Synthetic Sweet Spots in Tight Formations by Injection of Nano Encapsulated Reactants

Abstract

Provided is a method and composition for the in-situ generation of synthetic sweet spots in tight-gas formations. The composition can include gas generating compounds, which upon activation, exothermically react to generate heat and gas. The method of using the composition includes injecting the composition into a tight-gas formation such that upon activation, the heat and gas are generated, resulting in the formation of fractures and microfractures within the formation.

That which is claimed is: 
     
         1 . A reaction mixture for the in-situ generation of sweet spots within tight gas wells, the reaction mixture comprising:
 an encapsulated reactant, said reactant being encapsulated with a material that provides a specific delayed erosion rate, said reactant being capable or reacting exothermically to produce a volume of gas; and   a fracturing fluid.   
     
     
         2 . The reaction mixture of  claim 1  wherein the reactant reacts exothermically with water. 
     
     
         3 . The reaction mixture of  claim 1  wherein the encapsulating material erodes at a predefined rate upon exposure to heat and water. 
     
     
         4 . The reaction mixture of  claim 1 , wherein encapsulating material erodes at a predefined rate upon exposure to an acid. 
     
     
         5 . The reaction mixture of  claim 1 , wherein at least two reactants are supplied in the reaction mixture, wherein the at least two reactants are capable of exothermically reacting in the presence of the other to generate a gas. 
     
     
         6 . A method for stimulating production of gas in a tight-gas formation, the method comprising the steps of:
 injecting into the formation an aqueous solution comprising at least one encapsulated reactant, said reactant being capable of reacting exothermically to produce a volume of gas, said encapsulated reactant having a coating allowing for a delayed erosion thereof, wherein upon erosion of the encapsulating coating the reactant exothermically reacts to produce a volume of gas;   wherein upon producing the volume of gas, the fractures and microfractures are created within the formation, thereby improving production therefrom.   
     
     
         7 . The method of  claim 6 , wherein the step of injecting an aqueous solution comprising at least one encapsulated reactant is repeated multiple times. 
     
     
         8 . The method of  claim 6 , wherein the aqueous solution includes at least two reactants. 
     
     
         9 . The method of  claim 6 , wherein the at least one reactant reacts exothermically with water.