Correlation of IMU Bending Strain Features to Geohazard Locations: An Update

Abstract This paper presents an update to the results of Theriault et al. (2020) on the correlation of single-run IMU bending strain features to geohazard locations. Theriault et al. reviewed over 4,600 IMU-identified bending strain features from a single pipeline operator located in a variety of geographic settings and concluded that while the overall correlation between ILI vendor bending strain features and geohazards is low, higher maximum magnitude and in particular, higher horizontal magnitude, as reported by the ILI vendors, are strongly correlative to geohazard occurrence. Based on the review of over 17,000 bending strain features for this paper, similar results were observed to Theriault et al., but with lower correlation percentages at higher magnitudes. While the overall conclusions support the prior work by Theriault et al., the results of this analysis suggest that the conclusions of Theriault et al. may have been skewed by a relatively small sample size, particularly at higher magnitudes, and that while the overall correlation between high maximum magnitude and horizontal magnitude and geohazards is strong, geohazards are not the only sources of such conditions. As more data are collected and analyzed, a better representation of the correlation between ILI vendor-reported IMU bending strain features, geohazard occurrence, and other causes can be established. The paper provides further discussion and analysis of the correlation with individual geohazard types, the relative prevalence of reported IMU bending strain features by magnitude, and where multiple IMU runs have been performed, the correlation between reported strain change features and geohazards.