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Corrosion is a major cause of the loss of hermeticity in oil and gas pipelines. Corrosion defects affect the remaining life of in-service pipelines and can lead to failures, ruptures, hydrocarbon leakage, product loss, interruptions, environmental damage, economic losses, or, in the worst cases, fatalities. The existence of localized corrosion defects is a significant issue in pipeline integrity analysis, mainly because these structures are commonly buried and cover large extensions, amounting to hundreds or even thousands of miles; thus, it is difficult to size and locate all minor but possibly deep defects. Consequently, probabilistic and statistical modeling methods have been widely used to assess the integrity of corroded pipelines. Statistical modeling methods used to estimate the remaining life of the pipeline have focused on three main aspects: applications to estimate the defect depths and rates of corrosion, Bayesian applications in pipeline integrity to update the probability distribution for corrosion defects (depth, length, and spatial distribution), and pipeline reliability estimations. This paper reviews several methods proposed in the literature for these issues as well as their applications in real life. In addition, some of the present and future challenges related to preventing corrosion in the oil and gas pipeline industry are described.

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Corrosion was generated by the action of a jet impingement flow of sour brine on pipeline steel samples of X70. Flow assisted corrosion affected nature, number and peak intensity of the chemical species formed as corrosion products. Iron sulfides predominated in static and low flow rate conditions (1.1 m/s), whereas at 2.4 m/s iron oxides were mainly formed, which led to higher corrosion rates and suggested that oxides are less protective than sulfides. On inhibition, imidazoline seems to mitigate oxide formation and support sulfide formation balancing both species on steel surface. Ferrite phase in laminar pearlite was preferentially dissolved with/without inhibitor and mackinawite (FeS 2 ) was formed at every flow rate, angle with and without inhibitor. Theoretical stresses determined by computational flow dynamics for corrosion product removal showed a fair approximation to those proposed in the literature.