Offshore hydrocarbon pipelines are subject to complex internal and external corrosion mechanisms, yet integrity management remains largely reactive due to the fragmentation of high-resolution inspection data across multiple non-destructive testing (NDT) methods. Intelligent pigging (ILI), subsea ultrasonic thickness measurements, cathodic protection (CP) surveys, ROV visual inspections, and production chemistry analyses each generate detailed but isolated evidence of degradation, preventing operators from constructing a unified, forward-looking threat picture. This data-silo problem routinely leads to missed threats, inefficient resource allocation, and elevated risk of catastrophic failure. This research introduces the Predictive Corrosion Threat Index (PCTI), a novel, quantitative, and spatially explicit composite metric designed to overcome these limitations. The PCTI integrates multi-source NDT and operational data through a weighted-sum algorithm comprising an Internal Corrosion Score (ICS), External Corrosion Score (ECS), and Trend Severity Score (TSS). Inputs are spatially aligned to a common kilometre-post reference, normalised, and fused using weights calibrated against 173 confirmed corrosion-driven interventions across a 1,840 km fleet of 42 deepwater and shallow-water flowlines and export trunks in West Africa and the Gulf of Mexico.Retrospective validation and blind prospective testing demonstrated that the PCTI captures 94 % of actual failures within the top 100 ranked segments (versus 61–72 % for traditional ILI-only or semi-quantitative matrix methods) while flagging only 8–10 % of total pipeline length for heightened scrutiny. Segments exhibiting accelerating external corrosion beneath disbonded coatings—previously ranked low by ILI severity alone—were correctly elevated to top-tier urgency up to 15–36 months in advance. Predictive performance metrics on hold-out data yielded sensitivity of 0.94, specificity of 0.98, and AUC-ROC of 0.987.The PCTI transforms offshore pipeline integrity management from a fragmented, schedule-driven activity into a genuinely proactive, risk-prioritised discipline. By delivering diagnostic threat breakdowns and accurate forward projections, it enables precise repair scoping, dynamic optimisation of inspection intervals, and substantial capital savings. Implemented as an automated dashboard tool, the PCTI establishes a scalable blueprint for digitalised, data-driven integrity programmes that simultaneously enhance safety, environmental protection, and operational efficiency
Keywords: Cathodic protection surveys, Corrosion growth prediction, Data-driven integrity management, Deepwater flowlines, In-line inspection (ILI), Multi-source NDT data fusion, Offshore pipeline integrity, Predictive Corrosion Threat Index (PCTI), Proactive threat prioritization, Risk-based inspection
