Efficient Ways of Increasing InLine Inspection Reliability NPO

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

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

High magnetization level

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 shallow cracks with superimposed tiny corrosion is less than 60%

Advantages of EMAT In-Line Inspection “NPO SPETSNEFTEGAZ”

EMAT in-line inspection Pipe Coating Waves EMA system

Artificial crack signals TFI Length 41 mm Depth 4 mm Width 0. 01 mm Hole Crack EМАТ Hole Crack

EMAT in-line inspection TFI EМАТ

EMAT in-line inspection experience

EMAT in-line inspection experience

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