1 , wherein two or more slots are formed on the first section of the mandrel, and the two or more slots are operable to receive the two or more dog members and allow the two or more dog members to move relative to the mandrel along a longitudinal direction. 
     
     
         3 . The apparatus of  claim 1 , wherein the first section and the second section overlap to form an annular wall on the mandrel, and the annular wall defines a recess operable to retain a portion of the dog assembly. 
     
     
         4 . The apparatus of  claim 3 , wherein each of the two or more dog members includes a base and a protrusion, the protrusion includes an inclined surface operable to contact a well plug, and the recess is operable to receive the base of the dog members. 
     
     
         5 . The apparatus of  claim 1 , wherein the dog assembly further comprises a retainer disposed around the two or more dog members. 
     
     
         6 . The apparatus of  claim 1 , wherein the mandrel includes a third section operable to receive and support a well plug, and an outer diameter of the dog assembly in the retracted arrangement is smaller than an outer diameter of the third section of the mandrel. 
     
     
         7 . The apparatus of  claim 1 , further comprising:
 a sleeve movably coupled to the mandrel; and   a resilient element connected to the sleeve and operable to bias the sleeve towards the dog assembly.   
     
     
         8 . An apparatus for use in a wellbore, comprising:
 a mandrel;   a dog assembly disposed on the mandrel, wherein the dog assembly is movable along the mandrel between an extended arrangement and a retracted arrangement; and   a cover sleeve assembly coupled to the mandrel, wherein the cover sleeve assembly is operable to move the dog assembly along the mandrel.   
     
     
         9 . The apparatus of  claim 8 , wherein the dog assembly comprises two or more dog members operable to apply a setting force towards a well plug to be set. 
     
     
         10 . The apparatus of  claim 9 , wherein the dog assembly further comprises at least one retainer disposed around the two or more dog members to bias the dog assembly towards the retracted arrangement. 
     
     
         11 . The apparatus of  claim 9 , wherein the two or more dog members are movable along the mandrel from a first section to a second section, the first section is operable to support the dog assembly in the extended arrangement, and the second section is operable to support the dog assembly in the retracted arrangement. 
     
     
         12 . The apparatus of  claim 11 , wherein the mandrel includes two or more slots formed on the first section, the two or more slots are operable to receive the two or more dog members, and the two or more dog members are slidable along the two or more slots. 
     
     
         13 . The apparatus of  claim 12 , wherein the first section overlaps with the second section to form an annular wall on the mandrel, and the annular wall is operable to retain a portion of the dog assembly when the dog assembly is in the retracted arrangement. 
     
     
         14 . The apparatus of  claim 8 , wherein the cover sleeve assembly comprises:
 a sleeve disposed around the mandrel and in contact with the dog assembly; and   a resilient member disposed around the mandrel and operable to bias the sleeve towards the dog assembly.   
     
     
         15 . A method for setting a well plug, comprising:
 applying a setting force to the well plug through a dog assembly while positioning the dog assembly in an extended arrangement on a first section of a mandrel;   moving the dog assembly away from the first section of the mandrel to disengage the dog assembly from the well plug; and   retrieving the mandrel with the dog assembly.   
     
     
         16 . The method of  claim 15 , wherein moving the dog assembly comprises increasing the setting force to break a shearable connection. 
     
     
         17 . The method of  claim 15 , wherein moving the dog assembly comprises sliding the dog assembly along slots formed on the first section of the mandrel. 
     
     
         18 . The method of  claim 15 , further comprising moving the dog assembly from the first section to a second section on the mandrel and positioning the dog assembly at a retracted arrangement around the second section. 
     
     
         19 . The method of  claim 18 , further comprising moving the dog assembly along the second section to retain a portion of the dog assembly within an annular wall of the mandrel. 
     
     
         20 . The method of  claim 19 , wherein moving the dog assembly along the second section comprises extending a compressed resilient member in connection with the dog assembly.