Effect of CO2-cement Interaction on Well Integrity

Abstract

Wellbore integrity is a significant and fundamental challenge for CO2 sequestration wells to ensure efficient, economical, and environmentally friendly operations. The carbonation reaction between Portland cement and CO2 can change the microstructure of the cement skeleton, change the cement mechanical properties, damage the seal of the annulus, and finally induce CO2 leakage. This chapter aims to propose a straightforward and practical wellbore integrity evaluation workflow for the entire lifecycle of a CO2 sequestration well under representative downhole conditions. This workflow integrates laboratory experiments, geochemical analysis, and numerical modeling, including a CO2-cement degradation test, mechanical tests for strength and elastic properties, X-ray fluorescence and X-ray diffraction for composition analysis, and staged finite element framework for failure evaluation. An exemplary field-scale CO2 sequestration well is demonstrated, fully considering the downhole conditions. Cement samples reacting with CO2 for different periods are tested. Based on test data, further numerical prediction of wellbore integrity is performed. A systematic analysis is performed on the test results, including qualitative and quantitative comparisons and multiscale geochemistry analysis. Furthermore, a geochemical macro-meso-micro-scale analysis is illustrated to characterize the change of microstructures and pore size distribution of the cement after reacting with CO2 (We gratefully acknowledge the Carbon Capture Consortium for authorizing use of this material). Suggestions and recommendations are provided for maintaining the long-term wellbore integrity of CO2 sequestration wells.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

carbonation reaction; cement degradation; CO2 sequestration well; Portland cement

International Standard Book Number (ISBN)

978-032399587-0;978-032399586-3

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2025 Elsevier, All rights reserved.

Publication Date

01 Jan 2025

Link to Full Text

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