Proposal for Integration of DC Basis Technologies with Macro Tool Approach to Assess Active-Corrosion Sites in Buried Pipelines

Oil and gas pipelines systems deliver different high value commodities, most of these systems existed in buried conditions. Coating as one of the control solutions for protection against “corrosion” is applied to the pipeline to ensure a protective physical barrier layer. The cathodic protection reinforces external protection of the metallic structures. The chemical aggressiveness of the environment surrounding the metallic structures and the corrosion susceptibility is difficult to assess by using isolated methods/approaches or survey techniques. The use of DC basis technologies, such as DCVG and CIS characterize the state of the coating and the CP respectively, the unification with the fundamentals of the corrosion process can lead to maximize the outcome of the assessment of external corrosion. However, the complexity of the buried conditions required the unification of tools, fundamentals and theoretical modeling to maximize the control, mitigation and selection of inspection tools. In this work the integration of DC basis indirect surveys, DC theoretical modeling and electrochemical mechanistic analysis are used to increase the certainty of the external corrosion assessment of a buried 12” steel pipeline with coal tar enamel and impressed current as corrosion control methods.