How to combat CUI in O&G operations

CUI poses a persistent challenge for O&G operators.

According to industry reports, corrosion costs the global economy an estimated $2.2 trillion annually. This issue weighs heavily on O&G maintenance budgets. Some reports show that 10% of the maintenance budget is allocated for CUI repairs. CUI risks threaten the structural integrity of critical assets and compromise operational efficiency.

Understand CUI

CUI occurs when moisture infiltrates insulation systems, creating a corrosive environment beneath the metal surface. What contributes to CUI? Cyclic temperatures, soluble salts and reduced efficiency of wet insulation exacerbate the problem. High-risk zones include operating ranges from -4°C to 175°C because of frequent thermal cycling. For pipelines and equipment exposed to these conditions, corrosion rates can double with even slight temperature increases. Unchecked CUI leads to costly repairs, operational downtime and potential environmental hazards. Proactively addressing CUI remains critical to extending the life of assets and ensuring compliance with evolving global standards.

Know coating standards

Numerous industry standards help operators assess and mitigate CUI risks. Technical documents such as API 581 and The Association of Materials Protection and Performance SP0198 provide frameworks for risk-based inspection and material selection based on environmental conditions. The international standards ISO 19277 and NORSOK M-50, developed by the Norwegian petroleum industry, outline testing methodologies to ensure coatings meet performance benchmarks under thermal, chemical and mechanical stresses. Operators who understand these coatings standards can implement best practices and minimize CUI-related incidents.

Select the right coatings

The right protective coatings play a pivotal role in mitigating CUI. Specialized coatings, including epoxies, siloxanes and multipolymeric matrices, are capable of meeting the demands of extreme operational environments. Each technology offers advantages:

• Epoxies: These are known for their durability and immersion resistance. They protect surfaces from moisture and oxygen ingress. However, the organic chemistry of these materials limits their performance at elevated temperatures.
• Siloxanes: These offer significantly greater flexibility and higher temperature resistance than epoxies. They are less effective against corrosion in ambient temperature conditions.
• Multipolymeric matrices: These coatings combine thermal stability and flexibility. They adapt well to thermal cycling and shock, making them suitable for cyclic temperature ranges. Although they may have slightly higher initial costs, they often provide superior long-term performance.

Operators must evaluate coatings based on substrate compatibility, application conditions and service temperature ranges.

Best application practices

Effective CUI mitigation extends beyond coating selection. Application processes significantly influence performance. For example, surface preparation remains critical for optimal adhesion. Also, applying coatings in controlled conditions minimizes defects like blistering or delamination. Great advances in coating technology now allow faster curing times and applications at lower temperatures for shorter turnaround cycles during maintenance, saving operators time and money. The flexibility of the application, whether by spray, brush or roller, also proves important for operators. The easy-to-apply, single-coat solution should also be compatible with multi-coat systems.

What's ahead?

CUI remains a significant challenge for the O&G industry, but modern protective strategies offer a way forward. By understanding risk factors, adhering to established standards and employing advanced coating technologies, operators can mitigate risks, extend asset lifetimes and achieve greater operational efficiency.

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