CLOSED LOOP WELL TWINNING METHODS

• US 20130333946A1
• Filed: 06/15/2012
• Published: 12/19/2013
• Est. Priority Date: 06/15/2012
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Sugiura, Junichi
• Granted Patent: US 9,404,354 B2
• Time in Patent Office: Days
• US Class Current: 175/24
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 47/022 of the borehole, e.g. using geomagnetism
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003

Abstract

Closed loop methods for drilling twin wells are disclosed. The disclosed method make use of a bottom hole assembly including a rotary steerable tool. An electrical current is induced in the target well. The corresponding magnetic field about the target well is measured in the twin well and used to guide drilling of the twin well.

Claims

1. A closed loop method for drilling a twin well along a predetermined path with respect to a target well, the target well being cased with a metallic liner, the method comprising:

(a) rotary drilling the twin well using a drill string including a drill bit, a current generating tool, a rotary steerable tool, and a magnetic field sensor;

(b) inducing an electrical current in the target well liner using the current generating tool while rotary drilling in (a), said induced electrical current resulting in a magnetic field about the target well;

(c) making a plurality of magnetic field measurements using the magnetic field sensor while rotary drilling in (a);

(d) processing the plurality of magnetic field measurements made in (c) to obtain new rotary steerable tool settings; and

(e) changing a direction of rotary drilling using the new steering tool settings obtained in (d).

2. The method of claim 1, wherein the current generating tool comprises an insulating gap.

3. The method of claim 1, wherein rotary drilling in (a) comprises:

(i) circulating drilling fluid through the drill string so as to rotate the drill bit;

(ii) rotating the drill string; and

(iii) advancing the drill string into the twin well as required by a rate of penetration.

4. The method of claim 1, wherein the magnetic field sensor comprises a tri-axial magnetic field sensor.

5. The method of claim 1, wherein the processing in (d) further comprises:

(i) processing the plurality of magnetic field measurements to obtain a displacement vector;

(ii) processing the displacement vector to obtain a steering vector; and

(iii) processing the steering vector to obtain the new rotary steerable tool settings.

6. The method of claim 1, wherein (d) further comprises processing the plurality of magnetic field measurements in combination with a look-up table to obtain the new rotary steerable tool settings.

7. The method of claim 1, wherein the processing in (d) further comprises:

(i) processing the plurality of magnetic field measurements to obtain a displacement vector; and

(ii) processing the displacement vector to obtain the new rotary steerable tool settings.

8. A closed loop method for drilling a twin well along a predetermined path with respect to a target well, the target well being cased with a metallic liner, the method comprising:

(a) rotary drilling the twin well using a drill string including a drill bit, a current generating tool, a rotary steerable tool, and a magnetic field sensor;

(b) inducing an electrical current in the target well liner using the current generating tool while rotary drilling in (a), said induced electrical current resulting in a magnetic field about the target well;

(c) making at least three magnetic field measurements using the magnetic field sensor while rotary drilling in (a);

the at least three magnetic field measurements being made over a range of toolface angles greater than 180 degrees;

(d) computing an average of the at least three magnetic field measurements made in (c) to obtain an average magnetic field measurement;

(e) processing the average magnetic field measurement obtained in (d) to compute new rotary steerable tool settings; and

(f) changing a direction of rotary drilling using the new steering tool settings obtained in (e).

9. The method of claim 8, wherein the current generating tool comprises an insulating gap.

10. The method of claim 8, wherein the rotary steerable tool comprises a substantially non-rotating or slowly rotating outer blade housing, the magnetic field sensor being deployed in the outer blade housing.

11. The method of claim 8, wherein rotary drilling in (a) comprises:

(i) circulating drilling fluid through the drill string so as to rotate the drill bit;

(ii) rotating the drill string; and

(iii) advancing the drill string into the twin well as required by a rate of penetration.

12. The method of claim 8, wherein the processing in (e) further comprises:

(i) processing the average magnetic field measurement to obtain a displacement vector;

(ii) processing the displacement vector to obtain a steering vector; and

(iii) processing the steering vector to obtain the new rotary steerable tool settings.

13. The method of claim 8, wherein (d) further comprises processing the average magnetic field measurement in combination with a look-up table to obtain the new rotary steerable tool settings.

14. A closed loop method for drilling a twin well along a predetermined path with respect to a target well, the target well being cased with a metallic liner, the method comprising:

(a) rotary drilling the twin well using a drill string including a drill bit, a current generating tool, a rotary steerable tool, and a magnetic field sensor;

(b) inducing an electrical current in the target well liner using the current generating tool while rotary drilling in (a), said induced electrical current resulting in a magnetic field about the target well;

(c) making a plurality of magnetic field measurements using the magnetic field sensor while rotary drilling in (a);

(d) applying a band pass filter to the plurality of magnetic field measurements to obtain an undistorted signal component of the magnetic field measurements;

(e) processing the undistorted signal component of the magnetic field measurements to compute new rotary steerable tool settings; and

(f) changing a direction of rotary drilling using the new steering tool settings obtained in (e).

15. The method of claim 14, wherein the current generating tool comprises an insulating gap.

16. The method of claim 14, wherein rotary drilling in (a) comprises:

(i) circulating drilling fluid through the drill string so as to rotate the drill bit;

(ii) rotating the drill string; and

(iii) advancing the drill string into the twin well as required by a rate of penetration.

17. The method of claim 16, wherein the magnetic field sensor rotates with the drill string during rotary drilling.

18. The method of claim 14, wherein the processing in (e) further comprises:

(i) processing the undistorted signal component of the magnetic field measurements to obtain a displacement vector;

(ii) processing the displacement vector to obtain a steering vector; and

(iii) processing the steering vector to obtain the new rotary steerable tool settings.

19. The method of claim 14, wherein (d) further comprises processing the undistorted signal component of the magnetic field measurements in combination with a look-up table to obtain the new rotary steerable tool settings.

20. A closed loop method for drilling a twin well along a predetermined path with respect to a target well, the target well being cased with a metallic liner, the method comprising:

(a) rotary drilling the twin well using a drill string including a drill bit, a current generating tool, a rotary steerable tool, and a magnetic field sensor deployed in a roll-stabilized housing in the rotary steerable tool, said rotary drilling causing the rotary steerable tool to rotate at a first rate with respect to the borehole;

(b) rotating the roll-stabilized housing in the rotary steerable tool while rotary drilling in (a) thereby causing the magnetic field sensor to rotate at a second rate with respect to the borehole, wherein the second rate is less than the first rate;

(c) inducing an electrical current in the target well liner using the current generating tool while rotary drilling in (a), said induced electrical current resulting in a magnetic field about the target well;

(d) making a plurality of magnetic field measurements using the magnetic field sensor while rotary drilling in (a);

(e) applying a band pass filter to the plurality of magnetic field measurements to obtain an undistorted signal component of the magnetic field measurements;

(f) processing the undistorted signal component of the magnetic field measurements to compute new rotary steerable tool settings; and

(g) changing a direction of rotary drilling using the new steering tool settings obtained in (f).

21. The method of claim 20, wherein the current generating tool comprises an insulating gap.

22. The method of claim 20, wherein rotary drilling in (a) comprises:

(i) circulating drilling fluid through the drill string so as to rotate the drill bit;

(ii) rotating the drill string; and

(iii) advancing the drill string into the twin well as required by a rate of penetration.

23. The method of claim 22, wherein (b) comprises rotating the role-stabilized housing in a direction opposite to the drill string during rotary drilling.

24. The method of claim 20, wherein the processing in (e) further comprises:

(i) processing the undistorted signal component of the magnetic field measurements to obtain a displacement vector;

(ii) processing the displacement vector to obtain a steering vector; and

(iii) processing the steering vector to obtain the new rotary steerable tool settings.

25. The method of claim 20, wherein (d) further comprises processing the undistorted signal component of the magnetic field measurements in combination with a look-up table to obtain the new rotary steerable tool settings.