Apparatus and Methods for Well-Bore Proximity Measurement While Drilling

• US 20140111210A1
• Filed: 12/13/2012
• Published: 04/24/2014
• Est. Priority Date: 10/23/2012
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Fang, Sheng, Reiderman, Arcady
• Granted Patent: US 9,151,150 B2
• Time in Patent Office: Days
• US Class Current: 324/346
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: G01V 3/26 operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device with electromagnetic waves G01V3/30
• CPC Class Codes: G01V 3/28 using induction coils
• CPC Class Codes: G01V 3/32 operating with electron or nuclear magnetic resonance

Abstract

In one aspect an apparatus for determining a distance between a first borehole and a second borehole during drilling of the second borehole is disclosed that in one embodiment includes a magnet on a drilling tool that rotates in the second borehole to induce a primary magnetic field in a magnetic object in the first borehole, a substantially stationary sensor on the drilling tool that detects a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field, and a controller that determines the distance between the first borehole and the second borehole from the detected magnetic field. In another aspect a method of determining a distance between a first borehole and a second borehole, the in one embodiment includes inducing a primary magnetic field in a magnetic object in the first borehole using a rotating magnet in the second borehole, detecting a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field using a substantially stationary sensor in the second borehole, and determining the distance between the first borehole and the second borehole from the detected magnetic field.

Claims

1. A method of determining a distance between a first borehole and a second borehole, the method comprising:

inducing a primary magnetic field in a magnetic object in the first borehole using a rotating magnet in the second borehole;

detecting a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field using a substantially stationary sensor in the second borehole; and

determining the distance between the first borehole and the second borehole from the detected magnetic field.

2. The method of claim 1 further comprising determining an orientation of the second borehole relative to the first borehole using the detected magnetic field.

3. The method of claim 1 further comprising providing a bucking magnet between the rotating magnet and the substantially stationary sensor to reduce an effect of direct magnetic field from the rotating magnet on the substantially stationary sensor.

4. The method of claim 1, wherein the sensor is selected from a group consisting of:

a magnetometer; and

a coil.

5. The method of claim 1, wherein the sensor includes a plurality of sensors placed circumferentially spaced apart on a drilling tool in the second borehole.

6. The method of claim 1, wherein the sensor or magnet is detachably placed around a drilling tool.

7. The method of claim 1 further comprising rotating the rotating magnet at a plurality of rotational angles.

8. The method of claim 1 further comprising drilling the second borehole relative to the first borehole using the determined distance.

9. An apparatus for determining a distance between a first borehole and a second borehole during drilling of the second borehole, comprising:

a magnet on a drilling tool that rotates in the second borehole to induce a primary magnetic field in a magnetic object in the first borehole;

a substantially stationary sensor on the drilling tool that detects a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field; and

a controller that determines the distance between the first borehole and the second borehole from the detected magnetic field.

10. The apparatus of claim 9, wherein the controller determines an orientation of the second borehole relative to the first borehole using the detected magnetic field.

11. The apparatus of claim 9 further comprising a bucking magnet between the rotating magnet and the substantially stationary sensor that reduces an effect of direct magnetic field from the rotating magnet on the substantially stationary sensor.

12. The apparatus of claim 9, wherein the sensor is selected from a group consisting of:

a magnetometer; and

a coil.

13. The apparatus of claim 9, wherein the sensor includes a plurality of sensors placed circumferentially spaced apart on the drilling tool.

14. The apparatus of claim 9, wherein one of the sensor and the magnet is detachably placed around a drilling tool.

15. The apparatus of claim 9, wherein the magnet is configured to rotate at a plurality of rotational angles.

16. The apparatus claim 9 further comprising an additional sensor placed spaced apart from the sensor for detecting the secondary magnetic field from the magnetic object responsive to the induced primary magnetic field and wherein the controller:

determines the distance between the first borehole and the second borehole from the magnetic field detected by the additional sensor; and

determines an orientation of the second borehole with respect to the first borehole from the distances determined from the magnetic fields detected by the sensor and the additional sensor.

17. A method of determining a distance between a first borehole and a second borehole, the method comprising:

inducing a primary magnetic field in a magnetic object in the first borehole using a magnet in the second borehole rotating at a first rotational speed;

detecting a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field using a magnetometer in the second borehole rotating at same rotational seed; and

determining the distance between the first borehole and the second borehole from the detected magnetic field.

18. An apparatus for determining a distance between a first borehole and a second borehole, the method comprising:

a drilling tool having a magnet configured to rotate at a first rotating speed for inducing a primary magnetic field from the second borehole into a magnetic object in the first borehole;

a sensor on the drilling tool rotating at a second rotating speed for detecting a secondary magnetic field from the magnetic object responsive to the induced primary magnetic field, wherein the first rotational speed and second rotational speed are different; and

a controller that determines the distance between the first borehole and the second borehole from the detected magnetic field.

19. The apparatus of claim 18, wherein the sensor is selected from a group consisting of a:

magnetometer and coil.

20. The apparatus of claim 18, wherein the sensor includes a plurality of circumferentially spaced apart sensors on the drilling tool.

21. The apparatus of claim 18, wherein one of the magnet and the sensor is detachably placed on the drilling tool.