Transmitting power within a wellbore

Patent metadata

Field	Value
Publication number	US-9316063-B2
Application number	US-201314110915-A
Country	US
Kind code	B2
Filing date	Mar 14, 2013
Priority date	Nov 29, 2012
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

A system for applying power into a wellbore. The system can include a casing, a tubing string, a first and second isolator sub, a power source, and an electrical device. The casing has a first cavity running therethrough. The tubing string is disposed within the first cavity without contacting the casing, where the tubing string has a second cavity running therethrough. The first isolator sub is mechanically coupled to the tubing string and positioned between the neutral section and the power-transmitting section of the tubing string. The power source is electrically coupled to the power-transmitting section of the tubing string below the first isolator sub. The second isolator sub is mechanically coupled to the tubing string and positioned between the bottom neutral section and the power-transmitting section of the tubing string. The electrical device is electrically coupled to a bottom end of the power-transmitting section of the tubing string.

First claim

We claim:

1. A system for applying power into a wellbore within a subterranean formation, the system comprising:
a tubing string comprising a plurality of electrically conductive tubing pipes mechanically coupled end-to-end, wherein the tubing string comprises a top neutral section positioned proximate to an entry point of the wellbore and a power-transmitting section positioned below the top neutral section in the wellbore, and wherein the tubing string has a first cavity running therethrough;
a first isolator sub mechanically coupled to and positioned between the neutral section and the power-transmitting section of the tubing string, wherein the first isolator sub has the first cavity running therethrough, wherein the first isolator sub electrically separates the top neutral section from the power-transmitting section, and wherein the first isolator sub is configured to isolate direct current (DC) power and alternating current (AC) power from the top neutral section;
a second isolator sub mechanically coupled to the tubing string, wherein the tubing string further comprises a bottom neutral section positioned toward a distal end of the wellbore, wherein the second isolator sub is positioned between the bottom neutral section and the power-transmitting section of the tubing string, wherein the second isolator sub has the first cavity running therethrough, wherein the second isolator sub electrically separates the bottom neutral section from the power-transmitting section, and wherein the second isolator sub is configured to isolate the DC power and the AC power from the bottom neutral section;
a power source positioned above the entry point and electrically coupled to a top end of the power-transmitting section of the tubing string below the first isolator sub; and
an electrical device disposed within the wellbore and electrically coupled to the power-transmitting section of the tubing string above the second isolator sub.

2. The system of claim 1 , further comprising:
a power conditioner electrically coupled between the power-transmitting section of the tubing string and the electrical device, wherein the power conditioner converts the power generated by the power source to conditioned power suitable for consumption by the electrical device.

3. The system of claim 2 , wherein the power generated by the power source is single-phase AC power, and wherein the conditioned power is three-phase AC power.

4. The system of claim 1 , wherein the electrical device, when operating, delivers a product through the first cavity beyond the entry point.

5. The system of claim 1 , wherein the first isolator sub comprises material that can withstand temperatures above 600° F.

6. The system of claim 1 , wherein the first isolator sub is impervious to fluids and gases.

7. The system of claim 1 , wherein the first isolator sub comprises an insulator disposed within a shell of the first isolator sub, wherein the shell comprises electrically conductive material, and wherein the insulator comprises electrically non-conductive material and has a second cavity running therethrough.

8. The system of claim 7 , wherein the shell is mechanically coupled to the top neutral section of the tubing string, and wherein the shell is mechanically isolated from the power-transmitting section of the tubing string.

9. The system of claim 7 , wherein the insulating material comprises at least one selected from a group consisting of a ceramic material and a polymer.

10. The system of claim 1 , wherein the electrical device is, at least in part, electrically coupled to the power-transmitting section of the tubing string using a cable capable of transmitting a high current density.

11. The system of claim 1 , further comprising:
a casing disposed within the wellbore and comprising a plurality of electrically conductive casing pipes mechanically coupled end-to-end, wherein the casing has a second cavity running therethrough, wherein the tubing string is disposed within the second cavity without contacting the casing.

12. The system of claim 11 , further comprising:
a conductive interface disposed below the second isolator sub within the second cavity, wherein the conductive interface electrically couples the casing and the tubing string.

13. The system of claim 12 , wherein the conductive interface comprises at least one selected from a group consisting of a packer, an anchor assembly, and a seal.

14. The system of claim 11 , wherein the casing is an electrical ground for an electric circuit that comprises power generated by the power source.

15. The system of claim 11 , wherein the power source is further electrically coupled to the casing.

16. The system of claim 11 , further comprising:
a plurality of centralizers disposed inside the second cavity between the power-transmitting section of the tubing string and an inner wall of the casing, wherein the plurality of centralizers are made of an electrically non-conductive material.

17. The system of claim 1 , wherein the first isolator sub mechanically supports a weight in excess of 100,000 pounds, wherein the weight is comprised of the power-transmitting section of the tubing string, the bottom neutral section of the tubing string, and the second isolator sub.

18. An isolator sub disposed in a first cavity between casing walls in a wellbore of a subterranean formation, the isolator sub comprising:
an outer case comprising an electrically conductive material, a first aperture that traverses a top end of the outer case, and a second aperture that traverses a bottom end of the outer case;
an inner wall disposed within the outer case and forming a second cavity therethrough, wherein the second cavity is bounded by the first aperture and the second aperture, wherein the inner wall is mechanically coupled to a neutral portion of a tubing string adjacent to the top end of the outer case and to a power-transmitting portion of the tubing string adjacent to the bottom end of the outer case; and
an insulating material disposed between the outer case and the inner wall, wherein the insulating material is electrically nonconductive,
wherein the insulating material surrounds a portion of the power-transmitting portion of the tubing string,
wherein the power-transmitting portion of the tubing string is electrically coupled to a power source and is disposed between the casing walls in the wellbore,
wherein the outer case is configured to couple to the neutral portion of the tubing string at the first aperture, and
wherein the second aperture of the outer case avoids contact with the tubing string.

19. An isolator sub disposed in a first cavity between casing walls in a wellbore of a subterranean formation, the isolator sub comprising:
an outer case comprising an electrically conductive material, a first aperture that traverses a bottom end of the outer case, and a second aperture that traverses a top end of the outer case;
an inner wall disposed within the outer case and forming a second cavity therethrough, wherein the second cavity is bounded by the first aperture and the second aperture, wherein the inner wall is mechanically coupled to a neutral portion of a tubing string adjacent to the bottom end of the outer case and to a power-transmitting portion of the tubing string adjacent to the top end of the outer case; and
an insulating material disposed between the outer case and the inner wall, wherein the insulating material is electrically nonconductive,
wherein the insulating material surrounds a portion of the power-transmit

Assignees

• Gonzalez Manuel Eduardo
• Thompson Melvin Clark
• Archuleta Jacobo
• Rodriguez Patrick
• Beck David William
• Ellis Scot
• Ogg Wade
• Chevron Usa Inc

Inventors

• Gonzalez Manuel Eduardo
• Thompson Melvin Clark
• Archuleta Jacobo
• Rodriguez Patrick
• Beck David William
• Ellis Scot
• Ogg Wade

Classifications

• E21B43/128

  Adaptation of pump systems with down-hole electric drives · CPC title

• E21B17/0285 Primary

  characterised by electrically insulating elements · CPC title

• E21B17/028

  Electrical or electro-magnetic connections · CPC title

• E21B17/003 Primary

  with electrically conducting or insulating means (E21B17/028 and E21B17/023 take precedence) · CPC title