Risk mapping for oil–gas pipeline under mining-induced subsidence through analytical methods

Abstract Mining-induced surface subsidence often causes buried oil–gas pipelines deform, and the potential leakage risk can pose a safety hazard. In this work, a novel model for predicting the influence range of potential leakage risk from deformed pipelines was developed. First, the pipe instability deformation limit was corrected by the multi-indicator optimized screening method proposed in this paper. Then, the leakage risk influence radius of the pipe segment was defined by the failure probability. Next, the pipe segment' deformation and strength were assessed sequentially using the ratio and point methods. Combining the fuzzy logic inference method with the assessment results as input variable, and the failure probabilities as output variable, a quantitative assessment model for the pipeline leakage risk was established. Accordingly, the risk range and level of adjacent coal mines and surfaces were divided, and the verification method and forward countermeasures were proposed. Finally, an engineering case was used for analysis and verification. The results show that the gas pipeline with 650 m length was divided into seven regions and four risk levels. The influence radius of the risk levels from low to high were 12.75 m, 25.5 m, 38.25 m, and 51 m, and the influence widths on the surface were 25.28 m, 49.84 m, 76.34 m, and 101.84 m, correspondingly. The nearest distances from the risk area to the mine and village were 212.65 m and 329.08 m. The assessment of potentially threatened areas is significantly simplified by the assessment model combined with pipeline deformation, which has great practical importance for risk management and disaster prevention in adjacent space.