Magnetic Fishing Tool with Alternative Flow Capability and Method

Abstract

The magnetic fishing tool has an axial flow passage through a valve member and one or more magnets for initial dispersal of debris away from the fish. Once engaged to the fish the flow direction can be altered by moving the valve member to open lateral ports and to close the straight through path so that fluid circulates above the fish to clear debris from ahead of the fish on the trip out of the hole. This can be accomplished with an object landed on a seat in the valve member, which causes it to shift axially to expose the lateral ports. Optionally the valve member can be shifted with flow in which case the flow will continue axially as well as laterally for the retrieval of the fish.

We claim: 
     
         1 . A magnetic fishing tool for downhole use, comprising:
 a body comprising a through passage and at least one wall port;   at least one magnet mounted adjacent to a lower end of said body;   a flow diverter in said passage for selectively directing flow between a first direction toward said magnet and a second direction out said at least on wall port.   
     
     
         2 . The tool of  claim 1 , wherein:
 said flow diverter responsive to pressure differential.   
     
     
         3 . The tool of  claim 1 , wherein:
 said through passage passing through said at least one magnet.   
     
     
         4 . The tool of  claim 1 , wherein:
 said at least one wall port comprises multiple wall ports.   
     
     
         5 . The tool of  claim 4 , wherein:
 said wall ports oriented laterally to a longitudinal axis of said body or toward an uphole end of said body.   
     
     
         6 . The tool of  claim 4 , wherein:
 said wall ports oriented to create a swirling fluid motion in a direction toward an uphole end of said body.   
     
     
         7 . The tool of  claim 4 , wherein:
 said ports are identical and equally spaced.   
     
     
         8 . The tool of  claim 4 , wherein:
 said ports are different and randomly spaced.   
     
     
         9 . The tool of  claim 1 , wherein:
 said flow diverter selectively retained in said passage against axial movement.   
     
     
         10 . The tool of  claim 1 , wherein:
 said flow diverter formed to accept an object to close off said passage to allow pressure buildup for opening said at least one port.   
     
     
         11 . The tool of  claim 1 , wherein:
 said flow diverter capable of alternating flow between said first and second direction more than once.   
     
     
         12 . The tool of  claim 1 , wherein:
 said at least one magnet comprising a permanent magnet.   
     
     
         13 . The tool of  claim 1 , wherein:
 said body comprising an exterior thread adjacent a lower end thereof.   
     
     
         14 . The tool of  claim 1 , further comprising:
 a removable protective cover for said body for use during shipping.   
     
     
         15 . The tool of  claim 1 , wherein:
 at least a portion of said flow diverter disintegrates with exposure to downhole conditions or the passage of time.   
     
     
         16 . A fishing method for downhole use, comprising:
 providing a through passage in a body and at least one wall port;   locating at least one magnet adjacent to a lower end of said body;   selectively directing flow, with a flow diverter in said passage, between a first direction past said magnet on approach to a fish to be captured and a second direction out said at least on wall port as the fish is brought out of a downhole location.   
     
     
         17 . The method of  claim 16 , wherein:
 operating said flow diverter responsive to pressure differential.   
     
     
         18 . The method of  claim 16 , wherein:
 locating said through passage through said at least one magnet.   
     
     
         19 . The method of  claim 16 , wherein:
 providing multiple wall ports as said at least one wall port.   
     
     
         20 . The method of  claim 19 , wherein:
 orienting said wall ports laterally to a longitudinal axis of said body or toward an uphole end of said body.   
     
     
         21 . The method of  claim 19 , wherein:
 orienting said wall ports to create a swirling fluid motion in a direction toward an uphole end of said body.   
     
     
         22 . The method of  claim 19 , wherein:
 configuring said ports identically and with equal spacing.   
     
     
         23 . The method of  claim 19 , wherein:
 configuring said ports differently and with random spacing.   
     
     
         24 . The method of  claim 16 , wherein:
 selectively retaining said flow diverter in said passage against axial movement.   
     
     
         25 . The method of  claim 16 , wherein:
 forming said flow diverter to accept an object to close off said passage to allow building pressure for opening said at least one port.   
     
     
         26 . The method of  claim 16 , wherein:
 alternating flow in said flow diverter between said first and second direction more than once.   
     
     
         27 . The method of  claim 16 , wherein:
 providing a permanent magnet as said at least one magnet.   
     
     
         28 . The method of  claim 16 , wherein:
 locating an exterior thread adjacent a lower end of said body   
     
     
         29 . The method of  claim 16 , further comprising:
 covering said body during shipping with a removable protective cover.   
     
     
         30 . The method of  claim 16 , wherein:
 disintegrating at least a portion of said flow diverter with exposure to downhole conditions or the passage of time.