Risk Management of Subsea Pipeline Integrity and Failure Prevention

Abstract

Subsea pipelines are critical offshore infrastructures for transporting oil, gas, and produced fluids, but they are
exposed to structural degradation, environmental loading, and third-party interference that may lead to leakage or failure.
This study evaluates subsea pipeline damage risk by integrating Fault Tree Analysis (FTA), Event Tree Analysis (ETA), and
Bowtie Analysis. Risk identification classified the main hazards into pipeline structural integrity failure and third-party
interference. The FTA results show that the probability of subsea pipeline damage as the top event is 0.0297492, with pipeline
structural integrity failure contributing 0.0179766 and third-party interference contributing 0.0119882. The dominant basic
events are failure to conduct periodic inspection, corrosion, gasket failure, emergency anchoring, and severe weather
conditions. ETA was applied to assess consequence pathways after pipeline damage through six safety barriers: detection and
alarm, alarm verification and decision making, emergency shutdown and isolation, pressure and inventory control, area
control and secondary impact prevention, and emergency response, inspection, and repair. The results indicate that minor
damage with no significant fluid release has the highest probability, whereas catastrophic loss of containment has the lowest
probability but the most severe impact. Bowtie Analysis integrates the causal and consequence pathways into preventive and
mitigation controls for integrity.