Regenerative combustion device

• US 6,705,425 B2
• Filed: 05/28/2002
• Issued: 03/16/2004
• Est. Priority Date: 10/20/2000
• Status: Expired due to Fees

• Current Assignee: Battelle Energy Alliance LLC (Battelle Memorial Institute)
• Original Assignee: Bechtel BWXT Idaho, LLC
• Inventors: West, Phillip B.
• Primary Examiner(s): Lobo, Ian J.
• Application Number:
  US10/037,114
• Publication Number:
  US 20020141288A1
• Time in Patent Office: 658 Days
• Field of Search: 181/102, 181/106, 181/108, 181/113, 181/116, 181/117, 367/25, 367/145, 367/911
• US Class Current: 181/106
• CPC Class Codes: E21B 28/00 Vibration generating arrangements for boreholes or wells, e.g. for stimulating production for fishing for or freeing objects E21B31/005; for transmitting measuring-signals E21B47/14; for geophysical measurements G01V1/02
• CPC Class Codes: E21B 43/003 Vibrating earth formations
• CPC Class Codes: E21B 43/26 by forming crevices or fractures
• CPC Class Codes: F02G 3/00 Combustion-product positive-displacement engine plants
• CPC Class Codes: G01V 1/104 using explosive charges G01V1/157 takes precedence
• CPC Class Codes: G01V 1/40 specially adapted for well-logging

Abstract

A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

Claims

1. A regenerative combustion device, comprising:

a combustion zone comprising a space at least partially bounded by a subterranean surface of a well;

chemicals contained within the combustion zone, having a first equilibrium state, and a second combustible state;

means for transforming the chemicals from the first equilibrium state to the second combustible state; and

an igniter configured to ignite the chemicals in the second combustible state, wherein the chemicals in the first equilibrium state comprise an aqueous solution of water and an electrolyte and the chemicals in the second combustible state comprise gaseous hydrogen and gaseous oxygen and wherein combustion products of the ignition are contained within the combustion zone, and the chemicals are selected such that the combustion products substantially reversibly transform into the chemicals in the first equilibrium state following combustion.

2. The regenerative combustion device of claim 1, wherein the combustion zone further comprises a space at least partially bounded by at least one well packer positioned within the well.

3. The regenerative combustion device of claim 2, wherein the at least one well packer comprises a pair of well packers and the combustion zone further comprises a space at least partially bounded between the pair of well packers.

4. The regenerative combustion device of claim 3, further comprising a hose in communication with the combustion zone configured to pump at least some of the chemicals out of the combustion zone.

5. The regenerative combustion device of claim 1, wherein the combustion zone further comprises a space at least partially bounded by a gas trap positioned within the well.

6. The regenerative combustion device of claim 1, wherein the means for transforming the chemicals from the first equilibrium state to the second combustible state comprises at least one electrode disposed in contact with the aqueous solution.

7. The regenerative combustion device of claim 1, wherein the igniter comprises at least one of a spark plug, a hot wire, a plasma discharge device, a piezo-electric element, increased pressure, and shock applied to the chemical in the second combustible state.

8. The regenerative combustion device of claim 1, wherein the aqueous solution of water and an electrolyte comprises well water.

9. A regenerative seismic sound source for seismological surveys comprising:

a chamber at least partially bounded by a subterranean surface of a well and containing a liquid electrolyte and a head space;

a plurality of electrodes disposed in contact with the liquid electrolyte;

an igniter disposed in the head space; and

an electrical power source configured to provide electrical power to the electrodes so as to cause the electrolyte to form a combustible mixture within the head space and also to the igniter so as to ignite the combustible mixture within the head space and produce combustion products therefrom, the combustion products being entirely contained within the chamber, the combustible mixture being of a composition such that the combustion products substantially reversibly transform back into liquid electrolyte over time following combustion.

10. The regenerative seismic sound source of claim 9, wherein the liquid electrolyte comprises well water.

11. The regenerative seismic sound source of claim 9, wherein the combustible mixture comprises gaseous hydrogen and gaseous oxygen in the head space.

12. A system for conducting seismological surveys comprising:

a subterranean well;

a regenerative seismic sound source comprising;

a combustion zone at least partially bounded by a surface of the subterranean well;

chemicals contained within the combustion zone, having a first equilibrium state, and a second combustible state;

means for transforming the chemicals from the first equilibrium state to the second combustible state;

an igniter for igniting combustion of the chemicals in the second combustible state;

a positioning device configured to position the regenerative seismic sound source within the well;

an electrical power source coupled to the means for transforming the chemicals so as to transform the chemicals from the first equilibrium state to the second combustible state, and also coupled to the igniter to cause ignition and combustion of the combustible chemicals within the combustion zone; and

sensors for detecting seismic waves produced by the seismic sound source.

13. The system of claim 12, wherein the chemicals in the first equilibrium state comprise an aqueous solution of water and an electrolyte.

14. The system of claim 13, wherein the aqueous solution of water and an electrolyte comprises well water.

15. The system of claim 12, wherein the combustion zone is further bounded at a top portion thereof by a device comprising one of a well packer and a gas trap.

16. The system of claim 15, further comprising a conduit in communication with the combustion zone configured to provide pressurized air thereto and create a head space therein.

17. The system of claim 15, wherein the combustion zone is further bounded at a bottom portion thereof by a well packer.

18. The system of claim 17, further comprising a conduit in communication with the combustion zone configured to pump at least a portion of the chemicals out of the combustion zone.

19. A method of conducting seismological surveys, the method comprising:

positioning a regenerative combustion device at a first location within a subterranean well, wherein the combustion device has a combustion zone which is bounded at least partially by a surface of the subterranean well;

providing the regenerative combustion device with a supply of chemicals comprising aqueous solution of water and at least one electrolyte selected to produce a combustible gas having combustion products substantially transformable into the supply of the chemicals;

providing electrical current to the regenerative combustion device to cause production of a combustible gas within the combustion zone through electrolysis of at least a portion of the supply of chemicals, and to ignite the combustion of the combustible gas within the combustion zone; and

detecting seismic waves produced in the ground as a result of the combustion.

20. The method according to claim 19, wherein the positioning a regenerative combustion device within the well further comprises positioning within the well at least one additional packer below the igniter and a plurality of electrodes to further bound the combustion zone.

21. The method according to claim 20, further comprising pumping compressed air into the combustion zone so as to form a head space therein, disposing the igniter in the head space, and disposing the electrodes at least partly in water located below the packer.

22. The method according to claim 20, wherein the positioning a regenerative combustion device within the well further comprises positioning within the well at least one packer below the igniter and a plurality of electrodes to further bound the combustion zone.

23. The method according to claim 19, further comprising maintaining the regenerative combustion device within the well, providing electrical current to the regenerative combustion device a second time to regenerate the combustible gas within the combustion zone through electrolysis and igniting the regenerated combustible gas within the combustion zone.

24. The method according to claim 23, further comprising repositioning the regenerative combustion device to a second location within the well prior to the providing electrical current a second time.

25. A method of performing regenerative combustion, the method comprising:

forming a combustion chamber bounded at least in part by a subterranean surface;

disposing a liquid electrolyte within the combustion chamber;

creating a combustible mixture from at least a part of the liquid electrolyte;

igniting the combustible mixture and producing combustion products therefrom;

retaining the combustion products within the combustion chamber; and

substantially reversibly transforming the combustion products back into liquid electrolyte.

26. The method according to claim 25, wherein the disposing a liquid electrolyte comprises positioning a free water surface of a static water table within the combustion chamber.

27. The method according to claim 25, wherein the creating a combustible mixture includes creating gaseous hydrogen and gaseous oxygen.

28. The method according to claim 25, wherein the creating a combustible mixture includes subjecting the liquid electrolyte to electrolysis.

29. The method according to claim 25, wherein igniting the combustible mixture includes providing heat to the combustible mixture.

30. The method according to claim 25, wherein igniting the combustible mixture includes pressurizing the combustible mixture.