Systems and Methods for Generating Superheated Steam with Variable Flue Gas for Enhanced Oil Recovery

• US 20170321883A1
• Filed: 05/03/2017
• Published: 11/09/2017
• Est. Priority Date: 05/03/2016
• Status: Active Grant

• Current Assignee: Energy Analyst LLC
• Original Assignee: Energy Analyst LLC
• Inventors: Donaldson, A. Burl, Hughes, Brian
• Granted Patent: US 10,641,481 B2
• Time in Patent Office: Days
• CPC Class Codes: E21B 43/24 using heat, e.g. steam injection
• CPC Class Codes: F22D 1/02 with water tubes arranged in the boiler furnace, fire tubes, or flue ways heat-exchange tubes in general F28F
• CPC Class Codes: F22D 11/00 Feed-water supply not provided for in other main groups
• CPC Class Codes: F22G 1/12 by mixing steam with furnace gases or other combustion products
• CPC Class Codes: F22G 1/16 by using a separate heat source independent from heat supply of the steam boiler, e.g. by electricity, by auxiliary combustion of fuel oil
• CPC Class Codes: F22G 5/20 by combined controlling procedures
• CPC Class Codes: F22G 7/12 in flues

Abstract

Systems and methods are disclosed for producing a superheated steam having a specified ratio of water vapor to combustion gases for injection into a well to enhance heavy oil production. Embodiments comprise indirect-contact steam generators and direct-contact steam generators.

Claims

1. A system for generating superheated steam for injection into a well comprising:

a direct-contact superheater performing combustion and operating on feedwater in either a liquid state or a gas state or some combination of both states and generating a superheated steam having a specified ratio of non-condensable combustion gases to steam for injection into the well.

2. The system of claim 1 further comprising a water purifier for receiving the feedwater before the feedwater is operated on by said direct-contact superheater and purifying the feedwater such that the amount of solids within it does not exceed a nominal amount for delivery to said direct-contact superheater.

3. The system of claim 1 wherein said direct-contact superheater operates using compressed air, gaseous oxygen, and/or liquid oxidizers.

4. The system of claim 1 wherein said direct-contact superheater comprises a combustion chamber lined with a refractory material.

5. The system of claim 1 wherein said direct-contact superheater comprises a combustion chamber fabricated of a metal alloy with a low coefficient of thermal expansion.

6. The system of claim 1 wherein said direct-contact superheater is located within the well and below a thermal packer.

7. The system of claim 1 wherein said direct-contact superheater is compact for easy transport.

8. The system of claim 1 further comprising an indirect-contact steam generator connected to said direct-contact superheater, said indirect-contact steam generator operating on the feedwater before the feedwater is operated on by said direct-contact superheater, said indirect-contact steam generator generating a specified quantity and/or quality of feedwater vapor for delivery to said direct-contact superheater.

9. The system of claim 8 further comprising a water purifier for receiving the feedwater before the feedwater is operated on by said indirect-contact steam generator and purifying the feedwater such that the amount of solids within it does not exceed a nominal amount for delivery to said indirect-contact steam generator.

10. The system of claim 8 wherein said direct-contact steam generator comprises a combustion chamber comprising at least one fin on an external surface of said combustion chamber and a metal sleeve surrounding said at least one fin and said combustion chamber.

11. The system of claim 8 wherein said direct-contact superheater comprises a combustion chamber comprising openings to receive at least a fraction of feedwater vapor generated by said indirect-contact steam generator.

12. The system of claim 8 wherein said direct-contact superheater receives the feedwater for cooling before the feedwater is operated on by said indirect-contact steam generator.

13. The system of claim 8 further comprising a programmable logic control system for directing the operation of said direct-contact superheater and said indirect-contact steam generator.

14. A method for generating superheated steam for injection into a well comprising:

receiving feedwater either in a liquid state or a gas state or some combination of both states;

generating superheated steam having a specified ratio of non-condensable combustion gases to steam using a direct-contact superheater performing combustion and operating on the feedwater;

injecting the superheated steam into the well.

15. The method of claim 14 further comprising purifying the feedwater such that the amount of solids within it does not exceed a nominal amount.

16. The method of claim 14 further comprising generating feedwater vapor using an indirect-contact steam generator connected to the direct-contact superheater, wherein the indirect-contact steam generator operates on the feedwater before the feedwater is operated on by the direct-contact superheater, and wherein the indirect-contact steam generator generates a specified quantity and/or quality of feedwater vapor for delivery to the direct-contact superheater.

17. The method of claim 16 further comprising cooling the direct-contact superheater using at least a fraction of the feedwater vapor generated by the indirect-contact steam generator, wherein the direct-contact superheater comprises a combustion chamber comprising at least one fin on an external surface of the combustion chamber and a metal sleeve surrounding the at least one fin and the combustion chamber.

18. The method of claim 16 further comprising cooling the direct-contact superheater using at least a fraction of the feedwater vapor generated by the indirect-contact steam generator, wherein the direct-contact superheater comprises a combustion chamber comprising small openings to receive at least a fraction of the feedwater vapor generated by the indirect-contact steam generator.

19. The method of claim 16 further comprising cooling the direct-contact superheater using the feedwater before the feedwater is operated on by the indirect-contact steam generator.

20. A method for generating superheated steam for injection into a well comprising:

receiving feedwater;

generating feedwater vapor from the feedwater using an indirect-contact steam generator, wherein the indirect-contact steam generator comprises fuel and oxidizer inputs for combustion;

generating superheated steam using the feedwater vapor using a direct-contact superheater, wherein the direct-contact superheater comprises fuel and oxidizer inputs for combustion;

controlling the fuel and oxidizer inputs on the indirect-contact steam generator and the direct-contact superheater to specify a ratio of non-condensable combustion gases to steam.