Pipeline corrosion

Abstract

Corrosion, including corrosion assisted cracking, has been identified as the primary mechanism resulting in failures of oil/gas pipelines. 1,2 Pipeline corrosion is a quite complex phenomenon, and the complexity arises as a result of the interaction of multiple reactions and processes occurring simultaneously, which in turn, are very specific to both the material and the environmental interaction. Particularly, the environments where the pipelines are encountered range from highly corrosive ones in upstream oil/gas gathering lines, where high contents of gases such as CO 2 and H 2 S are dissolved in multi-phased flow fluids, to mildly corrosive ones at the soil side, where coating properties and performance, cathodic protection (CP), soil properties, microbial activity, etc., affect the corrosivity of the environment. While significant efforts and advances have been made in pipeline corrosion research, there are increasing uncertainties and ignorance to the emerging corrosion phenomena. In recent years, some broadly reported pipeline incidents resulted from corrosion. 3,4 Indeed, corrosion has been a vital issue affecting the pipeline safety, energy transportation, environmental conservation, and even the national policymaking, as seen in the widely watched Keystone XL and Northern Gateway pipeline projects in North America. 5,6 This special issue of Corrosion Engineering, Science and Technology features papers on the topic of pipeline corrosion. The specific focus is to establish a forum for the dissemination and discussion of recent research advances in the pipeline corrosion area with wide-range themes, including internal corrosion, external corrosion, stress corrosion cracking (SCC), coatings and CP, inspection techniques, corrosion modeling, and AC (alternating current) corrosion. The papers included in this issue are from reputed research groups in Australia, Canada, China, Italy and the USA, respectively.The issue starts with a paper by Eckert, 7 who reviewed the nature, affecting factors, monitoring and management of internal microbiologically influenced corrosion (MIC), one of the least understood corrosion phenomena in oil/gas pipeline systems. Eckert analysed the current method on enumeration of planktonic for MIC investigation, and concluded that the method is neither representative of sessile microorganisms in biofilms nor indicative of the potential for internal MIC in oil and gas systems. Increased emphasis on understanding the interaction between biofilm and metal is suggested in order to improve current MIC management capabilities for oil and gas assets. It is anticipated that the paper provides essential guides for pipeline MIC research and management. Continuing the theme of internal corrosion, Huang et al. 8 have looked to corrosion of pipeline steel in H 2 S/CO 2 containing environments. Undoubtedly, this is also a difficult research topic, especially at a testing pressure up to 10 MPa with the co-existence of H 2 S and CO 2 in the system. They characterised the competitive formation of carbo...

Failure Analysis of API 5L Grade B Underground Crude Oil Transfer Pipe

“…Corrosion costs of the oil industry are billions of dollars a year [4]. Pipeline corrosion is a quite complex phenomenon, and the complexity arises as a result of the interaction of multiple reactions and processes occurring simultaneously, which in turn are very specific to both the material and the environmental interaction [5]. Corrosion occurs as an electrochemical reaction [6].…”

Effects of temperature and applied strain on corrosion of X80 pipeline steel in chloride solutions

“…Pipelines can experience corrosion attack both internally and externally [6]. In recent years, the authors' group has made progress to investigate the internal corrosion of pipelines made of varied grades of steel [7][8][9].…”

Understanding the electrochemical processes at the interface of cathodically protected steel pipeline and soil during anodic transients

“…Recently passivation of steel surfaces in a CP-induced high pH environment has been considered as a critical mechanism for cathodically protecting buried pipelines [6,7]. Although the corrosion rate of a buried pipeline at these 'safe' CP potentials should decrease to an acceptable level, in practice locally insufficient CP remains a major issue and it may lead to incomplete protection of a buried pipeline [8]. One major cause of locally insufficient CP is the presence of stray currents [9][10][11].…”