Risk Assessment and Management Framework for Pipeline Corrosion Monitoring in the Trans-Niger Pipeline System, Rivers State

Pipeline corrosion management in the Trans-Niger Pipeline system, which traverses ecologically sensitive and conflict-affected communities in Rivers State, requires a rigorous and systematic risk-based approach to prevent catastrophic failures with environmental and social consequences. This study develops a risk assessment and management framework for internal and external corrosion monitoring in the Trans-Niger Pipeline, applicable to the operational context of the NNPC Pipelines and Products Marketing Company. The framework integrates quantitative risk assessment principles from AS/NZS 4360 with pipeline integrity management requirements of ASME B31.8S. Risk matrices are constructed for internal corrosion attributable to CO2-containing wet gas streams and external corrosion associated with soil aggressiveness and stray current interference in the Port Harcourt operational area. Inspection data from inline inspection runs conducted in 2019 and 2022 using magnetic flux leakage tools are analysed to establish corrosion growth rate distributions. Feature exceedance probability calculations identify the pipeline segments presenting the highest residual life risk. A risk-ranked inspection schedule is derived using probability of detection functions for the inspection technologies applied. The study further incorporates a consequence assessment module that quantifies financial and environmental impact of failure scenarios at high-consequence locations crossing water crossings and community zones. Recommendations include increased pig launcher and receiver access installation at strategic intervals to facilitate more frequent inline inspection. Keywords: pipeline corrosion, risk assessment, Trans-Niger Pipeline, inline inspection, Rivers State.