INDICATING SYSTEM FOR A DOWNHOLE APPARATUS AND A METHOD FOR LOCATING A DOWNHOLE APPARATUS

• US 20130002255A1
• Filed: 06/30/2011
• Published: 01/03/2013
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Shampine, Rod
• Granted Patent: US 9,116,016 B2
• Time in Patent Office: Days
• US Class Current: 324/326
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01D 5/2515 with magnetically controlled switches, e.g. by movement of a magnet
• CPC Class Codes: G01V 11/002 Details, e.g. power supply systems for logging instruments, transmitting or recording data, specially adapted for well logging, also if the prospecting method is irrelevant means for transmitting well survey signals E21B47/12; signal transmission systems in general G08C; transmission in general H04B

Abstract

A system for locating a downhole apparatus comprises a wellbore having an interior pressure cavity, wherein the apparatus is disposed in the pressure cavity, a magnetic device for generating a magnetic field in the pressure cavity, and a magnetic field indicator disposed external to the pressure cavity, the magnetic field indicator responsive to the magnetic field in the pressure cavity, wherein the magnetic field is indicative of a position of the apparatus in the pressure cavity.

Claims

1. A system for locating a downhole apparatus, the system comprising:

a wellbore having an interior pressure cavity, wherein the apparatus is disposed in the pressure cavity;

a magnetic device for generating a magnetic field in the pressure cavity; and

a magnetic field indicator disposed external to the pressure cavity, the magnetic field indicator responsive to the magnetic field in the pressure cavity, wherein the magnetic field is indicative of a position of the apparatus in the pressure cavity.

2. The system according to claim 1, further comprising a pressure barrier disposed in the wellbore and defining the interior pressure cavity.

3. The system according to claim 2, wherein the pressure barrier is formed from a magnetic material.

4. The system according to claim 2, wherein the pressure barrier is formed from a non-magnetic material.

5. The system according to claim 2, wherein the magnetic device is disposed external to the pressure cavity and generates the magnetic field through a wall of the pressure barrier.

6. The system according to claim 2, wherein the magnetic device comprises an inductive coil disposed external to the pressure cavity and generates the magnetic field through a wall of the pressure barrier.

7. The system according to claim 2, further comprising a permeable structure disposed adjacent the magnetic device and at least a portion of the pressure barrier, wherein the magnetic field is directed through at least a portion of the permeable structure

8. The system according to claim 1, wherein the magnetic device is coupled to the apparatus.

9. The system according to claim 1, further comprising a permeable structure disposed adjacent the magnetic device, wherein the magnetic field is directed through at least a portion of the permeable structure.

10. The system according to claim 1, wherein the magnetic field indicator comprises at least one indicator visible external to the pressure cavity.

11. The system according to claim 1, wherein the magnetic field indicator comprises at least one of a passive magnetic field detector, a Hall effect sensor, a magnetoresistance sensor, and a fluxgate magnetometer.

12. The system according to claim 1, wherein the magnetic field indicator comprises a reed relay that is automatically actuated in response to a predetermined magnitude of the magnetic field.

13. The system according to claim 1, wherein the magnetic device is disposed in the pressure cavity and in electrical communication with the magnetic field indicator to sense a change in the magnetic field generated by the magnetic device.

14. A method for locating a downhole apparatus, comprising:

generating a magnetic field in an interior pressure cavity of a wellbore;

passing the apparatus through the pressure cavity of the wellbore; and

monitoring at least one of a presence and a magnitude of the magnetic field, wherein the at least one of the presence and the magnitude of the magnetic field is indicative of a location of the apparatus in the pressure cavity.

15. The method according to claim 14, wherein a magnetic device is coupled to the apparatus to generate the magnetic field.

16. The method according to claim 14, wherein a magnetic device is disposed external to the pressure cavity to generate the magnetic field extending into the pressure cavity.

17. A method for locating a downhole apparatus disposed in a pressure cavity of a wellbore, the wellbore including a pressure barrier defining the pressure cavity, the method comprising the steps of:

generating a magnetic field in the pressure cavity of the wellbore, the magnetic field extending through the pressure barrier;

passing the apparatus through the pressure cavity of the wellbore; and

monitoring at least one of a presence and a magnitude of the magnetic field adjacent a pre-determined section of the pressure barrier, wherein the at least one of the presence and the magnitude of the magnetic field is indicative of a location of the apparatus in the pressure cavity.

18. The method according to claim 17, wherein the pressure barrier is formed from a magnetic material.

19. The method according to claim 17, wherein the pressure barrier is formed from a non-magnetic material.

20. The method according to claim 17, wherein the step of monitoring at least one of the presence and the magnitude of the magnetic field adjacent a pre-determined section of the pressure barrier is executed by a toggling of a reed relay.