Alkali-Activated Universal Fluid System for Drilling and Cementing

Abstract

Abstract. Achieving complete displacement of water-based drilling fluid during cementing presents a major challenge for zonal isolation, as residual non-setting mud exhibits poor adhesion to cement, often resulting in casing–casing–annulus (CCA) debonding and mud channeling. To address this issue, a universal fluid system (UFS) was developed that functions as a drilling fluid with controlled rheology and fluid loss, and transitions into a solid, cement-like material upon alkali activation. This study presents a systematic investigation of the formulated UFS, which is based on blast-furnace slag and remains stable in its fluid state prior to activation. Upon exposure to alkaline activators, the UFS undergoes geopolymerization, leading to a controlled fluid-to-solid transition and the development of high compressive strength at 160°F. Before activation, the UFS exhibits excellent rheological properties, suspension capability, and ultra-low fluid loss. After activation, it behaves as a high-performance cement, demonstrating tunable thickening time, rapid strength development, and robust mechanical properties. The developed UFS offers true dual functionality—serving as a drilling fluid before activation and a cementing material afterward. The system is formulated using low-carbon, cost-effective, and sustainable materials, reducing operational complexity, environmental impact, and carbon footprint. Its tunable behavior enables precise control of both drilling-fluid properties (rheology, fluid loss) and cementing properties (consistency, thickening time, and compressive strength), making it a promising solution for improved well construction and zonal isolation.