PLASMA SOURCE FOR GENERATING NONLINEAR, WIDE-BAND, PERIODIC, DIRECTED, ELASTIC OSCILLATIONS AND A SYSTEM AND METHOD FOR STIMULATING WELLS, DEPOSITS AND BOREHOLES USING THE PLASMA SOURCE

• US 20140027110A1
• Filed: 07/25/2013
• Published: 01/30/2014
• Est. Priority Date: 07/27/2012
• Status: Active Grant

• Current Assignee: Novas Energy Services LLC
• Original Assignee: Novas Energy Group Limited
• Inventors: Ageev, P. G., Molchanov, A. A.
• Granted Patent: US 9,181,788 B2
• Time in Patent Office: Days
• US Class Current: 166/249
• 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 43/11 Perforators; Permeators
• CPC Class Codes: E21B 43/24 using heat, e.g. steam injection
• CPC Class Codes: E21B 43/25 Methods for stimulating production by vibrating earth formations E21B43/003
• CPC Class Codes: H05H 1/247 using discharges in liquid media
• CPC Class Codes: H05H 1/52 using exploding wires or spark gaps H05H1/26 takes precedence; spark gaps in general H01T

Abstract

A plasma source for generating nonlinear, wide-band, periodic, directed, elastic oscillations in a fluid medium. The plasma source includes a plasma emitter having two electrodes defining a gap, a delivery device for introducing a metal conductor into the gap, and a high voltage transformer for powering the plasma emitter. A system and method for stimulating wells, deposits, and boreholes through controlled periodic oscillations generated using the plasma source. The system includes the plasma source, a ground control unit, and a support cable. In the method, the plasma source is submerged in the fluid medium of a well, deposit, or borehole and is used to create a metallic plasma in the gap. The metallic plasma emits a pressure pulse and shockwaves, which are directed into the fluid medium. Nonlinear, wide-band, periodic and elastic oscillations are generated in the fluid medium, including resonant oscillations by passage of the shockwaves.

Claims

1. A plasma source for generating nonlinear, wide-band, periodic, directed, elastic oscillations, comprising:

a plasma emitter having a first electrode and a second electrode, the electrodes defining an electrode gap, wherein the plasma emitter has a plurality of metal stands disposed adjacent to the electrode gap and uniformly spaced about a perimeter of the plasma emitter;

an enclosure housing attached to a distal end of the plasma emitter, the enclosure housing containing a delivery device configured so as to introduce a metal conductor through an axial opening in the second electrode into the electrode gap; and

a device housing attached to a proximal end of the plasma emitter, the device housing containing a high voltage transformer electrically connected to a capacitor unit, the capacitor unit electrically connected to a contactor, and the contactor electrically connected to the first electrode.

2. The plasma source of claim 1, wherein an emitter opening exists between each pair of the plurality of metal stands.

3. The plasma source of claim 2, wherein the plurality of metal stands comprises three metal stands, each metal stand having an apex angle oriented toward the electrode gap, said apex angle of each metal stand being equal and measuring between ten degrees and sixty degrees.

4. The plasma source of claim 3, wherein the apex angle of the metal stands measures forty-eight degrees.

5. The plasma source of claim 1, wherein the first electrode is a high voltage electrode and is coated or fusion bonded with a high melting point, refractory metal or alloy.

6. The plasma source of claim 1, wherein the first electrode is electrically insulated from the plasma emitter and the second electrode is electrically grounded to the plasma emitter.

7. The plasma source of claim 1, wherein a distal end of the enclosure housing is shaped as a cone, a tapered cone, a convex cone, a projective cone, a twisted cone, or a pyramid.

8. The plasma source of claim 1, wherein the distal end of the enclosure housing has straight, round or spiral surface channels.

9. The plasma source of claim 1, wherein the enclosure housing is sealed and contains a dielectric compensation liquid.

10. The plasma source of claim 1, wherein the metal conductor comprises a pure or homogenous, metal or metal alloy, electroconductive material or composite.

11. The plasma source of claim 1, wherein the device housing is sealed and contains a dielectric liquid.

12. The plasma source of claim 1, the device housing further containing electronic and relay blocks electrically connected between the transformer and capacitor unit, wherein the electronic and relay blocks control electrical signals passing through the capacitor, contactor, and first electrode.

13. The plasma source of claim 1, wherein the capacitor unit comprises a Rogovsky coil in an electric discharge circuit.

14. The plasma source of claim 1, wherein proximal and distal ends of the plasma emitter have a conical or hyperbolic shape.

15. A system for stimulating wells and deposits through controlled, periodic oscillations, comprising:

a plasma source according to claim 1;

a support cable having a fixed end physically connected to a mobile station and a remote end physically and electrically connected to the plasma source, the support cable configured such that the remote end may be deployed into a well or deposit; and

a ground control unit mounted on the mobile station and electrically connected to the fixed end of the support cable, wherein the ground control unit has a recording block configured to record and store data about the oscillations.

16. The system for stimulating wells and deposits of claim 15, further comprising a discharge interlock in the ground control unit, the discharge interlock in electronic communication with the delivery device, capacitor, contactor, and first electrode, wherein the discharge interlock is configurable so as to either allow or prevent a discharge of controlled, periodic oscillations from the plasma emitter.

17. A method for stimulating wells, deposits and boreholes through controlled oscillations, comprising the steps of:

providing a plasma source according to claim 1;

submerging the plasma source in a fluid medium in a well, deposit or borehole;

creating a metallic plasma in the electrode gap through an explosion of the metal conductor;

emitting a shockwave from the metallic plasma in the electrode gap;

directing the shockwave from the metallic plasma into the fluid medium; and

generating nonlinear, wide-band, periodic and elastic oscillations in the fluid medium by passage of the directed shockwave.

18. The method of claim 17, further comprising the step of repeating the creating, emitting and directing steps approximately every 50-55 microseconds.

19. The method of claim 17, wherein the nonlinear, wide-band, periodic and elastic oscillations have a frequency ranging from 1 Hz to 20 kHz.

20. The method of claim 17, further comprising the step of performing the inventive method in combination with agent-assisted fracturing, hydro-slotted perforation, or heating through chemical or biological agents.

21. The method of claim 17, wherein the generating step includes forming resonance oscillations in the fluid medium of the well, deposit or borehole.

22. The method of claim 17, further comprising the step of repeating the method through multiple, consecutive applications of the directed shockwave at various frequencies and/or at different locations within the well, deposit or borehole.

23. The method of claim 17, wherein the nonlinear, wide-band, periodic and elastic oscillations have a short pulse of approximately fifty to fifty-five microseconds and propagate through the fluid medium at low velocities.

24. The method of claim 17, wherein the well, deposit or borehole comprises a vertical well, an inclined well, a well having a changeable direction, a directional well without horizontal completion, a production well, a mature well, a depleted well, a land well, an onshore or offshore well, an open hole, an injection well, a carbon dioxide injection well, a waste disposal well, a conservation well, or any man-made or natural earth opening.

25. The method of claim 17, further comprising the step of excluding the use of chemicals that are harmful to humans or the environment.