Background: Efficient drilling operations hinge on the stability of drilling fluid properties, a factor often compromised by unavoidable contamination during drilling. This study delves into the impact of Sodium Carbonate (Na2CO3) and Sodium Bicarbonate (NaHCO3) contaminants on laboratory-prepared water-based drilling mud under ambient conditions. Results: Three distinct mud samples, each with varying concentrations of Na2CO3 and NaHCO3, were introduced to water-based mud (WBM) fluid. The study focused on key rheological properties, measuring pH, fluid loss, mud thickness, plastic viscosity, and yield point. The findings revealed an increase in mud thickness corresponding to elevated cement contaminations. Mud pH exhibited a rise with sodium carbonate concentration but a decline with bicarbonate concentration. Plastic viscosity decreased with rising concentrations of both cement contamination and the treating agent, while yield point increased with heightened cement contamination concentration. Fluid loss demonstrated a proportional increase with elevated contaminant concentrations. Conclusions: While the obtained results align with existing literature, it is imperative to note that the developed mud rheological properties warrant further exploration under conditions mirroring the elevated temperature and pressure encountered during actual oil or gas well drilling. This study underscores the need for comprehensive investigations to enhance our understanding of drilling fluid behaviors in real-world drilling scenarios.

Drilling fluid stability, Contaminants, Sodium Carbonate, Sodium Bicarbonate, Water-Based Mud (WBM), Rheological properties