Compression and Pipeline Inspection Data

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Compression and Pipeline Inspection Data Wei
Ching THAMSupervisor Dr Sandra I. Woolley
Electronic, Electrical and Computer Engineering
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Overview
 
 

• My PhD (Research)
• Pipeline Inspection Data
• -Why Inspect Pipelines?
• - PIGs Pipes Cracks?
• - Pipeline Inspection Techniques
• Compression
• - Why Compress?
• - Features, Wavelet, Evaluation Tool..
• Results.. ROI vs non-ROI?

 
 
 
 
 
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My PhD (Research)
Investigate new and efficient methods for the
compression of pipeline data, so that
significantly more pipeline data can be stored on
each inspection tape.
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Why Inspect Pipelines?
 
 
 
 
 
 
 
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PIGs
 
 
Intelligent Pipeline Inspection Gauges PIGs
PIG size ranges from 12 to 56 with 2 increment
 
 
 
 
 
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Pipes Cracks?
 
 
 
 
 
Third-party damage the most common cause of
pipeline failure
 
 
 
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Pipes Cracks?
 
 
 
 
 
raw image
 
Signals from a seam weld, and a section through
the crack (62 x 100 mm long).
 
 
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Magnetic Flux Leakage vs. Transverse Field
Inspection
 
 
 
False colour images showing a comparison of
transverse field and axial over the same regions
of pipe
 
 
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Why Compress?
 
TFI Systems
Average length of pipes 300km
1 Tape 12 GB (DDS3) DAT
 
 
On board electronics unit pre-processes data and
stores it for later retrieval
 
 
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Pipeline Features
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Big defect vs small defect
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Pre-processing Taking the background off
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Contour Plot
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3- level wavelet decompositions
 
External saw cut defect (ECS1)
db9
db2
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Evaluation Tool
 
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Results
 
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Results
The results indicate improved compression whilst
preserving essential defect signatures.
Bior 9/3 ROI SPIHT may be acceptable at 0.8bpp,
i.e., a compression ratio of 201.
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Thank you!