Methods of stabilizing shale surface to minimize proppant embedment and increase proppant-pack conductivity

Abstract

Embodiments of the invention relate to a method of treating a subterranean formation comprising shale comprising forming a fluid comprising potassium acetate, and introducing the fluid to a surface of the subterranean formation comprising shale, wherein geomechanical weakening of the formation is lower than if the formation were not in contact with the fluid. Embodiments of the invention relate to a method of treating a subterranean formation comprising shale, comprising forming a fluid comprising potassium chloride and ammonium acetate; and introducing the fluid to a surface of the subterranean formation comprising shale, wherein geomechanical weakening of the formation is lower than if the formation were not in contact with the fluid.

1 . A method of treating a subterranean formation comprising shale, comprising:
 forming a fluid comprising potassium acetate; and   introducing the fluid to a surface of the subterranean formation comprising shale;   wherein geomechanical weakening of the formation is lower than if the formation were not in contact with the fluid.   
     
     
         2 . The method of  claim 1 , wherein a pressure of the fluid during the introducing is at a pressure to fracture in the formation. 
     
     
         3 . The method of  claim 1 , wherein the fluid comprises a polar organic fluid. 
     
     
         4 . The method of  claim 3 , wherein the fluid comprises glycerine, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol. 
     
     
         5 . The method of  claim 1 , wherein the geomechanical weakening is measured by proppant embedment depth. 
     
     
         6 . The method of  claim 1 , wherein the geomechanical weakening is measured by proppant pack conductivity or permeability. 
     
     
         7 . The method of  claim 1 , wherein the geomechanical weakening is measured by Brinell hardness. 
     
     
         8 . The method of  claim 1 , wherein the concentration of the potassium acetate is selected based on formation characteristics. 
     
     
         9 . The method of  claim 8 , wherein the formation characteristics are selected from the group consisting of clay concentration, formation fracture model, type of clay, surface area of the formation, and a combination thereof. 
     
     
         10 . The method of  claim 1 , wherein the fluid comprises nitrogen, carbon dioxide, air and a mixture thereof. 
     
     
         11 . The method of  claim 1 , wherein the fluid further comprises a viscosifier, crosslinker, scale inhibitor, biocide, foamers, defoamers, anti-foamers, emulsifiers, de-emulsifiers, surfactants and/or a combination thereof. 
     
     
         12 . The method of  claim 1 , wherein the contacting is selected from the group consisting of hydraulic fracturing, matrix injection, completions, sand control, perforations, or a combination thereof. 
     
     
         13 . The method of  claim 1 , wherein the fluid further comprises a quaternary amine. 
     
     
         14 . The method of  claim 1 , wherein the quaternary amine is tetramethyl ammonium chloride. 
     
     
         15 . A method of treating a subterranean formation comprising shale, comprising:
 forming a fluid comprising potassium chloride and ammonium acetate; and   introducing the fluid to a surface of the subterranean formation comprising shale;   wherein geomechanical weakening of the formation is lower than if the formation were not in contact with the fluid.   
     
     
         16 . The method of  claim 15 , wherein a pressure of the fluid during the introducing is at a pressure to fracture in the formation. 
     
     
         17 . The method of  claim 15 , wherein the fluid comprises glycerine, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol and tripropylene glycol. 
     
     
         18 . The method of  claim 15 , wherein the geomechanical weakening is measured by proppant pack conductivity or permeability or Brinell hardness or a combination thereof. 
     
     
         19 . The method of  claim 15 , wherein the concentration of the potassium chloride and ammonium acetate is selected based on formation characteristics, wherein the formation characteristics are selected from the group consisting of clay concentration, formation fracture model, type of clay, surface area of the formation, and a combination thereof. 
     
     
         20 . The method of  claim 15 , wherein the fluid further comprises a quaternary amine.