Imaging underground objects using spatial sampling customization

• US 9,739,133 B2
• Filed: 03/15/2013
• Issued: 08/22/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Vermeer Corporation
• Original Assignee: Vermeer Corporation
• Inventors: Haddad, Waleed Sami, Hanson, David
• Primary Examiner(s): Toatley, Gregory J
• Assistant Examiner(s): Ishizuka, Yoshihisa
• Application Number:
  US13/836,045
• Publication Number:
  US 20140262509A1
• Time in Patent Office: 1,621 Days
• Field of Search: 702 9, 175 27, 175 24, 75 27, 75 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 44/02 Automatic control of the tool feed E21B44/005, E21B44/10 take precedence
• CPC Class Codes: G01V 3/18 specially adapted for well-logging

Abstract

A system includes a drill string to which a sensor is attached, a rotation unit configured to rotate the drill string, and a displacement unit configured to longitudinally displace the drill string. A processor is coupled to the rotation and displacement units. The processor is configured to coordinate sampling, by the sensor, of three-dimensional space surrounding the sensor while rotating and displacing the drill string. The processor is further configured to coordinate adjusting of at least one of drill string rotation and drill string displacement so that acceptable spatial sampling of the space surrounding the sensor is achieved.

Claims

1. A method, comprising:

rotating a drill string to which a sensor is attached, the sensor having a maximum sampling capability;

displacing the drill string along a bore path;

sampling, using the sensor, a three-dimensional space surrounding the sensor while rotating and displacing the drill string; and

adjusting at least one of drill string rotation and drill string displacement so that the maximum sampling capability of the sensor is not exceeded and at least a minimum angular sampling rate is achieved;

wherein adjusting at least one of the drill string rotation and the drill string displacement is based on a relationship between drill string rotation rate and drill string linear displacement rate given by;

2. The method of claim 1, wherein adjusting comprises decreasing at least one of drill string rotation and drill string displacement.

3. The method of claim 1, wherein adjusting comprises increasing at least one of drill string rotation and drill string displacement.

4. The method of claim 1, wherein adjusting comprises limiting at least one of drill string rotation and drill string displacement.

5. The method of claim 1, further comprising:

setting the drill string rotation at a desired rate; and

adjusting a rate of the drill string displacement so that the maximum sampling capability of the sensor is not exceeded and at least the minimum angular sampling rate is achieved.

6. The method of claim 1, further comprising:

setting the drill string displacement at a desired rate; and

adjusting a rate of the drill string rotation so that the maximum sampling capability of the sensor is not exceeded and at least the minimum angular sampling rate is achieved.

7. The method of claim 1, wherein the sampling of the space surrounding the sensor is based on:

a time required to acquire a sample by the sensor;

the maximum longitudinal step size, S_max; and

a maximum angular sampling rate for the sensor.

8. The method of claim 1, comprising:

setting the drill string rotation to a desired rate;

calculating the number of sensor samples that can be collected based on a time required to acquire a sample by the sensor;

calculating the maximum longitudinal step size, S_max; and

calculating a minimum number of angular samples.

9. The method of claim 1, wherein sampling the three-dimensional space surrounding the sensor comprises sampling a plurality of angular segments at regular angular positions on every rotation of the drill string.

10. The method of claim 9, wherein:

the sampling of the space surrounding the sensor is based at least on the maximum longitudinal step size, S_max; and

a plurality of samples, N_a, for each angular segment per rotation are separated from each other along an axis of the drill string by S_max/N_a.

11. The method of claim 9, wherein:

the sampling of the space surrounding the sensor is based at least on the maximum longitudinal step size, S_max;

the maximum longitudinal step size, S_max, is subdivided so that each angular segment is sampled within every maximum longitudinal step size, S_max; and

the samples for each angular segment are spaced by one maximum longitudinal step size, S_max, along an axis of the drill string.

12. The method of claim 1, wherein the sampling by the sensor facilitates detection of a subsurface object prior to a collision between the object and the drill string.

13. The method of claim 1, wherein the rotating and displacing of the drill string are implemented by a Horizontal Directional Drilling machine.

14. A system, comprising:

a drill string to which a sensor is attached, the sensor having a maximum sampling capability;

a rotation unit configured to rotate the drill string;

a displacement unit configured to longitudinally displace the drill string; and

a processor coupled to the rotation and displacement units and the sensor, the processor being configured to control sampling, by the sensor, of three-dimensional space surrounding the sensor and further configured to adjust at least one of drill string rotation and drill string displacement so that the-maximum sampling capability of the sensor is not exceeded and at least a minimum angular sampling rate is achieved;

wherein the processor is configured to;

coordinate sampling a plurality of angular segments at regular angular positions on every rotation of the drill string; and

sample the space surrounding the sensor based at least on a maximum longitudinal step size, S_max, along the bore path direction; and

a plurality of samples, N_a, for each angular segment per rotation are separated from each other along an axis of the drill string by S_max/N_a.

15. The system of claim 14, wherein the processor is configured to execute interlock logic that causes the processor to limit at least one of the drill string rotation and the drill string displacement so that the maximum sampling capability of the sensor is not exceeded and at least the minimum angular sampling rate is achieved.

16. The system of claim 14, wherein the processor, in response to setting the drill string rotation at a desired rate, is configured to adjust a rate of the drill string displacement so that the maximum sampling capability of the sensor is not exceeded and at least the minimum angular sampling rate is achieved.

17. The system of claim 14, wherein the processor, in response to setting the drill string displacement at a desired rate, is configured to adjust a rate of the drill string rotation so that the maximum sampling capability of the sensor is not exceeded and at least the minimum angular sampling rate is achieved.

18. The system of claim 14, wherein the processor, in response to setting the drill string rotation at a desired rate, is configured to:

calculate the number of sensor samples that can be collected based on a time required to acquire a sample by the sensor;

calculate the maximum longitudinal step size, S_max; and

calculate a minimum number of angular samples necessary to achieve at least the minimum angular sampling rate.

19. The system of claim 14, wherein the processor is configured to sample the space surrounding the sensor based on:

a time required to acquire a sample by the sensor;

the maximum longitudinal step size, S_max; and

a maximum angular sampling rate for the sensor.

20. The system of claim 14, wherein:

the processor is configured to sample the space surrounding the sensor based at least on the maximum longitudinal step size, S_max;

the maximum longitudinal step size, S_max, is subdivided so that each angular segment is sampled within every maximum longitudinal step size, S_max; and

the samples for each angular segment are spaced by one maximum longitudinal step size, S_max, along an axis of the drill string.

21. The system of claim 14, wherein the processor is configured to control a drill string rotation rate and a drill string linear displacement rate based on a relationship given by:

22. The system of claim 14, wherein the sensor comprises a ground penetrating radar.

23. The system of claim 14, wherein the sampling by the sensor facilitates detection of a subsurface object prior to a collision between the object and the drill string.

24. The system of claim 14, wherein the rotation unit and the displacement unit are integral to a Horizontal Directional Drilling machine.

25. A method, comprising:

rotating a drill string to which a sensor is attached;

displacing the drill string along a bore path;

sampling, using the sensor, three-dimensional space surrounding the sensor based on a predetermined relationship between a rate of drill string rotation and rate of linear displacement of the drill string, wherein the sampling of the space surrounding the sensor comprises sampling a plurality of angular segments at regular angular positions on every rotation of the drill string; and

adjusting at least one of drill string rotation and drill string displacement during the sampling of the space surrounding the sensor;

wherein;

sampling of the space surrounding the sensor is based at least on a maximum longitudinal step size, S_max, along the bore path direction; and

a plurality of samples, N_a, for each angular segment per rotation are separated from each other along an axis of the drill string by S_max/N_a.

26. A system, comprising:

a drill string to which a sensor is attached;

a rotation unit configured to rotate the drill string;

a displacement unit configured to longitudinally displace the drill string; and

a processor coupled to the rotation and displacement units and configured to control sampling by the sensor based on a predetermined relationship between a rate of drill string rotation and a rate of linear displacement of the drill string, the processor further configured to coordinate;

sampling, by the sensor, of a three-dimensional space surrounding the sensor while rotating and displacing the drill string;

adjusting at least one of the drill string rotation and the drill string displacement during sampling of the space surrounding the sensor; and

sampling a plurality of angular segments at regular angular positions on every rotation of the drill string;

wherein;

the processor is configured to sample the space surrounding the sensor based at least on a maximum longitudinal step size, S_max, along the bore path direction; and

a plurality of samples, N_a , for each angular segment per rotation are separated from each other along an axis of the drill string by S_max/N_a.