Method for Removing a Consumable Downhole Tool

Abstract

A method for removing a downhole tool from a well bore comprises consuming at least a portion of the downhole tool within the well bore via exposure of the tool to heat and a source of oxygen. Another method of removing a downhole tool from a well bore comprises exposing the downhole tool to heat and a source of oxygen in situ within the well bore to desirably consume at least a portion of the tool within the well bore.

1 . A method for removing a downhole tool from a well bore comprising:
 conveying the downhole tool comprising a flexible sealing element into a wellbore using a work string;   engaging the sealing element to a wellbore wall, wherein the sealing element substantially prevents a fluid flow around the downhole tool in at least one direction through the wellbore;   disconnecting the downhole tool from the work string; and   consuming at least a portion of the downhole tool within the well bore via exposure of the tool to heat and a source of oxygen.   
   
   
       2 . The method of  claim 1  wherein consuming comprises burning. 
   
   
       3 . The method of  claim 1  wherein the portion comprises a metal. 
   
   
       4 . The method of  claim 3  wherein the metal is magnesium. 
   
   
       5 . The method of  claim 4  wherein consuming comprises converting the magnesium metal to magnesium oxide. 
   
   
       6 . The method of  claim 1  further comprising igniting a fuel load to produce the heat and source of oxygen. 
   
   
       7 . The method of  claim 6  wherein the fuel load comprises a flammable, non-explosive solid. 
   
   
       8 . The method of  claim 6  wherein the fuel load comprises thermite. 
   
   
       9 . The method of  claim 6  wherein igniting comprises:
 triggering a firing mechanism; and   activating a heating source.   
   
   
       10 . The method of  claim 9  wherein triggering the firing mechanism comprises:
 setting a device to activate the heating source when pre-defined conditions are met.   
   
   
       11 . The method of  claim 10  wherein the pre-defined conditions comprise elapsed time, temperature, pressure, or any combination thereof. 
   
   
       12 . The method of  claim 11  wherein the device comprises an electronic timer, a mechanical timer, or a spring-wound timer. 
   
   
       13 . The method of  claim 12  wherein the timer is programmable to activate the heating source when the pre-defined conditions are met. 
   
   
       14 . The method of  claim 11  wherein the device comprises a pressure-actuated firing head. 
   
   
       15 . The method of  claim 9  wherein the firing mechanism is disposed on the tool. 
   
   
       16 . The method of  claim 9  wherein the firing mechanism is lowered to the tool on a work string. 
   
   
       17 . The method of  claim 9  wherein the heating source is disposed on the tool. 
   
   
       18 . The method of  claim 9  wherein the heating source is lowered to the tool on a work string. 
   
   
       19 . The method of  claim 1  wherein the downhole tool fails structurally during or after the portion of the downhole tool is consumed. 
   
   
       20 . The method of  claim 19  further comprising applying a load to the downhole tool to aid in the structural failure. 
   
   
       21 . The method of  claim 20  wherein the load comprises a pressure load, a mechanical load, or a combination thereof. 
   
   
       22 . The method of  claim 1  further comprising releasing the downhole tool from engagement with a wall of the well bore. 
   
   
       23 . The method of  claim 19  further comprising allowing the downhole tool to fall to the bottom of the well bore. 
   
   
       24 . The method of  claim 19  further comprising removing the downhole tool from the well bore. 
   
   
       25 . The method of  claim 1  wherein the downhole tool is a frac plug, a bridge plug, a packer, or a wellbore zonal isolation device. 
   
   
       26 . A method of removing a downhole tool from a well bore comprising:
 engaging the downhole tool to a casing string, wherein the downhole tool is substantially confined within the casing string, and wherein the downhole tool substantially prevents a fluid flow in at least one direction through the wellbore; and   exposing the downhole tool to heat and a source of oxygen in situ within the well bore to desirably consume at least a portion of the tool within the well bore, wherein the downhole tool is substantially free of any connection to the surface when the downhole tool is consumed.   
   
   
       27 . The method of  claim 26 , wherein the heat and oxygen source are produced by the burning of thermite. 
   
   
       28 . The method of  claim 1 , wherein the downhole tool is substantially free of any connection to the surface when the downhole tool is consumed. 
   
   
       29 . The method of  claim 1 , further comprising: allowing a fluid to flow through the downhole tool. 
   
   
       30 . A method comprising:
 engaging a tool comprising a fuel load to a wellbore wall, wherein the fuel load does not contact the wellbore wall, and wherein the downhole tool substantially prevents a fluid flow in at least one direction through the wellbore; and   consuming at least a portion of the tool using heat.   
   
   
       31 . The method of  claim 30 , wherein the heat is produced by the burning of thermite. 
   
   
       32 . The method of  claim 30 , wherein the heat is produced in a substantially radial direction at a plurality of locations spaced longitudinally apart along the tool. 
   
   
       33 . The method of  claim 1 , wherein downhole tool prevents downward fluid flow through the wellbore. 
   
   
       34 . The method of  claim 26 , wherein downhole tool prevents downward fluid flow through the wellbore. 
   
   
       35 . The method of  claim 1  further comprising flowing the fluid through the wellbore.