Video logging system having remote power source

• US 5,140,319 A
• Filed: 06/15/1990
• Issued: 08/18/1992
• Est. Priority Date: 06/15/1990
• Status: Expired due to Term

• Current Assignee: HSBC Corporate Trustee Co. (UK) Ltd. (HSBC Holdings plc)
• Original Assignee: Westech Geophysical Incorporated
• Inventors: Riordan, Mathew B.
• Primary Examiner(s): ELDRED, JOHN W
• Application Number:
  US07/540,573
• Time in Patent Office: 795 Days
• Field of Search: 340/854, 350/96.23, 358/100, 175/40, 175/49, 166/250, 354/63
• US Class Current: 340/854.9
• CPC Class Codes: E21B 47/0025 generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric
• CPC Class Codes: E21B 47/017 Protecting measuring instruments
• CPC Class Codes: E21B 47/135 using light waves, e.g. infrared or ultraviolet waves
• CPC Class Codes: G02B 6/4416 Heterogeneous cables
• CPC Class Codes: G02B 6/4427 Pressure resistant cables, e.g. undersea cables

Abstract

An instrument probe contains a video camera and light source which is positioned in front of the camera for illuminating the passage being inspected, such as a bore or a casing. The power source for the instrument probe is located at the surface. A support cable contains an optical fiber for conducting camera signals to the surface and electrical conductors for conducting power from the surface to the instrument probe. The outer electrical conductor includes strands of copper alternating with and in electrical contact with strength member strands. The cable is enclosed in a stainless steel outer sheath. The support cable is coupled to the instrument probe by three fluid seals. The first seals the outer sheath in the probe. The second seals at the breakaway connection and the third seals at the probe bulkhead. The second and third seals include the use of adhesive caulking.

Claims

1. An inspection system for inspecting the condition of an elongated passage, comprising:

a surface unit located near the entrance to the passage comprising a controller and a power source;

an instrument probe for placement in the passage, comprising a camera for generating images of the passage and providing signals representative of those images, wherein the instrument probe comprises a bulkhead;

a support cable connected between the instrument probe and the surface unit and having an optical fiber along which the camera signals are conducted to the controller, and for conducting electrical power from the power source to the instrument probe, the support cable also comprising a strength member connected to the instrument probe, and the support cable further comprises electrical conductors and an outer sheath; and

sealing means for sealing the instrument probe against eaxternal fluids at connections of the support cable to the instrument probe wherein the sealing means comprise;

a first seal for providing a seal between the outer sheath and the instrument probe near the connection point of the support cable to the instrument probe;

a second seal for providing a seal between the instrument probe and the cable in the area of the connection of the strength member to the instrument probe; and

a third seal for providing a seal between the instrument probe and the cable at the bulkhead.

2. The inspection system of claim 1 wherein the first seal comprises a flexible ring of fluid resistant material mounted on the outer sheath near the point of entry of the support cable to the instrument probe and means for compressing the ring of material between the outer sheath and the instrument probe to form a fluid seal.

3. The inspection system of claim 2 wherein the second seal comprises a sealing tube mounted over the strength member and electrical conductors and a fluid resistant, adhesive caulking within the tube in contact with the strength member and the electrical conductors such that a fluid seal is formed in the sealing tube.

4. The inspection system of claim 3 wherein the sealing tube is placed in contact with the electrical conductors of the support cable and forms an electrical path therewith.

5. The inspection system of claim 1 wherein the third seal comprises fluid resistant, adhesive caulking placed on the support cable, a compression sheath placed over the support cable and the caulking, and a compression fitting and coupler connected to the sheath and mounted in the bulkhead.

6. The inspection system of claim 5 wherein the compression coupler comprises pipe threads which are used to mount the coupler to the bulkhead.

7. The inspection system of claim 5 wherein:

the support cable also comprises a layer of inner electrical conductors, a layer of outer electrical conductors, and the strength member comprises strength member strands, the strength member strands being in electrical contact with and alternating with the outer conductor strands in the layer;

the second seal comprises a sealing tube mounted over the strength members and electrical conductors and a fluid resistant, adhesive caulking within the tube in contact with the strength members and the electrical conductors such that a fluid seal is formed in the sealing tube; and

the inner electrical conductors of the support cable are coupled to the instrument probe after the third seal.

8. An inspection system for inspecting the condition of an elongated passage, comprising:

a surface unit located near the entrance to the passage comprising a controller and a power source;

an instrument probe for placement in the passage, comprising a camera for generating images of the passage and providing signals representative of those images;

a support cable connected between the instrument probe and the surface unit and having an optical fiber along which the camera signals are conducted to the controller, and for conducting electrical power from the power source to the instrument probe, the support cable also comprising a strength member connected to the instrument probe, wherein the strength member comprises strength member strands;

the support cable also comprises a layer of inner electrical conductors and a layer of outer electrical conductors; and

wherein the strength member strands are in electrical contact with and are alternating with the outer conductor strands in the layer; and

sealing means for sealing the instrument probe against external fluids at connections of the support cable to the instrument probe.

9. An inspection system for inspecting the condition of an elongated passage, comprising:

a surface unit located near the entrance to the passage comprising a controller and a power source;

an instrument probe for placement in the passage, comprising a camera for generating images of the passage and providing signals representative of those images;

a support cable connected between the instrument probe and the surface unit and having an optical fiber along which the camera signals are conducted to the controller, and for conducting electrical power from the power source to the instrument probe, the support cable also comprising a strength member connected to the instrument probe;

wherein the cable comprises a continuous, sealed and smooth outer metallic sheath which surrounds the strength member and the optical fiber; and

sealing means for sealing the instrument probe against external fluids at connections of the support cable to the instrument probe.

10. The inspection system of claim 9 wherein the outer sheath comprises stainless steel.

11. An inspection system for inspecting the condition of an elongated passage, comprising:

a surface unit located near the entrance to the passage comprising a controller and a power source;

an instrument probe for placement in the passage, comprising a camera for generating images of the passage and providing signals representative of those images;

a support cable connected between the instrument probe and the surface unit and having an optical fiber along which the camera signals are conducted to the controller, and for conducting electrical power from the power source to the instrument probe, the support cable also comprising a strength member connected to the instrument probe; and

wherein the support cable is connected to the instrument probe with a breakaway connection which will cause disconnection of the cable from the instrument probe upon pulling the support cable with a predetermined amount of force;

sealing means for sealing the instrument probe against external fluids at connections of the support cable to the instrument probe.

12. An inspection system for inspecting the condition of an elongated passage, comprising:

a surface unit located near the entrance to the passage comprising a controller and a power source;

an instrument probe for placement in the passage, comprising a camera for generating images of the passage and providing signals representative of those images;

a support cable connected between the instrument probe and the surface unit and having an optical fiber along which the camera signals are conducted to the controller, and having an inner electrical conductor and an outer electrical conductor for conducting electrical power from the power source to the instrument probe, the outer electrical conductor comprising strength member strands connected to the instrument probe and electrically conductive strands, the strength member strands are in electrical contact with and are alternating with the outer conductor strands;

sealing means for sealing the instrument probe against external fluids at connections of the support cable to the instrument probe.

13. The inspection system of claim 12 wherein:

the support cable comprises an outer sheath;

the instrument probe further comprises a bulkhead; and

the sealing means comprise;

a first seal for providing a seal between the outer sheath and the instrument probe near the connection point of the support cable to the instrument probe;

a second seal for providing a seal between the instrument probe and the cable in the area of the connection of the strength member to the instrument probe; and

a third seal for providing a seal between the instrument probe and the cable at the bulkhead.

14. The inspection system of claim 13 wherein the first seal comprises a flexible ring of fluid resistant material mounted on the outer sheath near the point of entry of the support cable to the instrument probe and means for compressing the ring of material between the outer sheath and the instrument probe to form a fluid seal.

15. The inspection system of claim 14 wherein the second seal comprises a sealing tube mounted over the strength member and electrical conductors and a fluid resistant, adhesive caulking within the tube in contact with the strength member and the electrical conductors such that a fluid seal is formed in the sealing tube.

16. The inspection system of claim 15 wherein the sealing tube is placed in contact with outer electrical conductors of the support cable and forms an electrical path therewith.

17. The inspection system of claim 15 wherein the third seal comprises fluid resistant, adhesive caulking placed on the support cable, a compression sheath placed over the support cable and the caulking, and a compression fitting and coupler connected to the sheath and mounted in the bulkhead.

18. The inspection system of claim 17 wherein the compression coupler comprises pipe threads which are used to mount the coupler to the bulkhead.

19. The inspection system of claim 13 wherein the inner electrical conductors of the support cable are coupled to the instrument probe after the third seal.

20. The inspection system of claim 12 wherein the support cable comprises a continuous, sealed and smooth outer sheath which surrounds the strength member and the optical fiber.

21. The inspection system of claim 20 wherein the outer sheath comprises stainless steel.

22. The inspection system of claim 12 wherein the support cable is connected to the instrument probe with a breakaway connection which will cause disconnection of the cable from the instrument probe upon pulling the support cable with a predetermined amount of force, and the second seal is formed in conjunction with the breakaway connection.

23. An inspection system for inspecting the condition of an elongated passage, comprising:

a surface unit located near the entrance to the passage comprising a controller and a power source;

a controller located near the entrance to the passage;

an instrument probe for placement in the passage, comprising a bulkhead and a camera for generating images of the passage and providing signals representative of those images;

a support cable connected between the instrument probe and the surface unit and having an optical fiber along which the camera signals are conducted to the controller, and having an inner electrical conductor and an outer electrical conductor for conducting electrical power from the power source to the instrument probe, the outer electrical conductor comprising strength member strands connected to the instrument probe and electrically conductive strands, the strength member strands are in electrical contact with and are alternating with the outer conductor strands;

sealing means comprising;

a first seal for providing a seal between the outer sheath and the instrument probe near the connection point of the support cable to the instrument probe;

a second seal for providing a seal between the instrument probe and the cable in the area of the connection of the strength member to the instrument probe; and

a third seal for providing a seal between the instrument probe and the cable at the bulkhead.

24. The inspection system of claim 23 wherein the support cable comprises a continuous, sealed and smooth outer sheath which surrounds the strength member and the optical fiber.

25. The inspection system of claim 24 wherein the outer sheath comprises stainless steel.

26. The inspection system of claim 25 wherein the support cable is connected to the instrument probe with a breakaway connection which will cause disconnection of the cable from the instrument probe upon pulling the support cable with a predetermined amount of force, and the second seal is formed in conjunction with the breakaway connection.