Downhole activated packer plug magnetic debris tool

Abstract

A downhole magnetic debris tool is disclosed that may be connected to the bottom of a packer isolation plug. The downhole magnetic debris tool may include a magnetic shield assembly that shields the magnets and prevent the collection of magnetic debris as the packer isolation plug assembly is run into the well. The packer isolation plug assembly is inserted into the internal seal bore of a set packer. The assembly protects the seal bore from damage and prevents debris from moving downhole. The magnets of the downhole magnetic debris tool may be unsheathed upon removal of the packer isolation plug from the packer. The downhole magnetic debris tool may be used to collect magnetic debris that has collected on top of the packer. Additionally, the magnet shield assembly may act as a debris basket collecting downhole debris while the assembly is pulled from the hole.

1 . A device for collecting debris in a wellbore, the device comprising:
 a packer plug;   a mandrel connected to the packer plug;   at least one magnet connected to the mandrel;   a shield assembly selectively connected to the mandrel being movable along the mandrel from a first position that covers the at least one magnet to a second position along the mandrel that uncovers the at least one magnet;   wherein upon removal of the packer plug from a packer set within a wellbore the shield assembly moves from the first position to the second position.   
   
   
       2 . The device of  claim 1  wherein debris may be collected in an inner cavity when the shield assembly is in the second position along the mandrel. 
   
   
       3 . An apparatus for use to collect debris out of a wellbore, the apparatus comprising:
 a plug having an upper end and a lower end, wherein the plug may be inserted into a packer set within the wellbore;   a retrievable neck connected to the upper end of the plug;   a mandrel having an upper end and a lower end, the upper end of the mandrel being connected to the bottom of the plug;   a plurality of magnets connected to the mandrel;   a collet connected by a shearable device to the mandrel at a first position along the mandrel, wherein the collet is adapted to move to a second position along the mandrel upon shearing of the shearable device;   an outer shield connected to the collet, wherein in the first position the outer shield covers the plurality of magnets;   a bottom connector attached to the lower end of the mandrel; and   means for securing the collet at the second position along the mandrel.   
   
   
       4 . The apparatus of  claim 3  wherein the means for securing the collet at the second position is at least one spring loaded lug connected to the lower bottom connector. 
   
   
       5 . The apparatus of  claim 3  wherein the means for securing the collet at the second position includes a coupling on an end of a shaft, wherein the shaft is positioned within the mandrel. 
   
   
       6 . The apparatus of  claim 3  further comprising a nose guide attached to the bottom connector. 
   
   
       7 . The apparatus of  claim 6  wherein the nose guide includes at least one fluid passage. 
   
   
       8 . The apparatus of  claim 3  further comprising a cavity between the mandrel and the outer shield when the collet is in the second position along the mandrel. 
   
   
       9 . The apparatus of  claim 8  wherein the bottom connector includes at least one longitudinal opening in communication with the cavity between the mandrel and the outer shield. 
   
   
       10 . The apparatus of  claim 3  further comprising an inner shield connected to the outer shield. 
   
   
       11 . The apparatus of  claim 10  wherein one of the shields is steel tubing. 
   
   
       12 . The apparatus of  claim 11  wherein one of the shields is stainless steel tubing. 
   
   
       13 . The apparatus of  claim 3  wherein the plurality of magnets include at least one rare earth magnet. 
   
   
       14 . The apparatus of  claim 13  wherein the at least one rare earth magnet is neodymium. 
   
   
       15 . The apparatus of  claim 13  wherein the at least one rare earth magnet is samarium cobalt. 
   
   
       16 . A method for collecting debris from a wellbore, the method comprising:
 unsheathing magnets on the magnetic debris tool, wherein the magnetic debris tool is connected beneath a packer plug;   removing the packer plug from a set packer within the wellbore;   moving the packer plug up the wellbore, wherein the magnets on the magnetic debris tool collect metallic debris in the wellbore.   
   
   
       17 . The method of  claim 16  further comprising collecting non-metallic debris in the wellbore within a cavity of the magnetic debris tool. 
   
   
       18 . The method of  claim 16  further comprising draining fluid from the cavity of the magnetic debris tool. 
   
   
       19 . A method for collecting debris from off the top of a packer set within a wellbore, the method comprising:
 setting an isolation plug into a packer set within a wellbore, wherein a magnetic debris tool having at least one magnet and a shield assembly covering the at least one magnet is connected to the bottom of the isolation plug;   applying a force to the isolation plug;   releasing the shield assembly to uncover the at least one magnet of the magnetic debris tool;   removing the isolation plug from the packer; and   moving the at least one magnet past the top of the set packer, wherein the at least one magnet collect metallic debris from off of the top of the packer.   
   
   
       20 . The method of  claim 19  further comprising collecting non-metallic debris in a cavity of the shield assembly. 
   
   
       21 . The method of  claim 20  further comprising draining fluid from the cavity of the shield assembly. 
   
   
       22 . The method of  claim 18  wherein the shield assembly is comprised of a guide nose, collet, and a magnet shield.