Cost Effective Anti-Corrosion Strategies for Replacing Corrosion-Resistant Alloys CRA in CCUS Injection Wells
Authors: Zhao L. , Ren J. X. , Dunne T. , Li J. Y. , Cheng P. , Qi C. Y. 
Published: April 2024

It is widely acknowledged that Carbon Capture, Utilization, and Storage (CCUS) constitutes an indispensable component in the global endeavor to mitigate carbon emissions by 15-20%, thereby aligning with the 1.5°C (2.7°F) target set for 2050. Despite substantial governmental support, such as 45Q, progress in CCUS development and infrastructure remains sluggish, primarily attributed to the substantial initial capital outlays involved. A significant proportion of these costs can be attributed to the utilization of costly Corrosion-Resistant Alloys (CRA), necessitated by the harsh corrosion challenges posed by supercritical CO2 from the capture facility to the injection wells. To facilitate the advancement of CCUS technology in China, extensive research, testing, and development endeavors have been undertaken to identify and implement advanced materials and anti-corrosion technologies capable of replacing CRA within the CCUS injection well infrastructure.

The conditions of CO2 injection wells in four major oil fields in China have undergone thorough investigation and categorization. Minimum CRA requirements have been determined through a combination of field data and computer simulations, establishing cost upper limits for selecting new materials. Extensive testing has been conducted on a diverse range of new materials and anti-corrosion solutions, encompassing various grades of coatings, platings, liners, coil tubings, inhibitors, and their combinations. These tests have been carried out under simulated laboratory conditions as well as in the field to assess their long-term effectiveness.

Drawing upon comprehensive test results, the operational scope of each technology has been outlined. Among these, coating technology, encompassing various polymer coatings and alloy plating, emerges as the most cost-effective solution but offers relatively short-term protection (typically less than 5 years) when used independently. However, Ni-P or Ni-W plating, complemented by compatible inhibitor protocols, can reliably extend protection for 5-10 years. Polymer composite liners, such as Glass Reinforced Epoxy (GRE) liners, provide extended lifespans (typically 20-50 years) and obviate the need for corrosion inhibitors due to their substantial thickness, albeit at roughly twice the cost. In exceptionally harsh conditions and for prolonged storage periods, CRA coil tubing emerges as a cost-efficient alternative to traditional CRA tubing. It offers cost savings by eliminating the fabrication and testing requirements associated with conventional gas-tight tubular connections.

To the best of our knowledge, this study marks the first endeavor to provide substantive recommendations for replacing expensive traditional CRA in CCUS injection wells with alternative anti-corrosion solutions, substantiated by rigorous testing and extensive field experience. The findings of this research have the potential to empower operators worldwide to significantly reduce their project costs while maintaining safety and reliability. As a result, it can foster the expansion of CCUS initiatives, contributing to the attainment of global objectives in sustainable energy production and climate control.