Apparatus and Method for Generating Sector Residence Time Images of Downhole Tools

• US 20100038137A1
• Filed: 08/12/2009
• Published: 02/18/2010
• Est. Priority Date: 08/14/2008
• Status: Active Grant

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Morris, Stephen A.
• Granted Patent: US 8,245,794 B2
• Time in Patent Office: Days
• US Class Current: 175/45
• CPC Class Codes: E21B 47/002 by visual inspection
• CPC Class Codes: E21B 47/0025 generating an image of the borehole wall using down-hole measurements, e.g. acoustic or electric

Abstract

An apparatus and method for providing images of a downhole tool during drilling of a wellbore are provided. A sensor on a rotating tool occupies a number of azimuthal sectors of the wellbore which are determined by a processor. The processor determines a time during which the sensor is in each of the azimuthal sectors during each revolution of the tool and provides a depth-correlated image of the sector residence times for the tool.

Claims

1. A method of determining a parameter relating to a downhole tool during drilling of a wellbore, comprising:

defining a plurality of sectors relating to the downhole tool;

estimating time taken by the sectors in the plurality of sectors to span the wellbore during rotation of the downhole tool in the wellbore (“

sector residence time”

); and

determining the parameter of the bottomhole assembly utilizing the sector residence times.

2. The method of claim 1, wherein the sector residence time is time taken by a sensor to span individual sectors.

3. The method of claim 1 further comprising displaying an image of the parameter as one of:

(i) a log of numbers in a suitable unit;

(ii) a log of residence sector times over depth; and

(iii) a log of residence sector times over depth showing colors corresponding to the estimated sector residence times.

4. The method of claim 2, wherein the sensor is at least one of:

(i) a gamma ray sensor; and

(ii) a nuclear sensor.

5. The method of claim 1, wherein the parameter is at least one of:

(i) stick-slip;

(ii) whirl; and

(iii) vibration.

6. The method of claim 1 further comprising displaying an image of the downhole tool relating to the parameter.

7. The method of claim 1 further comprising altering a drilling parameter for continued drilling of the wellbore based at least in part on the estimated sector residence times.

8. The method of claim 5, wherein the drilling parameter is at least one of:

(i) weight-on-bit;

(ii) drill string rotational speed;

(iii) drilling fluid flow rate through the drill string;

(iv) rotational speed of the bottomhole assembly.

9. The method of claim 1 further comprising estimating at least one of:

angular velocity of the plurality of sectors; and

rotational speed of the bottomhole assembly.

10. The method of claim 1 further comprising estimating from the sector residence times at least one of:

a smooth rotation;

a railroad rotation;

an angular fast-slow movement that does not shift with depth;

an uneven rotation; and

an uneven rotation with precession.

11. The method of claim 6, wherein the image is independent of downhole tool orientation reference.

12. An apparatus for use in a wellbore, comprising:

a downhole tool configured to be conveyed into the wellbore at an end of a drill string;

a storage device containing information about a plurality of sectors relating to the downhole tool;

a processor configured to;

estimate time taken by a sensor to span the sectors in the plurality of sectors during rotation of the downhole tool in the wellbore (“

sector residence time”

); and

provide the image corresponding to the plurality of sectors utilizing the sector residence times.

13. The apparatus of claim 12, wherein the processor is further configured to estimate the sector residence time for a particular sector in the plurality of sectors by stacking sector residence times for the particular sector measured during a plurality of revolutions of the downhole tool.

14. The apparatus of claim 12, wherein the processor is further configured to provide the image as one of:

(i) a log of numbers in a suitable unit;

(ii) a log of residence sector times over depth; and

(iii) a log of residence sector times over depth showing colors corresponding to the lengths of the sector residence times.

15. The apparatus of claim 12, wherein the sensor is at least one of:

(i) a gamma ray sensor; and

(ii) a nuclear sensor.

16. The apparatus of claim 12, wherein the processor is further configured to provide information about altering a drilling parameter based at least in part on the sector residence times for continued drilling of the wellbore.

17. The apparatus of claim 12, wherein the image corresponds to a map of the downhole tool rotation in an azimuthal orientation.

18. The apparatus of claim 12, wherein the drilling parameter is at least one of:

(i) weight-on-bit;

(ii) drill string rotational speed; and

(iii) drilling fluid flow rate through the drill string.

19. The apparatus of claim 12 wherein the processor is further configured to estimate a drill string rotation parameter from the image that is at least one of:

(i) stick slip;

(ii) whirl;

and (iii) vibration.

20. The apparatus of claim 12 wherein the processor is further configured to estimate angular velocity of the sectors from the sector residence times and the rotational speed of the downhole tool.

21. The apparatus of claim 12 wherein the processor is further configured to estimate from the image a presence of at least one of:

a smooth rotation;

a railroad rotation;

an angular fast-slow movement that does not shift with depth;

an uneven rotation; and

an uneven rotation with precession.

22. A computer-readable medium having stored thereon instructions which when used by at least one processor performs a method, the method comprising:

defining a plurality of sectors relating a downhole tool;

estimating time taken by a sensor to span each the sectors during rotation of the downhole tool in the wellbore (“

sector residence time”

); and

providing an image corresponding to the plurality of sectors utilizing the sector residence times.