“NPO SPETSNEFTEGAZ” Efficient Ways of Increasing In-Line Inspection Reliability

Statistics of In-Line Inspection of GAZPROM pipelines during the last 5 years Total 77,900 km gas pipelines were inspected in “GAZPROM” JSC More than 1.5 million pipeline defects were detected 6947 stress corrosion cracking zones were located and sized

Quantitative Statistics on Types of Detected Defects

Main Disadvantages of MFL method High magnetization level Estimation of defect severity level strongly depends on pipeline defect identification

High magnetization level

Active electronic bypass (speed control) device V = 0 V = 4 m/s

High magnetization level Advantages of ordinary SNG ILI tools

High magnetization level Alternative magnetization scheme Very high friction

Disadvantages of MFL method In-line inspection of pipelines with thick walls is limited due to necessity to magnetize full pipe wall thickness up to outer pipe wall surface All new Russian pipelines including Nord-Stream pipeline are thick wall pipelines Only limited inspection is possible on almost all offshore pipelines

Comparison of ILI technologies detection of cracks with superimposed general corrosion

Photo of cracks on corrosion background

Pipeline defects identification statistics Dig verification statistics reveals real ILI tool sensitivity Latest results of MFL &TFI methods usage: –POD of cracks less than 20% p.w.t. deep is 90% –POI of cracks less than 20% p.w.t. deep is 90% –POI of shallow cracks with superimposed tiny corrosion is less than 60%

“NPO SPETSNEFTEGAZ” Advantages of EMAT In-Line Inspection

EMAT in-line inspection Pipe Coating EMA system Waves

Artificial crack signals EМАТ TFI Crack Hole Length41 mm Depth4 mm Width 0.01 mm Crack Hole

EMAT in-line inspection EМАТ TFI

EMAT in-line inspection experience

EMAT in-line inspection challenge Cracks with nearly zero opening –Detection –Identification –Sizing Thick pipe wall corrosion damage – Detection – Identification – Sizing