GB2208310A

GB2208310A - Identification of pipeline sections

Info

Publication number: GB2208310A
Application number: GB8717281A
Authority: GB
Inventors: Andrew C Palmer
Original assignee: Andrew Palmer & Associates Lim
Current assignee: Andrew Palmer & Associates Lim
Priority date: 1987-07-22
Filing date: 1987-07-22
Publication date: 1989-03-22
Anticipated expiration: 2007-07-22
Also published as: NO883251D0; GB8717281D0; GB2208310B; NO883251L

Abstract

A section has a coded identification, preferably a bar code, located closely adjacent each end thereof in a location readable from the interior of the pipe section. Preferably the bar code identification is also readable from the exterior of the pipeline section, either by being applied directly to the exterior of the pipeline section or by being readable through the pipeline section as by being at least partially opaque to X-rays or the like and/or having acoustic properties different from that of the pipeline. The identification may be readable either optically or chemically in some embodiments and preferably includes details of the manufacture of the pipeline section as well as identifying the specific pipeline section.

Description

"IMPROVEMENTS IN OR RELATING TO THE IDENTIFICATION OF PIPELINE SECTIONS" A pipeline is built from several thousand lengths of pipe, typically about 12 m in length, sometimes metal and sometimes other materials such as polyethylene, glass reinforced polymer and various rubbers and plastics. The lenghts ("joints") are manufactured in pipe mills, inspected and hydrostatically tested, coated (sometimes in more than one plant), transported to the site of the pipeline, aligned, and connected end-to-end, usually but not always by welding. The welds are inspected, often by X-ray or gamma-ray radiography and by ultrasonics. The completed pipeline is hydrostatically tested, and then commissioned.During its operating life, it is inspected externally, by visual inspection and occasionally by ultrasonic re-testing of welds, and internally by measurement pigs, which pass through the pipe and measure corrosion damage and dimensional changes.

Throughout the manufacture, construction and operation of the pipeline, it is important to be able to identify the individual sections of pipe from which the pipeline was made, and to be able to trace each section back to its manufacturer. This is particularly important if a fault should occur. A lack of identification, and an inability to relate the actual joints in the pipeline to the original records, then make it more difficult to plan repairs and maintenance, and almost impossible to assign legal responsibility.

Identification of circumferential welds between pipes is equally vital. It has to be possible to record a radiograph of each weld, clearly and indisputably identified, and linked to a clear identification of the pipe sections on either side. If a radiograph is lost, or if it is uncertain which weld it refers to, it is excessively expensive and difficult to repeat the radiography. Deliberate falsification of welding records has been encountered on at least one pipeline, and only a permanent weld and pipe identification system prevents this.

The conventional system is to mark each section by painted numbers and words, on both the external and internal surfaces. The external markings are covered by the coating. The internal markings are inaccessible once the sections have been aligned. The welds are separately identified, by lead numbers temporarily attached to the outside of the line at the jonts, but no attempt is made to relate the weld numbers to the section numbers. The paint numbers cannot be read by pigs. In the case of submarine pipelines, another number is painted on the coating before the pipeline is lowered into the water: these numbers soon become illegible and covered by marine growth.

Intelligent pigs are becoming more and more widely used. If the pig discovers damage, it is often uncertain exactly where the damage is, because there is no positive identification of pig location. The location can only be established by counting welds from an end (or from an identifiable feature such as a valve), and this is unreliable and laborious.

The objective is to provide a permanent identification of each section of pipe. The identification becomes part of the record of each weld, and can be read by pigs.

According to the invention there is provided a pipeline section which has a coded identification, preferably a bar code, located near each end thereof in a location readable from the interior of the pipe section.

Preferably the bar code identification is also provided on the exterior of the pipeline section at each end thereof although in some cases it may be adequate to rely upon the interior provision of the bar code when it is formed in such a way as to be detectable from outside the pipeline, for example by being at least partially opaque to X-rays and gamma-rays, as is, in any event, preferred, and/or by having acoustic properties different from that of the pipeline so that it can be identified either from inside or through the wall of the pipeline.

Additionally, it is preferred that the bar code will have a contrasting colour, and possibly also be fluorescent, so as to be readable by an optical sensor.

Additionally, or alternatively, the code may be applied by diffusing identifiable components into the surface of the pipeline section, Each section of pipe is identified by a bar aode, located outside and inside each end, and close enough to the end so that it is within the field of the radiograph of a girth weld. The bar code is made from a coating applied to the pipe and normally will have all or some of the following properties: 1. It is partially opaque to X-rays and gamma-rays, so that it appears on any radiograph of a circumferential weld, and can be automatically read from the radiograph.

2. Its acoustic impedance and reflectivity are different from that of the pipe. This allows it to be identified through the pipe wall during external ultrasonic testing. Thus as the acoustic properties are different from those of the pipe, the code can be read acoustically by a sensor mounted on a pig travelling along the inside of the pipeline.

3. The code has a contrasting colour, and is fluorescent, so that the internally applied code can be read by an optical sensor mounted on a pig. As it can also be read externally, at any stage during manufacture, testing, inspection, coating, transport, stringing and alignment the pipe data can be tracked, recorded and checked.

4. The coating includes metallic or non-metallic chemical components which diffuse into the surface of the pipe (whether metal or polymeric), and mark it chemically The marking can then be read by chemical methods, even if the coating is accidentally or deliberately removed.

Normally, the code will include details of the pipe manufacturer, heat temperature during manufacture, material data, and a cross-reference to master records.

The coating does not significantly add to the internal roughness of the pipeline, and does not generate corrosion.

Claims

1. A pipeline section which has a coded identification located near each end thereof in a location readable from the interior of the pipe section when assembled in a pipeline.

2. A pipeline section according to claim 1, wherein the coded information is a bar code.

3. A pipeline section according to claim 1 or 2, wherein the coded identification is also provided on the exterior of the pipeline section at each end thereof.

4. A pipeline section according to any preceding claim, wherein the coded identification is so formed on the interior of the pipe section as to be detectable and identifiable from outside the pipeline.

5. A pipeline section according to claim 4, wherein the coded identification is at least partially opaque to X-rays.

6. A pipeline section according to any preceding claim, wherein the coded identification is identifiable from outside the pipeline by having acoustic properties different from that of the pipeline.

7. A pipeline section according to any preceding claim, wherein the bar code has a contrasting colour, preferably being fluorescent, so as to be readable by an optical sensor internally of the pipeline.

8. A pipeline section according to any preceding claim, wherein the coded identification is applied to the pipeline section by the diffusion of identifiable components into the surface of the pipeline section.

9. A pipeline section according to any preceding claim, wherein the coded identification is provided sufficiently close to each end of the section as to be within the field of a radiograph of a girth weld.

10. A pipeline section according to any preceding claim, wherein the coded information includes details of the manufacture of the section as well as identification of the specific pipeline section.

11. A pipeline section according to claim 1, and substantially as hereinbefore described.

12. A pipeline comprising a plurality of pipeline sections in accordance with any preceding claim with the pipeline sections being welded one to the other in series, each of the pipeline sections having individual identification code applied to both ends thereof, permitting specific identification of any particular pipeline section in the pipeline.