Rotary Shoe Direct Fluid Flow System

Abstract

The circulation system for a rotary shoe features a fluid diversion to a peripheral zone from which the flow is directed by tubes or housing bores to the vicinity of the cutting structure to improve cooling and removal of debris. Some of the fluid is directed straight through into the mandrel of the tool being milled. If the formation below is at low pressure a packer cup is added to the grip tool attached to the shoe at one end and to the fish at the other end. A swivel is used to prevent the packer cup rotation. Fluid diverted by the packer cup comes up out of the mandrel and into an annular space between the mandrel and the inner wall of the shoe and out from under the shoe by flowing past the cutters. Fluid loss to the formation is minimized and cooling and cutting removal is enhanced.

1 . A milling shoe assembly for milling an object at a subterranean location and having a mandrel or body, comprising:
 a tubular housing having an inlet fluid passage and defined by a wall, said wall further comprising at least one peripherally mounted lower end cutter, said wall having an open lower end to advance over an object being milled by said cutter;   said wall comprising at least one cutter passage extending from said inlet fluid passage to adjacent said cutters.   
     
     
         2 . The assembly of  claim 1 , wherein:
 said cutter passage is formed at least in part within said wall.   
     
     
         3 . The assembly of  claim 1 , wherein:
 said cutter passage comprises at least one tube.   
     
     
         4 . The assembly of  claim 3 , wherein:
 said tube is disposed in a recess on an inner or an outer face of said wall.   
     
     
         5 . The assembly of  claim 1 , wherein:
 a flow distributor in said inlet fluid passage further comprising an inlet and at least one lateral outlet adjacent an end of said cutter passage.   
     
     
         6 . The assembly of  claim 5 , wherein:
 said flow distributor further comprises spaced seals that straddle said end of said cutter passage.   
     
     
         7 . The assembly of  claim 6 , wherein:
 said at least one cutter comprises a plurality of cutters;   said at least one cutter passage comprises a plurality of spaced passages in said wall, said wall defining an annular inlet straddled by said seals.   
     
     
         8 . The assembly of  claim 7 , wherein:
 said cutter passage is formed at least in part within said wall.   
     
     
         9 . The assembly of  claim 7 , wherein:
 said cutter passage comprises at least one tube.   
     
     
         10 . The assembly of  claim 9 , wherein:
 said tube is disposed in a recess on an inner or an outer face of said wall.   
     
     
         11 . The assembly of  claim 7 , wherein:
 said diverter having an axially oriented outlet for directing flow at the mandrel or body.   
     
     
         12 . The assembly of  claim 11 , wherein:
 said wall defines an annular passage between itself and the mandrel to direct flow through said axially directed outlet to said cutters.   
     
     
         13 . The assembly of  claim 12 , further comprising:
 a retaining device to engage the mandrel or body extending through said open lower end of said housing and supported from said housing with a swivel to allow the retaining device to remain stationary as said housing rotates;   a seal on said retaining device to engage the mandrel to redirect flow from said axially oriented outlet to said cutters and away from flowing through the mandrel.   
     
     
         14 . The assembly of  claim 1 , wherein:
 said seal comprises at least one cup seal having an open end directed toward said axially oriented outlet.   
     
     
         15 . The assembly of  claim 1 , further comprising:
 a retaining device to engage the mandrel or body extending through said open lower end of said housing and supported from said housing with a swivel to allow the retaining device to remain stationary as said housing rotates;   a seal on said retaining device to engage the mandrel to redirect flow from said axially oriented outlet to said cutter and away from flowing through the mandrel.   
     
     
         16 . The assembly of  claim 15 , wherein:
 said seal comprises at least one cup seal having an open end directed toward said fluid inlet passage.   
     
     
         17 . The assembly of  claim 15 , wherein:
 said cutter passage is formed at least in part within said wall.   
     
     
         18 . The assembly of  claim 15 , wherein:
 said cutter passage comprises at least one tube.   
     
     
         19 . The assembly of  claim 18 , wherein:
 said tube is disposed in a recess on an inner or an outer face of said wall.