Method and Materials for Employing Fractures in Mining Operations

Abstract

Methods for augmenting mining operations with hydraulic fractures. The methods may comprise forming one or more hydraulic fractures near an ore body, which may be filled with an impermeable material, thereby forming an artificial aquitard or a barrier to contaminant migration. The methods may also comprise forming one or more hydraulic fractures within an ore body, injecting a proppant material into the fractures, and cycling a solution through the fractures to perform in-situ mining, or cycling a working fluid through the fractures to provide a mode of heat exchange. The methods may further comprise forming one or more hydraulic fractures at a site of interest to locally influence stress fields in order to prepare the site for material extraction, or disposing within the fractures an energetic material, and detonating the energetic material to extend a single fracture, to form multiple fractures, or to highly fragment rock.

What is claimed is: 
     
         1 . A method of forming an artificial base aquitard to collect a fluid introduced to an ore body, comprising:
 drilling a wellbore in proximity to an ore body;   initiating a fracture at a bottom of the wellbore;   propagating the fracture horizontally;   filling the fracture with an impermeable material to form an artificial base aquitard;   introducing a fluid into the ore body; and   collecting the fluid in the artificial base aquitard.   
     
     
         2 . The method of  claim 1 , wherein the propagating comprises propagating the fracture with a high radius to depth ratio. 
     
     
         3 . The method of  claim 1 , wherein the wellbore comprises a plurality of wellbores, the fracture comprises a plurality of fractures, and the artificial base aquitard comprises a plurality of artificial base aquitards which surround one or more portions of the ore body. 
     
     
         4 . The method of  claim 3 , wherein the plurality of base aquitards is formed in locations which allow channeling a flow of the fluid through the ore body. 
     
     
         5 . A method of producing a mineral of interest from an ore body, comprising:
 drilling a wellbore in proximity to an ore body;   forming a horizontal fracture at a bottom of the wellbore;   filling the fracture with proppant to form a channel through which a fluid may be circulated through the ore body;   cycling the fluid from the wellbore into the ore body to dissolve a mineral of interest located in the ore body;   returning the fluid to the wellbore, wherein the fluid includes the mineral of interest; and   retrieving the fluid from the wellbore, thereby producing the mineral of interest at a surface from which the wellbore was drilled.   
     
     
         6 . The method of  claim 5 , wherein the wellbore comprises a plurality of wellbores, and the fractures comprise a plurality of fractures formed along or across the ore body. 
     
     
         7 . The method of  claim 6 , wherein the plurality of fractures connect and allow the fluid to circulate through the connected plurality of fractures before the fluid is retrieved from one of the plurality of wellbores. 
     
     
         8 . A method of forming an artificial vertical aquitard to collect a fluid introduced to an ore body, comprising:
 drilling a wellbore in proximity to an ore body and down-dip from said ore body;   initiating a fracture along the wellbore proximal to the ore body;   propagating the fracture vertically;   filling the fracture with an impermeable material to form an artificial vertical aquitard;   introducing a fluid into the ore body via a second wellbore; and   collecting the fluid in a natural or artificial base aquitard.   
     
     
         9 . The method of  claim 8 , wherein the wellbore comprises a plurality of wellbores, the fracture comprises a plurality of fractures, and the artificial vertical aquitard comprises a plurality of artificial vertical aquitards which surround one or more portions of the ore body. 
     
     
         10 . The method of  claim 9 , wherein the plurality of artificial vertical aquitards is formed in locations which allow channeling a flow of the fluid through the ore body.