Methods and Systems for In-Situ Extraction of Bitumen

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.