Influence of Applied Potential and Temperature on the Cathodic Disbondment for Offshore Structures

In the oil fields of North District in Venezuela one of the common characteristics is the high temperatures of the oil ( up to 150 °C) that have a direct impact in the performance of the pipeline´s coating. Internal and external corrosion are the common problems in the performance of these flowline systems. One of the possible solutions to mitigate the external corrosion in the pipelines is with the use of liquid epoxy resins. The main purpose of this paper is to present one possible solution to the external corrosion of the flowline system based in the use of liquid resins as a method to control external corrosion. In this study were used three different types of liquids coatings systems (A, B and C) epoxy based. For this evaluation were prepared coupons of carbon steel coated with all the organic coatings systems. Impact test, Aging test, Hollidays test, Adhesion test, Abrasion test, Scanning Electron Microscopy (SEM), EDX, EIS and CDT techniques were performed in order to classify the corrosion control properties of the coating systems. CDT results at different temperatures gradients shown that the coating system B presents best resistant properties than the systems A and C.  This results points that the organic coating B can be use as method to control external corrosion in flowlines up to 150 °C.

KEYWORDS: Organic Coating, High Temperature, Liquid resins, Cathodic Disbonding.