Method for controlling combustion gas output in direct steam generation for oil recovery

1. A method of recovery of oil from a hydrocarbon-containing reservoir using steam, comprising:

(a) delivering a fuel and an oxygen-containing gas mixture to a direct combustion steam generator at a pressure exceeding atmospheric pressure, wherein a portion of the oxygen-containing gas mixture is provided by a supply of air delivered to the combustion steam generator;

(b) delivering a supply of supplemental oxygen to the combustion steam generator at a delivery pressure exceeding atmospheric pressure, wherein a portion of the oxygen-containing gas mixture is provided by said supplemental oxygen;

(c) burning the fuel and the oxygen-containing gas mixture in the direct combustion steam generator to generate an effluent stream comprising combustion products in the form of CO 2 , and N 2 and water in the form of steam;

(d) sensing a presence of, or a quantity of, one or more of said combustion products, or a ratio of one of said combustion products to another of said combustion products, in said effluent stream;

(e) regulating, via one or more flow regulators, and without said effluent stream being recirculated to said combustion steam generator, a rate of said supplemental oxygen supplied to the combustion steam generator relative to a rate of said air supplied to said combustion steam generator to thereby adjust oxygen content of the oxygen-containing gas mixture so as to produce said effluent stream having a desired composition of one or more of said combustion products in said effluent stream; and

(f) injecting the effluent stream into an injection well in said reservoir.

2. The method according to claim 1 , further comprising delivering a supply of water to the combustion steam generator to add additional steam to said effluent stream produced by the combustion steam generator.

3. The method according to claim 1 , wherein the method of recovery of oil from the reservoir is steam assisted gravity drainage (SAGD).

4. The method according to claim 1 , wherein the method of recovery of oil from the reservoir is Cyclic Steam Stimulation (CSS).

5. The method according to claim 1 , further comprising delivering a supply of water to the combustion steam generator to adjust the quality of the steam generated by the combustion steam generator.

6. The method according to claim 1 , further comprising delivering a supply of water onto an inner wall of the combustion steam generator to cool the temperature of the inner wall of the combustion steam generator.

7. The method according to claim 6 , further when delivering said supply of water to the combustion chamber further adjusting the quality of the steam generated by the combustion chamber.

8. The method according to claim 1 , wherein the air is further supplemented by the supply of supplemental oxygen to adjust the oxygen content of the oxygen-containing gas mixture to a level sufficient to produce a combustion product having a ratio of CO 2 to N 2 that enhances the steam assisted recovery of oil from the hydrocarbon-containing reservoir.

9. The method according to claim 8 , further comprising delivering a supply of water to the combustion steam generator to add additional steam to said effluent stream produced by the combustion steam generator.

10. The method according to claim 8 , further comprising delivering a supply of water onto an inner wall of the combustion steam generator to cool the temperature of the inner wall of the combustion steam generator.

11. The method according to claim 8 , further comprising delivering a supply of water to the combustion steam generator to adjust the quality of the steam generated by the combustion steam generator.

12. The method as claimed in claim 1 , wherein said step of sensing a presence of, or a quantity of, one or more of said combustion products, or a ratio of one of said combustion products to another of said combustion products in said effluent stream, comprises sensing a ratio of CO 2 to N 2 in said effluent stream.

13. The method according to claim 12 , further comprising delivering a supply of water to the combustion steam generator to add additional steam to said effluent stream produced by the combustion steam generator.

14. The method according to claim 12 , further comprising delivering a supply of water to the combustion steam generator to adjust the quality of the steam generated by the combustion steam generator.

15. The method according to claim 12 , further comprising delivering a supply of water onto an inner wall of the combustion steam generator to cool the temperature of the inner wall of the combustion steam generator.

16. The method according to claim 15 , further when delivering said supply of water to the combustion chamber further adjusting the quality of the steam generated by the combustion chamber.

17. The method according to claim 15 , further when delivering said supply of water to the combustion chamber further adjusting the quality of the steam generated by the combustion chamber.

18. The method as claimed in claim 12 , further comprising monitoring conditions of the reservoir to determine an optimum ratio of CO 2 to N 2 in said combustion products for optimum production of hydrocarbon from said reservoir, and adjusting said one or more flow regulators to maintain said optimum ratio.

19. The method according to claim 18 , further comprising delivering a supply of water to the combustion steam generator to adjust the quality of the steam generated by the combustion steam generator.

20. The method according to claim 18 , further comprising delivering a supply of water to the combustion steam generator to add additional steam to said effluent stream produced by the combustion steam generator.

21. The method according to claim 18 , further comprising delivering a supply of water onto an inner wall of the combustion steam generator to cool the temperature of the inner wall of the combustion steam generator.