Auto-extending/retracting electrically isolated conductors in a segmented drill string

• US 7,028,779 B2
• Filed: 12/16/2004
• Issued: 04/18/2006
• Est. Priority Date: 05/24/1999
• Status: Expired due to Term

• Current Assignee: Digital Control Incorporated
• Original Assignee: Merlin Technologies Incorporated
• Inventors: Chau, Albert W.
• Primary Examiner(s): NEUDER, WILLIAM P
• Application Number:
  US11/014,430
• Publication Number:
  US 20050098356A1
• Time in Patent Office: 488 Days
• Field of Search: 166/380, 166/65.1, 175/320, 439/557, 439/578
• US Class Current: 166/380
• CPC Class Codes: E21B 17/003 with electrically conducting or insulating means E21B17/028 and E21B17/023 take precedence
• CPC Class Codes: E21B 17/0285 characterised by electrically insulating elements
• CPC Class Codes: E21B 47/0232 at least one of the energy sources or one of the detectors being located on or above the ground surface
• CPC Class Codes: E21B 47/024 of devices in the borehole determining slope or direction of the borehole E21B47/022
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003
• CPC Class Codes: H01R 13/533 Bases, cases made for use in extreme conditions, e.g. high temperature, radiation, vibration, corrosive environment, pressure H01R13/52 takes precedence

Abstract

A system includes a drill string made up of a plurality of connectable pipe sections. An assembly is provided for use with each pipe section including contact arrangement for forming an isolated electrical connection between attached pipe sections at each end of each pipe section. An electrically conductive arrangement is located in the innermost passage of each pipe section and is in electrical communication with the contact arrangement to extend therebetween in a way which provides an electrically conductive path that is arranged against the inner wall of the innermost passage of each pipe section in cooperation with the contact arrangement to form an overall electrically isolated conductive path through the drill string. The electrically conductive arrangement resiliently biases the electrically conductive path against the inner wall, which path may take the form of a helix.

Claims

1. In a system including a drill string having a length which is configured for extension and/or retraction, said drill string being made up of a plurality of pipe sections having opposing first and second ends and a section length having an inner wall defining an innermost passage and all of which pipe sections are configured for removable attachment with one another by physically connecting the first end of one pipe section with the second end of another pipe section to facilitate extension of the drill string by at least one section length at a time, an assembly for use with each one of the pipe sections, said assembly comprising:

an electrical contacting arrangement for forming an isolated electrical connection between attached ones of the pipe sections and located within the innermost passage at each opposing end of each pipe section; and

an electrical conductor located in the innermost passage of each pipe section and in electrical communication with said electrical contacting arrangement at each opposing end of each pipe section to extend therebetween in a way which provides an electrically conductive path that is arranged against the inner wall of the innermost passage of each pipe section and which electrically conductive path cooperates with the electrical contacting arrangement to form an overall electrically isolated conductive path through the drill string.

2. The assembly of claim 1 wherein said electrical contacting arrangement includes a pair of adapters for installation of a first one of the adapters in a first end of the innermost passage of each one of said pipe sections and installation of a second one of the adapters in a second end of the innermost passage of each one of the pipe sections, said first and second adapters being configured for establishing said isolated electrical connection between attached ones of the pipe sections.

3. The assembly of claim 1 wherein the electrical conductor is resiliently biased against the inner wall.

4. The assembly of claim 3 wherein said electrically conductive path at least generally forms a helix that is biased against the inner wall and said helix having opposing helix ends that are electrically attached to the electrical contacting arrangement at opposing ends of each pipe section.

5. The assembly of claim 1 wherein said electrical conductor is a coil spring having a coiled length that is extended along the innermost passage of each pipe section and having opposing spring ends that are electrically attached to the electrical contacting arrangement at the opposing ends of each pipe section and said coiled length is configured to resiliently bias against the inner wall of the innermost passage.

6. The assembly of claim 5 wherein said innermost passage includes a passage diameter and wherein said coiled length, prior to insertion into the innermost passage, includes an outer diameter that is greater than the passage diameter of the innermost passage.

7. The assembly of claim 6 wherein said coiled length includes a cylindrical outline defining said outer diameter.

8. The assembly of claim 5 wherein said coil spring is a helical coil spring.

9. The assembly of claim 5 wherein said coil spring includes an outermost electrical insulating layer.

10. The assembly of claim 5 wherein said coil spring includes a base wire, having an electrical resistance, coated with a lower resistance layer.

11. The assembly of claim 10 wherein said lower resistance layer is a copper cladding.

12. The assembly of claim 11 including an electrically insulating jacket covering said copper cladding.

13. The assembly of claim 5 wherein said coil spring includes a base wire that is generally circular in cross-section.

14. The assembly of claim 5 wherein said coil spring includes a base wire that is generally rectangular in cross-section.

15. The assembly of claim 5 wherein said coil spring includes a base wire having a pair of opposing major surfaces.

16. The assembly of claim 1 wherein the electrical conductor is electrically insulated extending between the electrical contacting arrangement at opposing ends of each pipe section and said assembly includes a support arrangement which supports the insulated electrical conductor proximate to the inner wall.

17. The assembly of claim 16 wherein the support arrangement is configured for resiliently supporting the electrical conductor proximate to the inner wall.

18. The assembly of claim 17 wherein the support arrangement includes a helical coil spring for supporting the electrical conductor along a helical path proximate to the inner wall.