Use of encapsulated acid in acid fracturing treatments

A method of acid fracturing a subterranean formation, said subterranean formation being in fluid communication with the surface, said method comprising:

• injecting into said formation a pad fluid, said pad fluid being under a hydraulic pressure sufficient to create an open fracture in said formation, said open fracture having one or more fracture faces;
• injecting into said open fracture an encapsulated formation etching agent, said encapsulated formation etching agent including a formation etching agent being encapsulated by an encapsulating agent, wherein said formation etching agent is capable of etching the fracture faces of said formation;
• etching the fracture faces with said formation etching agent so as to give one or more etched fracture faces;
• and
• releasing the hydraulic pressure on the formation so as to close the open fracture thus forming one or more flow channels, said flow channels being defined by the etched fracture faces.

A method of increasing the production of hydrocarbon fluids from a hydrocarbon fluid bearing subterranean formation, said formation being in fluid communication with the surface by way of a well, said method comprising:

• injecting into said formation a pad fluid by way of said well;
• pressurizing said pad fluid so as to create open fractures in said subterranean formation, said fractures having one or more fracture faces;
• injecting into said open fractures a formation treating composition, said formation treating composition including an encapsulated formation etching agent and a carrier fluid, said encapsulated formation etching agent including a formation etching agent being encapsulated by an encapsulating agent and wherein said formation etching agent being capable of etching the fracture faces of said formation;
• shutting-in said well for a sufficient time so as to allow said formation treating agent to be released from said encapsulating agent thus etching said fracture faces and giving etched fracture faces;
• and
• depresurizing said fluid so as to close the open fractures thus forming one or more flow channels, said flow channels being defined by the etched fracture faces, wherein said flow channels increase the production of hydrocarbon fluids from said hydrocarbon fluid bearing subterranean formation.