Abstract

Iron carbonate (FeCO3) is a common corrosion product found on steel surfaces in carbon dioxide (CO2)-containing aqueous environments. The formation of this corrosion product on the internal walls of carbon steel pipelines can suppress material dissolution by over an order of magnitude, providing an effective form of corrosion inhibition. One significant limitation associated with relying upon solely FeCO3 to suppress material dissolution is its propensity to be locally removed by chemical or mechanical mechanisms. Here we report a novel strategy, implemented to generate a mineral-polymer nanocomposite layer in situ on an X65 steel surface in a CO2 corrosion environment. The formation of the layer is achieved through the intercalation of functionalized polystyrene nanospheres into the developing FeCO3 corrosion product. We demonstrate the feasibility of microsphere intercalation into the FeCO3 crystal layer through appropriate functionalization. Such intercalation produces a composite structure that affords excellent corrosion protection analogous to ‘natural’ FeCO3. Additionally, the composite FeCO3 layer offers unique, enhanced physical-mechanical properties compared with naturally formed FeCO3 layer. The process provides a potential means of improving the resistance of corrosion product layers to mechanical removal, and hence, the initiation of localized corrosion.

Introduction

Hydrocarbons still remain as a fundamental contributor towards meeting the worldwide demand for energy, despite the growth of other alternative sources such as renewable and nuclear options.1 Due to low cost and availability, carbon steel, remains as the most commonly used material for pipelines in down and upstream activities within the oil and gas industry.2 However, carbon steel is not an exceptional metal alloy from the perspective of internal corrosion resistance. The economical cost for its degradation and related failures represent 10% to 30% of the maintenance budget in petroleum industry.3 It is therefore crucial that the corrosion of such a susceptible steel is managed and controlled accordingly.

Approximately, half of pipeline failures are attributed to either carbon dioxide (CO2), so called ‘sweet’ corrosion, or hydrogen sulfide (H2S), known as ‘sour’ corrosion.4 Controlling corrosion is an expensive protocol based on various strategies proposed by materials and/or corrosion engineers, for instance: modification of materials or solutions5–10, coatings11,12, corrosion inhibitors13,14 and improvements of operations15. Among the aforementioned strategies, arguably the most efficient and certified method to control corrosion is using corrosion inhibitors owing to the general cost and returns on investments.2

This content is only available via PDF.
You can access this article if you purchase or spend a download.