Citation

Bao J, Zhou W. Struct. Saf. 2021; 91: e102095.

Copyright

(Copyright © 2021, Elsevier Publishing)

DOI

10.1016/j.strusafe.2021.102095

PMID

unavailable

Abstract

This paper proposes a random field model to characterize the corrosion depth on the external surface of buried steel oil and gas pipelines. The model addresses the intermingling of corroded and corrosion-free areas on the pipe surface, similar to the spatial intermittency of rainfall accumulation within a geographic area, by using a latent homogeneous Gaussian random field and a spatial position-dependent threshold associated with the latent Gaussian field. High-resolution corrosion measurement data obtained from corroded pipe segments removed from in-service pipelines are used to estimate parameters of the proposed model, including the probability of corrosion at a given point, marginal distribution of the nonzero corrosion depth and correlation structure of the latent Gaussian field. The results indicate that the nonzero corrosion depth follows a shifted lognormal distribution. The isotropic -exponential correlation function is adequate to characterize the correlation structure of the latent Gaussian field with the correlation length varying from 17 to 50 mm and from 0.69 to 0.82. A comparison of simulated and measured corrosion fields suggests that the proposed model is able to capture the characteristics of naturally-occurring corrosion field on the pipe surface. The proposed model provides a useful tool for developing fitness-for-service assessment methodologies for corroded pipelines. copyright 2021 Elsevier

Language: en

Keywords

Pipeline corrosion; Pipelines; Steel corrosion; Corrosive effects; Underground corrosion; Gaussian distribution