Completion liner delivery method with bridge plug capture

Abstract

In an underbalanced or overbalanced completion, the packer that isolates a portion of the wellbore is preferably a composite mechanically set bridge plug. The composite materials are selected to expedite mill out the plug. A coring mill envelopes the plug as it cuts away the grip of the slips. Internal uphole oriented wickers inside the coring mill grab hold of it before the slip grip is lost to capture the plug in the coring mill. The liner string is rotated to operate the mill or alternatively a downhole motor can be used to run the coring mill. After the bridge plug is milled to a release and capture position, the liner string that can be slotted liner or screen or other tubular is advanced into position further down the usually deviated wellbore.

1 . A downhole completion assembly comprising:
 a non-inflatable plug settable in a wellbore to isolate one portion of the wellbore from another;   a release tool supported from a string and designed to release said plug and retain it as said string is further advanced downhole.   
   
   
       2 . The assembly of  claim 1 , wherein:
 said release tool comprises an internal core to at least in part retain said plug after its release.   
   
   
       3 . The assembly of  claim 2 , wherein:
 said release tool mills said plug.   
   
   
       4 . The assembly of  claim 3 , wherein:
 said plug comprises at least one slip milled out by said release tool.   
   
   
       5 . The assembly of  claim 2 , wherein:
 said plug comprises a slip that is mechanically released by said releasing tool.   
   
   
       6 . The assembly of  claim 2 , wherein:
 said core comprises a retaining member to hold said plug after its release.   
   
   
       7 . The assembly of  claim 2 , wherein:
 said core defines at least one bypass passage to allow flow around said plug when retained in said core.   
   
   
       8 . The assembly of  claim 6 , wherein:
 said retaining member comprises a plurality of wickers oriented in the opposite direction from movement of the release tool that brings said plug into said core.   
   
   
       9 . The assembly of  claim 8 , wherein:
 said retaining member defines at least one flow passage running along said wickers.   
   
   
       10 . The assembly of  claim 2 , wherein:
 said plug is releasable from said core after its retention therein.   
   
   
       11 . The assembly of  claim 2 , wherein:
 said plug is extendable from said core after being retained therein.   
   
   
       12 . The assembly of  claim 11 , wherein:
 said plug is resettable after being extended from said core.   
   
   
       13 . The assembly of  claim 3 , wherein:
 said plug is made of substantially non-metallic materials.   
   
   
       14 . The assembly of  claim 13 , wherein:
 said plug is made of substantially composite materials.   
   
   
       15 . The assembly of  claim 3 , wherein:
 said release tool is operated by string rotation from the surface of the wellbore.   
   
   
       16 . The assembly of  claim 3 , wherein:
 said release tool is operated by a downhole motor mounted in said string.   
   
   
       17 . The assembly of  claim 2 , wherein:
 said string further comprises a hanger.   
   
   
       18 . The assembly of  claim 17 , wherein:
 said string comprises openings for subsequent production.   
   
   
       19 . The assembly of  claim 17 , wherein:
 said string comprises a float collar.   
   
   
       20 . The assembly of  claim 2 , wherein:
 said plug comprises upper and lower slips with a sealing element in between and a substantially non-metallic body;   said release tool milling said slips as it captures said body in said core.