Assessing a Novel Glass-Based Fluid for Annular Barrier Remediation in Cemented Well Sections

Abstract This study investigates a novel glass-based fluid for sealing microannuli in cemented well sections, aiming to enhance well integrity. The research focuses on assessing the material's sealing efficiency, permeability changes before and after remediation, and performance under pressure and drying conditions. Tests were performed on a vertically-oriented, 50 cm-long cemented annulus section, constructed using 7-inch inside 9-⅝ inch diameter casing pipe. After inducing a microannulus, baseline permeability was measured using gas and water at 80°C. Subsequently, glass-based fluid was injected using a modified hesitation squeeze method. Post-remediation tests showed a significant reduction in water permeability, from 4.8 mD to 10 µd, demonstrating successful sealing. Durability was further evaluated through pressure loading, drying, and self-sealing tests, confirming the material's effectiveness under various conditions. The study revealed that the fluid's sealing properties and water-like rheology enable it to address microannuli where traditional squeeze cementing operations struggle, particularly in low-injectivity scenarios. Although some challenges remain, such as performance in larger defects and long-term durability, the findings indicate that glass-based fluids have significant potential for sealing defects in cement. The study also recommends further research to optimize operational procedures for field application of the glass-based fluid in well environments.