Apparatus and method for locating tool joint

1. A method for locating a tubular feature, comprising:

capturing a first two dimensional image of a tubular;

projecting two laser marks on to the tubular;

capturing a second two dimensional image of the tubular including a reference, wherein the reference includes the two laser marks;

identifying a tubular joint or stick-up of the tubular from the first or second two dimensional image; and

determining a vertical position of the tubular joint or stick-up of the tubular using the reference.

2. The method of claim 1 , wherein projecting two laser marks comprises:

projecting two laser marks at different locations along a longitudinal axis of the tubular.

3. The method of claim 2 , further comprising comparing the first and second images to detect locations of the two laser marks in the second image.

4. The method of claim 1 , wherein identifying the tubular joint or stick-up comprises:

identifying the tubular by detecting parallel vertical lines in the first or second two dimensional image; and

selecting a region of interest in the first or second two dimensional image according to the identified tubular.

5. The method of claim 4 , wherein identifying the tubular joint or stick-up further comprising:

identifying the tubular joint or stick-up by detecting horizontal lines in the region of interest.

6. The method of claim 5 , wherein identifying the tubular joint or stick-up further comprises reducing the region of interest prior to identifying the tubular joint or stick-up.

7. The method of claim 6 , wherein reducing the region of interest comprises:

identifying a shoulder feature in each tubular associated with the tubular joint or stick-up; and

reducing the region of interest according to the identified shoulder feature(s).

8. The method of claim 1 , further comprising aligning a tong assembly with the tubular joint or stick-up according to the determined vertical position.

9. The method of claim 1 , wherein each laser mark includes two or more colors.

10. A method of locating a tubular joint, comprising:

capturing a two dimensional image including a tubular segment wherein a first tubular is connected to a second tubular by a tubular joint;

identifying edges of the tubular segment from the two dimensional image by detecting parallel lines along an axis of the tubular segment;

identifying a first feature in the first tubular and a second feature in the second tubular;

defining a region of interest in the two dimensional image, wherein the region of interest is defined between the edges of the tubular segment and between the first feature and the second feature; and

identifying the tubular joint within the region of interest.

11. The method of claim 10 , further comprising cropping the two dimensional image according to the identified edges of the tubular segment.

12. The method of claim 11 , wherein identifying a first feature in the first tubular and a second feature in the second tubular comprises:

scanning the cropped image along a plurality of horizontal levels for edge points;

creating a contiguous tubular segment using the edge points in each horizontal level;

merging contiguous tubular segments having the same width to form tubular segments; and

compare widths of the tubular segments for the first feature and the second feature.

13. The method of claim 11 , wherein identifying a first feature in the first tubular and a second feature in the second tubular comprises:

creating templates for the first and second features; and

moving the templates within the cropped image to merge the templates with the cropped image.

14. The method of claim 10 , wherein the first feature of the first tubular is a shoulder feature in the first tubular and the second feature of the second tubular is a shoulder feature of the second tubular.

15. The method of claim 10 , further comprising:

projecting two laser marks at known locations on the tubular segment and capturing a second two dimensional image of the tubular segment with the laser marks; and

determining an actual position of the tubular joint using the two laser marks as reference.

16. The method of claim 10 , wherein identifying the tubular joint within the region of interest comprises detecting horizontal lines within the region of interest.

17. A system for locating a tubular joint on a rig floor, comprising:

a first laser positioned to project a first marker onto a tubular structure;

a second laser positioned to project a second marker onto the tubular structure, wherein a distance between the first marker and the second marker is known;

a camera positioned to capture two dimensional images of the tubular structure of a region including the first and second markers; and

a controller connected to the first laser, second laser, and the camera.

18. The system of claim 17 , wherein the first laser, the second laser and the camera are fixedly positioned relative to the rig floor.

19. The system of claim 18 , wherein the controller is configured to compare a first two dimensional image of the tubular structure without any markers to a second two dimensional image of the tubular structure with the first and second markers to detect locations of the first and second markers in the second two dimensional image.

20. The system of claim 17 , wherein the first laser, the second laser, and the camera are attached to a tong assembly positioned on the rig floor, and the controller is configured to move the tong assembly.

21. A method for locating a tubular feature, comprising:

capturing a first two dimensional image of a tubular;

capturing a second two dimensional image of the tubular including a reference;

identifying a tubular joint or stick-up of the tubular from the first or second two dimensional image by detecting parallel vertical lines in the first or second two dimensional image; and

selecting a region of interest in the first or second two dimensional image according to the identified tubular; and

determining a vertical position of the tubular joint or stick-up of the tubular using the reference.

22. The method of claim 21 , wherein identifying the tubular joint or stick-up further comprising:

identifying the tubular joint or stick-up by detecting horizontal lines in the region of interest.