Offshore carbon capture, utilization and storage (CCUS) can be coupled with offshore energy resources, but it also adds a harsh marine environment to the carbon dioxide (CO 2 )-transport problem. In a review in the KeAi's Journal of Pipeline Science and Engineering , a team of researchers from China described the recent progress on corrosion and anti-corrosion measures for supercritical offshore CO 2 pipelines, and organize the offshore CO 2 pipeline corrosion problem into a practical engineering map. This map focuses on four areas: (1) external corrosion driven by the marine environment, (2) internal corrosion driven by CO 2 -water-impurity chemistry and operating conditions, then (3) prediction models and standards, and finally (4) mitigation options and research priorities for safer deployment.
Unlike onshore pipelines, offshore pipelines face combined stressors such as seawater exposure and erosion, hydrostatic pressure, and microbiologically influenced corrosion (MIC). The review notes that offshore pipelines are often installed on or buried in seabed mud, where low oxygen and rich microbial communities can strongly influence corrosion behavior; seawater pH and salinity, plus flow-induced scouring, further shape degradation risk. Thus, in this condition, corrosion is not just an engineering nuisance, but also a leading contributor to CO 2 pipeline failure risk.
The review separates corrosion in offshore supercritical CO 2 pipelines into external and internal processes, then links them to prediction needs, standards, and mitigation. Notably, external corrosion depends strongly on marine exposure conditions across atmospheric, splash, tidal, immersion, and mud zones, with microbiologically influenced corrosion highlighted as a major offshore driver and scouring by currents accelerating damage by removing protective films and enhancing mass transfer.
Meanwhile, internal corrosion is governed by operating pressure-temperature conditions, water availability, and multi-impurity chemistry in CO 2 streams, with seawater cooling and phase transitions potentially promoting precipitation and free-water formation; the review also reiterates that water is the enabling condition for corrosion in supercritical CO 2 systems.
For engineering control, the authors stressed that multiple impurities can change mechanisms and undermine existing models. Further, there is an absent of a unified international CO 2 pipeline fluid-quality standard. Mitigation is framed as matching measures to drivers, using internal coatings and inhibitors alongside external coatings and cathodic protection, and calling for durable, non-toxic antifouling and coating solutions suitable for offshore deployment.
In the paper's own words, the review “identifies significant challenges...such as understanding corrosion mechanisms of CO 2 with multiple impurities...and developing corrosion inhibitors and new non-toxic antifouling coatings.”
Looking ahead, the authors propose research priorities including international standards, improved understanding of multi-species biofilm interactions in MIC, better thermodynamic models for CO 2 -water-impurity systems, and more durable coatings/inhibitors suitable for high-pressure offshore conditions.
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Contact the author: Yuxing Li, Shandong Key Laboratory of Oil & Gas Storage and Transportation Safety, China University of Petroleum (East China), Qingdao, Shandong 266580, China. E-mail address: liyx@upc.edu.cn
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Journal of Pipeline Science and Engineering
Literature review
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A critical review on corrosion challenges and prospects in supercritical offshore CO₂ pipelines
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.