The UK gas distribution network consists of 265,000 km of pipelines,
which vary in size from 63mm to 1200mm diameter. The effective management
of this infrastructure demands the availability of a range of high resolution,
in-pipe, non-destructive testing (NDT) tools. These tools are used to
detect and determine the size of significant instances of metal loss
and cracks in the pipes. These results are then used to prioritise essential
pipeline replacement and maintenance programmes.
Part of the BG plc group, BG Technology, employs over 600 people and
had a turnover of 66 MEURO in 1997. The company supplies a range of
research and technical consultancy services in gas exploration, production
and transportation. BG Technology is responsible for the design, manufacture
and operation of non-destructive pipeline inspection equipment for the
low-pressure gas distribution market. Current electronic expertise applied
in these product developments includes field programmable gate array
(FGPA), microcontroller and surface-mount component technologies.
BG plc currently uses a range of in-pipe inspection vehicles, based
on magnetic sensing to revalidate its gas transmission network. These
devices are supplied by an external inspection company that services
both oil and gas undertakings world-wide, concentrating on large diameter
pipes. However existing technology prohibits the use of this type of
equipment for low pressure pipes of less than 150mm diameter and is
limited to ferrous materials.
The objective of the application experiment was to miniaturise the
current tethered in-pipe tool to allow the inspection of currently inaccessible
pipelines. This would enable pipeline inspection to take place under
live gas conditions in pipe of 100mm diameter containing bends of centre-line
radius equal to the pipe diameter (1D) and protrusions up to 15mm.
The technical objective of this application experiment was to use
Multi-Chip Modules (MCM) to reduce the size of the electronics within
the existing product, thereby reducing the overall system size.
The use of MCM technology resulted in:
- High packaging density enabling testing of smaller diameter pipes
combined with more powerful data analysis.
- Increased reliability of the electronic subsystems through a significant
reduction in interconnections and more versatile on board calibration
- Economic benefits in:
- Construction (reduced component count)
- Operation through built in programmability
- The sales area by the potential exploitation of the smaller
diameter inspection market.
The Application Experiment commenced on 1st May '98, with a planned
duration of 8 months. By the end of 1998, sample MCM sensors had been
delivered and tested. However, additional production runs were required
in order to incorporate design corrections and to provide sufficient
units for the field evaluation process to be completed. The total duration
of the experiment, including field evaluations, was 12 months.
The improved product is expected to provide a potential increase in
sales of inspection services in pipe diameters less than 150mm. Current
projections indicate that the MCM development costs of 92kEURO will
be recouped after approximately 16 months of operation. The return on
investment throughout the product life is estimated to be 490%.