Well treatment

Abstract

A combustible foamed fluid energized with gaseous fuel and combustion oxidant sources. Also, an energized fluid system, a treatment method using the combustible foamed fluid, and a method to prepare the combustible foamed fluid are disclosed.

1 . A treatment method, comprising:
 introducing downhole a quantity of a treatment fluid comprising a combustible foamed fluid comprising a mixture of a fuel source and a combustion oxidant source, wherein a gas phase of the foam comprises the mixture of the fuel source and the combustion oxidation source;   placing the combustible foamed fluid in a downhole structure under non-combustion conditions free of an active ignition source;   thereafter igniting the combustible foamed fluid to combust the fuel source in the downhole structure forming a post-combustion fluid.   
     
     
         2 . (canceled) 
     
     
         3 . The method of  claim 1 , wherein the combustion decomposes the foamed fluid. 
     
     
         4 . The method of  claim 1 , further comprising cooling the post-combustion fluid to a reduced specific volume relative to the combustible foamed fluid. 
     
     
         5 . The method of  claim 1 , wherein the treatment fluid further comprises proppant. 
     
     
         6 . The method of  claim 1 , wherein the downhole structure comprises a fracture above a fracturing pressure. 
     
     
         7 . The method of  claim 1 , wherein the downhole structure comprises a formation matrix below a fracturing pressure. 
     
     
         8 . The method of  claim 1 , wherein the fuel source is selected from hydrogen, hydrocarbon gases, or a mixture thereof. 
     
     
         9 . The method of  claim 1 , wherein the combustion oxidant source comprises molecular oxygen. 
     
     
         10 . The method of  claim 1 , further comprising preparing the combustible foamed fluid at a surface location and introducing the mixture into a wellbore. 
     
     
         11 . The method of  claim 1 , further comprising introducing the combustion oxidant source into a wellbore in a first stream separate from a second stream comprising the fuel source, and mixing the first and second streams downhole to form the combustible foamed fluid. 
     
     
         12 . An energized fluid system, comprising:
 a combustible energized fluid comprising a combustible gaseous mixture dispersed in a continuous liquid phase;   a downhole structure to receive the combustible foamed fluid under non-combustion conditions free of an active ignition source; and   an ignition source in communication with the downhole structure activatable to initiate combustion of the dispersed gaseous mixture.   
     
     
         13 . The energized fluid system of  claim 12 , wherein the combustible gaseous mixture comprises oxygen mixed with a fuel source selected from hydrogen, hydrocarbon gases and combinations thereof. 
     
     
         14 . The energized fluid system of  claim 12 , wherein the downhole structure comprises a formation matrix. 
     
     
         15 . The energized fluid system of  claim 12 , wherein the structure comprises a fracture. 
     
     
         16 . The energized fluid system of  claim 12 , further comprising a controller to remotely activate the ignition source, wherein the ignition source comprises an electrical or chemical igniter. 
     
     
         17 . A method, comprising:
 dispersing a gaseous fuel source and a gaseous combustion oxidant source into a continuous liquid phase to form a combustible foamed fluid; and   isolating the combustible foamed fluid in a downhole structure under non-combustion conditions free of an active ignition source.   
     
     
         18 . The method of  claim 17 , wherein the gaseous fuel source and gaseous combustion oxidant are delivered in separate streams through a wellbore and mixed downhole. 
     
     
         19 . The method of  claim 17 , wherein the gaseous fuel source comprises hydrogen, the gaseous combustion oxidant comprises oxygen, and the continuous liquid phase comprises water, and further comprising passing the liquid phase through an electrolysis cell to generate the oxygen and hydrogen in the liquid phase. 
     
     
         20 . The method of  claim 17 , wherein the downhole structure comprises a fracture above a fracturing pressure, or a formation matrix below the fracturing pressure.