Consumable downhole tools

Abstract

A downhole tool having a body or structural component comprises a material that is at least partially consumed when exposed to heat and a source of oxygen. The material may comprise a metal, such as magnesium, which is converted to magnesium oxide when exposed to heat and a source of oxygen. The downhole tool may further comprise a torch with a fuel load that produces the heat and source of oxygen when burned. The fuel load may comprise a flammable, non-explosive solid, such as thermite.

1 . A downhole tool comprising:
 a plurality of slips;   a body or structural component coupled to the slips and comprising a cavity and a material that is at least partially consumed when exposed to heat and a source of oxygen; and   a torch coupled to the body and comprising:
 a fuel load that produces the heat and source of oxygen when burned; and 
 a torch body with a plurality of nozzles distributed along its length, 
 wherein at least one of the nozzles is positioned within the cavity. 
   
   
   
       2 . The downhole tool of  claim 1  wherein the material comprises a metal. 
   
   
       3 . The downhole tool of  claim 2  wherein the metal is magnesium. 
   
   
       4 . The downhole tool of  claim 3  wherein the magnesium metal is converted to magnesium oxide when exposed to heat and a source of oxygen. 
   
   
       5 . The downhole tool of  claim 1  wherein the fuel load comprises a flammable, non-explosive solid. 
   
   
       6 . The downhole tool of  claim 1  wherein the fuel load comprises thermite. 
   
   
       7 . The downhole tool of  claim 1  wherein the nozzles distribute molten plasma produced when the fuel load is burned. 
   
   
       8 . The downhole tool of  claim 1  wherein the torch further comprises a firing mechanism with a heat source to ignite the fuel load. 
   
   
       9 . The downhole tool of  claim 8  wherein the firing mechanism further comprises a device to activate the heat source. 
   
   
       10 . The downhole tool of  claim 8  wherein the firing mechanism is an electronic igniter. 
   
   
       11 . The downhole tool of  claim 9  wherein the device comprises an electronic timer, a mechanical timer, a spring-wound timer, a volume timer, or a measured flow timer. 
   
   
       12 . The downhole tool of  claim 11  wherein the timer is programmable to activate the heat source when pre-defined conditions are met. 
   
   
       13 . The downhole tool of  claim 12  wherein the pre-defined conditions comprise elapsed time, temperature, pressure, volume, or any combination thereof. 
   
   
       14 . The downhole tool of  claim 9  wherein the device comprises a pressure-actuated firing head. 
   
   
       15 . The downhole tool of  claim 1  further comprising an enclosure for storing an accelerant. 
   
   
       16 . The downhole tool of  claim 1  wherein the tool is a frac plug, a bridge plug, a packer, or a well bore zonal isolation device. 
   
   
       17 . The downhole tool of  claim 1  wherein the body or structural component comprises a packer and a plurality of slips. 
   
   
       18 . The downhole tool of  claim 1  wherein the body or structural component comprises a check valve. 
   
   
       19 . The downhole tool of  claim 1  wherein the cavity is an axial flowbore. 
   
   
       20 . The downhole tool of  claim 1  wherein the nozzles have a higher melting temperature than the body or structural component. 
   
   
       21 . A downhole tool comprising:
 a body having an axial flowbore;   a packer and one or more slips disposed around the body; and   a torch having a plurality of nozzles distributed along its length, wherein one or more of the nozzles are disposed within the axial flowbore,   wherein at least a portion of the tool is consumed when exposed to heat and a source of oxygen produced by the torch.   
   
   
       22 . The downhole tool of  claim 21  wherein the torch comprises thermite that produces the heat and source of oxygen when ignited. 
   
   
       23 . The downhole tool of  claim 22  wherein the body, packer, or slips comprise magnesium that is converted to magnesium oxide when exposed to the heat and source of oxygen. 
   
   
       24 . The downhole tool of  claim 21  wherein an annular flow space exists between the torch and axial flowbore. 
   
   
       25 . The downhole tool of  claim 1  wherein the nozzles are angled to direct a flow exiting the nozzles towards an inner surface of the body or structural component. 
   
   
       26 . The downhole tool of  claim 21  wherein the nozzles are angled to direct a flow exiting the nozzles towards an inner surface of the body or structural component. 
   
   
       27 . The downhole tool of  claim 1  wherein two or more nozzles are positioned within the cavity. 
   
   
       28 . The downhole tool of  claim 21  wherein two or more nozzles are disposed within the axial flowbore. 
   
   
       29 . The downhole tool of  claim 1  wherein the fuel load is external to the cavity. 
   
   
       30 . The downhole tool of  claim 21  wherein the torch further comprises a fuel load external to the axial flowbore.