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Ultrasonic mechanised devices for internal pipeline inspection

Development of self-contained devices to inspect the inside
of pipelines designed for the transportation of liquid with
the purpose of detecting wall defects such as corrosion and
cracks.

The worldwide increasing number of ageing pipelines for the transport of hydrocarbons requires regular inspection to establish their integrity. The existence and use of inspection tools will have a positive effect on the environment, safety and economy. To establish the condition of a pipeline usually an on-line inspection tool, the so-called "intelligent pig" can be used. Such a self-contained tool propelled by the flowing medium in the pipe carries a number of sensors which measure the condition of the pipe wall. The results, which are stored in an on-board memory of the inspection can be retrieved at the end of an inspection run for data elaboration, interpretation and presentation (graphic and alphanumeric). The inspection technique and type of selected sensor is dictated by the kind of anomaly to be detected. Commonly, the Magnetic Stray Flux principle is applied to detect metal loss. Several parameters such as material properties and purity, wall thickness, surface condition, deposits, tool speed, medium in the pipes, etc. Tools using the magnetic stray flux principle are extremely good for the detection of metal loss, but usually cannot cope with all the mentioned parameters and are considered insufficiently quantitative. For this reason, it is often necessary (particularly for offshore lines) to verify results obtained with flux pigs with more accurate techniques. As practice proved, the ultrasonic technique is very suitable to quantify metal loss. Moreover, the ultrasonic method is much more suitable to detect cracks than the magnetic flux method. At present, only a few attempts to construct the needed ultrasonic tools are known. Pipeline operators cannot freely select inspection services from the commercial market, this is an unwanted situation. Hence, there is an increasing demand for accurate metal loss and crack detection tools for the inspection of pipelines which have been in operation for many years. Such inspections provide the data to determine their structural integrity, remaining lifetime and/or necessity for reconditioning. The aim of the project is the development of self-contained tools to inspect from the inside of pipelines designed for the transport of liquid, with the purpose of detecting corrosion, cracks and gouges. For pipelines transporting liquids, improved ultrasonic sensors should be used. For gas pipelines, conventional sensors cannot work and "dry" sensors (not requiring a liquid as acoustic coupling medium) are necessary. Hence, the project also aims to develop "dry" sensors which can be implemented in intelligent pigs to operate in gas pipelines for the detection of corrosion and cracks. The development of the project requires the implementation of advanced techniques for mechanical and electronic miniaturization of the detection system and the device for pre-possessing and storage of data. Particularly, in the case of the "dry" sensor system for gas pipelines, it involv es the development and the design of instrumentation and transducers suitable for use in "dry" circumstances. Data elaboration and advanced techniques to identify defects must also be developed. It is envisaged to carry out the project in three stages: Phase 1: - preparation of detailed project definition, project organisation, planning, technical resources, financial resources, marketing resources, marketing prospects, commercial partners, contractual matters, etc. Phase 2: - design and construction of two inspection tools for liquid pipelines where the innovative part relates to the electronics for detection, pre-processing and data reduction/storage - to be implemented with existing inspection tool technologies. One tool for metal loss detection and sizing and the other for crack detection. The tools will be tested on loops before being validated during field tests. Phase 3: - development of "dry" sensor system suitable for the detection of metal loss and cracks in gas pipelines. In the event of positive results, the dry sensors will be the base for continuation of Phase 3 which involves the construction of the actual inspection tools. The construction of an intelligent pig for gas pipelines inspection provided with "dry" sensors suitable for metal loss and crack detection. The tool will be tested on loops before being validated during field tests.
Acronym: 
DUMIP
Project ID: 
419
Start date: 
01-06-1990
Project Duration: 
66months
Project costs: 
18 250 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.