Investigating Crude Oil Pipeline Incidents in Southeastern Türkiye: Causes, Consequences, and the Environmental Cost Analysis

Crude oil is a critical energy resource and is predominantly transported by pipeline, which is widely regarded as the safest mode of transport. Nevertheless, pipeline incidents persist and pose risks to infrastructure, public health, and the environment. These incidents are influenced by multiple interacting factors, making it difficult to assess both their causes and consequences in a consistent risk framework. In this study, we analyzed 192 crude oil pipeline incidents that occurred between 2019 and 2024 in southeastern Türkiye, with a focus on causal factors, background factors, and consequence severity. External interference (43%) and corrosion (39%) were identified as the dominant causes of incidents, while illegal tapping and internal corrosion emerged as the most frequent sub-causes. Although fires and explosions were rare (2% of incidents), environmental contamination occurred in 86.5% of cases. Statistical analysis indicated that incident costs varied significantly by causal factor (Kruskal–Wallis, p = 0.0001). In multivariate analysis, pipe material emerged as the strongest independent predictor of high-cost incidents, with fiberglass pipelines associated with substantially higher odds of high-cost incidents than carbon steel (OR = 3.6, p < 0.05), while corrosion and external interference showed comparable cost (OR = 1.58, p > 0.05). These findings demonstrate that incident consequences are not randomly distributed, but are strongly associated with failure mechanisms and design characteristics. By linking causal factors to consequence severity, this study supports the integration of cause-dependent consequence metrics into pipeline risk assessment and integrity management, and provides empirical insights relevant to crude oil pipeline networks operating under similar conditions.