Fluid Loss Control and Strength Development in Latex-Modified Geopolymer Well Cement for Elevated Temperature and Pressure Subsurface Applications

Geopolymer cement has garnered increasing attention as a low-carbon alternative to ordinary Portland cement (OPC) for wellbore cementing applications, particularly in CO₂-rich subsurface environments where OPC is prone to chemical degradation. The study investigates the mechanical and structural effects of incorporating styrene-butadiene latex—a colloidal polymer dispersion commonly employed for fluid loss mitigation—into geopolymer formulations subjected to elevated temperature and pressure conditions.

Geopolymer cement slurries were prepared using Class F fly ash, activated by sodium silicate and sodium hydroxide solutions, and modified with varying latex dosages ranging from 0 to 10 wt.% relative to fly ash mass. The specimens were cured at 100 °C and 3,000 psi for 48 hours, followed by evaluations of compressive strength, microstructure, and elemental distribution. The optimal latex concentration of 4 wt.% yielded a maximum compressive strength of 2,937 psi, marginally outperforming the control sample. Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDX) revealed that latex incorporation facilitated silica-rich film formation, needle-like structure, and enhanced microstructural connectivity. In contrast, excessive latex concentrations produced flocculated domains and phase irregularities, resulting in mechanical impairment.

The preliminary findings establish styrene-butadiene latex as a promising fluid loss control agent capable of contributing to early strength gain and structural refinement in geopolymer cement systems under elevated conditions. Future studies should explore co-additive synergies, long-term durability and phase stability to optimize cement integrity for demanding wellbore environments.