Method for producing viscous hydrocarbon using steam and carbon dioxide

1. A method for producing hydrocarbons from a reservoir, comprising:

positioning a burner having a combustion chamber in a first well;

supplying a fuel, an oxidant, and one of water or steam from the surface to the burner in the first well;

supplying a viscosity-reducing gas from the surface to the reservoir in a conduit separate from the fuel;

igniting the fuel and the oxidant in the combustion chamber to generate heat and steam in the burner;

injecting the viscosity-reducing gas and steam into the reservoir to reduce the viscosity of and heat hydrocarbons within the reservoir; and

recovering hydrocarbons from the reservoir.

2. The method of claim 1 , wherein the hydrocarbons are recovered from the reservoir through the first well or through a second well that is spaced from or intersects the first well.

3. The method of claim 2 , wherein at least one of the first and second wells comprise at least one horizontal, vertical, and slanted well section.

4. The method of claim 2 , wherein the viscosity-reducing gas injected into the reservoir drives the hydrocarbons to the first or second well.

5. The method of claim 1 , wherein the conduit for supplying the viscosity-reducing gas to the reservoir comprises an annulus of the first well.

6. The method of claim 1 , wherein the viscosity-reducing gas and steam are simultaneously or intermittently injected into the reservoir.

7. The method of claim 1 , wherein the viscosity-reducing gas and steam form a gaseous product comprising carbon dioxide.

8. The method of claim 7 , wherein the gaseous product comprises at least 5 percent carbon dioxide by moles of steam and hydrogen.

9. The method of claim 7 , wherein the gaseous product comprises 10 percent or more carbon dioxide by moles of steam and hydrogen.

10. The method of claim 7 , wherein the gaseous product comprises 25 percent or more carbon dioxide by moles of steam and hydrogen.

11. The method of claim 7 , further comprising reducing a steam/oil ratio of the recovered hydrocarbons by increasing a percentage of carbon dioxide in the gaseous product.

12. The method of claim 7 , further comprising reducing a steam/oil ratio of the recovered hydrocarbons to below 14.3 by increasing a percentage of carbon dioxide in the gaseous product.

13. The method of claim 7 , further comprising reducing a steam/oil ratio of the recovered hydrocarbons to about 5.65 by increasing a percentage of carbon dioxide in the gaseous product.

14. The method of claim 7 , further comprising increasing cumulative oil production of the recovered hydrocarbons by increasing a percentage of carbon dioxide in the gaseous product.

15. The method of claim 1 , wherein the viscosity-reducing gas is flowed to the burner with the oxidant or the water or steam.

16. The method of claim 1 , further comprising at least one of elevating the temperature of the viscosity-reducing gas using heat generated by the burner to deliver heat to the reservoir, and using the viscosity-reducing gas to increase formation pressure in the reservoir.

17. The method of claim 1 , wherein the viscosity-reducing gas comprises carbon dioxide.

18. A method for producing hydrocarbons from a reservoir, comprising:

positioning a burner comprising a combustion chamber in a first well;

supplying a fuel, an oxidant, and one of water or steam from the surface to the burner in the first well;

supplying a viscosity-reducing gas from the surface to the reservoir in a conduit separate from the fuel;

igniting the fuel and the oxidant in the combustion chamber to generate heat and steam in the burner;

injecting the viscosity-reducing gas and steam into the reservoir to reduce the viscosity of and heat hydrocarbons within the reservoir; and

recovering hydrocarbons from the reservoir through a second well that is spaced from or intersects the first well.

19. The method of claim 18 , wherein the conduit for supplying the viscosity-reducing gas to the reservoir comprises an annulus of the first well.

20. The method of claim 18 , wherein the viscosity-reducing gas and steam are simultaneously or intermittently injected into the reservoir.

21. The method of claim 18 , wherein the viscosity-reducing gas and steam form a gaseous product comprising carbon dioxide.

22. The method of claim 21 , wherein the gaseous product comprises at least 5 percent carbon dioxide by moles of steam and hydrogen.

23. The method of claim 21 , wherein the gaseous product comprises 10 percent or more carbon dioxide by moles of steam and hydrogen.

24. The method of claim 21 , wherein the gaseous product comprises 25 percent or more carbon dioxide by moles of steam and hydrogen.

25. The method of claim 21 , further comprising reducing a steam/oil ratio of the recovered hydrocarbons by increasing a percentage of carbon dioxide in the gaseous product.

26. The method of claim 21 , further comprising reducing a steam/oil ratio of the recovered hydrocarbons to below 14.3 by increasing a percentage of carbon dioxide in the gaseous product.

27. The method of claim 21 , further comprising reducing a steam/oil ratio of the recovered hydrocarbons to about 5.65 by increasing a percentage of carbon dioxide in the gaseous product.

28. The method of claim 21 , further comprising increasing cumulative oil production of the recovered hydrocarbons by increasing a percentage of carbon dioxide in the gaseous product.

29. The method of claim 18 , further comprising at least one of elevating the temperature of the viscosity-reducing gas using heat generated by the burner to deliver heat to the reservoir, and using the viscosity-reducing gas to increase formation pressure in the reservoir.

30. The method of claim 18 , wherein the viscosity-reducing gas comprises carbon dioxide.

31. The method of claim 18 , wherein the viscosity-reducing gas is flowed to the burner with the oxidant or the water or steam.

32. The method of claim 18 , wherein at least one of the first and second wells comprise at least one horizontal, vertical, and slanted well section.