Evaluation of Pipeline Integrity Using Risk Based Inspection: A Case Study of Liquefied Natural Gas Pipeline in Nigeria

This research work evaluated pipeline integrity using riskbased inspection on Liquefied Natural Gas Pipeline in Nigeria. The pipeline hazards addressed include; mechanical failure, failure due to corrosion, operational failure, third-party activity and natural hazard. Quantitative and qualitative risk analysis methods were employed to evaluate the integrity of the pipeline. Broad based results revealed that for the total risk measure in Naira at every segment for leaks, holes and ruptures, the second segment (km-2) of the proposed pipeline is poised with the highest risk at N 5,720,670/year and the seventh segment (km-7) of the proposed pipeline is poised with the lowest risk at N 426,589/year. The total risk value determined for the entire 8km pipeline is N 21,422,146/year. Based on the analyzed probability and consequences of failures, the first and seventh segments (KP1 and KP7) of the pipeline were classified as low-risk segments while pipeline segments (KP2, KP3, KP4, KP5, KP6 and KP8) were classified as medium risk segments. The total failure rates for leaks, holes and rupture in the pipeline were 2.63 x 10-4, 1.25 x 10-4 and 2.29 x 10-5/yr.km respectively. The individual risk experienced by a segment in a year was lower than 10-6/yr. ANOVA analysis performed on the risk measures at every segment for leaks, holes and rupture showed that the risk values are statistically significant as the p-value gotten was less than the 0.05 significant level. A framework that evaluates the integrity of the pipeline using risk-based inspection was established ultimately.