WO2017124194A1

WO2017124194A1 - Narrow band ultrasonic scanner for pipeline use

Info

Publication number: WO2017124194A1
Application number: PCT/CA2017/050065
Authority: WO
Inventors: Dale Rohan RAMPERSAD
Original assignee: Shawcor Ltd.
Priority date: 2016-01-21
Filing date: 2017-01-20
Publication date: 2017-07-27

Abstract

A band and an ultrasonic scanner for inspection of pipeline girth welds. The band and ultrasonic scanner are configured to orient components in a radial direction defined relative to the pipeline, reducing the footprint of the assembly.

Description

NARROW BAND ULTRASONIC SCANNER FOR PIPELINE USE

FIELD

[0001] The present disclosure is related to the field of ultrasonic girth weld inspection, in particular for oil and gas pipelines.

BACKGROUND

[0002] An oil and gas pipeline is typically made from a plurality of lengths of coated pipe joined together. The lengths of pipe are typically coated for insulation, impact resistance, water proofing, and corrosion resistance. The coating is often a quite thick layer on top of the steel pipe length. To facilitate welding the pipe lengths together, the coating ends before the steel end of the pipe, leaving a region, often about 40" wide, of exposed steel pipe, at the ends of the pipe before the coating begins. This is known as the "cutback region".

[0003] Pipe lengths are typically welded together in the field, utilizing what is called a "girth weld" - a weld around the perimeter of the steel pipe. Then the cutback region is covered or filled (or both) to provide insulation, impact resistance, water proofing, and corrosion resistance equal to the rest of the pipe coating. As can be appreciated, covering or filling the cutback region in the field is a much more expensive process than coating the pipe at the factory, and typically involves more expensive materials, but a much smaller length of pipe.

[0004] Best practices dictate that each girth weld must be inspected to ensure it meets certain quality criteria, before the cutback is filled . There are a variety of methods for girth weld inspection, but one of the most common is an ultrasonic inspection. A metal band is attached around the pipe and the ultrasonic scanner is attached to the band . The scanner rotates around the band and scans the weld . The cutback region must be wide enough to accommodate the scanner and band during the inspection. SUMMARY OF THE INVENTION

[0005] According to one aspect of the invention is provided an apparatus for external inspection of a pipeline girth weld, the apparatus comprising : a band body mountable circumferentially in the vicinity of the pipeline girth weld ; a guide rail on the band body; and a scanner frame assembly moveable along the guide rail; wherein the guide rail is configured to support the scanner frame assembly in a radial direction defined relative to the pipeline, and the scanner frame assembly and the guide rail are configured to enable mounting of an ultrasonic scanner in the radial direction.

[0006] In certain embodiments, the scanner frame assembly comprises a drive system for moving the scanner frame assembly along the guide rail, the drive system being oriented in the radial direction.

[0007] In certain embodiments, the apparatus further comprises adjustable clamps for mounting the band body to the pipeline.

[0008] In certain embodiments, the adjustable clamps are configured to enable apparatus to be adjustable to accommodate pipelines of different diameters.

[0009] In certain embodiments, the apparatus is adjustable to

accommodate pipelines having diameters in the range of about 6.625" to about 12.75".

[0010] In certain embodiments, the scanner frame assembly is further configured to enable mounting of a welder in the radial direction .

[0011] According to a further aspect of the present invention is provided an ultrasonic scanner for external inspection of a pipeline girth weld, the scanner comprising : a scanner body; and a scanner head on the scanner body, the scanner head comprising one or more ultrasonic transducers; wherein the scanner body is configured to enable mounting of the scanner to a support rail in a radial direction defined relative to the pipeline.

[0012] In certain embodiments, the scanner has a weight in the range of about 45 lbs to about 50 lbs. [0013] In certain embodiments, the scanner further comprises extruded rails for coupling to the support rail.

[0014] In certain embodiments, the scanner further comprises a spring/cam system for spring-loading the one or more ultrasonic transducers against the pipeline.

[0015] In certain embodiments, the scanner further comprises an exchangeable side rail, the side rail being exchangeable with alternative side rails of different sizes, to enable the scanner to accommodate pipelines of different diameters.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Reference will now be made, by way of example, to the

accompanying drawings which show example embodiments of the present application, and in which :

[0017] FIG. 1 is a perspective view of an example of the disclosed band with an ultrasonic scanner attached thereto;

[0018] FIG. 2 is a front plan view of the example band of FIG. 1 ;

[0019] FIG. 3 is a left plan view of the example band of FIG. 1 ;

[0020] FIG. 4 is a further left plan view of the example band of FIG. 1 ;

[0021] FIG. 5 is a top plan view of the example band of FIG. 1 ;

[0022] FIG. 6 is a perspective view of the example band of FIG. 1 mounted near a girth weld ;

[0023] FIG. 7 is a side plan view of FIG. 6;

[0024] FIG. 8 is a longitudinal cross-sectional view of FIG. 7; and

[0025] FIG. 9 is a front plan view of FIG. 6.

[0026] FIG. 10 is a perspective view of an example of the disclosed band, in isolation (without an ultrasonic scanner attached thereto);

[0027] FIG 11 is a front plan view of the example band of FIG. 10; [0028] FIG 12 is a back plan view of the example band of FIG. 10;

[0029] FIG 13 is a left side plan view of the example band of FIG. 10;

[0030] FIG 14 is a top view of a prior art band;

[0031] FIG 15 is a bottom view of the band of FIG. 14;

[0032] FIG 16 is a front view of the band of FIG 14;

[0033] FIG 17 is a left side view of the band of FIG 14;

[0034] FIG 18 is a right side view of the band of FIG 14;

[0035] FIG 19 is a left perspective view of the band of FIG 14;

[0036] FIG 20 is a right perspective view of the band of FIG 14;

[0037] FIG. 21 is a perspective view of a portion of example of an ultrasonic scanner and mounting assembly.

[0038] FIG. 22 is a perspective view of a portion of an ultrasonic scanner and mounting assembly of the present invention.

[0039] Similar reference numerals may have been used in different figures to denote similar components.

DESCRIPTION OF EXAMPLE EMBODIMENTS

[0040] In various examples, the present disclosure describes a band for support of an ultrasonic scanner, suitable for inspection of a girth weld. The band may be narrower than bands conventionally used for girth weld inspection. In various examples, the present disclosure also describes an ultrasonic scanner suitable for inspection of a girth weld . The disclosed band and disclosed ultrasonic scanner may be used together for inspection of a girth weld . The disclosed band may also be used with any other suitable ultrasonic scanner, including any suitable conventional ultrasonic scanner. Similarly, the disclosed ultrasonic scanner may be used with any other suitable band, including any suitable conventional band. [0041] At present, there is no dedicated band for ultrasonic scanners. Typically, a CRC welding band, which is designed for use with external welding machines which travel around the pipe as they make the girth weld, is used to support the ultrasonic scanner for inspection of the girth weld. The CRC bands are usually manufactured from 5" wide spring steel, rolled to a diameter 4" greater than the overall diameter of the pipe. A conventional band used to support the ultrasonic scanner is typically 4"-4.5" or wider, with a weight of about 12- 13.5 lb.

[0042] FIGS. 1-5 show different views of an example band in accordance with some of the examples disclosed herein, supporting an ultrasonic scanner. FIGS 10- 13 show the same example band, in isolation of the scanner.

[0043] The example disclosed band is narrower than the conventional band. For example, the disclosed band may be about 2.375" in thickness and may have a weight of about 16 lbs. This thinner band is still strong enough to mount the ultrasonic scanner, but the narrower width may be useful in that, the narrower the band and scanner are, the smaller the cutback region needs to be on the pipe to accommodate the band and scanner. This means that more of the pipe coating can be applied at the factory, and the filling of the cutback region in the field may be thus cheaper and/or easier, since the field coating is smaller, it will typically cure more quickly, decreasing pipe laying production times.

[0044] A challenge in making a narrower band is that the band must have sufficient structural strength to not flex or otherwise move with the weight of the mounted scanner. Any unintended movement of the band or scanner relative to the pipe may result in inaccurate scanner readings. In the present disclosure, the band may be made narrower by being oriented in a vertically standing fashion, rather than lying flat on the pipe as in conventional bands. This vertically standing orientation allows for the band to be narrower without sacrificing structural rigidity. In the present disclosure, "vertical" may be used to refer to the radial direction defined with respect to the pipe. By using the vertical orientation, the rigid ity of the band may be maintained or even increased, compared to conventional bands, while reducing the width. This configuration in the disclosed band provides sufficient structural integrity and rigidity to support the scanner without undesirable flexing or movement. Any flexing or movement of the band and scanner may result in erroneous inspection results, since inspection calculations are based on time-of-flight information from the scanner to the inspection target. Flexing of the conventional bands have been found to be of particular concern when the scanner is at positions along the band that are more susceptible to flexing due to gravity (e.g., 3 and 9 o'clock positions). We have found that an aluminum frame 1.25 inches in width, standing vertically, solid, or optionally with some lighting pockets machined out, provided ample rigidity and structural integrity for supporting a traditional ultrasonic scanner.

[0045] In the example shown, the band 100 is formed from an upper clamshell 105 and a lower clamshell 110, which may be assembled together over the pipe to form a continuous band encircling the pipe. Each of the upper and lower clamshells 105, 110 provide upper and lower guide rails 115, 120, respectively. Upper 125 and lower (not shown) gear racks are provided on the upper guide rail 115 and lower guide rail 120, respectively. When the upper and lower clamshells 105, 110 are assembled together, the upper and lower guide rails 115, 120 are continuous and similarly the upper and lower gear racks 125, (not shown) are continuous. It would be appreciated that the lower gear rack (not shown), would look and be positioned identically to the upper gear rack 125. The figures are shown without the lower gear rack in place, to show the details of the upper and lower guide rails 115, 120, and to show lighting pockets 116.

[0046] A scanner frame assembly 135 may be mounted onto on the guide rails 115, 120 and gear racks 125, 130. An ultrasonic scanner may be mounted to the scanner frame assembly 135. Both the scanner frame assembly 135 and the ultrasonic scanner may be conventional, commercially available, prior art, or they may be as described herein. A drive motor and gearbox assembly 140 serve to drive the scanner frame assembly 135 along the guide rails 115, 120 and gear racks 125, 130. By mounting the drive system vertically, the footprint of the band 100 may be reduced compared with conventional bands, as shown in Figs 14-20. [0047] The band 100 may be attached over the pipe by various clamps. In the example shown, the band 100 may include a cam action clamp 145, and three adjustable clamps 150. The cam action clamp 145 serves to lock the main body of the band together; the three adjustable clamps 150 serve to position and clamp the band on the pipe. A cam lock bug assembly 155 on the scanner frame assembly 135 serves to lock the drive wheels 157 to the band guide rails 115, 120. The adjustable clamps 150 may enable the band 100 to be mounted on pipes of various diameters (e.g., in the range of about 6.625" to about 12.75"). Different adjustable clamps 150 may be used with the band 100, to enable the band 100 to be mounted on pipes of different diameters.

Conventional bands are typically designed for use with pipes having a specific diameter, requiring multiple bands of different sizes being made available in the field. The example band 100 disclosed herein may be adjustable such that reduced number of bands 100 may be used for inspection in the field. In some examples, the band 100 may be designed to accommodate a pipe in a defined range of diameters. For example, in order to accommodate pipes having diameters ranging from 2.375" to 16", two bands 100 of different sizes may be used . This may still reduce the number of bands 100 required, as compared to conventional bands. This may help to speed up and/or reduce cost of in-field projects.

[0048] It shou ld be noted that the band 100 may help to reduce or eliminate about 9" of overhang typically found the back side of conventional bands which use conventional bug drives, due to the moving of the new drive system to the front of the narrow band.

[0049] The band, despite being thinner than conventional bands, is much more stable, and as a result provides much better ultrasonic scanner readings. Further, the disclosed band is specifically designed for the scanner rather than being a band designed for a welding machine which is used for the scanner, as in conventional bands.

[0050] The band described herein may be suitable for use with any ultrasonic scanner for inspection of a girth weld. For example, the scanner frame assembly 135 may be configured to enable mounting of any ultrasonic scanner. [0051] The band described herein may also be used for welding

applications. For example, a welder may be mounted on the band, and used with a positive drive system. The band may enable welding of pipe joints using less cutback length, while providing sufficient stability without flexing, as the welder travels at different positions on the band .

[0052] In Figures 1-9, the band is shown with an example ultrasonic scanner suitable for inspection of a girth weld, in accordance with some examples disclosed herein.

[0053] A conventional ultrasonic scanner is typically about 27" wide. When mounted to a conventional band, this results in a total width requirement of about 31". The present disclosure describes an ultrasonic scanner with a reduced size and/or weight, which may help to reduce the amount of cutback required on the pipe. In some examples, the disclosed scanner has a length of about 15", when mounted on the disclosed narrower band. The use of the new scanner with the new band thus may more than half the required width of exposed pipe around the girth weld, as compared to conventional setups.

[0054] The scanner described herein may be mounted to the scanner frame assembly 135 vertically, which may help to decreases unintended movement (e.g., flexing) when the scanner travels at certain positions about the pipe, in particular the 3, 6 and 9 o'clock positions. This may help to provide an improved signal and reduce reading error. The scanner may be mounted on a precision bearing idler wheel, on a V-groove track, enabling smooth movement of the scanner on the band.

[0055] The scanner may be smaller and lighter compared to conventional scanners (e.g., about 45-50 lbs compared to approximately 75 lbs for a conventional scanner), and therefore may be safely lifted and fastened to the band by a single operator (many companies have a weight limit of 55 lbs for one person operation).

[0056] The scanner may use any suitable scan head technology, including any suitable arrays and configurations. [0057] The PA scanner includes extruded rails to allow access to both sides of the guide rails 115, 120 of the band 100. This may enable accommodation of more inspection configurations (e.g., four inspection configurations) on one set of guide rails, compared to conventional designs (which typically allow two inspection configurations per set of guide rail). The scanner is based on a "box" design, with a bridge from back to front which eliminates scanning . By using 4 PA transducers, this eliminates the requirement for extra conventional rails, thus reducing the arc length of the scanner.

[0058] The scanner may include springs to activate the inspection sensors mounted on a center rail. The springs may bias the inspection sensors against the surface of the pipe. With this biasing, the section of the scanner supporting the sensors may be able to cam up and down to maintain contact with the pipe surface throughout the inspection process. This may also help to release the spring tension off the pipe to remove the scanner, compared to conventional scanners. Typically, conventional scanners use springs on the sensors, with the result that technicians often find it d ifficult to mount the scanner on the band since the scanner is already pre-loaded.

[0059] The disclosed scanner may use this spring loading/cam system, instead of pneumatics. Thus, the scanner does not require the use of

compressed air intakes (and the resultant hoses and compressed air source), does not require air cylinders, and does not require a compressor. The scanner thus has less moving parts, be lighter, and may be cheaper to manufacture, compared to conventional scanners.

[0060] The disclosed scanner may have reconfigured and optimized placement of components to reduce its footprint. The footprint is also reduced by mounting to the front of the narrow band (traditionally, the scanner was mounted to the back of the band), thus creating an overlap between the body of the scanner and the width of the band.

[0061] The disclosed scanner may articulate to accommodate pipes of different diameters, which may be useful since most projects typically have multiple pipe sizes. For example, the scanner may have three ranges of side rails to accommodate pipe sizes ranging from about 2.75" to 48". [0062] FIGS. 6-9 illustrate an example of how the band 100 may be mounted on for inspection of a girth weld 10 between two pipe sections 5a, 5b. In the example shown, the band 100 is mounted on pipe sections 5a, 5b having diameters of about 10.75". As illustrated in the example of FIG. 8, the use of the disclosed band 100 may enable the length of the cutback to be about 15" for each pipe section 5a, 5b. As illustrated in the example of FIG. 9, when mounted on the pipe the band 100 and scanner do not exhibit flexing, for example maintaining a substantially constant position from the pipe centerline (in this example, about 16.26" from the pipe centerline).

[0063] The embodiments of the present disclosure described above are intended to be examples only. The present disclosure may be embodied in other specific forms. Alterations, modifications and variations to the disclosure may be made without departing from the intended scope of the present disclosure. While the system, devices and processes disclosed and shown herein may comprise a specific number of elements/components, the systems, devices and assemblies could be modified to include addition or fewer of such elements/components. For example, while any of the elements/components disclosed may be referenced as being singular, the embodiments disclosed herein could be modified to include a plurality of such elements/components. Selected features from one or more of the above-described embodiments may be combined to create alternative embodiments not explicitly described . All values and sub-ranges within disclosed ranges are also disclosed. The subject matter described herein intends to cover and embrace all suitable changes in technology. All references mentioned are hereby incorporated by reference in their entirety.

Claims

1. An apparatus for external inspection of a pipeline girth weld, the apparatus comprising :

a band body mountable circumferentially in the vicinity of the pipeline girth weld;

a guide rail on the band body; and

a scanner frame assembly moveable along the guide rail;

wherein the guide rail is configured to support the scanner frame assembly in a radial direction defined relative to the pipeline, and the scanner frame assembly and the guide rail are configured to enable mounting of an ultrasonic scanner in the radial direction.

2. The apparatus of claim 1, wherein the scanner frame assembly comprises a drive system for moving the scanner frame assembly along the guide rail, the drive system being oriented in the radial direction.

3. The apparatus of claim 1, further comprising adjustable clamps for mounting the band body to the pipeline.

4. The apparatus of claim 3, wherein the adjustable clamps are configured to enable apparatus to be adjustable to accommodate pipelines of different diameters.

5. The apparatus of claim 4, wherein the apparatus is adjustable to

6. The apparatus of claim 1, wherein the scanner frame assembly is further configured to enable mounting of a welder in the radial direction .

7. An ultrasonic scanner for external inspection of a pipeline girth weld, the scanner comprising :

a scanner body; and

a scanner head on the scanner body, the scanner head comprising one or more ultrasonic transducers; wherein the scanner body is configured to enable mounting of the scanner to a support rail in a radial direction defined relative to the pipeline.

8. The scanner of claim 7, wherein the scanner has a weight in the range of about 45 lbs to about 50 lbs.

9. The scanner of claim 7, further comprising extruded rails for coupling to the support rail.

10. The scanner of claim 7, further comprising a spring/cam system for spring- loading the one or more ultrasonic transducers against the pipeline.

11. The scanner of claim 7, further comprising an exchangeable side rail, the side rail being exchangeable with alternative side rails of different sizes, to enable the scanner to accommodate pipelines of different diameters.