Methods and Systems for In-Situ Extraction of Bitumen

Abstract

A method for carrying out in-situ bitumen extraction can include a step of forming one or more vertical freeze walls within or around a deposit of bituminous material and establishing a laterally confined deposit of bituminous material; a step of injecting a solvent within the laterally confined deposit of bituminous material; a step of withdrawing a mixture of dissolved bitumen and solvent from within the laterally confined deposit of bituminous material; a step of injecting water within the laterally confined deposit of bituminous material; and a step of withdrawing a mixture of solvent and water from within the laterally confined deposit of bituminous material.

1 . A method of in-situ bitumen extraction comprising:
 forming one or more vertical freeze walls within or around a deposit of bituminous material and establishing a laterally confined deposit of bituminous material;   injecting a solvent within the laterally confined deposit of bituminous material; and   withdrawing a mixture of dissolved bitumen and solvent from within the laterally confined deposit of bituminous material.   
     
     
         2 . The method as recited in  claim 1 , further comprising:
 injecting water within the laterally confined deposit of bituminous material; and   withdrawing a mixture of solvent and water from within the laterally confined deposit of bituminous material.   
     
     
         3 . The method as recited in  claim 1 , wherein the solvent comprises a paraffinic solvent. 
     
     
         4 . The method as recited in  claim 1 , wherein the solvent comprises pentante. 
     
     
         5 . The method as recited in  claim 1 , wherein the method further comprises forming one or more horizontal freeze walls within the deposit of bituminous material and vertically confining the laterally confined deposit of bituminous material. 
     
     
         6 . The method as recited in  claim 1 , wherein the one or more vertical freeze walls abut an impervious geological material located below the deposit of bituminous material. 
     
     
         7 . The method as recited in  claim 1 , wherein forming one or more vertical freeze walls within or around the deposit of bituminous material comprises:
 drilling a plurality of spaced apart vertical bores within or around the deposit of bituminous material; and   circulating a refrigerant through the vertical bores.   
     
     
         8 . The method as recited in  claim 1 , wherein injecting the solvent within the laterally confined deposit of bituminous material comprises:
 drilling one or more vertical injection bores within the laterally confined deposit of bituminous material; and   injecting the solvent within the laterally confined deposit of bituminous material through the one or more vertical injection bores.   
     
     
         9 . The method as recited in  claim 8 , wherein withdrawing the mixture of dissolved bitumen and solvent from within the laterally confined deposit of bituminous material comprises:
 drilling one or more vertical production bores within the laterally confined deposit of bituminous material; and   withdrawing the mixture of dissolved bitumen and solvent from the laterally confined deposit of bituminous material through the one or more vertical production bores.   
     
     
         10 . The method as recited in  claim 9 , wherein:
 the one or more vertical injection bores are arranged in a straight line;   the one or more vertical production bores are arranged in a straight line parallel to and spaced a distance away from the straight line of vertical injection bores; and   the solvent is injected into the laterally confined deposit of bituminous material in a direction towards the straight line of one or more vertical production bores.   
     
     
         11 . The method as recited in  claim 1 , further comprising:
 separating the mixture of dissolved bitumen and solvent withdrawn from within the laterally confined deposit of bituminous material into a bitumen stream and a solvent stream; and   reusing the solvent stream in the step of injecting solvent within the laterally confined deposit of bituminous material.   
     
     
         12 . The method as recited in  claim 1 , wherein the solvent comprises a mixture of water and a peroxide. 
     
     
         13 . The method as recited in  claim 12 , wherein the mixture comprises from 10 wt % to 60 wt % peroxide. 
     
     
         14 . The method as recited in  claim 12 , wherein the peroxide is hydrogen peroxide. 
     
     
         15 . The method as recited in  claim 1 , further comprising
 agitating the deposit of bituminous material prior to injecting the solvent within the laterally confined deposit of bituminous material.   
     
     
         16 . A system for in-situ bitumen extraction comprising:
 a plurality of vertical freeze wall bores formed in a deposit of bituminous material and aligned in a geometric pattern;   a refrigerant source in fluid communication with the plurality of vertical freeze wall bores;   a plurality of vertical injection bores formed win the deposit of bituminous material and located within the geometric pattern of the plurality of freeze walls;   a solvent source in fluid communication with the plurality of vertical injection bores; and   a plurality of vertical production wells formed in the deposit of bituminous material and located within the geometric pattern of the plurality of freeze walls.   
     
     
         17 . The system as recited in  claim 16 , further comprising:
 a bitumen-solvent separator in fluid communication with the plurality of vertical production wells.   
     
     
         18 . The system as recited in  claim 16 , wherein the plurality of vertical freeze wall bores are in fluid communication with one another. 
     
     
         19 . The system as recited in  claim 16 , further comprising a water source in fluid communication with the plurality of vertical injection bores. 
     
     
         20 . The system as recited in  claim 19 , wherein the plurality of vertical injection bores each comprises:
 an inner passage;   a co-annular outer passage separated from the inner passage by a partition;   a plurality of inner passage injection ports extending from the inner passage to the exterior of the vertical injection bore; and   a plurality of outer passage injection ports extending to the exterior of the vertical injection bore.   
     
     
         21 . The system as recited in  claim 20 , wherein the inner passage is in fluid communication with only the water source and the outer passage is in fluid communication with only the solvent source.